duckstation

codec.h (13211B)

---

 /*
  * AVCodec public API
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef AVCODEC_CODEC_H
 #define AVCODEC_CODEC_H
 
 #include <stdint.h>
 
 #include "libavutil/avutil.h"
 #include "libavutil/hwcontext.h"
 #include "libavutil/log.h"
 #include "libavutil/pixfmt.h"
 #include "libavutil/rational.h"
 #include "libavutil/samplefmt.h"
 
 #include "libavcodec/codec_id.h"
 #include "libavcodec/version_major.h"
 
 /**
  * @addtogroup lavc_core
  * @{
  */
 
 /**
  * Decoder can use draw_horiz_band callback.
  */
 #define AV_CODEC_CAP_DRAW_HORIZ_BAND     (1 <<  0)
 /**
  * Codec uses get_buffer() or get_encode_buffer() for allocating buffers and
  * supports custom allocators.
  * If not set, it might not use get_buffer() or get_encode_buffer() at all, or
  * use operations that assume the buffer was allocated by
  * avcodec_default_get_buffer2 or avcodec_default_get_encode_buffer.
  */
 #define AV_CODEC_CAP_DR1                 (1 <<  1)
 /**
  * Encoder or decoder requires flushing with NULL input at the end in order to
  * give the complete and correct output.
  *
  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
  *       with NULL data. The user can still send NULL data to the public encode
  *       or decode function, but libavcodec will not pass it along to the codec
  *       unless this flag is set.
  *
  * Decoders:
  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
  * returns frames.
  *
  * Encoders:
  * The encoder needs to be fed with NULL data at the end of encoding until the
  * encoder no longer returns data.
  *
  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
  *       flag also means that the encoder must set the pts and duration for
  *       each output packet. If this flag is not set, the pts and duration will
  *       be determined by libavcodec from the input frame.
  */
 #define AV_CODEC_CAP_DELAY               (1 <<  5)
 /**
  * Codec can be fed a final frame with a smaller size.
  * This can be used to prevent truncation of the last audio samples.
  */
 #define AV_CODEC_CAP_SMALL_LAST_FRAME    (1 <<  6)
 
 #if FF_API_SUBFRAMES
 /**
  * Codec can output multiple frames per AVPacket
  * Normally demuxers return one frame at a time, demuxers which do not do
  * are connected to a parser to split what they return into proper frames.
  * This flag is reserved to the very rare category of codecs which have a
  * bitstream that cannot be split into frames without timeconsuming
  * operations like full decoding. Demuxers carrying such bitstreams thus
  * may return multiple frames in a packet. This has many disadvantages like
  * prohibiting stream copy in many cases thus it should only be considered
  * as a last resort.
  */
 #define AV_CODEC_CAP_SUBFRAMES           (1 <<  8)
 #endif
 
 /**
  * Codec is experimental and is thus avoided in favor of non experimental
  * encoders
  */
 #define AV_CODEC_CAP_EXPERIMENTAL        (1 <<  9)
 /**
  * Codec should fill in channel configuration and samplerate instead of container
  */
 #define AV_CODEC_CAP_CHANNEL_CONF        (1 << 10)
 /**
  * Codec supports frame-level multithreading.
  */
 #define AV_CODEC_CAP_FRAME_THREADS       (1 << 12)
 /**
  * Codec supports slice-based (or partition-based) multithreading.
  */
 #define AV_CODEC_CAP_SLICE_THREADS       (1 << 13)
 /**
  * Codec supports changed parameters at any point.
  */
 #define AV_CODEC_CAP_PARAM_CHANGE        (1 << 14)
 /**
  * Codec supports multithreading through a method other than slice- or
  * frame-level multithreading. Typically this marks wrappers around
  * multithreading-capable external libraries.
  */
 #define AV_CODEC_CAP_OTHER_THREADS       (1 << 15)
 /**
  * Audio encoder supports receiving a different number of samples in each call.
  */
 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
 /**
  * Decoder is not a preferred choice for probing.
  * This indicates that the decoder is not a good choice for probing.
  * It could for example be an expensive to spin up hardware decoder,
  * or it could simply not provide a lot of useful information about
  * the stream.
  * A decoder marked with this flag should only be used as last resort
  * choice for probing.
  */
 #define AV_CODEC_CAP_AVOID_PROBING       (1 << 17)
 
 /**
  * Codec is backed by a hardware implementation. Typically used to
  * identify a non-hwaccel hardware decoder. For information about hwaccels, use
  * avcodec_get_hw_config() instead.
  */
 #define AV_CODEC_CAP_HARDWARE            (1 << 18)
 
 /**
  * Codec is potentially backed by a hardware implementation, but not
  * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
  * implementation provides some sort of internal fallback.
  */
 #define AV_CODEC_CAP_HYBRID              (1 << 19)
 
 /**
  * This encoder can reorder user opaque values from input AVFrames and return
  * them with corresponding output packets.
  * @see AV_CODEC_FLAG_COPY_OPAQUE
  */
 #define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)
 
 /**
  * This encoder can be flushed using avcodec_flush_buffers(). If this flag is
  * not set, the encoder must be closed and reopened to ensure that no frames
  * remain pending.
  */
 #define AV_CODEC_CAP_ENCODER_FLUSH   (1 << 21)
 
 /**
  * The encoder is able to output reconstructed frame data, i.e. raw frames that
  * would be produced by decoding the encoded bitstream.
  *
  * Reconstructed frame output is enabled by the AV_CODEC_FLAG_RECON_FRAME flag.
  */
 #define AV_CODEC_CAP_ENCODER_RECON_FRAME (1 << 22)
 
 /**
  * AVProfile.
  */
 typedef struct AVProfile {
     int profile;
     const char *name; ///< short name for the profile
 } AVProfile;
 
 /**
  * AVCodec.
  */
 typedef struct AVCodec {
     /**
      * Name of the codec implementation.
      * The name is globally unique among encoders and among decoders (but an
      * encoder and a decoder can share the same name).
      * This is the primary way to find a codec from the user perspective.
      */
     const char *name;
     /**
      * Descriptive name for the codec, meant to be more human readable than name.
      * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
      */
     const char *long_name;
     enum AVMediaType type;
     enum AVCodecID id;
     /**
      * Codec capabilities.
      * see AV_CODEC_CAP_*
      */
     int capabilities;
     uint8_t max_lowres;                     ///< maximum value for lowres supported by the decoder
     const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
     const enum AVPixelFormat *pix_fmts;     ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
     const int *supported_samplerates;       ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
     const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
     const AVClass *priv_class;              ///< AVClass for the private context
     const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {AV_PROFILE_UNKNOWN}
 
     /**
      * Group name of the codec implementation.
      * This is a short symbolic name of the wrapper backing this codec. A
      * wrapper uses some kind of external implementation for the codec, such
      * as an external library, or a codec implementation provided by the OS or
      * the hardware.
      * If this field is NULL, this is a builtin, libavcodec native codec.
      * If non-NULL, this will be the suffix in AVCodec.name in most cases
      * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
      */
     const char *wrapper_name;
 
     /**
      * Array of supported channel layouts, terminated with a zeroed layout.
      */
     const AVChannelLayout *ch_layouts;
 } AVCodec;
 
 /**
  * Iterate over all registered codecs.
  *
  * @param opaque a pointer where libavcodec will store the iteration state. Must
  *               point to NULL to start the iteration.
  *
  * @return the next registered codec or NULL when the iteration is
  *         finished
  */
 const AVCodec *av_codec_iterate(void **opaque);
 
 /**
  * Find a registered decoder with a matching codec ID.
  *
  * @param id AVCodecID of the requested decoder
  * @return A decoder if one was found, NULL otherwise.
  */
 const AVCodec *avcodec_find_decoder(enum AVCodecID id);
 
 /**
  * Find a registered decoder with the specified name.
  *
  * @param name name of the requested decoder
  * @return A decoder if one was found, NULL otherwise.
  */
 const AVCodec *avcodec_find_decoder_by_name(const char *name);
 
 /**
  * Find a registered encoder with a matching codec ID.
  *
  * @param id AVCodecID of the requested encoder
  * @return An encoder if one was found, NULL otherwise.
  */
 const AVCodec *avcodec_find_encoder(enum AVCodecID id);
 
 /**
  * Find a registered encoder with the specified name.
  *
  * @param name name of the requested encoder
  * @return An encoder if one was found, NULL otherwise.
  */
 const AVCodec *avcodec_find_encoder_by_name(const char *name);
 /**
  * @return a non-zero number if codec is an encoder, zero otherwise
  */
 int av_codec_is_encoder(const AVCodec *codec);
 
 /**
  * @return a non-zero number if codec is a decoder, zero otherwise
  */
 int av_codec_is_decoder(const AVCodec *codec);
 
 /**
  * Return a name for the specified profile, if available.
  *
  * @param codec the codec that is searched for the given profile
  * @param profile the profile value for which a name is requested
  * @return A name for the profile if found, NULL otherwise.
  */
 const char *av_get_profile_name(const AVCodec *codec, int profile);
 
 enum {
     /**
      * The codec supports this format via the hw_device_ctx interface.
      *
      * When selecting this format, AVCodecContext.hw_device_ctx should
      * have been set to a device of the specified type before calling
      * avcodec_open2().
      */
     AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX = 0x01,
     /**
      * The codec supports this format via the hw_frames_ctx interface.
      *
      * When selecting this format for a decoder,
      * AVCodecContext.hw_frames_ctx should be set to a suitable frames
      * context inside the get_format() callback.  The frames context
      * must have been created on a device of the specified type.
      *
      * When selecting this format for an encoder,
      * AVCodecContext.hw_frames_ctx should be set to the context which
      * will be used for the input frames before calling avcodec_open2().
      */
     AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX = 0x02,
     /**
      * The codec supports this format by some internal method.
      *
      * This format can be selected without any additional configuration -
      * no device or frames context is required.
      */
     AV_CODEC_HW_CONFIG_METHOD_INTERNAL      = 0x04,
     /**
      * The codec supports this format by some ad-hoc method.
      *
      * Additional settings and/or function calls are required.  See the
      * codec-specific documentation for details.  (Methods requiring
      * this sort of configuration are deprecated and others should be
      * used in preference.)
      */
     AV_CODEC_HW_CONFIG_METHOD_AD_HOC        = 0x08,
 };
 
 typedef struct AVCodecHWConfig {
     /**
      * For decoders, a hardware pixel format which that decoder may be
      * able to decode to if suitable hardware is available.
      *
      * For encoders, a pixel format which the encoder may be able to
      * accept.  If set to AV_PIX_FMT_NONE, this applies to all pixel
      * formats supported by the codec.
      */
     enum AVPixelFormat pix_fmt;
     /**
      * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
      * setup methods which can be used with this configuration.
      */
     int methods;
     /**
      * The device type associated with the configuration.
      *
      * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
      * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
      */
     enum AVHWDeviceType device_type;
 } AVCodecHWConfig;
 
 /**
  * Retrieve supported hardware configurations for a codec.
  *
  * Values of index from zero to some maximum return the indexed configuration
  * descriptor; all other values return NULL.  If the codec does not support
  * any hardware configurations then it will always return NULL.
  */
 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
 
 /**
  * @}
  */
 
 #endif /* AVCODEC_CODEC_H */