libjxl

FORK: libjxl patches used on blog
git clone https://git.neptards.moe/blog/libjxl.git
Log | Files | Refs | Submodules | README | LICENSE

image_metadata.cc (20390B)


      1 // Copyright (c) the JPEG XL Project Authors. All rights reserved.
      2 //
      3 // Use of this source code is governed by a BSD-style
      4 // license that can be found in the LICENSE file.
      5 
      6 #include "lib/jxl/image_metadata.h"
      7 
      8 #include <limits>
      9 #include <utility>
     10 
     11 #include "lib/jxl/alpha.h"
     12 #include "lib/jxl/base/byte_order.h"
     13 #include "lib/jxl/cms/opsin_params.h"
     14 #include "lib/jxl/fields.h"
     15 #include "lib/jxl/frame_header.h"
     16 #include "lib/jxl/quantizer.h"
     17 
     18 namespace jxl {
     19 BitDepth::BitDepth() { Bundle::Init(this); }
     20 Status BitDepth::VisitFields(Visitor* JXL_RESTRICT visitor) {
     21   JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &floating_point_sample));
     22   // The same fields (bits_per_sample and exponent_bits_per_sample) are read
     23   // in a different way depending on floating_point_sample's value. It's still
     24   // default-initialized correctly so using visitor->Conditional is not
     25   // required.
     26   if (!floating_point_sample) {
     27     JXL_QUIET_RETURN_IF_ERROR(visitor->U32(
     28         Val(8), Val(10), Val(12), BitsOffset(6, 1), 8, &bits_per_sample));
     29     exponent_bits_per_sample = 0;
     30   } else {
     31     JXL_QUIET_RETURN_IF_ERROR(visitor->U32(
     32         Val(32), Val(16), Val(24), BitsOffset(6, 1), 32, &bits_per_sample));
     33     // The encoded value is exponent_bits_per_sample - 1, encoded in 3 bits
     34     // so the value can be in range [1, 8].
     35     const uint32_t offset = 1;
     36     exponent_bits_per_sample -= offset;
     37     JXL_QUIET_RETURN_IF_ERROR(
     38         visitor->Bits(4, 8 - offset, &exponent_bits_per_sample));
     39     exponent_bits_per_sample += offset;
     40   }
     41 
     42   // Error-checking for floating point ranges.
     43   if (floating_point_sample) {
     44     if (exponent_bits_per_sample < 2 || exponent_bits_per_sample > 8) {
     45       return JXL_FAILURE("Invalid exponent_bits_per_sample: %u",
     46                          exponent_bits_per_sample);
     47     }
     48     int mantissa_bits =
     49         static_cast<int>(bits_per_sample) - exponent_bits_per_sample - 1;
     50     if (mantissa_bits < 2 || mantissa_bits > 23) {
     51       return JXL_FAILURE("Invalid bits_per_sample: %u", bits_per_sample);
     52     }
     53   } else {
     54     if (bits_per_sample > 31) {
     55       return JXL_FAILURE("Invalid bits_per_sample: %u", bits_per_sample);
     56     }
     57   }
     58   return true;
     59 }
     60 
     61 #if JXL_DEBUG_V_LEVEL >= 1
     62 std::string BitDepth::DebugString() const {
     63   std::ostringstream os;
     64   os << (floating_point_sample ? "F" : "U");
     65   os << bits_per_sample;
     66   if (floating_point_sample) os << "." << exponent_bits_per_sample;
     67   return os.str();
     68 }
     69 #endif
     70 
     71 CustomTransformData::CustomTransformData() { Bundle::Init(this); }
     72 Status CustomTransformData::VisitFields(Visitor* JXL_RESTRICT visitor) {
     73   if (visitor->AllDefault(*this, &all_default)) {
     74     // Overwrite all serialized fields, but not any nonserialized_*.
     75     visitor->SetDefault(this);
     76     return true;
     77   }
     78   if (visitor->Conditional(nonserialized_xyb_encoded)) {
     79     JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&opsin_inverse_matrix));
     80   }
     81   JXL_QUIET_RETURN_IF_ERROR(visitor->Bits(3, 0, &custom_weights_mask));
     82   if (visitor->Conditional((custom_weights_mask & 0x1) != 0)) {
     83     // 4 5x5 kernels, but all of them can be obtained by symmetry from one,
     84     // which is symmetric along its main diagonal. The top-left kernel is
     85     // defined by
     86     //
     87     // 0  1  2  3  4
     88     // 1  5  6  7  8
     89     // 2  6  9 10 11
     90     // 3  7 10 12 13
     91     // 4  8 11 13 14
     92     float constexpr kWeights2[15] = {
     93         -0.01716200f, -0.03452303f, -0.04022174f, -0.02921014f, -0.00624645f,
     94         0.14111091f,  0.28896755f,  0.00278718f,  -0.01610267f, 0.56661550f,
     95         0.03777607f,  -0.01986694f, -0.03144731f, -0.01185068f, -0.00213539f};
     96     for (size_t i = 0; i < 15; i++) {
     97       JXL_QUIET_RETURN_IF_ERROR(
     98           visitor->F16(kWeights2[i], &upsampling2_weights[i]));
     99     }
    100   }
    101   if (visitor->Conditional((custom_weights_mask & 0x2) != 0)) {
    102     // 16 5x5 kernels, but all of them can be obtained by symmetry from
    103     // three, two of which are symmetric along their main diagonals. The top
    104     // left 4 kernels are defined by
    105     //
    106     // 0  1  2  3  4   5  6  7  8  9
    107     // 1 10 11 12 13  14 15 16 17 18
    108     // 2 11 19 20 21  22 23 24 25 26
    109     // 3 12 20 27 28  29 30 31 32 33
    110     // 4 13 21 28 34  35 36 37 38 39
    111     //
    112     // 5 14 22 29 35  40 41 42 43 44
    113     // 6 15 23 30 36  41 45 46 47 48
    114     // 7 16 24 31 37  42 46 49 50 51
    115     // 8 17 25 32 38  43 47 50 52 53
    116     // 9 18 26 33 39  44 48 51 53 54
    117     constexpr float kWeights4[55] = {
    118         -0.02419067f, -0.03491987f, -0.03693351f, -0.03094285f, -0.00529785f,
    119         -0.01663432f, -0.03556863f, -0.03888905f, -0.03516850f, -0.00989469f,
    120         0.23651958f,  0.33392945f,  -0.01073543f, -0.01313181f, -0.03556694f,
    121         0.13048175f,  0.40103025f,  0.03951150f,  -0.02077584f, 0.46914198f,
    122         -0.00209270f, -0.01484589f, -0.04064806f, 0.18942530f,  0.56279892f,
    123         0.06674400f,  -0.02335494f, -0.03551682f, -0.00754830f, -0.02267919f,
    124         -0.02363578f, 0.00315804f,  -0.03399098f, -0.01359519f, -0.00091653f,
    125         -0.00335467f, -0.01163294f, -0.01610294f, -0.00974088f, -0.00191622f,
    126         -0.01095446f, -0.03198464f, -0.04455121f, -0.02799790f, -0.00645912f,
    127         0.06390599f,  0.22963888f,  0.00630981f,  -0.01897349f, 0.67537268f,
    128         0.08483369f,  -0.02534994f, -0.02205197f, -0.01667999f, -0.00384443f};
    129     for (size_t i = 0; i < 55; i++) {
    130       JXL_QUIET_RETURN_IF_ERROR(
    131           visitor->F16(kWeights4[i], &upsampling4_weights[i]));
    132     }
    133   }
    134   if (visitor->Conditional((custom_weights_mask & 0x4) != 0)) {
    135     // 64 5x5 kernels, all of them can be obtained by symmetry from
    136     // 10, 4 of which are symmetric along their main diagonals. The top
    137     // left 16 kernels are defined by
    138     //  0  1  2  3  4   5  6  7  8  9   a  b  c  d  e   f 10 11 12 13
    139     //  1 14 15 16 17  18 19 1a 1b 1c  1d 1e 1f 20 21  22 23 24 25 26
    140     //  2 15 27 28 29  2a 2b 2c 2d 2e  2f 30 31 32 33  34 35 36 37 38
    141     //  3 16 28 39 3a  3b 3c 3d 3e 3f  40 41 42 43 44  45 46 47 48 49
    142     //  4 17 29 3a 4a  4b 4c 4d 4e 4f  50 51 52 53 54  55 56 57 58 59
    143 
    144     //  5 18 2a 3b 4b  5a 5b 5c 5d 5e  5f 60 61 62 63  64 65 66 67 68
    145     //  6 19 2b 3c 4c  5b 69 6a 6b 6c  6d 6e 6f 70 71  72 73 74 75 76
    146     //  7 1a 2c 3d 4d  5c 6a 77 78 79  7a 7b 7c 7d 7e  7f 80 81 82 83
    147     //  8 1b 2d 3e 4e  5d 6b 78 84 85  86 87 88 89 8a  8b 8c 8d 8e 8f
    148     //  9 1c 2e 3f 4f  5e 6c 79 85 90  91 92 93 94 95  96 97 98 99 9a
    149 
    150     //  a 1d 2f 40 50  5f 6d 7a 86 91  9b 9c 9d 9e 9f  a0 a1 a2 a3 a4
    151     //  b 1e 30 41 51  60 6e 7b 87 92  9c a5 a6 a7 a8  a9 aa ab ac ad
    152     //  c 1f 31 42 52  61 6f 7c 88 93  9d a6 ae af b0  b1 b2 b3 b4 b5
    153     //  d 20 32 43 53  62 70 7d 89 94  9e a7 af b6 b7  b8 b9 ba bb bc
    154     //  e 21 33 44 54  63 71 7e 8a 95  9f a8 b0 b7 bd  be bf c0 c1 c2
    155 
    156     //  f 22 34 45 55  64 72 7f 8b 96  a0 a9 b1 b8 be  c3 c4 c5 c6 c7
    157     // 10 23 35 46 56  65 73 80 8c 97  a1 aa b2 b9 bf  c4 c8 c9 ca cb
    158     // 11 24 36 47 57  66 74 81 8d 98  a2 ab b3 ba c0  c5 c9 cc cd ce
    159     // 12 25 37 48 58  67 75 82 8e 99  a3 ac b4 bb c1  c6 ca cd cf d0
    160     // 13 26 38 49 59  68 76 83 8f 9a  a4 ad b5 bc c2  c7 cb ce d0 d1
    161     constexpr float kWeights8[210] = {
    162         -0.02928613f, -0.03706353f, -0.03783812f, -0.03324558f, -0.00447632f,
    163         -0.02519406f, -0.03752601f, -0.03901508f, -0.03663285f, -0.00646649f,
    164         -0.02066407f, -0.03838633f, -0.04002101f, -0.03900035f, -0.00901973f,
    165         -0.01626393f, -0.03954148f, -0.04046620f, -0.03979621f, -0.01224485f,
    166         0.29895328f,  0.35757708f,  -0.02447552f, -0.01081748f, -0.04314594f,
    167         0.23903219f,  0.41119301f,  -0.00573046f, -0.01450239f, -0.04246845f,
    168         0.17567618f,  0.45220643f,  0.02287757f,  -0.01936783f, -0.03583255f,
    169         0.11572472f,  0.47416733f,  0.06284440f,  -0.02685066f, 0.42720050f,
    170         -0.02248939f, -0.01155273f, -0.04562755f, 0.28689496f,  0.49093869f,
    171         -0.00007891f, -0.01545926f, -0.04562659f, 0.21238920f,  0.53980934f,
    172         0.03369474f,  -0.02070211f, -0.03866988f, 0.14229550f,  0.56593398f,
    173         0.08045181f,  -0.02888298f, -0.03680918f, -0.00542229f, -0.02920477f,
    174         -0.02788574f, -0.02118180f, -0.03942402f, -0.00775547f, -0.02433614f,
    175         -0.03193943f, -0.02030828f, -0.04044014f, -0.01074016f, -0.01930822f,
    176         -0.03620399f, -0.01974125f, -0.03919545f, -0.01456093f, -0.00045072f,
    177         -0.00360110f, -0.01020207f, -0.01231907f, -0.00638988f, -0.00071592f,
    178         -0.00279122f, -0.00957115f, -0.01288327f, -0.00730937f, -0.00107783f,
    179         -0.00210156f, -0.00890705f, -0.01317668f, -0.00813895f, -0.00153491f,
    180         -0.02128481f, -0.04173044f, -0.04831487f, -0.03293190f, -0.00525260f,
    181         -0.01720322f, -0.04052736f, -0.05045706f, -0.03607317f, -0.00738030f,
    182         -0.01341764f, -0.03965629f, -0.05151616f, -0.03814886f, -0.01005819f,
    183         0.18968273f,  0.33063684f,  -0.01300105f, -0.01372950f, -0.04017465f,
    184         0.13727832f,  0.36402234f,  0.01027890f,  -0.01832107f, -0.03365072f,
    185         0.08734506f,  0.38194295f,  0.04338228f,  -0.02525993f, 0.56408126f,
    186         0.00458352f,  -0.01648227f, -0.04887868f, 0.24585519f,  0.62026135f,
    187         0.04314807f,  -0.02213737f, -0.04158014f, 0.16637289f,  0.65027023f,
    188         0.09621636f,  -0.03101388f, -0.04082742f, -0.00904519f, -0.02790922f,
    189         -0.02117818f, 0.00798662f,  -0.03995711f, -0.01243427f, -0.02231705f,
    190         -0.02946266f, 0.00992055f,  -0.03600283f, -0.01684920f, -0.00111684f,
    191         -0.00411204f, -0.01297130f, -0.01723725f, -0.01022545f, -0.00165306f,
    192         -0.00313110f, -0.01218016f, -0.01763266f, -0.01125620f, -0.00231663f,
    193         -0.01374149f, -0.03797620f, -0.05142937f, -0.03117307f, -0.00581914f,
    194         -0.01064003f, -0.03608089f, -0.05272168f, -0.03375670f, -0.00795586f,
    195         0.09628104f,  0.27129991f,  -0.00353779f, -0.01734151f, -0.03153981f,
    196         0.05686230f,  0.28500998f,  0.02230594f,  -0.02374955f, 0.68214326f,
    197         0.05018048f,  -0.02320852f, -0.04383616f, 0.18459474f,  0.71517975f,
    198         0.10805613f,  -0.03263677f, -0.03637639f, -0.01394373f, -0.02511203f,
    199         -0.01728636f, 0.05407331f,  -0.02867568f, -0.01893131f, -0.00240854f,
    200         -0.00446511f, -0.01636187f, -0.02377053f, -0.01522848f, -0.00333334f,
    201         -0.00819975f, -0.02964169f, -0.04499287f, -0.02745350f, -0.00612408f,
    202         0.02727416f,  0.19446600f,  0.00159832f,  -0.02232473f, 0.74982506f,
    203         0.11452620f,  -0.03348048f, -0.01605681f, -0.02070339f, -0.00458223f};
    204     for (size_t i = 0; i < 210; i++) {
    205       JXL_QUIET_RETURN_IF_ERROR(
    206           visitor->F16(kWeights8[i], &upsampling8_weights[i]));
    207     }
    208   }
    209   return true;
    210 }
    211 
    212 ExtraChannelInfo::ExtraChannelInfo() { Bundle::Init(this); }
    213 Status ExtraChannelInfo::VisitFields(Visitor* JXL_RESTRICT visitor) {
    214   if (visitor->AllDefault(*this, &all_default)) {
    215     // Overwrite all serialized fields, but not any nonserialized_*.
    216     visitor->SetDefault(this);
    217     return true;
    218   }
    219 
    220   // General
    221   JXL_QUIET_RETURN_IF_ERROR(visitor->Enum(ExtraChannel::kAlpha, &type));
    222 
    223   JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&bit_depth));
    224 
    225   JXL_QUIET_RETURN_IF_ERROR(
    226       visitor->U32(Val(0), Val(3), Val(4), BitsOffset(3, 1), 0, &dim_shift));
    227   if ((1U << dim_shift) > 8) {
    228     return JXL_FAILURE("dim_shift %u too large", dim_shift);
    229   }
    230 
    231   JXL_QUIET_RETURN_IF_ERROR(VisitNameString(visitor, &name));
    232 
    233   // Conditional
    234   if (visitor->Conditional(type == ExtraChannel::kAlpha)) {
    235     JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &alpha_associated));
    236   }
    237   if (visitor->Conditional(type == ExtraChannel::kSpotColor)) {
    238     for (float& c : spot_color) {
    239       JXL_QUIET_RETURN_IF_ERROR(visitor->F16(0, &c));
    240     }
    241   }
    242   if (visitor->Conditional(type == ExtraChannel::kCFA)) {
    243     JXL_QUIET_RETURN_IF_ERROR(visitor->U32(Val(1), Bits(2), BitsOffset(4, 3),
    244                                            BitsOffset(8, 19), 1, &cfa_channel));
    245   }
    246 
    247   if (type == ExtraChannel::kUnknown ||
    248       (static_cast<int>(ExtraChannel::kReserved0) <= static_cast<int>(type) &&
    249        static_cast<int>(type) <= static_cast<int>(ExtraChannel::kReserved7))) {
    250     return JXL_FAILURE("Unknown extra channel (bits %u, shift %u, name '%s')\n",
    251                        bit_depth.bits_per_sample, dim_shift, name.c_str());
    252   }
    253   return true;
    254 }
    255 
    256 #if JXL_DEBUG_V_LEVEL >= 1
    257 std::string ExtraChannelInfo::DebugString() const {
    258   std::ostringstream os;
    259   os << (type == ExtraChannel::kAlpha           ? "Alpha"
    260          : type == ExtraChannel::kDepth         ? "Depth"
    261          : type == ExtraChannel::kSpotColor     ? "Spot"
    262          : type == ExtraChannel::kSelectionMask ? "Mask"
    263          : type == ExtraChannel::kBlack         ? "Black"
    264          : type == ExtraChannel::kCFA           ? "CFA"
    265          : type == ExtraChannel::kThermal       ? "Thermal"
    266                                                 : "Unknown");
    267   if (type == ExtraChannel::kAlpha && alpha_associated) os << "(premul)";
    268   os << " " << bit_depth.DebugString();
    269   os << " shift: " << dim_shift;
    270   return os.str();
    271 }
    272 #endif
    273 
    274 ImageMetadata::ImageMetadata() { Bundle::Init(this); }
    275 Status ImageMetadata::VisitFields(Visitor* JXL_RESTRICT visitor) {
    276   if (visitor->AllDefault(*this, &all_default)) {
    277     // Overwrite all serialized fields, but not any nonserialized_*.
    278     visitor->SetDefault(this);
    279     return true;
    280   }
    281 
    282   // Bundle::AllDefault does not allow usage when reading (it may abort the
    283   // program when a codestream has invalid values), but when reading we
    284   // overwrite the extra_fields value, so do not need to call AllDefault.
    285   bool tone_mapping_default =
    286       visitor->IsReading() ? false : Bundle::AllDefault(tone_mapping);
    287 
    288   bool extra_fields = (orientation != 1 || have_preview || have_animation ||
    289                        have_intrinsic_size || !tone_mapping_default);
    290   JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &extra_fields));
    291   if (visitor->Conditional(extra_fields)) {
    292     orientation--;
    293     JXL_QUIET_RETURN_IF_ERROR(visitor->Bits(3, 0, &orientation));
    294     orientation++;
    295     // (No need for bounds checking because we read exactly 3 bits)
    296 
    297     JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &have_intrinsic_size));
    298     if (visitor->Conditional(have_intrinsic_size)) {
    299       JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&intrinsic_size));
    300     }
    301     JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &have_preview));
    302     if (visitor->Conditional(have_preview)) {
    303       JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&preview_size));
    304     }
    305     JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &have_animation));
    306     if (visitor->Conditional(have_animation)) {
    307       JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&animation));
    308     }
    309   } else {
    310     orientation = 1;  // identity
    311     have_intrinsic_size = false;
    312     have_preview = false;
    313     have_animation = false;
    314   }
    315 
    316   JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&bit_depth));
    317   JXL_QUIET_RETURN_IF_ERROR(
    318       visitor->Bool(true, &modular_16_bit_buffer_sufficient));
    319 
    320   num_extra_channels = extra_channel_info.size();
    321   JXL_QUIET_RETURN_IF_ERROR(visitor->U32(Val(0), Val(1), BitsOffset(4, 2),
    322                                          BitsOffset(12, 1), 0,
    323                                          &num_extra_channels));
    324 
    325   if (visitor->Conditional(num_extra_channels != 0)) {
    326     if (visitor->IsReading()) {
    327       extra_channel_info.resize(num_extra_channels);
    328     }
    329     for (ExtraChannelInfo& eci : extra_channel_info) {
    330       JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&eci));
    331     }
    332   }
    333 
    334   JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(true, &xyb_encoded));
    335   JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&color_encoding));
    336   if (visitor->Conditional(extra_fields)) {
    337     JXL_QUIET_RETURN_IF_ERROR(visitor->VisitNested(&tone_mapping));
    338   }
    339 
    340   // Treat as if only the fields up to extra channels exist.
    341   if (visitor->IsReading() && nonserialized_only_parse_basic_info) {
    342     return true;
    343   }
    344 
    345   JXL_QUIET_RETURN_IF_ERROR(visitor->BeginExtensions(&extensions));
    346   // Extensions: in chronological order of being added to the format.
    347   return visitor->EndExtensions();
    348 }
    349 
    350 OpsinInverseMatrix::OpsinInverseMatrix() { Bundle::Init(this); }
    351 Status OpsinInverseMatrix::VisitFields(Visitor* JXL_RESTRICT visitor) {
    352   if (visitor->AllDefault(*this, &all_default)) {
    353     // Overwrite all serialized fields, but not any nonserialized_*.
    354     visitor->SetDefault(this);
    355     return true;
    356   }
    357   for (int i = 0; i < 9; ++i) {
    358     JXL_QUIET_RETURN_IF_ERROR(
    359         visitor->F16(jxl::cms::DefaultInverseOpsinAbsorbanceMatrix()[i],
    360                      &inverse_matrix[i]));
    361   }
    362   for (int i = 0; i < 3; ++i) {
    363     JXL_QUIET_RETURN_IF_ERROR(visitor->F16(
    364         jxl::cms::kNegOpsinAbsorbanceBiasRGB[i], &opsin_biases[i]));
    365   }
    366   for (int i = 0; i < 4; ++i) {
    367     JXL_QUIET_RETURN_IF_ERROR(
    368         visitor->F16(kDefaultQuantBias[i], &quant_biases[i]));
    369   }
    370   return true;
    371 }
    372 
    373 ToneMapping::ToneMapping() { Bundle::Init(this); }
    374 Status ToneMapping::VisitFields(Visitor* JXL_RESTRICT visitor) {
    375   if (visitor->AllDefault(*this, &all_default)) {
    376     // Overwrite all serialized fields, but not any nonserialized_*.
    377     visitor->SetDefault(this);
    378     return true;
    379   }
    380 
    381   JXL_QUIET_RETURN_IF_ERROR(
    382       visitor->F16(kDefaultIntensityTarget, &intensity_target));
    383   if (intensity_target <= 0.f) {
    384     return JXL_FAILURE("invalid intensity target");
    385   }
    386 
    387   JXL_QUIET_RETURN_IF_ERROR(visitor->F16(0.0f, &min_nits));
    388   if (min_nits < 0.f || min_nits > intensity_target) {
    389     return JXL_FAILURE("invalid min %f vs max %f", min_nits, intensity_target);
    390   }
    391 
    392   JXL_QUIET_RETURN_IF_ERROR(visitor->Bool(false, &relative_to_max_display));
    393 
    394   JXL_QUIET_RETURN_IF_ERROR(visitor->F16(0.0f, &linear_below));
    395   if (linear_below < 0 || (relative_to_max_display && linear_below > 1.0f)) {
    396     return JXL_FAILURE("invalid linear_below %f (%s)", linear_below,
    397                        relative_to_max_display ? "relative" : "absolute");
    398   }
    399 
    400   return true;
    401 }
    402 
    403 Status ReadImageMetadata(BitReader* JXL_RESTRICT reader,
    404                          ImageMetadata* JXL_RESTRICT metadata) {
    405   return Bundle::Read(reader, metadata);
    406 }
    407 
    408 void ImageMetadata::SetAlphaBits(uint32_t bits, bool alpha_is_premultiplied) {
    409   std::vector<ExtraChannelInfo>& eciv = extra_channel_info;
    410   ExtraChannelInfo* alpha = Find(ExtraChannel::kAlpha);
    411   if (bits == 0) {
    412     if (alpha != nullptr) {
    413       // Remove the alpha channel from the extra channel info. It's
    414       // theoretically possible that there are multiple, remove all in that
    415       // case. This ensure a next HasAlpha() will return false.
    416       const auto is_alpha = [](const ExtraChannelInfo& eci) {
    417         return eci.type == ExtraChannel::kAlpha;
    418       };
    419       eciv.erase(std::remove_if(eciv.begin(), eciv.end(), is_alpha),
    420                  eciv.end());
    421     }
    422   } else {
    423     if (alpha == nullptr) {
    424       ExtraChannelInfo info;
    425       info.type = ExtraChannel::kAlpha;
    426       info.bit_depth.bits_per_sample = bits;
    427       info.dim_shift = 0;
    428       info.alpha_associated = alpha_is_premultiplied;
    429       // Prepend rather than append: in case there already are other extra
    430       // channels, prefer alpha channel to be listed first.
    431       eciv.insert(eciv.begin(), info);
    432     } else {
    433       // Ignores potential extra alpha channels, only sets to first one.
    434       alpha->bit_depth.bits_per_sample = bits;
    435       alpha->bit_depth.floating_point_sample = false;
    436       alpha->bit_depth.exponent_bits_per_sample = 0;
    437       alpha->alpha_associated = alpha_is_premultiplied;
    438     }
    439   }
    440   num_extra_channels = extra_channel_info.size();
    441   if (bits > 12) modular_16_bit_buffer_sufficient = false;
    442 }
    443 
    444 #if JXL_DEBUG_V_LEVEL >= 1
    445 std::string ImageMetadata::DebugString() const {
    446   std::ostringstream os;
    447   os << bit_depth.DebugString();
    448   if (modular_16_bit_buffer_sufficient) {
    449     os << " (modular 16)";
    450   }
    451   os << (xyb_encoded ? " xyb encoded" : " orig profile");
    452   os << " " << Description(color_encoding);
    453   if (num_extra_channels > 0) {
    454     os << " extra channels:";
    455     for (size_t i = 0; i < num_extra_channels; ++i) {
    456       os << " (" << extra_channel_info[i].DebugString() << ")";
    457       if (i + 1 < num_extra_channels) os << ",";
    458     }
    459   }
    460   if (have_preview) {
    461     os << " preview: " << preview_size.xsize() << "x" << preview_size.ysize();
    462   }
    463   if (orientation != 1) {
    464     os << " orientation: " << orientation;
    465   }
    466   return os.str();
    467 }
    468 
    469 std::string CodecMetadata::DebugString() const {
    470   std::ostringstream os;
    471   os << size.xsize() << "x" << size.ysize();
    472   os << " " << m.DebugString();
    473   return os.str();
    474 }
    475 #endif
    476 
    477 }  // namespace jxl