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FFmpeg/libavcodec/codec_par.h
James Almer b360c91752 avcodec/codecpar: mention how to allocate coded_side_data
Signed-off-by: James Almer <jamrial@gmail.com>
2023-11-14 14:26:42 -03:00

266 lines
8.0 KiB
C

/*
* Codec parameters 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_PAR_H
#define AVCODEC_CODEC_PAR_H
#include <stdint.h>
#include "libavutil/avutil.h"
#include "libavutil/channel_layout.h"
#include "libavutil/rational.h"
#include "libavutil/pixfmt.h"
#include "codec_id.h"
#include "defs.h"
#include "packet.h"
/**
* @addtogroup lavc_core
* @{
*/
/**
* This struct describes the properties of an encoded stream.
*
* sizeof(AVCodecParameters) is not a part of the public ABI, this struct must
* be allocated with avcodec_parameters_alloc() and freed with
* avcodec_parameters_free().
*/
typedef struct AVCodecParameters {
/**
* General type of the encoded data.
*/
enum AVMediaType codec_type;
/**
* Specific type of the encoded data (the codec used).
*/
enum AVCodecID codec_id;
/**
* Additional information about the codec (corresponds to the AVI FOURCC).
*/
uint32_t codec_tag;
/**
* Extra binary data needed for initializing the decoder, codec-dependent.
*
* Must be allocated with av_malloc() and will be freed by
* avcodec_parameters_free(). The allocated size of extradata must be at
* least extradata_size + AV_INPUT_BUFFER_PADDING_SIZE, with the padding
* bytes zeroed.
*/
uint8_t *extradata;
/**
* Size of the extradata content in bytes.
*/
int extradata_size;
/**
* - video: the pixel format, the value corresponds to enum AVPixelFormat.
* - audio: the sample format, the value corresponds to enum AVSampleFormat.
*/
int format;
/**
* The average bitrate of the encoded data (in bits per second).
*/
int64_t bit_rate;
/**
* The number of bits per sample in the codedwords.
*
* This is basically the bitrate per sample. It is mandatory for a bunch of
* formats to actually decode them. It's the number of bits for one sample in
* the actual coded bitstream.
*
* This could be for example 4 for ADPCM
* For PCM formats this matches bits_per_raw_sample
* Can be 0
*/
int bits_per_coded_sample;
/**
* This is the number of valid bits in each output sample. If the
* sample format has more bits, the least significant bits are additional
* padding bits, which are always 0. Use right shifts to reduce the sample
* to its actual size. For example, audio formats with 24 bit samples will
* have bits_per_raw_sample set to 24, and format set to AV_SAMPLE_FMT_S32.
* To get the original sample use "(int32_t)sample >> 8"."
*
* For ADPCM this might be 12 or 16 or similar
* Can be 0
*/
int bits_per_raw_sample;
/**
* Codec-specific bitstream restrictions that the stream conforms to.
*/
int profile;
int level;
/**
* Video only. The dimensions of the video frame in pixels.
*/
int width;
int height;
/**
* Video only. The aspect ratio (width / height) which a single pixel
* should have when displayed.
*
* When the aspect ratio is unknown / undefined, the numerator should be
* set to 0 (the denominator may have any value).
*/
AVRational sample_aspect_ratio;
/**
* Video only. The order of the fields in interlaced video.
*/
enum AVFieldOrder field_order;
/**
* Video only. Additional colorspace characteristics.
*/
enum AVColorRange color_range;
enum AVColorPrimaries color_primaries;
enum AVColorTransferCharacteristic color_trc;
enum AVColorSpace color_space;
enum AVChromaLocation chroma_location;
/**
* Video only. Number of delayed frames.
*/
int video_delay;
#if FF_API_OLD_CHANNEL_LAYOUT
/**
* Audio only. The channel layout bitmask. May be 0 if the channel layout is
* unknown or unspecified, otherwise the number of bits set must be equal to
* the channels field.
* @deprecated use ch_layout
*/
attribute_deprecated
uint64_t channel_layout;
/**
* Audio only. The number of audio channels.
* @deprecated use ch_layout.nb_channels
*/
attribute_deprecated
int channels;
#endif
/**
* Audio only. The number of audio samples per second.
*/
int sample_rate;
/**
* Audio only. The number of bytes per coded audio frame, required by some
* formats.
*
* Corresponds to nBlockAlign in WAVEFORMATEX.
*/
int block_align;
/**
* Audio only. Audio frame size, if known. Required by some formats to be static.
*/
int frame_size;
/**
* Audio only. The amount of padding (in samples) inserted by the encoder at
* the beginning of the audio. I.e. this number of leading decoded samples
* must be discarded by the caller to get the original audio without leading
* padding.
*/
int initial_padding;
/**
* Audio only. The amount of padding (in samples) appended by the encoder to
* the end of the audio. I.e. this number of decoded samples must be
* discarded by the caller from the end of the stream to get the original
* audio without any trailing padding.
*/
int trailing_padding;
/**
* Audio only. Number of samples to skip after a discontinuity.
*/
int seek_preroll;
/**
* Audio only. The channel layout and number of channels.
*/
AVChannelLayout ch_layout;
/**
* Video only. Number of frames per second, for streams with constant frame
* durations. Should be set to { 0, 1 } when some frames have differing
* durations or if the value is not known.
*
* @note This field correponds to values that are stored in codec-level
* headers and is typically overridden by container/transport-layer
* timestamps, when available. It should thus be used only as a last resort,
* when no higher-level timing information is available.
*/
AVRational framerate;
/**
* Additional data associated with the entire stream.
*
* Should be allocated with av_packet_side_data_new() or
* av_packet_side_data_add(), and will be freed by avcodec_parameters_free().
*/
AVPacketSideData *coded_side_data;
/**
* Amount of entries in @ref coded_side_data.
*/
int nb_coded_side_data;
} AVCodecParameters;
/**
* Allocate a new AVCodecParameters and set its fields to default values
* (unknown/invalid/0). The returned struct must be freed with
* avcodec_parameters_free().
*/
AVCodecParameters *avcodec_parameters_alloc(void);
/**
* Free an AVCodecParameters instance and everything associated with it and
* write NULL to the supplied pointer.
*/
void avcodec_parameters_free(AVCodecParameters **par);
/**
* Copy the contents of src to dst. Any allocated fields in dst are freed and
* replaced with newly allocated duplicates of the corresponding fields in src.
*
* @return >= 0 on success, a negative AVERROR code on failure.
*/
int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src);
/**
* This function is the same as av_get_audio_frame_duration(), except it works
* with AVCodecParameters instead of an AVCodecContext.
*/
int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes);
/**
* @}
*/
#endif // AVCODEC_CODEC_PAR_H