libjxl

encode.cc (109217B)

---

 // Copyright (c) the JPEG XL Project Authors. All rights reserved.
 //
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include <brotli/encode.h>
 #include <jxl/cms.h>
 #include <jxl/codestream_header.h>
 #include <jxl/encode.h>
 #include <jxl/types.h>
 #include <jxl/version.h>
 
 #include <algorithm>
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
 
 #include "lib/jxl/base/byte_order.h"
 #include "lib/jxl/base/common.h"
 #include "lib/jxl/base/data_parallel.h"
 #include "lib/jxl/base/exif.h"
 #include "lib/jxl/base/printf_macros.h"
 #include "lib/jxl/base/span.h"
 #include "lib/jxl/base/status.h"
 #include "lib/jxl/codec_in_out.h"
 #include "lib/jxl/enc_aux_out.h"
 #include "lib/jxl/enc_bit_writer.h"
 #include "lib/jxl/enc_cache.h"
 #include "lib/jxl/enc_external_image.h"
 #include "lib/jxl/enc_fast_lossless.h"
 #include "lib/jxl/enc_fields.h"
 #include "lib/jxl/enc_frame.h"
 #include "lib/jxl/enc_icc_codec.h"
 #include "lib/jxl/enc_params.h"
 #include "lib/jxl/encode_internal.h"
 #include "lib/jxl/jpeg/enc_jpeg_data.h"
 #include "lib/jxl/luminance.h"
 #include "lib/jxl/memory_manager_internal.h"
 #include "lib/jxl/padded_bytes.h"
 #include "lib/jxl/sanitizers.h"
 
 struct JxlErrorOrStatus {
   // NOLINTNEXTLINE(google-explicit-constructor)
   operator jxl::Status() const {
     switch (error_) {
       case JXL_ENC_SUCCESS:
         return jxl::OkStatus();
       case JXL_ENC_NEED_MORE_OUTPUT:
         return jxl::StatusCode::kNotEnoughBytes;
       default:
         return jxl::StatusCode::kGenericError;
     }
   }
   // NOLINTNEXTLINE(google-explicit-constructor)
   operator JxlEncoderStatus() const { return error_; }
 
   static JxlErrorOrStatus Success() {
     return JxlErrorOrStatus(JXL_ENC_SUCCESS);
   }
 
   static JxlErrorOrStatus MoreOutput() {
     return JxlErrorOrStatus(JXL_ENC_NEED_MORE_OUTPUT);
   }
 
   static JxlErrorOrStatus Error() { return JxlErrorOrStatus(JXL_ENC_ERROR); }
 
  private:
   explicit JxlErrorOrStatus(JxlEncoderStatus error) : error_(error) {}
   JxlEncoderStatus error_;
 };
 
 // Debug-printing failure macro similar to JXL_FAILURE, but for the status code
 // JXL_ENC_ERROR
 #ifdef JXL_CRASH_ON_ERROR
 #define JXL_API_ERROR(enc, error_code, format, ...)                          \
   (enc->error = error_code,                                                  \
    ::jxl::Debug(("%s:%d: " format "\n"), __FILE__, __LINE__, ##__VA_ARGS__), \
    ::jxl::Abort(), JxlErrorOrStatus::Error())
 #define JXL_API_ERROR_NOSET(format, ...)                                     \
   (::jxl::Debug(("%s:%d: " format "\n"), __FILE__, __LINE__, ##__VA_ARGS__), \
    ::jxl::Abort(), JxlErrorOrStatus::Error())
 #else  // JXL_CRASH_ON_ERROR
 #define JXL_API_ERROR(enc, error_code, format, ...)                            \
   (enc->error = error_code,                                                    \
    ((JXL_DEBUG_ON_ERROR) &&                                                    \
     ::jxl::Debug(("%s:%d: " format "\n"), __FILE__, __LINE__, ##__VA_ARGS__)), \
    JxlErrorOrStatus::Error())
 #define JXL_API_ERROR_NOSET(format, ...)                                     \
   (::jxl::Debug(("%s:%d: " format "\n"), __FILE__, __LINE__, ##__VA_ARGS__), \
    JxlErrorOrStatus::Error())
 #endif  // JXL_CRASH_ON_ERROR
 
 jxl::StatusOr<JxlOutputProcessorBuffer>
 JxlEncoderOutputProcessorWrapper::GetBuffer(size_t min_size,
                                             size_t requested_size) {
   JXL_ASSERT(min_size > 0);
   JXL_ASSERT(!has_buffer_);
   if (stop_requested_) return jxl::StatusCode::kNotEnoughBytes;
   requested_size = std::max(min_size, requested_size);
 
   // If we support seeking, output_position_ == position_.
   if (external_output_processor_ && external_output_processor_->seek) {
     JXL_ASSERT(output_position_ == position_);
   }
   // Otherwise, output_position_ <= position_.
   JXL_ASSERT(output_position_ <= position_);
   size_t additional_size = position_ - output_position_;
 
   if (external_output_processor_) {
     // TODO(veluca): here, we cannot just ask for a larger buffer, as it will be
     // released with a prefix of the buffer that has not been written yet.
     // Figure out if there is a good way to do this more efficiently.
     if (additional_size == 0) {
       size_t size = requested_size;
       uint8_t* user_buffer =
           static_cast<uint8_t*>(external_output_processor_->get_buffer(
               external_output_processor_->opaque, &size));
       if (size == 0 || user_buffer == nullptr) {
         stop_requested_ = true;
         return jxl::StatusCode::kNotEnoughBytes;
       }
       if (size < min_size) {
         external_output_processor_->release_buffer(
             external_output_processor_->opaque, 0);
       } else {
         internal_buffers_.emplace(position_, InternalBuffer());
         has_buffer_ = true;
         return JxlOutputProcessorBuffer(user_buffer, size, 0, this);
       }
     }
   } else {
     if (min_size + additional_size < *avail_out_) {
       internal_buffers_.emplace(position_, InternalBuffer());
       has_buffer_ = true;
       return JxlOutputProcessorBuffer(*next_out_ + additional_size,
                                       *avail_out_ - additional_size, 0, this);
     }
   }
 
   // Otherwise, we need to allocate our own buffer.
   auto it = internal_buffers_.emplace(position_, InternalBuffer()).first;
   InternalBuffer& buffer = it->second;
   size_t alloc_size = requested_size;
   it++;
   if (it != internal_buffers_.end()) {
     alloc_size = std::min(alloc_size, it->first - position_);
     JXL_ASSERT(alloc_size >= min_size);
   }
   buffer.owned_data.resize(alloc_size);
   has_buffer_ = true;
   return JxlOutputProcessorBuffer(buffer.owned_data.data(), alloc_size, 0,
                                   this);
 }
 
 void JxlEncoderOutputProcessorWrapper::Seek(size_t pos) {
   JXL_ASSERT(!has_buffer_);
   if (external_output_processor_ && external_output_processor_->seek) {
     external_output_processor_->seek(external_output_processor_->opaque, pos);
     output_position_ = pos;
   }
   JXL_ASSERT(pos >= finalized_position_);
   position_ = pos;
 }
 
 void JxlEncoderOutputProcessorWrapper::SetFinalizedPosition() {
   JXL_ASSERT(!has_buffer_);
   if (external_output_processor_ && external_output_processor_->seek) {
     external_output_processor_->set_finalized_position(
         external_output_processor_->opaque, position_);
   }
   finalized_position_ = position_;
   FlushOutput();
 }
 
 bool JxlEncoderOutputProcessorWrapper::SetAvailOut(uint8_t** next_out,
                                                    size_t* avail_out) {
   if (external_output_processor_) return false;
   avail_out_ = avail_out;
   next_out_ = next_out;
   FlushOutput();
   return true;
 }
 
 void JxlEncoderOutputProcessorWrapper::CopyOutput(std::vector<uint8_t>& output,
                                                   uint8_t* next_out,
                                                   size_t& avail_out) {
   while (HasOutputToWrite()) {
     SetAvailOut(&next_out, &avail_out);
     if (avail_out == 0) {
       size_t offset = next_out - output.data();
       output.resize(output.size() * 2);
       next_out = output.data() + offset;
       avail_out = output.size() - offset;
     }
   }
   output.resize(output.size() - avail_out);
 }
 
 void JxlEncoderOutputProcessorWrapper::ReleaseBuffer(size_t bytes_used) {
   JXL_ASSERT(has_buffer_);
   has_buffer_ = false;
   auto it = internal_buffers_.find(position_);
   JXL_ASSERT(it != internal_buffers_.end());
   if (bytes_used == 0) {
     if (external_output_processor_) {
       external_output_processor_->release_buffer(
           external_output_processor_->opaque, bytes_used);
     }
     internal_buffers_.erase(it);
     return;
   }
   it->second.written_bytes = bytes_used;
   position_ += bytes_used;
 
   auto it_to_next = it;
   it_to_next++;
   if (it_to_next != internal_buffers_.end()) {
     JXL_ASSERT(it_to_next->first >= position_);
   }
 
   if (external_output_processor_) {
     // If the buffer was given by the user, tell the user it is not needed
     // anymore.
     if (it->second.owned_data.empty()) {
       external_output_processor_->release_buffer(
           external_output_processor_->opaque, bytes_used);
       // If we don't support seeking, this implies we will never modify again
       // the bytes that were written so far. Advance the finalized position and
       // flush the output to clean up the internal buffers.
       if (!external_output_processor_->seek) {
         SetFinalizedPosition();
         JXL_ASSERT(output_position_ == finalized_position_);
         JXL_ASSERT(output_position_ == position_);
       } else {
         // Otherwise, advance the output position accordingly.
         output_position_ += bytes_used;
         JXL_ASSERT(output_position_ >= finalized_position_);
         JXL_ASSERT(output_position_ == position_);
       }
     } else if (external_output_processor_->seek) {
       // If we had buffered the data internally, flush it out to the external
       // processor if we can.
       external_output_processor_->seek(external_output_processor_->opaque,
                                        position_ - bytes_used);
       output_position_ = position_ - bytes_used;
       while (output_position_ < position_) {
         size_t num_to_write = position_ - output_position_;
         if (!AppendBufferToExternalProcessor(it->second.owned_data.data() +
                                                  output_position_ - position_ +
                                                  bytes_used,
                                              num_to_write)) {
           return;
         }
       }
       it->second.owned_data.clear();
     }
   }
 }
 
 // Tries to write all the bytes up to the finalized position.
 void JxlEncoderOutputProcessorWrapper::FlushOutput() {
   JXL_ASSERT(!has_buffer_);
   while (output_position_ < finalized_position_ &&
          (avail_out_ == nullptr || *avail_out_ > 0)) {
     JXL_ASSERT(!internal_buffers_.empty());
     auto it = internal_buffers_.begin();
     // If this fails, we are trying to move the finalized position past data
     // that was not written yet. This is a library programming error.
     JXL_ASSERT(output_position_ >= it->first);
     JXL_ASSERT(it->second.written_bytes != 0);
     size_t buffer_last_byte = it->first + it->second.written_bytes;
     if (!it->second.owned_data.empty()) {
       size_t start_in_buffer = output_position_ - it->first;
       // Guaranteed by the invariant on `internal_buffers_`.
       JXL_ASSERT(buffer_last_byte > output_position_);
       size_t num_to_write =
           std::min(buffer_last_byte, finalized_position_) - output_position_;
       if (avail_out_ != nullptr) {
         size_t n = std::min(num_to_write, *avail_out_);
         memcpy(*next_out_, it->second.owned_data.data() + start_in_buffer, n);
         *avail_out_ -= n;
         *next_out_ += n;
         output_position_ += n;
       } else {
         if (!AppendBufferToExternalProcessor(
                 it->second.owned_data.data() + start_in_buffer, num_to_write)) {
           return;
         }
       }
     } else {
       size_t advance =
           std::min(buffer_last_byte, finalized_position_) - output_position_;
       output_position_ += advance;
       if (avail_out_ != nullptr) {
         *next_out_ += advance;
         *avail_out_ -= advance;
       }
     }
     if (buffer_last_byte == output_position_) {
       internal_buffers_.erase(it);
     }
     if (external_output_processor_ && !external_output_processor_->seek) {
       external_output_processor_->set_finalized_position(
           external_output_processor_->opaque, output_position_);
     }
   }
 }
 
 bool JxlEncoderOutputProcessorWrapper::AppendBufferToExternalProcessor(
     void* data, size_t count) {
   JXL_ASSERT(external_output_processor_);
   size_t n = count;
   void* user_buffer = external_output_processor_->get_buffer(
       external_output_processor_->opaque, &n);
   if (user_buffer == nullptr || n == 0) {
     stop_requested_ = true;
     return false;
   }
   n = std::min(n, count);
   memcpy(user_buffer, data, n);
   external_output_processor_->release_buffer(external_output_processor_->opaque,
                                              n);
   output_position_ += n;
   return true;
 }
 
 namespace jxl {
 
 size_t WriteBoxHeader(const jxl::BoxType& type, size_t size, bool unbounded,
                       bool force_large_box, uint8_t* output) {
   uint64_t box_size = 0;
   bool large_size = false;
   if (!unbounded) {
     if (box_size >= kLargeBoxContentSizeThreshold || force_large_box) {
       large_size = true;
       // TODO(firsching): send a separate CL for this (+ test),
       // quick fix in the old code: box_size += 8
       box_size = size + kLargeBoxHeaderSize;
     } else {
       box_size = size + kSmallBoxHeaderSize;
     }
   }
 
   size_t idx = 0;
   {
     const uint64_t store = large_size ? 1 : box_size;
     for (size_t i = 0; i < 4; i++) {
       output[idx++] = store >> (8 * (3 - i)) & 0xff;
     }
   }
   for (size_t i = 0; i < 4; i++) {
     output[idx++] = type[i];
   }
 
   if (large_size) {
     for (size_t i = 0; i < 8; i++) {
       output[idx++] = box_size >> (8 * (7 - i)) & 0xff;
     }
   }
   return idx;
 }
 }  // namespace jxl
 
 template <typename WriteBox>
 jxl::Status JxlEncoderStruct::AppendBox(const jxl::BoxType& type,
                                         bool unbounded, size_t box_max_size,
                                         const WriteBox& write_box) {
   size_t current_position = output_processor.CurrentPosition();
   bool large_box = false;
   size_t box_header_size = 0;
   if (box_max_size >= jxl::kLargeBoxContentSizeThreshold && !unbounded) {
     box_header_size = jxl::kLargeBoxHeaderSize;
     large_box = true;
   } else {
     box_header_size = jxl::kSmallBoxHeaderSize;
   }
   output_processor.Seek(current_position + box_header_size);
   size_t box_contents_start = output_processor.CurrentPosition();
   JXL_RETURN_IF_ERROR(write_box());
   size_t box_contents_end = output_processor.CurrentPosition();
   output_processor.Seek(current_position);
   JXL_ASSERT(box_contents_end >= box_contents_start);
   if (box_contents_end - box_contents_start > box_max_size) {
     return JXL_API_ERROR(this, JXL_ENC_ERR_GENERIC,
                          "Internal error: upper bound on box size was "
                          "violated, upper bound: %" PRIuS ", actual: %" PRIuS,
                          box_max_size, box_contents_end - box_contents_start);
   }
   // We need to release the buffer before Seek.
   {
     JXL_ASSIGN_OR_RETURN(
         auto buffer,
         output_processor.GetBuffer(box_contents_start - current_position));
     const size_t n =
         jxl::WriteBoxHeader(type, box_contents_end - box_contents_start,
                             unbounded, large_box, buffer.data());
     JXL_ASSERT(n == box_header_size);
     buffer.advance(n);
   }
   output_processor.Seek(box_contents_end);
   output_processor.SetFinalizedPosition();
   return jxl::OkStatus();
 }
 
 template <typename BoxContents>
 jxl::Status JxlEncoderStruct::AppendBoxWithContents(
     const jxl::BoxType& type, const BoxContents& contents) {
   size_t size = std::end(contents) - std::begin(contents);
   return AppendBox(type, /*unbounded=*/false, size,
                    [&]() { return AppendData(output_processor, contents); });
 }
 
 uint32_t JxlEncoderVersion(void) {
   return JPEGXL_MAJOR_VERSION * 1000000 + JPEGXL_MINOR_VERSION * 1000 +
          JPEGXL_PATCH_VERSION;
 }
 
 namespace {
 
 void WriteJxlpBoxCounter(uint32_t counter, bool last, uint8_t* buffer) {
   if (last) counter |= 0x80000000;
   for (size_t i = 0; i < 4; i++) {
     buffer[i] = counter >> (8 * (3 - i)) & 0xff;
   }
 }
 
 void WriteJxlpBoxCounter(uint32_t counter, bool last,
                          JxlOutputProcessorBuffer& buffer) {
   uint8_t buf[4];
   WriteJxlpBoxCounter(counter, last, buf);
   buffer.append(buf, 4);
 }
 
 void QueueFrame(
     const JxlEncoderFrameSettings* frame_settings,
     jxl::MemoryManagerUniquePtr<jxl::JxlEncoderQueuedFrame>& frame) {
   if (frame_settings->values.lossless) {
     frame->option_values.cparams.SetLossless();
   }
 
   jxl::JxlEncoderQueuedInput queued_input(frame_settings->enc->memory_manager);
   queued_input.frame = std::move(frame);
   frame_settings->enc->input_queue.emplace_back(std::move(queued_input));
   frame_settings->enc->num_queued_frames++;
 }
 
 void QueueFastLosslessFrame(const JxlEncoderFrameSettings* frame_settings,
                             JxlFastLosslessFrameState* fast_lossless_frame) {
   jxl::JxlEncoderQueuedInput queued_input(frame_settings->enc->memory_manager);
   queued_input.fast_lossless_frame.reset(fast_lossless_frame);
   frame_settings->enc->input_queue.emplace_back(std::move(queued_input));
   frame_settings->enc->num_queued_frames++;
 }
 
 void QueueBox(JxlEncoder* enc,
               jxl::MemoryManagerUniquePtr<jxl::JxlEncoderQueuedBox>& box) {
   jxl::JxlEncoderQueuedInput queued_input(enc->memory_manager);
   queued_input.box = std::move(box);
   enc->input_queue.emplace_back(std::move(queued_input));
   enc->num_queued_boxes++;
 }
 
 // TODO(lode): share this code and the Brotli compression code in enc_jpeg_data
 JxlEncoderStatus BrotliCompress(int quality, const uint8_t* in, size_t in_size,
                                 jxl::PaddedBytes* out) {
   std::unique_ptr<BrotliEncoderState, decltype(BrotliEncoderDestroyInstance)*>
       enc(BrotliEncoderCreateInstance(nullptr, nullptr, nullptr),
           BrotliEncoderDestroyInstance);
   if (!enc) return JXL_API_ERROR_NOSET("BrotliEncoderCreateInstance failed");
 
   BrotliEncoderSetParameter(enc.get(), BROTLI_PARAM_QUALITY, quality);
   BrotliEncoderSetParameter(enc.get(), BROTLI_PARAM_SIZE_HINT, in_size);
 
   constexpr size_t kBufferSize = 128 * 1024;
   jxl::PaddedBytes temp_buffer(kBufferSize);
 
   size_t avail_in = in_size;
   const uint8_t* next_in = in;
 
   size_t total_out = 0;
 
   for (;;) {
     size_t avail_out = kBufferSize;
     uint8_t* next_out = temp_buffer.data();
     jxl::msan::MemoryIsInitialized(next_in, avail_in);
     if (!BrotliEncoderCompressStream(enc.get(), BROTLI_OPERATION_FINISH,
                                      &avail_in, &next_in, &avail_out, &next_out,
                                      &total_out)) {
       return JXL_API_ERROR_NOSET("Brotli compression failed");
     }
     size_t out_size = next_out - temp_buffer.data();
     jxl::msan::UnpoisonMemory(next_out - out_size, out_size);
     out->resize(out->size() + out_size);
     memcpy(out->data() + out->size() - out_size, temp_buffer.data(), out_size);
     if (BrotliEncoderIsFinished(enc.get())) break;
   }
 
   return JxlErrorOrStatus::Success();
 }
 
 // The JXL codestream can have level 5 or level 10. Levels have certain
 // restrictions such as max allowed image dimensions. This function checks the
 // level required to support the current encoder settings. The debug_string is
 // intended to be used for developer API error messages, and may be set to
 // nullptr.
 int VerifyLevelSettings(const JxlEncoder* enc, std::string* debug_string) {
   const auto& m = enc->metadata.m;
 
   uint64_t xsize = enc->metadata.size.xsize();
   uint64_t ysize = enc->metadata.size.ysize();
   // The uncompressed ICC size, if it is used.
   size_t icc_size = 0;
   if (m.color_encoding.WantICC()) {
     icc_size = m.color_encoding.ICC().size();
   }
 
   // Level 10 checks
 
   if (xsize > (1ull << 30ull) || ysize > (1ull << 30ull) ||
       xsize * ysize > (1ull << 40ull)) {
     if (debug_string) *debug_string = "Too large image dimensions";
     return -1;
   }
   if (icc_size > (1ull << 28)) {
     if (debug_string) *debug_string = "Too large ICC profile size";
     return -1;
   }
   if (m.num_extra_channels > 256) {
     if (debug_string) *debug_string = "Too many extra channels";
     return -1;
   }
 
   // Level 5 checks
 
   if (!m.modular_16_bit_buffer_sufficient) {
     if (debug_string) *debug_string = "Too high modular bit depth";
     return 10;
   }
   if (xsize > (1ull << 18ull) || ysize > (1ull << 18ull) ||
       xsize * ysize > (1ull << 28ull)) {
     if (debug_string) *debug_string = "Too large image dimensions";
     return 10;
   }
   if (icc_size > (1ull << 22)) {
     if (debug_string) *debug_string = "Too large ICC profile";
     return 10;
   }
   if (m.num_extra_channels > 4) {
     if (debug_string) *debug_string = "Too many extra channels";
     return 10;
   }
   for (size_t i = 0; i < m.extra_channel_info.size(); ++i) {
     if (m.extra_channel_info[i].type == jxl::ExtraChannel::kBlack) {
       if (debug_string) *debug_string = "CMYK channel not allowed";
       return 10;
     }
   }
 
   // TODO(lode): also need to check if consecutive composite-still frames total
   // pixel amount doesn't exceed 2**28 in the case of level 5. This should be
   // done when adding frame and requires ability to add composite still frames
   // to be added first.
 
   // TODO(lode): also need to check animation duration of a frame. This should
   // be done when adding frame, but first requires implementing setting the
   // JxlFrameHeader for a frame.
 
   // TODO(lode): also need to check properties such as num_splines, num_patches,
   // modular_16bit_buffers and multiple properties of modular trees. However
   // these are not user-set properties so cannot be checked here, but decisions
   // the C++ encoder should be able to make based on the level.
 
   // All level 5 checks passes, so can return the more compatible level 5
   return 5;
 }
 
 JxlEncoderStatus CheckValidBitdepth(uint32_t bits_per_sample,
                                     uint32_t exponent_bits_per_sample) {
   if (!exponent_bits_per_sample) {
     // The spec allows up to 31 for bits_per_sample here, but
     // the code does not (yet) support it.
     if (!(bits_per_sample > 0 && bits_per_sample <= 24)) {
       return JXL_API_ERROR_NOSET("Invalid value for bits_per_sample");
     }
   } else if ((exponent_bits_per_sample > 8) ||
              (bits_per_sample > 24 + exponent_bits_per_sample) ||
              (bits_per_sample < 3 + exponent_bits_per_sample)) {
     return JXL_API_ERROR_NOSET("Invalid float description");
   }
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus VerifyInputBitDepth(JxlBitDepth bit_depth,
                                      JxlPixelFormat format) {
   return JxlErrorOrStatus::Success();
 }
 
 inline bool EncodeVarInt(uint64_t value, size_t output_size, size_t* output_pos,
                          uint8_t* output) {
   // While more than 7 bits of data are left,
   // store 7 bits and set the next byte flag
   while (value > 127) {
     // TODO(eustas): should it be `>=` ?
     if (*output_pos > output_size) return false;
     // |128: Set the next byte flag
     output[(*output_pos)++] = (static_cast<uint8_t>(value & 127)) | 128;
     // Remove the seven bits we just wrote
     value >>= 7;
   }
   // TODO(eustas): should it be `>=` ?
   if (*output_pos > output_size) return false;
   output[(*output_pos)++] = static_cast<uint8_t>(value & 127);
   return true;
 }
 
 bool EncodeFrameIndexBox(const jxl::JxlEncoderFrameIndexBox& frame_index_box,
                          std::vector<uint8_t>& buffer_vec) {
   bool ok = true;
   int NF = 0;
   for (size_t i = 0; i < frame_index_box.entries.size(); ++i) {
     if (i == 0 || frame_index_box.entries[i].to_be_indexed) {
       ++NF;
     }
   }
   // Frame index box contents varint + 8 bytes
   // continue with NF * 3 * varint
   // varint max length is 10 for 64 bit numbers, and these numbers
   // are limited to 63 bits.
   static const int kVarintMaxLength = 10;
   static const int kFrameIndexBoxHeaderLength = kVarintMaxLength + 8;
   static const int kFrameIndexBoxElementLength = 3 * kVarintMaxLength;
   const int buffer_size =
       kFrameIndexBoxHeaderLength + NF * kFrameIndexBoxElementLength;
   buffer_vec.resize(buffer_size);
   uint8_t* buffer = buffer_vec.data();
   size_t output_pos = 0;
   ok &= EncodeVarInt(NF, buffer_vec.size(), &output_pos, buffer);
   StoreBE32(frame_index_box.TNUM, &buffer[output_pos]);
   output_pos += 4;
   StoreBE32(frame_index_box.TDEN, &buffer[output_pos]);
   output_pos += 4;
   // When we record a frame in the index, the record needs to know
   // how many frames until the next indexed frame. That is why
   // we store the 'prev' record. That 'prev' record needs to store
   // the offset byte position to previously recorded indexed frame,
   // that's why we also trace previous to the previous frame.
   int prev_prev_ix = -1;  // For position offset (OFFi) delta coding.
   int prev_ix = 0;
   int T_prev = 0;
   int T = 0;
   for (size_t i = 1; i < frame_index_box.entries.size(); ++i) {
     if (frame_index_box.entries[i].to_be_indexed) {
       // Now we can record the previous entry, since we need to store
       // there how many frames until the next one.
       int64_t OFFi = frame_index_box.entries[prev_ix].OFFi;
       if (prev_prev_ix != -1) {
         // Offi needs to be offset of start byte of this frame compared to start
         // byte of previous frame from this index in the JPEG XL codestream. For
         // the first frame, this is the offset from the first byte of the JPEG
         // XL codestream.
         OFFi -= frame_index_box.entries[prev_prev_ix].OFFi;
       }
       int32_t Ti = T_prev;
       int32_t Fi = i - prev_ix;
       ok &= EncodeVarInt(OFFi, buffer_vec.size(), &output_pos, buffer);
       ok &= EncodeVarInt(Ti, buffer_vec.size(), &output_pos, buffer);
       ok &= EncodeVarInt(Fi, buffer_vec.size(), &output_pos, buffer);
       prev_prev_ix = prev_ix;
       prev_ix = i;
       T_prev = T;
       T += frame_index_box.entries[i].duration;
     }
   }
   {
     // Last frame.
     size_t i = frame_index_box.entries.size();
     int64_t OFFi = frame_index_box.entries[prev_ix].OFFi;
     if (prev_prev_ix != -1) {
       OFFi -= frame_index_box.entries[prev_prev_ix].OFFi;
     }
     int32_t Ti = T_prev;
     int32_t Fi = i - prev_ix;
     ok &= EncodeVarInt(OFFi, buffer_vec.size(), &output_pos, buffer);
     ok &= EncodeVarInt(Ti, buffer_vec.size(), &output_pos, buffer);
     ok &= EncodeVarInt(Fi, buffer_vec.size(), &output_pos, buffer);
   }
   // Enough buffer has been allocated, this function should never fail in
   // writing.
   JXL_ASSERT(ok);
   buffer_vec.resize(output_pos);
   return ok;
 }
 
 }  // namespace
 
 jxl::Status JxlEncoderStruct::ProcessOneEnqueuedInput() {
   jxl::PaddedBytes header_bytes;
 
   jxl::JxlEncoderQueuedInput& input = input_queue[0];
 
   // TODO(lode): split this into 3 functions: for adding the signature and other
   // initial headers (jbrd, ...), one for adding frame, and one for adding user
   // box.
 
   if (!wrote_bytes) {
     // First time encoding any data, verify the level 5 vs level 10 settings
     std::string level_message;
     int required_level = VerifyLevelSettings(this, &level_message);
     // Only level 5 and 10 are defined, and the function can return -1 to
     // indicate full incompatibility.
     JXL_ASSERT(required_level == -1 || required_level == 5 ||
                required_level == 10);
     // codestream_level == -1 means auto-set to the required level
     if (codestream_level == -1) codestream_level = required_level;
     if (codestream_level == 5 && required_level != 5) {
       // If the required level is 10, return error rather than automatically
       // setting the level to 10, to avoid inadvertently creating a level 10
       // JXL file while intending to target a level 5 decoder.
       return JXL_API_ERROR(
           this, JXL_ENC_ERR_API_USAGE, "%s",
           ("Codestream level verification for level 5 failed: " + level_message)
               .c_str());
     }
     if (required_level == -1) {
       return JXL_API_ERROR(
           this, JXL_ENC_ERR_API_USAGE, "%s",
           ("Codestream level verification for level 10 failed: " +
            level_message)
               .c_str());
     }
     jxl::AuxOut* aux_out =
         input.frame ? input.frame->option_values.aux_out : nullptr;
     jxl::BitWriter writer;
     if (!WriteCodestreamHeaders(&metadata, &writer, aux_out)) {
       return JXL_API_ERROR(this, JXL_ENC_ERR_GENERIC,
                            "Failed to write codestream header");
     }
     // Only send ICC (at least several hundred bytes) if fields aren't enough.
     if (metadata.m.color_encoding.WantICC()) {
       if (!jxl::WriteICC(metadata.m.color_encoding.ICC(), &writer,
                          jxl::kLayerHeader, aux_out)) {
         return JXL_API_ERROR(this, JXL_ENC_ERR_GENERIC,
                              "Failed to write ICC profile");
       }
     }
     // TODO(lode): preview should be added here if a preview image is added
 
     jxl::BitWriter::Allotment allotment(&writer, 8);
     writer.ZeroPadToByte();
     allotment.ReclaimAndCharge(&writer, jxl::kLayerHeader, aux_out);
 
     header_bytes = std::move(writer).TakeBytes();
 
     // Not actually the end of frame, but the end of metadata/ICC, but helps
     // the next frame to start here for indexing purposes.
     codestream_bytes_written_end_of_frame += header_bytes.size();
 
     if (MustUseContainer()) {
       // Add "JXL " and ftyp box.
       {
         JXL_ASSIGN_OR_RETURN(auto buffer, output_processor.GetBuffer(
                                               jxl::kContainerHeader.size()));
         buffer.append(jxl::kContainerHeader);
       }
       if (codestream_level != 5) {
         // Add jxll box directly after the ftyp box to indicate the codestream
         // level.
         JXL_ASSIGN_OR_RETURN(auto buffer, output_processor.GetBuffer(
                                               jxl::kLevelBoxHeader.size() + 1));
         buffer.append(jxl::kLevelBoxHeader);
         uint8_t cl = codestream_level;
         buffer.append(&cl, 1);
       }
 
       // Whether to write the basic info and color profile header of the
       // codestream into an early separate jxlp box, so that it comes before
       // metadata or jpeg reconstruction boxes. In theory this could simply
       // always be done, but there's no reason to add an extra box with box
       // header overhead if the codestream will already come immediately after
       // the signature and level boxes.
       bool partial_header =
           store_jpeg_metadata ||
           (use_boxes && (!input.frame && !input.fast_lossless_frame));
 
       if (partial_header) {
         JXL_RETURN_IF_ERROR(AppendBox(
             jxl::MakeBoxType("jxlp"), /*unbounded=*/false,
             header_bytes.size() + 4, [&]() {
               JXL_ASSIGN_OR_RETURN(auto buffer, output_processor.GetBuffer(
                                                     header_bytes.size() + 4));
               WriteJxlpBoxCounter(jxlp_counter++, /*last=*/false, buffer);
               buffer.append(header_bytes);
               return jxl::OkStatus();
             }));
         header_bytes.clear();
       }
 
       if (store_jpeg_metadata && !jpeg_metadata.empty()) {
         JXL_RETURN_IF_ERROR(
             AppendBoxWithContents(jxl::MakeBoxType("jbrd"), jpeg_metadata));
       }
     }
     wrote_bytes = true;
   }
 
   output_processor.SetFinalizedPosition();
 
   // Choose frame or box processing: exactly one of the two unique pointers (box
   // or frame) in the input queue item is non-null.
   if (input.frame || input.fast_lossless_frame) {
     jxl::MemoryManagerUniquePtr<jxl::JxlEncoderQueuedFrame> input_frame =
         std::move(input.frame);
     jxl::FJXLFrameUniquePtr fast_lossless_frame =
         std::move(input.fast_lossless_frame);
     input_queue.erase(input_queue.begin());
     num_queued_frames--;
     if (input_frame) {
       for (unsigned idx = 0; idx < input_frame->ec_initialized.size(); idx++) {
         if (!input_frame->ec_initialized[idx]) {
           return JXL_API_ERROR(this, JXL_ENC_ERR_API_USAGE,
                                "Extra channel %u is not initialized", idx);
         }
       }
 
       // TODO(zond): If the input queue is empty and the frames_closed is true,
       // then mark this frame as the last.
 
       // TODO(zond): Handle progressive mode like EncodeFile does it.
       // TODO(zond): Handle animation like EncodeFile does it, by checking if
       //             JxlEncoderCloseFrames has been called and if the frame
       //             queue is empty (to see if it's the last animation frame).
 
       if (metadata.m.xyb_encoded) {
         input_frame->option_values.cparams.color_transform =
             jxl::ColorTransform::kXYB;
       } else {
         // TODO(zond): Figure out when to use kYCbCr instead.
         input_frame->option_values.cparams.color_transform =
             jxl::ColorTransform::kNone;
       }
     }
 
     uint32_t duration;
     uint32_t timecode;
     if (input_frame && metadata.m.have_animation) {
       duration = input_frame->option_values.header.duration;
       timecode = input_frame->option_values.header.timecode;
     } else {
       // If have_animation is false, the encoder should ignore the duration and
       // timecode values. However, assigning them to ib will cause the encoder
       // to write an invalid frame header that can't be decoded so ensure
       // they're the default value of 0 here.
       duration = 0;
       timecode = 0;
     }
 
     const bool last_frame = frames_closed && (num_queued_frames == 0);
 
     uint32_t max_bits_per_sample = metadata.m.bit_depth.bits_per_sample;
     for (const auto& info : metadata.m.extra_channel_info) {
       max_bits_per_sample =
           std::max(max_bits_per_sample, info.bit_depth.bits_per_sample);
     }
     // Heuristic upper bound on how many bits a single pixel in a single channel
     // can use.
     uint32_t bits_per_channels_estimate =
         std::max(24u, max_bits_per_sample + 3);
     size_t upper_bound_on_compressed_size_bits =
         metadata.xsize() * metadata.ysize() *
         (metadata.m.color_encoding.Channels() + metadata.m.num_extra_channels) *
         bits_per_channels_estimate;
     // Add a 1MB = 0x100000 for an heuristic upper bound on small sizes.
     size_t upper_bound_on_compressed_size_bytes =
         0x100000 + (upper_bound_on_compressed_size_bits >> 3);
     bool use_large_box = upper_bound_on_compressed_size_bytes >=
                          jxl::kLargeBoxContentSizeThreshold;
     size_t box_header_size =
         use_large_box ? jxl::kLargeBoxHeaderSize : jxl::kSmallBoxHeaderSize;
 
     const size_t frame_start_pos = output_processor.CurrentPosition();
     if (MustUseContainer()) {
       if (!last_frame || jxlp_counter > 0) {
         // If this is the last frame and no jxlp boxes were used yet, it's
         // slightly more efficient to write a jxlc box since it has 4 bytes
         // less overhead.
         box_header_size += 4;  // jxlp_counter field
       }
       output_processor.Seek(frame_start_pos + box_header_size);
     }
     const size_t frame_codestream_start = output_processor.CurrentPosition();
 
     JXL_RETURN_IF_ERROR(AppendData(output_processor, header_bytes));
 
     if (input_frame) {
       frame_index_box.AddFrame(codestream_bytes_written_end_of_frame, duration,
                                input_frame->option_values.frame_index_box);
 
       size_t save_as_reference =
           input_frame->option_values.header.layer_info.save_as_reference;
       if (save_as_reference >= 3) {
         return JXL_API_ERROR(
             this, JXL_ENC_ERR_API_USAGE,
             "Cannot use save_as_reference values >=3 (found: %d)",
             static_cast<int>(save_as_reference));
       }
 
       jxl::FrameInfo frame_info;
       frame_info.is_last = last_frame;
       frame_info.save_as_reference = save_as_reference;
       frame_info.source =
           input_frame->option_values.header.layer_info.blend_info.source;
       frame_info.clamp = FROM_JXL_BOOL(
           input_frame->option_values.header.layer_info.blend_info.clamp);
       frame_info.alpha_channel =
           input_frame->option_values.header.layer_info.blend_info.alpha;
       frame_info.extra_channel_blending_info.resize(
           metadata.m.num_extra_channels);
       // If extra channel blend info has not been set, use the blend mode from
       // the layer_info.
       JxlBlendInfo default_blend_info =
           input_frame->option_values.header.layer_info.blend_info;
       for (size_t i = 0; i < metadata.m.num_extra_channels; ++i) {
         auto& to = frame_info.extra_channel_blending_info[i];
         const auto& from =
             i < input_frame->option_values.extra_channel_blend_info.size()
                 ? input_frame->option_values.extra_channel_blend_info[i]
                 : default_blend_info;
         to.mode = static_cast<jxl::BlendMode>(from.blendmode);
         to.source = from.source;
         to.alpha_channel = from.alpha;
         to.clamp = (from.clamp != 0);
       }
       frame_info.origin.x0 =
           input_frame->option_values.header.layer_info.crop_x0;
       frame_info.origin.y0 =
           input_frame->option_values.header.layer_info.crop_y0;
       frame_info.blendmode = static_cast<jxl::BlendMode>(
           input_frame->option_values.header.layer_info.blend_info.blendmode);
       frame_info.blend =
           input_frame->option_values.header.layer_info.blend_info.blendmode !=
           JXL_BLEND_REPLACE;
       frame_info.image_bit_depth = input_frame->option_values.image_bit_depth;
       frame_info.duration = duration;
       frame_info.timecode = timecode;
       frame_info.name = input_frame->option_values.frame_name;
 
       if (!jxl::EncodeFrame(input_frame->option_values.cparams, frame_info,
                             &metadata, input_frame->frame_data, cms,
                             thread_pool.get(), &output_processor,
                             input_frame->option_values.aux_out)) {
         return JXL_API_ERROR(this, JXL_ENC_ERR_GENERIC,
                              "Failed to encode frame");
       }
     } else {
       JXL_CHECK(fast_lossless_frame);
       auto runner = +[](void* void_pool, void* opaque, void fun(void*, size_t),
                         size_t count) {
         auto* pool = reinterpret_cast<jxl::ThreadPool*>(void_pool);
         JXL_CHECK(jxl::RunOnPool(
             pool, 0, count, jxl::ThreadPool::NoInit,
             [&](size_t i, size_t) { fun(opaque, i); }, "Encode fast lossless"));
       };
       JxlFastLosslessProcessFrame(fast_lossless_frame.get(), last_frame,
                                   thread_pool.get(), runner, &output_processor);
     }
 
     const size_t frame_codestream_end = output_processor.CurrentPosition();
     const size_t frame_codestream_size =
         frame_codestream_end - frame_codestream_start;
 
     codestream_bytes_written_end_of_frame +=
         frame_codestream_size - header_bytes.size();
 
     if (MustUseContainer()) {
       output_processor.Seek(frame_start_pos);
       std::vector<uint8_t> box_header(box_header_size);
       if (!use_large_box &&
           frame_codestream_size >= jxl::kLargeBoxContentSizeThreshold) {
         // Assuming our upper bound estimate is correct, this should never
         // happen.
         return JXL_API_ERROR(
             this, JXL_ENC_ERR_GENERIC,
             "Box size was estimated to be small, but turned out to be large. "
             "Please file this error in size estimation as a bug.");
       }
       if (last_frame && jxlp_counter == 0) {
 #if JXL_ENABLE_ASSERT
         const size_t n =
 #endif
             jxl::WriteBoxHeader(jxl::MakeBoxType("jxlc"), frame_codestream_size,
                                 /*unbounded=*/false, use_large_box,
                                 box_header.data());
         JXL_ASSERT(n == box_header_size);
       } else {
 #if JXL_ENABLE_ASSERT
         const size_t n =
 #endif
             jxl::WriteBoxHeader(
                 jxl::MakeBoxType("jxlp"), frame_codestream_size + 4,
                 /*unbounded=*/false, use_large_box, box_header.data());
         JXL_ASSERT(n == box_header_size - 4);
         WriteJxlpBoxCounter(jxlp_counter++, last_frame,
                             &box_header[box_header_size - 4]);
       }
       JXL_RETURN_IF_ERROR(AppendData(output_processor, box_header));
       JXL_ASSERT(output_processor.CurrentPosition() == frame_codestream_start);
       output_processor.Seek(frame_codestream_end);
     }
     output_processor.SetFinalizedPosition();
     if (input_frame) {
       last_used_cparams = input_frame->option_values.cparams;
     }
     if (last_frame && frame_index_box.StoreFrameIndexBox()) {
       std::vector<uint8_t> index_box_content;
       EncodeFrameIndexBox(frame_index_box, index_box_content);
       JXL_RETURN_IF_ERROR(AppendBoxWithContents(jxl::MakeBoxType("jxli"),
                                                 jxl::Bytes(index_box_content)));
     }
   } else {
     // Not a frame, so is a box instead
     jxl::MemoryManagerUniquePtr<jxl::JxlEncoderQueuedBox> box =
         std::move(input.box);
     input_queue.erase(input_queue.begin());
     num_queued_boxes--;
 
     if (box->compress_box) {
       jxl::PaddedBytes compressed(4);
       // Prepend the original box type in the brob box contents
       for (size_t i = 0; i < 4; i++) {
         compressed[i] = static_cast<uint8_t>(box->type[i]);
       }
       if (JXL_ENC_SUCCESS !=
           BrotliCompress((brotli_effort >= 0 ? brotli_effort : 4),
                          box->contents.data(), box->contents.size(),
                          &compressed)) {
         return JXL_API_ERROR(this, JXL_ENC_ERR_GENERIC,
                              "Brotli compression for brob box failed");
       }
 
       JXL_RETURN_IF_ERROR(
           AppendBoxWithContents(jxl::MakeBoxType("brob"), compressed));
     } else {
       JXL_RETURN_IF_ERROR(AppendBoxWithContents(box->type, box->contents));
     }
   }
 
   return jxl::OkStatus();
 }
 
 JxlEncoderStatus JxlEncoderSetColorEncoding(JxlEncoder* enc,
                                             const JxlColorEncoding* color) {
   if (!enc->basic_info_set) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE, "Basic info not yet set");
   }
   if (enc->color_encoding_set) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Color encoding is already set");
   }
   if (!enc->metadata.m.color_encoding.FromExternal(*color)) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_GENERIC, "Error in color conversion");
   }
   if (enc->metadata.m.color_encoding.GetColorSpace() ==
       jxl::ColorSpace::kGray) {
     if (enc->basic_info.num_color_channels != 1) {
       return JXL_API_ERROR(
           enc, JXL_ENC_ERR_API_USAGE,
           "Cannot use grayscale color encoding with num_color_channels != 1");
     }
   } else {
     if (enc->basic_info.num_color_channels != 3) {
       return JXL_API_ERROR(
           enc, JXL_ENC_ERR_API_USAGE,
           "Cannot use RGB color encoding with num_color_channels != 3");
     }
   }
   enc->color_encoding_set = true;
   if (!enc->intensity_target_set) {
     jxl::SetIntensityTarget(&enc->metadata.m);
   }
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetICCProfile(JxlEncoder* enc,
                                          const uint8_t* icc_profile,
                                          size_t size) {
   if (!enc->basic_info_set) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE, "Basic info not yet set");
   }
   if (enc->color_encoding_set) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "ICC profile is already set");
   }
   if (size == 0) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_BAD_INPUT, "Empty ICC profile");
   }
   jxl::IccBytes icc;
   icc.assign(icc_profile, icc_profile + size);
   if (enc->cms_set) {
     if (!enc->metadata.m.color_encoding.SetICC(std::move(icc), &enc->cms)) {
       return JXL_API_ERROR(enc, JXL_ENC_ERR_BAD_INPUT,
                            "ICC profile could not be set");
     }
   } else {
     enc->metadata.m.color_encoding.SetICCRaw(std::move(icc));
   }
   if (enc->metadata.m.color_encoding.GetColorSpace() ==
       jxl::ColorSpace::kGray) {
     if (enc->basic_info.num_color_channels != 1) {
       return JXL_API_ERROR(
           enc, JXL_ENC_ERR_BAD_INPUT,
           "Cannot use grayscale ICC profile with num_color_channels != 1");
     }
   } else {
     if (enc->basic_info.num_color_channels != 3) {
       return JXL_API_ERROR(
           enc, JXL_ENC_ERR_BAD_INPUT,
           "Cannot use RGB ICC profile with num_color_channels != 3");
     }
     // TODO(jon): also check that a kBlack extra channel is provided in the CMYK
     // case
   }
   enc->color_encoding_set = true;
   if (!enc->intensity_target_set) {
     jxl::SetIntensityTarget(&enc->metadata.m);
   }
 
   if (!enc->basic_info.uses_original_profile && enc->cms_set) {
     enc->metadata.m.color_encoding.DecideIfWantICC(enc->cms);
   }
 
   return JxlErrorOrStatus::Success();
 }
 
 void JxlEncoderInitBasicInfo(JxlBasicInfo* info) {
   info->have_container = JXL_FALSE;
   info->xsize = 0;
   info->ysize = 0;
   info->bits_per_sample = 8;
   info->exponent_bits_per_sample = 0;
   info->intensity_target = 0.f;
   info->min_nits = 0.f;
   info->relative_to_max_display = JXL_FALSE;
   info->linear_below = 0.f;
   info->uses_original_profile = JXL_FALSE;
   info->have_preview = JXL_FALSE;
   info->have_animation = JXL_FALSE;
   info->orientation = JXL_ORIENT_IDENTITY;
   info->num_color_channels = 3;
   info->num_extra_channels = 0;
   info->alpha_bits = 0;
   info->alpha_exponent_bits = 0;
   info->alpha_premultiplied = JXL_FALSE;
   info->preview.xsize = 0;
   info->preview.ysize = 0;
   info->intrinsic_xsize = 0;
   info->intrinsic_ysize = 0;
   info->animation.tps_numerator = 10;
   info->animation.tps_denominator = 1;
   info->animation.num_loops = 0;
   info->animation.have_timecodes = JXL_FALSE;
 }
 
 void JxlEncoderInitFrameHeader(JxlFrameHeader* frame_header) {
   // For each field, the default value of the specification is used. Depending
   // on whether an animation frame, or a composite still blending frame,
   // is used, different fields have to be set up by the user after initing
   // the frame header.
   frame_header->duration = 0;
   frame_header->timecode = 0;
   frame_header->name_length = 0;
   // In the specification, the default value of is_last is !frame_type, and the
   // default frame_type is kRegularFrame which has value 0, so is_last is true
   // by default. However, the encoder does not use this value (the field exists
   // for the decoder to set) since last frame is determined by usage of
   // JxlEncoderCloseFrames instead.
   frame_header->is_last = JXL_TRUE;
   frame_header->layer_info.have_crop = JXL_FALSE;
   frame_header->layer_info.crop_x0 = 0;
   frame_header->layer_info.crop_y0 = 0;
   // These must be set if have_crop is enabled, but the default value has
   // have_crop false, and these dimensions 0. The user must set these to the
   // desired size after enabling have_crop (which is not yet implemented).
   frame_header->layer_info.xsize = 0;
   frame_header->layer_info.ysize = 0;
   JxlEncoderInitBlendInfo(&frame_header->layer_info.blend_info);
   frame_header->layer_info.save_as_reference = 0;
 }
 
 void JxlEncoderInitBlendInfo(JxlBlendInfo* blend_info) {
   // Default blend mode in the specification is 0. Note that combining
   // blend mode of replace with a duration is not useful, but the user has to
   // manually set duration in case of animation, or manually change the blend
   // mode in case of composite stills, so initing to a combination that is not
   // useful on its own is not an issue.
   blend_info->blendmode = JXL_BLEND_REPLACE;
   blend_info->source = 0;
   blend_info->alpha = 0;
   blend_info->clamp = 0;
 }
 
 JxlEncoderStatus JxlEncoderSetBasicInfo(JxlEncoder* enc,
                                         const JxlBasicInfo* info) {
   if (!enc->metadata.size.Set(info->xsize, info->ysize)) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE, "Invalid dimensions");
   }
   if (JXL_ENC_SUCCESS != CheckValidBitdepth(info->bits_per_sample,
                                             info->exponent_bits_per_sample)) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE, "Invalid bit depth");
   }
 
   enc->metadata.m.bit_depth.bits_per_sample = info->bits_per_sample;
   enc->metadata.m.bit_depth.exponent_bits_per_sample =
       info->exponent_bits_per_sample;
   enc->metadata.m.bit_depth.floating_point_sample =
       (info->exponent_bits_per_sample != 0u);
   enc->metadata.m.modular_16_bit_buffer_sufficient =
       (!FROM_JXL_BOOL(info->uses_original_profile) ||
        info->bits_per_sample <= 12) &&
       info->alpha_bits <= 12;
   if ((info->intrinsic_xsize > 0 || info->intrinsic_ysize > 0) &&
       (info->intrinsic_xsize != info->xsize ||
        info->intrinsic_ysize != info->ysize)) {
     if (info->intrinsic_xsize > (1ull << 30ull) ||
         info->intrinsic_ysize > (1ull << 30ull) ||
         !enc->metadata.m.intrinsic_size.Set(info->intrinsic_xsize,
                                             info->intrinsic_ysize)) {
       return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                            "Invalid intrinsic dimensions");
     }
     enc->metadata.m.have_intrinsic_size = true;
   }
 
   // The number of extra channels includes the alpha channel, so for example and
   // RGBA with no other extra channels, has exactly num_extra_channels == 1
   enc->metadata.m.num_extra_channels = info->num_extra_channels;
   enc->metadata.m.extra_channel_info.resize(enc->metadata.m.num_extra_channels);
   if (info->num_extra_channels == 0 && info->alpha_bits) {
     return JXL_API_ERROR(
         enc, JXL_ENC_ERR_API_USAGE,
         "when alpha_bits is non-zero, the number of channels must be at least "
         "1");
   }
   // If the user provides non-zero alpha_bits, we make the channel info at index
   // zero the appropriate alpha channel.
   if (info->alpha_bits) {
     JxlExtraChannelInfo channel_info;
     JxlEncoderInitExtraChannelInfo(JXL_CHANNEL_ALPHA, &channel_info);
     channel_info.bits_per_sample = info->alpha_bits;
     channel_info.exponent_bits_per_sample = info->alpha_exponent_bits;
     if (JxlEncoderSetExtraChannelInfo(enc, 0, &channel_info)) {
       return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                            "Problem setting extra channel info for alpha");
     }
   }
 
   enc->metadata.m.xyb_encoded = !FROM_JXL_BOOL(info->uses_original_profile);
   if (info->orientation > 0 && info->orientation <= 8) {
     enc->metadata.m.orientation = info->orientation;
   } else {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid value for orientation field");
   }
   if (info->num_color_channels != 1 && info->num_color_channels != 3) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid number of color channels");
   }
   if (info->intensity_target != 0) {
     enc->metadata.m.SetIntensityTarget(info->intensity_target);
     enc->intensity_target_set = true;
   } else if (enc->color_encoding_set) {
     // If this is false, JxlEncoderSetColorEncoding will be called later and we
     // will get one more chance to call jxl::SetIntensityTarget, after the color
     // encoding is indeed set.
     jxl::SetIntensityTarget(&enc->metadata.m);
     enc->intensity_target_set = true;
   }
   enc->metadata.m.tone_mapping.min_nits = info->min_nits;
   enc->metadata.m.tone_mapping.relative_to_max_display =
       FROM_JXL_BOOL(info->relative_to_max_display);
   enc->metadata.m.tone_mapping.linear_below = info->linear_below;
   enc->basic_info = *info;
   enc->basic_info_set = true;
 
   enc->metadata.m.have_animation = FROM_JXL_BOOL(info->have_animation);
   if (info->have_animation) {
     if (info->animation.tps_denominator < 1) {
       return JXL_API_ERROR(
           enc, JXL_ENC_ERR_API_USAGE,
           "If animation is used, tps_denominator must be >= 1");
     }
     if (info->animation.tps_numerator < 1) {
       return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                            "If animation is used, tps_numerator must be >= 1");
     }
     enc->metadata.m.animation.tps_numerator = info->animation.tps_numerator;
     enc->metadata.m.animation.tps_denominator = info->animation.tps_denominator;
     enc->metadata.m.animation.num_loops = info->animation.num_loops;
     enc->metadata.m.animation.have_timecodes =
         FROM_JXL_BOOL(info->animation.have_timecodes);
   }
   std::string level_message;
   int required_level = VerifyLevelSettings(enc, &level_message);
   if (required_level == -1 ||
       (static_cast<int>(enc->codestream_level) < required_level &&
        enc->codestream_level != -1)) {
     return JXL_API_ERROR(
         enc, JXL_ENC_ERR_API_USAGE, "%s",
         ("Codestream level verification for level " +
          std::to_string(enc->codestream_level) + " failed: " + level_message)
             .c_str());
   }
   return JxlErrorOrStatus::Success();
 }
 
 void JxlEncoderInitExtraChannelInfo(JxlExtraChannelType type,
                                     JxlExtraChannelInfo* info) {
   info->type = type;
   info->bits_per_sample = 8;
   info->exponent_bits_per_sample = 0;
   info->dim_shift = 0;
   info->name_length = 0;
   info->alpha_premultiplied = JXL_FALSE;
   info->spot_color[0] = 0;
   info->spot_color[1] = 0;
   info->spot_color[2] = 0;
   info->spot_color[3] = 0;
   info->cfa_channel = 0;
 }
 
 JXL_EXPORT JxlEncoderStatus JxlEncoderSetUpsamplingMode(JxlEncoder* enc,
                                                         const int64_t factor,
                                                         const int64_t mode) {
   // for convenience, allow calling this with factor 1 and just make it a no-op
   if (factor == 1) return JxlErrorOrStatus::Success();
   if (factor != 2 && factor != 4 && factor != 8) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid upsampling factor");
   }
   if (mode < -1)
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE, "Invalid upsampling mode");
   if (mode > 1) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_NOT_SUPPORTED,
                          "Unsupported upsampling mode");
   }
 
   const size_t count = (factor == 2 ? 15 : (factor == 4 ? 55 : 210));
   auto& td = enc->metadata.transform_data;
   float* weights = (factor == 2 ? td.upsampling2_weights
                                 : (factor == 4 ? td.upsampling4_weights
                                                : td.upsampling8_weights));
   if (mode == -1) {
     // Default fancy upsampling: don't signal custom weights
     enc->metadata.transform_data.custom_weights_mask &= ~(factor >> 1);
   } else if (mode == 0) {
     // Nearest neighbor upsampling
     enc->metadata.transform_data.custom_weights_mask |= (factor >> 1);
     memset(weights, 0, sizeof(float) * count);
     if (factor == 2) {
       weights[9] = 1.f;
     } else if (factor == 4) {
       for (int i : {19, 24, 49}) weights[i] = 1.f;
     } else if (factor == 8) {
       for (int i : {39, 44, 49, 54, 119, 124, 129, 174, 179, 204}) {
         weights[i] = 1.f;
       }
     }
   } else if (mode == 1) {
     // 'Pixel dots' upsampling (nearest-neighbor with cut corners)
     JxlEncoderSetUpsamplingMode(enc, factor, 0);
     if (factor == 4) {
       weights[19] = 0.f;
       weights[24] = 0.5f;
     } else if (factor == 8) {
       for (int i : {39, 44, 49, 119}) weights[i] = 0.f;
       for (int i : {54, 124}) weights[i] = 0.5f;
     }
   }
   return JxlErrorOrStatus::Success();
 }
 
 JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelInfo(
     JxlEncoder* enc, size_t index, const JxlExtraChannelInfo* info) {
   if (index >= enc->metadata.m.num_extra_channels) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid value for the index of extra channel");
   }
   if (JXL_ENC_SUCCESS != CheckValidBitdepth(info->bits_per_sample,
                                             info->exponent_bits_per_sample)) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE, "Invalid bit depth");
   }
 
   jxl::ExtraChannelInfo& channel = enc->metadata.m.extra_channel_info[index];
   channel.type = static_cast<jxl::ExtraChannel>(info->type);
   channel.bit_depth.bits_per_sample = info->bits_per_sample;
   enc->metadata.m.modular_16_bit_buffer_sufficient &=
       info->bits_per_sample <= 12;
   channel.bit_depth.exponent_bits_per_sample = info->exponent_bits_per_sample;
   channel.bit_depth.floating_point_sample = info->exponent_bits_per_sample != 0;
   channel.dim_shift = info->dim_shift;
   channel.name = "";
   channel.alpha_associated = (info->alpha_premultiplied != 0);
   channel.cfa_channel = info->cfa_channel;
   channel.spot_color[0] = info->spot_color[0];
   channel.spot_color[1] = info->spot_color[1];
   channel.spot_color[2] = info->spot_color[2];
   channel.spot_color[3] = info->spot_color[3];
   std::string level_message;
   int required_level = VerifyLevelSettings(enc, &level_message);
   if (required_level == -1 ||
       (static_cast<int>(enc->codestream_level) < required_level &&
        enc->codestream_level != -1)) {
     return JXL_API_ERROR(
         enc, JXL_ENC_ERR_API_USAGE, "%s",
         ("Codestream level verification for level " +
          std::to_string(enc->codestream_level) + " failed: " + level_message)
             .c_str());
   }
   return JxlErrorOrStatus::Success();
 }
 
 JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelName(JxlEncoder* enc,
                                                           size_t index,
                                                           const char* name,
                                                           size_t size) {
   if (index >= enc->metadata.m.num_extra_channels) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid value for the index of extra channel");
   }
   enc->metadata.m.extra_channel_info[index].name =
       std::string(name, name + size);
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderFrameSettings* JxlEncoderFrameSettingsCreate(
     JxlEncoder* enc, const JxlEncoderFrameSettings* source) {
   auto opts = jxl::MemoryManagerMakeUnique<JxlEncoderFrameSettings>(
       &enc->memory_manager);
   if (!opts) return nullptr;
   opts->enc = enc;
   if (source != nullptr) {
     opts->values = source->values;
   } else {
     opts->values.lossless = false;
   }
   opts->values.cparams.level = enc->codestream_level;
   opts->values.cparams.ec_distance.resize(enc->metadata.m.num_extra_channels,
                                           0);
 
   JxlEncoderFrameSettings* ret = opts.get();
   enc->encoder_options.emplace_back(std::move(opts));
   return ret;
 }
 
 JxlEncoderStatus JxlEncoderSetFrameLossless(
     JxlEncoderFrameSettings* frame_settings, const JXL_BOOL lossless) {
   if (lossless && frame_settings->enc->basic_info_set &&
       frame_settings->enc->metadata.m.xyb_encoded) {
     return JXL_API_ERROR(
         frame_settings->enc, JXL_ENC_ERR_API_USAGE,
         "Set uses_original_profile=true for lossless encoding");
   }
   frame_settings->values.lossless = FROM_JXL_BOOL(lossless);
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetFrameDistance(
     JxlEncoderFrameSettings* frame_settings, float distance) {
   if (distance < 0.f || distance > 25.f) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Distance has to be in [0.0..25.0] (corresponding to "
                          "quality in [0.0..100.0])");
   }
   if (distance > 0.f && distance < 0.01f) {
     distance = 0.01f;
   }
   frame_settings->values.cparams.butteraugli_distance = distance;
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetExtraChannelDistance(
     JxlEncoderFrameSettings* frame_settings, size_t index, float distance) {
   if (index >= frame_settings->enc->metadata.m.num_extra_channels) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid value for the index of extra channel");
   }
   if (distance != -1.f && (distance < 0.f || distance > 25.f)) {
     return JXL_API_ERROR(
         frame_settings->enc, JXL_ENC_ERR_API_USAGE,
         "Distance has to be -1 or in [0.0..25.0] (corresponding to "
         "quality in [0.0..100.0])");
   }
   if (distance > 0.f && distance < 0.01f) {
     distance = 0.01f;
   }
 
   if (index >= frame_settings->values.cparams.ec_distance.size()) {
     // This can only happen if JxlEncoderFrameSettingsCreate() was called before
     // JxlEncoderSetBasicInfo().
     frame_settings->values.cparams.ec_distance.resize(
         frame_settings->enc->metadata.m.num_extra_channels, 0);
   }
 
   frame_settings->values.cparams.ec_distance[index] = distance;
   return JxlErrorOrStatus::Success();
 }
 
 float JxlEncoderDistanceFromQuality(float quality) {
   return quality >= 100.0 ? 0.0
          : quality >= 30
              ? 0.1 + (100 - quality) * 0.09
              : 53.0 / 3000.0 * quality * quality - 23.0 / 20.0 * quality + 25.0;
 }
 
 JxlEncoderStatus JxlEncoderFrameSettingsSetOption(
     JxlEncoderFrameSettings* frame_settings, JxlEncoderFrameSettingId option,
     int64_t value) {
   // check if value is -1, 0 or 1 for Override-type options
   switch (option) {
     case JXL_ENC_FRAME_SETTING_NOISE:
     case JXL_ENC_FRAME_SETTING_DOTS:
     case JXL_ENC_FRAME_SETTING_PATCHES:
     case JXL_ENC_FRAME_SETTING_GABORISH:
     case JXL_ENC_FRAME_SETTING_MODULAR:
     case JXL_ENC_FRAME_SETTING_KEEP_INVISIBLE:
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER:
     case JXL_ENC_FRAME_SETTING_RESPONSIVE:
     case JXL_ENC_FRAME_SETTING_PROGRESSIVE_AC:
     case JXL_ENC_FRAME_SETTING_QPROGRESSIVE_AC:
     case JXL_ENC_FRAME_SETTING_LOSSY_PALETTE:
     case JXL_ENC_FRAME_SETTING_JPEG_RECON_CFL:
     case JXL_ENC_FRAME_SETTING_JPEG_COMPRESS_BOXES:
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_EXIF:
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_XMP:
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_JUMBF:
       if (value < -1 || value > 1) {
         return JXL_API_ERROR(
             frame_settings->enc, JXL_ENC_ERR_API_USAGE,
             "Option value has to be -1 (default), 0 (off) or 1 (on)");
       }
       break;
     default:
       break;
   }
 
   switch (option) {
     case JXL_ENC_FRAME_SETTING_EFFORT:
       if (frame_settings->enc->allow_expert_options) {
         if (value < 1 || value > 11) {
           return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                                "Encode effort has to be in [1..11]");
         }
       } else {
         if (value < 1 || value > 10) {
           return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                                "Encode effort has to be in [1..10]");
         }
       }
       frame_settings->values.cparams.speed_tier =
           static_cast<jxl::SpeedTier>(10 - value);
       break;
     case JXL_ENC_FRAME_SETTING_BROTLI_EFFORT:
       if (value < -1 || value > 11) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Brotli effort has to be in [-1..11]");
       }
       // set cparams for brotli use in JPEG frames
       frame_settings->values.cparams.brotli_effort = value;
       // set enc option for brotli use in brob boxes
       frame_settings->enc->brotli_effort = value;
       break;
     case JXL_ENC_FRAME_SETTING_DECODING_SPEED:
       if (value < 0 || value > 4) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                              "Decoding speed has to be in [0..4]");
       }
       frame_settings->values.cparams.decoding_speed_tier = value;
       break;
     case JXL_ENC_FRAME_SETTING_RESAMPLING:
       if (value != -1 && value != 1 && value != 2 && value != 4 && value != 8) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Resampling factor has to be 1, 2, 4 or 8");
       }
       frame_settings->values.cparams.resampling = value;
       break;
     case JXL_ENC_FRAME_SETTING_EXTRA_CHANNEL_RESAMPLING:
       // TODO(lode): the jxl codestream allows choosing a different resampling
       // factor for each extra channel, independently per frame. Move this
       // option to a JxlEncoderFrameSettings-option that can be set per extra
       // channel, so needs its own function rather than
       // JxlEncoderFrameSettingsSetOption due to the extra channel index
       // argument required.
       if (value != -1 && value != 1 && value != 2 && value != 4 && value != 8) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Resampling factor has to be 1, 2, 4 or 8");
       }
       frame_settings->values.cparams.ec_resampling = value;
       break;
     case JXL_ENC_FRAME_SETTING_ALREADY_DOWNSAMPLED:
       if (value < 0 || value > 1) {
         return JxlErrorOrStatus::Error();
       }
       frame_settings->values.cparams.already_downsampled = (value == 1);
       break;
     case JXL_ENC_FRAME_SETTING_NOISE:
       frame_settings->values.cparams.noise = static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_DOTS:
       frame_settings->values.cparams.dots = static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_PATCHES:
       frame_settings->values.cparams.patches =
           static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_EPF:
       if (value < -1 || value > 3) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "EPF value has to be in [-1..3]");
       }
       frame_settings->values.cparams.epf = static_cast<int>(value);
       break;
     case JXL_ENC_FRAME_SETTING_GABORISH:
       frame_settings->values.cparams.gaborish =
           static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_MODULAR:
       frame_settings->values.cparams.modular_mode = (value == 1);
       break;
     case JXL_ENC_FRAME_SETTING_KEEP_INVISIBLE:
       frame_settings->values.cparams.keep_invisible =
           static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER:
       frame_settings->values.cparams.centerfirst = (value == 1);
       break;
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER_CENTER_X:
       if (value < -1) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Center x coordinate has to be -1 or positive");
       }
       frame_settings->values.cparams.center_x = static_cast<size_t>(value);
       break;
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER_CENTER_Y:
       if (value < -1) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Center y coordinate has to be -1 or positive");
       }
       frame_settings->values.cparams.center_y = static_cast<size_t>(value);
       break;
     case JXL_ENC_FRAME_SETTING_RESPONSIVE:
       frame_settings->values.cparams.responsive = value;
       break;
     case JXL_ENC_FRAME_SETTING_PROGRESSIVE_AC:
       frame_settings->values.cparams.progressive_mode =
           static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_QPROGRESSIVE_AC:
       frame_settings->values.cparams.qprogressive_mode =
           static_cast<jxl::Override>(value);
       break;
     case JXL_ENC_FRAME_SETTING_PROGRESSIVE_DC:
       if (value < -1 || value > 2) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Progressive DC has to be in [-1..2]");
       }
       frame_settings->values.cparams.progressive_dc = value;
       break;
     case JXL_ENC_FRAME_SETTING_PALETTE_COLORS:
       if (value < -1 || value > 70913) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..70913]");
       }
       if (value == -1) {
         frame_settings->values.cparams.palette_colors = 1 << 10;
       } else {
         frame_settings->values.cparams.palette_colors = value;
       }
       break;
     case JXL_ENC_FRAME_SETTING_LOSSY_PALETTE:
       // TODO(lode): the defaults of some palette settings depend on others.
       // See the logic in cjxl. Similar for other settings. This should be
       // handled in the encoder during JxlEncoderProcessOutput (or,
       // alternatively, in the cjxl binary like now)
       frame_settings->values.cparams.lossy_palette = (value == 1);
       break;
     case JXL_ENC_FRAME_SETTING_COLOR_TRANSFORM:
       if (value < -1 || value > 2) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..2]");
       }
       if (value == -1) {
         frame_settings->values.cparams.color_transform =
             jxl::ColorTransform::kXYB;
       } else {
         frame_settings->values.cparams.color_transform =
             static_cast<jxl::ColorTransform>(value);
       }
       break;
     case JXL_ENC_FRAME_SETTING_MODULAR_COLOR_SPACE:
       if (value < -1 || value > 41) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..41]");
       }
       frame_settings->values.cparams.colorspace = value;
       break;
     case JXL_ENC_FRAME_SETTING_MODULAR_GROUP_SIZE:
       if (value < -1 || value > 3) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..3]");
       }
       frame_settings->values.cparams.modular_group_size_shift = value;
       break;
     case JXL_ENC_FRAME_SETTING_MODULAR_PREDICTOR:
       if (value < -1 || value > 15) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..15]");
       }
       frame_settings->values.cparams.options.predictor =
           static_cast<jxl::Predictor>(value);
       break;
     case JXL_ENC_FRAME_SETTING_MODULAR_NB_PREV_CHANNELS:
       // The max allowed value can in theory be higher. However, it depends on
       // the effort setting. 11 is the highest safe value that doesn't cause
       // tree_samples to be >= 64 in the encoder. The specification may allow
       // more than this. With more fine tuning higher values could be allowed.
       // For N-channel images, the largest useful value is N-1.
       if (value < -1 || value > 11) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..11]");
       }
       if (value == -1) {
         frame_settings->values.cparams.options.max_properties = 0;
       } else {
         frame_settings->values.cparams.options.max_properties = value;
       }
       break;
     case JXL_ENC_FRAME_SETTING_JPEG_RECON_CFL:
       if (value == -1) {
         frame_settings->values.cparams.force_cfl_jpeg_recompression = true;
       } else {
         frame_settings->values.cparams.force_cfl_jpeg_recompression = value;
       }
       break;
     case JXL_ENC_FRAME_INDEX_BOX:
       if (value < 0 || value > 1) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                              "Option value has to be 0 or 1");
       }
       frame_settings->values.frame_index_box = true;
       break;
     case JXL_ENC_FRAME_SETTING_PHOTON_NOISE:
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                            "Float option, try setting it with "
                            "JxlEncoderFrameSettingsSetFloatOption");
     case JXL_ENC_FRAME_SETTING_JPEG_COMPRESS_BOXES:
       frame_settings->values.cparams.jpeg_compress_boxes = value;
       break;
     case JXL_ENC_FRAME_SETTING_BUFFERING:
       if (value < -1 || value > 3) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                              "Buffering has to be in [-1..3]");
       }
       frame_settings->values.cparams.buffering = value;
       break;
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_EXIF:
       frame_settings->values.cparams.jpeg_keep_exif = value;
       break;
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_XMP:
       frame_settings->values.cparams.jpeg_keep_xmp = value;
       break;
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_JUMBF:
       frame_settings->values.cparams.jpeg_keep_jumbf = value;
       break;
     case JXL_ENC_FRAME_SETTING_USE_FULL_IMAGE_HEURISTICS:
       if (value < 0 || value > 1) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                              "Option value has to be 0 or 1");
       }
       frame_settings->values.cparams.use_full_image_heuristics = value;
       break;
 
     default:
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                            "Unknown option");
   }
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderFrameSettingsSetFloatOption(
     JxlEncoderFrameSettings* frame_settings, JxlEncoderFrameSettingId option,
     float value) {
   switch (option) {
     case JXL_ENC_FRAME_SETTING_PHOTON_NOISE:
       if (value < 0) return JXL_ENC_ERROR;
       // TODO(lode): add encoder setting to set the 8 floating point values of
       // the noise synthesis parameters per frame for more fine grained control.
       frame_settings->values.cparams.photon_noise_iso = value;
       return JxlErrorOrStatus::Success();
     case JXL_ENC_FRAME_SETTING_MODULAR_MA_TREE_LEARNING_PERCENT:
       if (value < -1.f || value > 100.f) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be smaller than 100");
       }
       // This value is called "iterations" or "nb_repeats" in cjxl, but is in
       // fact a fraction in range 0.0-1.0, with the default value 0.5.
       // Convert from floating point percentage to floating point fraction here.
       if (value < -.5f) {
         // TODO(lode): for this and many other settings (also in
         // JxlEncoderFrameSettingsSetOption), avoid duplicating the default
         // values here and in enc_params.h and options.h, have one location
         // where the defaults are specified.
         frame_settings->values.cparams.options.nb_repeats = 0.5f;
       } else {
         frame_settings->values.cparams.options.nb_repeats = value * 0.01f;
       }
       return JxlErrorOrStatus::Success();
     case JXL_ENC_FRAME_SETTING_CHANNEL_COLORS_GLOBAL_PERCENT:
       if (value < -1.f || value > 100.f) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..100]");
       }
       if (value < -.5f) {
         frame_settings->values.cparams.channel_colors_pre_transform_percent =
             95.0f;
       } else {
         frame_settings->values.cparams.channel_colors_pre_transform_percent =
             value;
       }
       return JxlErrorOrStatus::Success();
     case JXL_ENC_FRAME_SETTING_CHANNEL_COLORS_GROUP_PERCENT:
       if (value < -1.f || value > 100.f) {
         return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                              "Option value has to be in [-1..100]");
       }
       if (value < -.5f) {
         frame_settings->values.cparams.channel_colors_percent = 80.0f;
       } else {
         frame_settings->values.cparams.channel_colors_percent = value;
       }
       return JxlErrorOrStatus::Success();
     case JXL_ENC_FRAME_SETTING_EFFORT:
     case JXL_ENC_FRAME_SETTING_DECODING_SPEED:
     case JXL_ENC_FRAME_SETTING_RESAMPLING:
     case JXL_ENC_FRAME_SETTING_EXTRA_CHANNEL_RESAMPLING:
     case JXL_ENC_FRAME_SETTING_ALREADY_DOWNSAMPLED:
     case JXL_ENC_FRAME_SETTING_NOISE:
     case JXL_ENC_FRAME_SETTING_DOTS:
     case JXL_ENC_FRAME_SETTING_PATCHES:
     case JXL_ENC_FRAME_SETTING_EPF:
     case JXL_ENC_FRAME_SETTING_GABORISH:
     case JXL_ENC_FRAME_SETTING_MODULAR:
     case JXL_ENC_FRAME_SETTING_KEEP_INVISIBLE:
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER:
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER_CENTER_X:
     case JXL_ENC_FRAME_SETTING_GROUP_ORDER_CENTER_Y:
     case JXL_ENC_FRAME_SETTING_RESPONSIVE:
     case JXL_ENC_FRAME_SETTING_PROGRESSIVE_AC:
     case JXL_ENC_FRAME_SETTING_QPROGRESSIVE_AC:
     case JXL_ENC_FRAME_SETTING_PROGRESSIVE_DC:
     case JXL_ENC_FRAME_SETTING_PALETTE_COLORS:
     case JXL_ENC_FRAME_SETTING_LOSSY_PALETTE:
     case JXL_ENC_FRAME_SETTING_COLOR_TRANSFORM:
     case JXL_ENC_FRAME_SETTING_MODULAR_COLOR_SPACE:
     case JXL_ENC_FRAME_SETTING_MODULAR_GROUP_SIZE:
     case JXL_ENC_FRAME_SETTING_MODULAR_PREDICTOR:
     case JXL_ENC_FRAME_SETTING_MODULAR_NB_PREV_CHANNELS:
     case JXL_ENC_FRAME_SETTING_JPEG_RECON_CFL:
     case JXL_ENC_FRAME_INDEX_BOX:
     case JXL_ENC_FRAME_SETTING_BROTLI_EFFORT:
     case JXL_ENC_FRAME_SETTING_FILL_ENUM:
     case JXL_ENC_FRAME_SETTING_JPEG_COMPRESS_BOXES:
     case JXL_ENC_FRAME_SETTING_BUFFERING:
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_EXIF:
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_XMP:
     case JXL_ENC_FRAME_SETTING_JPEG_KEEP_JUMBF:
     case JXL_ENC_FRAME_SETTING_USE_FULL_IMAGE_HEURISTICS:
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                            "Int option, try setting it with "
                            "JxlEncoderFrameSettingsSetOption");
     default:
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_NOT_SUPPORTED,
                            "Unknown option");
   }
 }
 JxlEncoder* JxlEncoderCreate(const JxlMemoryManager* memory_manager) {
   JxlMemoryManager local_memory_manager;
   if (!jxl::MemoryManagerInit(&local_memory_manager, memory_manager)) {
     return nullptr;
   }
 
   void* alloc =
       jxl::MemoryManagerAlloc(&local_memory_manager, sizeof(JxlEncoder));
   if (!alloc) return nullptr;
   JxlEncoder* enc = new (alloc) JxlEncoder();
   enc->memory_manager = local_memory_manager;
   // TODO(sboukortt): add an API function to set this.
   enc->cms = *JxlGetDefaultCms();
   enc->cms_set = true;
 
   // Initialize all the field values.
   JxlEncoderReset(enc);
 
   return enc;
 }
 
 void JxlEncoderReset(JxlEncoder* enc) {
   enc->thread_pool.reset();
   enc->input_queue.clear();
   enc->num_queued_frames = 0;
   enc->num_queued_boxes = 0;
   enc->encoder_options.clear();
   enc->codestream_bytes_written_end_of_frame = 0;
   enc->wrote_bytes = false;
   enc->jxlp_counter = 0;
   enc->metadata = jxl::CodecMetadata();
   enc->last_used_cparams = jxl::CompressParams();
   enc->frames_closed = false;
   enc->boxes_closed = false;
   enc->basic_info_set = false;
   enc->color_encoding_set = false;
   enc->intensity_target_set = false;
   enc->use_container = false;
   enc->use_boxes = false;
   enc->codestream_level = -1;
   enc->output_processor = JxlEncoderOutputProcessorWrapper();
   JxlEncoderInitBasicInfo(&enc->basic_info);
 }
 
 void JxlEncoderDestroy(JxlEncoder* enc) {
   if (enc) {
     JxlMemoryManager local_memory_manager = enc->memory_manager;
     // Call destructor directly since custom free function is used.
     enc->~JxlEncoder();
     jxl::MemoryManagerFree(&local_memory_manager, enc);
   }
 }
 
 JxlEncoderError JxlEncoderGetError(JxlEncoder* enc) { return enc->error; }
 
 JxlEncoderStatus JxlEncoderUseContainer(JxlEncoder* enc,
                                         JXL_BOOL use_container) {
   if (enc->wrote_bytes) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "this setting can only be set at the beginning");
   }
   enc->use_container = FROM_JXL_BOOL(use_container);
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderStoreJPEGMetadata(JxlEncoder* enc,
                                              JXL_BOOL store_jpeg_metadata) {
   if (enc->wrote_bytes) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "this setting can only be set at the beginning");
   }
   enc->store_jpeg_metadata = FROM_JXL_BOOL(store_jpeg_metadata);
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetCodestreamLevel(JxlEncoder* enc, int level) {
   if (level != -1 && level != 5 && level != 10) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_NOT_SUPPORTED, "invalid level");
   }
   if (enc->wrote_bytes) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "this setting can only be set at the beginning");
   }
   enc->codestream_level = level;
   return JxlErrorOrStatus::Success();
 }
 
 int JxlEncoderGetRequiredCodestreamLevel(const JxlEncoder* enc) {
   return VerifyLevelSettings(enc, nullptr);
 }
 
 void JxlEncoderSetCms(JxlEncoder* enc, JxlCmsInterface cms) {
   jxl::msan::MemoryIsInitialized(&cms, sizeof(cms));
   enc->cms = cms;
   enc->cms_set = true;
 }
 
 JxlEncoderStatus JxlEncoderSetParallelRunner(JxlEncoder* enc,
                                              JxlParallelRunner parallel_runner,
                                              void* parallel_runner_opaque) {
   if (enc->thread_pool) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "parallel runner already set");
   }
   enc->thread_pool = jxl::MemoryManagerMakeUnique<jxl::ThreadPool>(
       &enc->memory_manager, parallel_runner, parallel_runner_opaque);
   if (!enc->thread_pool) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_GENERIC,
                          "error setting parallel runner");
   }
   return JxlErrorOrStatus::Success();
 }
 
 namespace {
 JxlEncoderStatus GetCurrentDimensions(
     const JxlEncoderFrameSettings* frame_settings, size_t& xsize,
     size_t& ysize) {
   xsize = frame_settings->enc->metadata.xsize();
   ysize = frame_settings->enc->metadata.ysize();
   if (frame_settings->values.header.layer_info.have_crop) {
     xsize = frame_settings->values.header.layer_info.xsize;
     ysize = frame_settings->values.header.layer_info.ysize;
   }
   if (frame_settings->values.cparams.already_downsampled) {
     size_t factor = frame_settings->values.cparams.resampling;
     xsize = jxl::DivCeil(xsize, factor);
     ysize = jxl::DivCeil(ysize, factor);
   }
   if (xsize == 0 || ysize == 0) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "zero-sized frame is not allowed");
   }
   return JxlErrorOrStatus::Success();
 }
 }  // namespace
 
 JxlEncoderStatus JxlEncoderAddJPEGFrame(
     const JxlEncoderFrameSettings* frame_settings, const uint8_t* buffer,
     size_t size) {
   if (frame_settings->enc->frames_closed) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Frame input is already closed");
   }
 
   jxl::CodecInOut io;
   if (!jxl::jpeg::DecodeImageJPG(jxl::Bytes(buffer, size), &io)) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_BAD_INPUT,
                          "Error during decode of input JPEG");
   }
 
   if (!frame_settings->enc->color_encoding_set) {
     SetColorEncodingFromJpegData(
         *io.Main().jpeg_data, &frame_settings->enc->metadata.m.color_encoding);
     frame_settings->enc->color_encoding_set = true;
   }
 
   if (!frame_settings->enc->basic_info_set) {
     JxlBasicInfo basic_info;
     JxlEncoderInitBasicInfo(&basic_info);
     basic_info.xsize = io.Main().jpeg_data->width;
     basic_info.ysize = io.Main().jpeg_data->height;
     basic_info.uses_original_profile = JXL_TRUE;
     if (JxlEncoderSetBasicInfo(frame_settings->enc, &basic_info) !=
         JXL_ENC_SUCCESS) {
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                            "Error setting basic info");
     }
   }
 
   size_t xsize;
   size_t ysize;
   if (GetCurrentDimensions(frame_settings, xsize, ysize) != JXL_ENC_SUCCESS) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                          "bad dimensions");
   }
   if (xsize != static_cast<size_t>(io.Main().jpeg_data->width) ||
       ysize != static_cast<size_t>(io.Main().jpeg_data->height)) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                          "JPEG dimensions don't match frame dimensions");
   }
 
   if (frame_settings->enc->metadata.m.xyb_encoded) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Can't XYB encode a lossless JPEG");
   }
   if (!io.blobs.exif.empty()) {
     JxlOrientation orientation = static_cast<JxlOrientation>(
         frame_settings->enc->metadata.m.orientation);
     jxl::InterpretExif(io.blobs.exif, &orientation);
     frame_settings->enc->metadata.m.orientation = orientation;
   }
   if (!io.blobs.exif.empty() && frame_settings->values.cparams.jpeg_keep_exif) {
     size_t exif_size = io.blobs.exif.size();
     // Exif data in JPEG is limited to 64k
     if (exif_size > 0xFFFF) {
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                            "Exif larger than possible in JPEG?");
     }
     exif_size += 4;  // prefix 4 zero bytes for tiff offset
     std::vector<uint8_t> exif(exif_size);
     memcpy(exif.data() + 4, io.blobs.exif.data(), io.blobs.exif.size());
     JxlEncoderUseBoxes(frame_settings->enc);
     JxlEncoderAddBox(
         frame_settings->enc, "Exif", exif.data(), exif_size,
         TO_JXL_BOOL(frame_settings->values.cparams.jpeg_compress_boxes));
   }
   if (!io.blobs.xmp.empty() && frame_settings->values.cparams.jpeg_keep_xmp) {
     JxlEncoderUseBoxes(frame_settings->enc);
     JxlEncoderAddBox(
         frame_settings->enc, "xml ", io.blobs.xmp.data(), io.blobs.xmp.size(),
         TO_JXL_BOOL(frame_settings->values.cparams.jpeg_compress_boxes));
   }
   if (!io.blobs.jumbf.empty() &&
       frame_settings->values.cparams.jpeg_keep_jumbf) {
     JxlEncoderUseBoxes(frame_settings->enc);
     JxlEncoderAddBox(
         frame_settings->enc, "jumb", io.blobs.jumbf.data(),
         io.blobs.jumbf.size(),
         TO_JXL_BOOL(frame_settings->values.cparams.jpeg_compress_boxes));
   }
   if (frame_settings->enc->store_jpeg_metadata) {
     if (!frame_settings->values.cparams.jpeg_keep_exif ||
         !frame_settings->values.cparams.jpeg_keep_xmp) {
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                            "Need to preserve EXIF and XMP to allow JPEG "
                            "bitstream reconstruction");
     }
     jxl::jpeg::JPEGData data_in = *io.Main().jpeg_data;
     std::vector<uint8_t> jpeg_data;
     if (!jxl::jpeg::EncodeJPEGData(data_in, &jpeg_data,
                                    frame_settings->values.cparams)) {
       return JXL_API_ERROR(
           frame_settings->enc, JXL_ENC_ERR_JBRD,
           "JPEG bitstream reconstruction data cannot be encoded");
     }
     frame_settings->enc->jpeg_metadata = jpeg_data;
   }
 
   jxl::JxlEncoderChunkedFrameAdapter frame_data(
       xsize, ysize, frame_settings->enc->metadata.m.num_extra_channels);
   frame_data.SetJPEGData(*io.Main().jpeg_data);
 
   auto queued_frame = jxl::MemoryManagerMakeUnique<jxl::JxlEncoderQueuedFrame>(
       &frame_settings->enc->memory_manager,
       // JxlEncoderQueuedFrame is a struct with no constructors, so we use the
       // default move constructor there.
       jxl::JxlEncoderQueuedFrame{
           frame_settings->values, std::move(frame_data), {}});
   if (!queued_frame) {
     // TODO(jon): when can this happen? is this an API usage error?
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                          "No frame queued?");
   }
   queued_frame->ec_initialized.resize(
       frame_settings->enc->metadata.m.num_extra_channels);
 
   QueueFrame(frame_settings, queued_frame);
   return JxlErrorOrStatus::Success();
 }
 
 static bool CanDoFastLossless(const JxlEncoderFrameSettings* frame_settings,
                               const JxlPixelFormat* pixel_format,
                               bool has_alpha) {
   if (!frame_settings->values.lossless) {
     return false;
   }
   // TODO(veluca): many of the following options could be made to work, but are
   // just not implemented in FJXL's frame header handling yet.
   if (frame_settings->values.frame_index_box) {
     return false;
   }
   if (frame_settings->values.header.layer_info.have_crop) {
     return false;
   }
   if (frame_settings->enc->metadata.m.have_animation) {
     return false;
   }
   if (frame_settings->values.cparams.speed_tier != jxl::SpeedTier::kLightning) {
     return false;
   }
   if (frame_settings->values.image_bit_depth.type ==
           JxlBitDepthType::JXL_BIT_DEPTH_CUSTOM &&
       frame_settings->values.image_bit_depth.bits_per_sample !=
           frame_settings->enc->metadata.m.bit_depth.bits_per_sample) {
     return false;
   }
   // TODO(veluca): implement support for LSB-padded input in fast_lossless.
   if (frame_settings->values.image_bit_depth.type ==
           JxlBitDepthType::JXL_BIT_DEPTH_FROM_PIXEL_FORMAT &&
       frame_settings->values.image_bit_depth.bits_per_sample % 8 != 0) {
     return false;
   }
   if (!frame_settings->values.frame_name.empty()) {
     return false;
   }
   // No extra channels other than alpha.
   if (!(has_alpha && frame_settings->enc->metadata.m.num_extra_channels == 1) &&
       frame_settings->enc->metadata.m.num_extra_channels != 0) {
     return false;
   }
   if (frame_settings->enc->metadata.m.bit_depth.bits_per_sample > 16) {
     return false;
   }
   if (pixel_format->data_type != JxlDataType::JXL_TYPE_FLOAT16 &&
       pixel_format->data_type != JxlDataType::JXL_TYPE_UINT16 &&
       pixel_format->data_type != JxlDataType::JXL_TYPE_UINT8) {
     return false;
   }
   if ((frame_settings->enc->metadata.m.bit_depth.bits_per_sample > 8) !=
       (pixel_format->data_type == JxlDataType::JXL_TYPE_UINT16 ||
        pixel_format->data_type == JxlDataType::JXL_TYPE_FLOAT16)) {
     return false;
   }
   if (!((pixel_format->num_channels == 1 || pixel_format->num_channels == 3) &&
         !has_alpha) &&
       !((pixel_format->num_channels == 2 || pixel_format->num_channels == 4) &&
         has_alpha)) {
     return false;
   }
 
   return true;
 }
 
 namespace {
 JxlEncoderStatus JxlEncoderAddImageFrameInternal(
     const JxlEncoderFrameSettings* frame_settings, size_t xsize, size_t ysize,
     bool streaming, jxl::JxlEncoderChunkedFrameAdapter frame_data) {
   JxlPixelFormat pixel_format = {4, JXL_TYPE_UINT8, JXL_NATIVE_ENDIAN, 0};
   {
     JxlChunkedFrameInputSource input = frame_data.GetInputSource();
     input.get_color_channels_pixel_format(input.opaque, &pixel_format);
   }
   uint32_t num_channels = pixel_format.num_channels;
   size_t has_interleaved_alpha =
       static_cast<size_t>(num_channels == 2 || num_channels == 4);
 
   if (!frame_settings->enc->basic_info_set) {
     // Basic Info must be set. Otherwise, this is an API misuse.
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Basic info or color encoding not set yet");
   }
   if (frame_settings->enc->frames_closed) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Frame input already closed");
   }
   if (num_channels < 3) {
     if (frame_settings->enc->basic_info.num_color_channels != 1) {
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                            "Grayscale pixel format input for an RGB image");
     }
   } else {
     if (frame_settings->enc->basic_info.num_color_channels != 3) {
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                            "RGB pixel format input for a grayscale image");
     }
   }
   if (frame_settings->values.lossless &&
       frame_settings->enc->metadata.m.xyb_encoded) {
     return JXL_API_ERROR(
         frame_settings->enc, JXL_ENC_ERR_API_USAGE,
         "Set uses_original_profile=true for lossless encoding");
   }
   if (JXL_ENC_SUCCESS !=
       VerifyInputBitDepth(frame_settings->values.image_bit_depth,
                           pixel_format)) {
     return JXL_API_ERROR_NOSET("Invalid input bit depth");
   }
   if (has_interleaved_alpha >
       frame_settings->enc->metadata.m.num_extra_channels) {
     return JXL_API_ERROR(
         frame_settings->enc, JXL_ENC_ERR_API_USAGE,
         "number of extra channels mismatch (need 1 extra channel for alpha)");
   }
 
   bool has_alpha = frame_settings->enc->metadata.m.HasAlpha();
 
   // All required conditions to do fast-lossless.
   if (CanDoFastLossless(frame_settings, &pixel_format, has_alpha)) {
     const bool big_endian =
         pixel_format.endianness == JXL_BIG_ENDIAN ||
         (pixel_format.endianness == JXL_NATIVE_ENDIAN && !IsLittleEndian());
 
     auto runner = +[](void* void_pool, void* opaque, void fun(void*, size_t),
                       size_t count) {
       auto* pool = reinterpret_cast<jxl::ThreadPool*>(void_pool);
       JXL_CHECK(jxl::RunOnPool(
           pool, 0, count, jxl::ThreadPool::NoInit,
           [&](size_t i, size_t) { fun(opaque, i); }, "Encode fast lossless"));
     };
     JXL_BOOL oneshot = TO_JXL_BOOL(!frame_data.StreamingInput());
     auto* frame_state = JxlFastLosslessPrepareFrame(
         frame_data.GetInputSource(), xsize, ysize, num_channels,
         frame_settings->enc->metadata.m.bit_depth.bits_per_sample,
         TO_JXL_BOOL(big_endian),
         /*effort=*/2, oneshot);
     if (!streaming) {
       JxlFastLosslessProcessFrame(frame_state, /*is_last=*/false,
                                   frame_settings->enc->thread_pool.get(),
                                   runner, nullptr);
     }
     QueueFastLosslessFrame(frame_settings, frame_state);
     return JxlErrorOrStatus::Success();
   }
 
   if (!streaming) {
     // The input callbacks are only guaranteed to be available during frame
     // encoding when both the input and the output is streaming. In all other
     // cases we need to create an internal copy of the frame data.
     if (!frame_data.CopyBuffers()) {
       return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                            "Invalid chunked frame input source");
     }
   }
 
   if (!frame_settings->enc->color_encoding_set) {
     jxl::ColorEncoding c_current;
     if ((pixel_format.data_type == JXL_TYPE_FLOAT) ||
         (pixel_format.data_type == JXL_TYPE_FLOAT16)) {
       c_current = jxl::ColorEncoding::LinearSRGB(num_channels < 3);
     } else {
       c_current = jxl::ColorEncoding::SRGB(num_channels < 3);
     }
     frame_settings->enc->metadata.m.color_encoding = c_current;
   }
 
   auto queued_frame = jxl::MemoryManagerMakeUnique<jxl::JxlEncoderQueuedFrame>(
       &frame_settings->enc->memory_manager,
       // JxlEncoderQueuedFrame is a struct with no constructors, so we use the
       // default move constructor there.
       jxl::JxlEncoderQueuedFrame{
           frame_settings->values, std::move(frame_data), {}});
 
   if (!queued_frame) {
     // TODO(jon): when can this happen? is this an API usage error?
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                          "No frame queued?");
   }
 
   for (auto& ec_info : frame_settings->enc->metadata.m.extra_channel_info) {
     if (has_interleaved_alpha && ec_info.type == jxl::ExtraChannel::kAlpha) {
       queued_frame->ec_initialized.push_back(1);
       has_interleaved_alpha = 0;  // only first Alpha is initialized
     } else {
       queued_frame->ec_initialized.push_back(0);
     }
   }
   queued_frame->option_values.cparams.level =
       frame_settings->enc->codestream_level;
 
   QueueFrame(frame_settings, queued_frame);
   return JxlErrorOrStatus::Success();
 }
 }  // namespace
 
 JxlEncoderStatus JxlEncoderAddImageFrame(
     const JxlEncoderFrameSettings* frame_settings,
     const JxlPixelFormat* pixel_format, const void* buffer, size_t size) {
   size_t xsize;
   size_t ysize;
   if (GetCurrentDimensions(frame_settings, xsize, ysize) != JXL_ENC_SUCCESS) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                          "bad dimensions");
   }
   jxl::JxlEncoderChunkedFrameAdapter frame_data(
       xsize, ysize, frame_settings->enc->metadata.m.num_extra_channels);
   if (!frame_data.SetFromBuffer(0, reinterpret_cast<const uint8_t*>(buffer),
                                 size, *pixel_format)) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "provided image buffer too small");
   }
   return JxlEncoderAddImageFrameInternal(frame_settings, xsize, ysize,
                                          /*streaming=*/false,
                                          std::move(frame_data));
 }
 
 JxlEncoderStatus JxlEncoderAddChunkedFrame(
     const JxlEncoderFrameSettings* frame_settings, JXL_BOOL is_last_frame,
     JxlChunkedFrameInputSource chunked_frame_input) {
   size_t xsize;
   size_t ysize;
   if (GetCurrentDimensions(frame_settings, xsize, ysize) != JXL_ENC_SUCCESS) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_GENERIC,
                          "bad dimensions");
   }
   bool streaming = frame_settings->enc->output_processor.OutputProcessorSet();
   jxl::JxlEncoderChunkedFrameAdapter frame_data(
       xsize, ysize, frame_settings->enc->metadata.m.num_extra_channels);
   frame_data.SetInputSource(chunked_frame_input);
   auto status = JxlEncoderAddImageFrameInternal(frame_settings, xsize, ysize,
                                                 streaming, frame_data);
   if (status != JXL_ENC_SUCCESS) return status;
 
   auto& queued_frame = frame_settings->enc->input_queue.back();
   if (queued_frame.frame) {
     for (auto& val : queued_frame.frame->ec_initialized) val = 1;
   }
 
   if (is_last_frame) {
     JxlEncoderCloseInput(frame_settings->enc);
   }
   if (streaming) {
     return JxlEncoderFlushInput(frame_settings->enc);
   }
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderUseBoxes(JxlEncoder* enc) {
   if (enc->wrote_bytes) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "this setting can only be set at the beginning");
   }
   enc->use_boxes = true;
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderAddBox(JxlEncoder* enc, const JxlBoxType type,
                                   const uint8_t* contents, size_t size,
                                   JXL_BOOL compress_box) {
   if (!enc->use_boxes) {
     return JXL_API_ERROR(
         enc, JXL_ENC_ERR_API_USAGE,
         "must set JxlEncoderUseBoxes at the beginning to add boxes");
   }
   if (enc->boxes_closed) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Box input already closed");
   }
   if (compress_box) {
     if (memcmp("jxl", type, 3) == 0) {
       return JXL_API_ERROR(
           enc, JXL_ENC_ERR_API_USAGE,
           "brob box may not contain a type starting with \"jxl\"");
     }
     if (memcmp("jbrd", type, 4) == 0) {
       return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                            "jbrd box may not be brob compressed");
     }
     if (memcmp("brob", type, 4) == 0) {
       // The compress_box will compress an existing non-brob box into a brob
       // box. If already giving a valid brotli-compressed brob box, set
       // compress_box to false since it is already compressed.
       return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                            "a brob box cannot contain another brob box");
     }
   }
 
   auto box = jxl::MemoryManagerMakeUnique<jxl::JxlEncoderQueuedBox>(
       &enc->memory_manager);
 
   box->type = jxl::MakeBoxType(type);
   box->contents.assign(contents, contents + size);
   box->compress_box = FROM_JXL_BOOL(compress_box);
   QueueBox(enc, box);
   return JxlErrorOrStatus::Success();
 }
 
 JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelBuffer(
     const JxlEncoderFrameSettings* frame_settings,
     const JxlPixelFormat* pixel_format, const void* buffer, size_t size,
     uint32_t index) {
   if (index >= frame_settings->enc->metadata.m.num_extra_channels) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid value for the index of extra channel");
   }
   if (!frame_settings->enc->basic_info_set ||
       !frame_settings->enc->color_encoding_set) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Basic info has to be set first");
   }
   if (frame_settings->enc->input_queue.empty()) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "First add image frame, then extra channels");
   }
   if (frame_settings->enc->frames_closed) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Frame input already closed");
   }
   JxlPixelFormat ec_format = *pixel_format;
   ec_format.num_channels = 1;
   if (JXL_ENC_SUCCESS !=
       VerifyInputBitDepth(frame_settings->values.image_bit_depth, ec_format)) {
     return JXL_API_ERROR_NOSET("Invalid input bit depth");
   }
   const uint8_t* uint8_buffer = reinterpret_cast<const uint8_t*>(buffer);
   auto* queued_frame = frame_settings->enc->input_queue.back().frame.get();
   if (!queued_frame->frame_data.SetFromBuffer(1 + index, uint8_buffer, size,
                                               ec_format)) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "provided image buffer too small");
   }
   queued_frame->ec_initialized[index] = 1;
 
   return JxlErrorOrStatus::Success();
 }
 
 void JxlEncoderCloseFrames(JxlEncoder* enc) { enc->frames_closed = true; }
 
 void JxlEncoderCloseBoxes(JxlEncoder* enc) { enc->boxes_closed = true; }
 
 void JxlEncoderCloseInput(JxlEncoder* enc) {
   JxlEncoderCloseFrames(enc);
   JxlEncoderCloseBoxes(enc);
 }
 
 JXL_EXPORT JxlEncoderStatus JxlEncoderFlushInput(JxlEncoder* enc) {
   if (!enc->output_processor.OutputProcessorSet()) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Cannot flush input without setting output "
                          "processor with JxlEncoderSetOutputProcessor");
   }
   while (!enc->input_queue.empty()) {
     if (!enc->ProcessOneEnqueuedInput()) {
       return JxlErrorOrStatus::Error();
     }
   }
   return JxlErrorOrStatus::Success();
 }
 
 JXL_EXPORT JxlEncoderStatus JxlEncoderSetOutputProcessor(
     JxlEncoder* enc, JxlEncoderOutputProcessor output_processor) {
   if (enc->output_processor.HasAvailOut()) {
     return JXL_API_ERROR(
         enc, JXL_ENC_ERR_API_USAGE,
         "Cannot set an output processor when some output was already produced");
   }
   if (!output_processor.set_finalized_position ||
       !output_processor.get_buffer || !output_processor.release_buffer) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Missing output processor functions");
   }
   enc->output_processor = JxlEncoderOutputProcessorWrapper(output_processor);
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderProcessOutput(JxlEncoder* enc, uint8_t** next_out,
                                          size_t* avail_out) {
   if (!enc->output_processor.SetAvailOut(next_out, avail_out)) {
     return JXL_API_ERROR(enc, JXL_ENC_ERR_API_USAGE,
                          "Cannot call JxlEncoderProcessOutput after calling "
                          "JxlEncoderSetOutputProcessor");
   }
   while (*avail_out != 0 && !enc->input_queue.empty()) {
     if (!enc->ProcessOneEnqueuedInput()) {
       return JxlErrorOrStatus::Error();
     }
   }
 
   if (!enc->input_queue.empty() || enc->output_processor.HasOutputToWrite()) {
     return JxlErrorOrStatus::MoreOutput();
   }
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetFrameHeader(
     JxlEncoderFrameSettings* frame_settings,
     const JxlFrameHeader* frame_header) {
   if (frame_header->layer_info.blend_info.source > 3) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "invalid blending source index");
   }
   // If there are no extra channels, it's ok for the value to be 0.
   if (frame_header->layer_info.blend_info.alpha != 0 &&
       frame_header->layer_info.blend_info.alpha >=
           frame_settings->enc->metadata.m.extra_channel_info.size()) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "alpha blend channel index out of bounds");
   }
 
   frame_settings->values.header = *frame_header;
   // Setting the frame header resets the frame name, it must be set again with
   // JxlEncoderSetFrameName if desired.
   frame_settings->values.frame_name = "";
 
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetExtraChannelBlendInfo(
     JxlEncoderFrameSettings* frame_settings, size_t index,
     const JxlBlendInfo* blend_info) {
   if (index >= frame_settings->enc->metadata.m.num_extra_channels) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "Invalid value for the index of extra channel");
   }
 
   if (frame_settings->values.extra_channel_blend_info.size() !=
       frame_settings->enc->metadata.m.num_extra_channels) {
     JxlBlendInfo default_blend_info;
     JxlEncoderInitBlendInfo(&default_blend_info);
     frame_settings->values.extra_channel_blend_info.resize(
         frame_settings->enc->metadata.m.num_extra_channels, default_blend_info);
   }
   frame_settings->values.extra_channel_blend_info[index] = *blend_info;
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetFrameName(JxlEncoderFrameSettings* frame_settings,
                                         const char* frame_name) {
   std::string str = frame_name ? frame_name : "";
   if (str.size() > 1071) {
     return JXL_API_ERROR(frame_settings->enc, JXL_ENC_ERR_API_USAGE,
                          "frame name can be max 1071 bytes long");
   }
   frame_settings->values.frame_name = str;
   frame_settings->values.header.name_length = str.size();
   return JxlErrorOrStatus::Success();
 }
 
 JxlEncoderStatus JxlEncoderSetFrameBitDepth(
     JxlEncoderFrameSettings* frame_settings, const JxlBitDepth* bit_depth) {
   if (bit_depth->type != JXL_BIT_DEPTH_FROM_PIXEL_FORMAT &&
       bit_depth->type != JXL_BIT_DEPTH_FROM_CODESTREAM) {
     return JXL_API_ERROR_NOSET(
         "Only JXL_BIT_DEPTH_FROM_PIXEL_FORMAT and "
         "JXL_BIT_DEPTH_FROM_CODESTREAM is implemented "
         "for input buffers.");
   }
   frame_settings->values.image_bit_depth = *bit_depth;
   return JxlErrorOrStatus::Success();
 }
 
 void JxlColorEncodingSetToSRGB(JxlColorEncoding* color_encoding,
                                JXL_BOOL is_gray) {
   *color_encoding =
       jxl::ColorEncoding::SRGB(FROM_JXL_BOOL(is_gray)).ToExternal();
 }
 
 void JxlColorEncodingSetToLinearSRGB(JxlColorEncoding* color_encoding,
                                      JXL_BOOL is_gray) {
   *color_encoding =
       jxl::ColorEncoding::LinearSRGB(FROM_JXL_BOOL(is_gray)).ToExternal();
 }
 
 void JxlEncoderAllowExpertOptions(JxlEncoder* enc) {
   enc->allow_expert_options = true;
 }
 
 JXL_EXPORT void JxlEncoderSetDebugImageCallback(
     JxlEncoderFrameSettings* frame_settings, JxlDebugImageCallback callback,
     void* opaque) {
   frame_settings->values.cparams.debug_image = callback;
   frame_settings->values.cparams.debug_image_opaque = opaque;
 }
 
 JXL_EXPORT JxlEncoderStats* JxlEncoderStatsCreate() {
   return new JxlEncoderStats();
 }
 
 JXL_EXPORT void JxlEncoderStatsDestroy(JxlEncoderStats* stats) { delete stats; }
 
 JXL_EXPORT void JxlEncoderCollectStats(JxlEncoderFrameSettings* frame_settings,
                                        JxlEncoderStats* stats) {
   if (!stats) return;
   frame_settings->values.aux_out = &stats->aux_out;
 }
 
 JXL_EXPORT size_t JxlEncoderStatsGet(const JxlEncoderStats* stats,
                                      JxlEncoderStatsKey key) {
   if (!stats) return 0;
   const jxl::AuxOut& aux_out = stats->aux_out;
   switch (key) {
     case JXL_ENC_STAT_HEADER_BITS:
       return aux_out.layers[jxl::kLayerHeader].total_bits;
     case JXL_ENC_STAT_TOC_BITS:
       return aux_out.layers[jxl::kLayerTOC].total_bits;
     case JXL_ENC_STAT_DICTIONARY_BITS:
       return aux_out.layers[jxl::kLayerDictionary].total_bits;
     case JXL_ENC_STAT_SPLINES_BITS:
       return aux_out.layers[jxl::kLayerSplines].total_bits;
     case JXL_ENC_STAT_NOISE_BITS:
       return aux_out.layers[jxl::kLayerNoise].total_bits;
     case JXL_ENC_STAT_QUANT_BITS:
       return aux_out.layers[jxl::kLayerQuant].total_bits;
     case JXL_ENC_STAT_MODULAR_TREE_BITS:
       return aux_out.layers[jxl::kLayerModularTree].total_bits;
     case JXL_ENC_STAT_MODULAR_GLOBAL_BITS:
       return aux_out.layers[jxl::kLayerModularGlobal].total_bits;
     case JXL_ENC_STAT_DC_BITS:
       return aux_out.layers[jxl::kLayerDC].total_bits;
     case JXL_ENC_STAT_MODULAR_DC_GROUP_BITS:
       return aux_out.layers[jxl::kLayerModularDcGroup].total_bits;
     case JXL_ENC_STAT_CONTROL_FIELDS_BITS:
       return aux_out.layers[jxl::kLayerControlFields].total_bits;
     case JXL_ENC_STAT_COEF_ORDER_BITS:
       return aux_out.layers[jxl::kLayerOrder].total_bits;
     case JXL_ENC_STAT_AC_HISTOGRAM_BITS:
       return aux_out.layers[jxl::kLayerAC].total_bits;
     case JXL_ENC_STAT_AC_BITS:
       return aux_out.layers[jxl::kLayerACTokens].total_bits;
     case JXL_ENC_STAT_MODULAR_AC_GROUP_BITS:
       return aux_out.layers[jxl::kLayerModularAcGroup].total_bits;
     case JXL_ENC_STAT_NUM_SMALL_BLOCKS:
       return aux_out.num_small_blocks;
     case JXL_ENC_STAT_NUM_DCT4X8_BLOCKS:
       return aux_out.num_dct4x8_blocks;
     case JXL_ENC_STAT_NUM_AFV_BLOCKS:
       return aux_out.num_afv_blocks;
     case JXL_ENC_STAT_NUM_DCT8_BLOCKS:
       return aux_out.num_dct8_blocks;
     case JXL_ENC_STAT_NUM_DCT8X32_BLOCKS:
       return aux_out.num_dct16_blocks;
     case JXL_ENC_STAT_NUM_DCT16_BLOCKS:
       return aux_out.num_dct16x32_blocks;
     case JXL_ENC_STAT_NUM_DCT16X32_BLOCKS:
       return aux_out.num_dct32_blocks;
     case JXL_ENC_STAT_NUM_DCT32_BLOCKS:
       return aux_out.num_dct32x64_blocks;
     case JXL_ENC_STAT_NUM_DCT32X64_BLOCKS:
       return aux_out.num_dct32x64_blocks;
     case JXL_ENC_STAT_NUM_DCT64_BLOCKS:
       return aux_out.num_dct64_blocks;
     case JXL_ENC_STAT_NUM_BUTTERAUGLI_ITERS:
       return aux_out.num_butteraugli_iters;
     default:
       return 0;
   }
 }
 
 JXL_EXPORT void JxlEncoderStatsMerge(JxlEncoderStats* stats,
                                      const JxlEncoderStats* other) {
   if (!stats || !other) return;
   stats->aux_out.Assimilate(other->aux_out);
 }