This struct describes the properties of an encoded stream. More...

#include <libavcodec/codec_par.h>

Data Fields
enum AVMediaType	codec_type
	General type of the encoded data.
enum AVCodecID	codec_id
	Specific type of the encoded data (the codec used).
uint32_t	codec_tag
	Additional information about the codec (corresponds to the AVI FOURCC).
uint8_t *	extradata
	Extra binary data needed for initializing the decoder, codec-dependent.
int	extradata_size
	Size of the extradata content in bytes.
AVPacketSideData *	coded_side_data
	Additional data associated with the entire stream.
int	nb_coded_side_data
	Amount of entries in coded_side_data.
int	format
int64_t	bit_rate
	The average bitrate of the encoded data (in bits per second).
int	bits_per_coded_sample
	The number of bits per sample in the codedwords.
int	bits_per_raw_sample
	The number of valid bits in each output sample.
int	profile
	Codec-specific bitstream restrictions that the stream conforms to.
int	level
int	width
	The width of the video frame in pixels.
int	height
	The height of the video frame in pixels.
AVRational	sample_aspect_ratio
	The aspect ratio (width/height) which a single pixel should have when displayed.
AVRational	framerate
	Number of frames per second, for streams with constant frame durations.
enum AVFieldOrder	field_order
	The order of the fields in interlaced video.
enum AVColorRange	color_range
	Additional colorspace characteristics.
enum AVColorPrimaries	color_primaries
enum AVColorTransferCharacteristic	color_trc
enum AVColorSpace	color_space
enum AVChromaLocation	chroma_location
int	video_delay
	Number of delayed frames.
AVChannelLayout	ch_layout
	The channel layout and number of channels.
int	sample_rate
	The number of audio samples per second.
int	block_align
	The number of bytes per coded audio frame, required by some formats.
int	frame_size
	Audio frame size, if known.
int	initial_padding
	Number of padding audio samples at the start.
int	trailing_padding
	Number of padding audio samples at the end.
int	seek_preroll
	Number of audio samples to skip after a discontinuity.
enum AVAlphaMode	alpha_mode
	Video with alpha channel only.

Related Symbols
(Note that these are not member symbols.)
int	avcodec_parameters_from_context (struct AVCodecParameters par, const AVCodecContext codec)
	Fill the parameters struct based on the values from the supplied codec context.
int	avcodec_parameters_to_context (AVCodecContext codec, const struct AVCodecParameters par)
	Fill the codec context based on the values from the supplied codec parameters.

AVCodecParameters *	avcodec_parameters_alloc (void)
	Allocate a new AVCodecParameters and set its fields to default values (unknown/invalid/0).
void	avcodec_parameters_free (AVCodecParameters **par)
	Free an AVCodecParameters instance and everything associated with it and write NULL to the supplied pointer.
int	avcodec_parameters_copy (AVCodecParameters dst, const AVCodecParameters src)
	Copy the contents of `src` to `dst`.
int	av_get_audio_frame_duration2 (AVCodecParameters *par, int frame_bytes)
	This function is the same as av_get_audio_frame_duration(), except it works with AVCodecParameters instead of an AVCodecContext.

Detailed Description

This struct describes the properties of an encoded stream.

Note: The sizeof(AVCodecParameters) is not a part of the public ABI, therefore this struct must be allocated with ::avcodec_parameters_alloc() and freed with ::avcodec_parameters_free().

Examples: remux.c.

Definition at line 49 of file codec_par.h.

Field Documentation

◆ codec_type

enum AVMediaType AVCodecParameters::codec_type

General type of the encoded data.

Examples: remux.c.

Definition at line 53 of file codec_par.h.

Referenced by main().

◆ codec_id

enum AVCodecID AVCodecParameters::codec_id

Specific type of the encoded data (the codec used).

Examples: demux_decode.c, qsv_decode.c, qsv_transcode.c, transcode.c, and transcode_aac.c.

Definition at line 57 of file codec_par.h.

Referenced by main(), open_codec_context(), open_input_file(), open_input_file(), and open_input_file().

◆ codec_tag

uint32_t AVCodecParameters::codec_tag

Additional information about the codec (corresponds to the AVI FOURCC).

Examples: remux.c.

Definition at line 61 of file codec_par.h.

Referenced by main().

◆ extradata

uint8_t* AVCodecParameters::extradata

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.

Examples: qsv_decode.c.

Definition at line 71 of file codec_par.h.

Referenced by main().

◆ extradata_size

int AVCodecParameters::extradata_size

Size of the extradata content in bytes.

Examples: qsv_decode.c.

Definition at line 75 of file codec_par.h.

Referenced by main().

◆ coded_side_data

AVPacketSideData* AVCodecParameters::coded_side_data

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().

Definition at line 83 of file codec_par.h.

◆ nb_coded_side_data

int AVCodecParameters::nb_coded_side_data

Amount of entries in coded_side_data.

Definition at line 88 of file codec_par.h.

◆ format

int AVCodecParameters::format

Video: the pixel format, the value corresponds to enum AVPixelFormat.
Audio: the sample format, the value corresponds to enum AVSampleFormat.

Definition at line 94 of file codec_par.h.

◆ bit_rate

int64_t AVCodecParameters::bit_rate

The average bitrate of the encoded data (in bits per second).

Definition at line 99 of file codec_par.h.

◆ bits_per_coded_sample

int AVCodecParameters::bits_per_coded_sample

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.

Definition at line 113 of file codec_par.h.

◆ bits_per_raw_sample

int AVCodecParameters::bits_per_raw_sample

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.

Definition at line 130 of file codec_par.h.

◆ profile

int AVCodecParameters::profile

Codec-specific bitstream restrictions that the stream conforms to.

Definition at line 135 of file codec_par.h.

◆ level

int AVCodecParameters::level

Definition at line 136 of file codec_par.h.

◆ width

int AVCodecParameters::width

The width of the video frame in pixels.

Video only.

Definition at line 143 of file codec_par.h.

◆ height

int AVCodecParameters::height

The height of the video frame in pixels.

Video only.

Definition at line 150 of file codec_par.h.

◆ sample_aspect_ratio

AVRational AVCodecParameters::sample_aspect_ratio

The aspect ratio (width/height) which a single pixel should have when displayed.

When the aspect ratio is unknown or undefined, the numerator should be set to 0 (the denominator may have any value).

Video only.

Definition at line 161 of file codec_par.h.

◆ framerate

AVRational AVCodecParameters::framerate

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 corresponds 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.

Video only.

Definition at line 175 of file codec_par.h.

◆ field_order

enum AVFieldOrder AVCodecParameters::field_order

The order of the fields in interlaced video.

Video only.

Definition at line 182 of file codec_par.h.

◆ color_range

enum AVColorRange AVCodecParameters::color_range

Additional colorspace characteristics.

Video only.

Definition at line 189 of file codec_par.h.

◆ color_primaries

enum AVColorPrimaries AVCodecParameters::color_primaries

Definition at line 190 of file codec_par.h.

◆ color_trc

enum AVColorTransferCharacteristic AVCodecParameters::color_trc

Definition at line 191 of file codec_par.h.

◆ color_space

enum AVColorSpace AVCodecParameters::color_space

Definition at line 192 of file codec_par.h.

◆ chroma_location

enum AVChromaLocation AVCodecParameters::chroma_location

Definition at line 193 of file codec_par.h.

◆ video_delay

int AVCodecParameters::video_delay

Number of delayed frames.

Video only.

Definition at line 200 of file codec_par.h.

◆ ch_layout

AVChannelLayout AVCodecParameters::ch_layout

The channel layout and number of channels.

Audio only.

Definition at line 207 of file codec_par.h.

◆ sample_rate

int AVCodecParameters::sample_rate

The number of audio samples per second.

Audio only.

Definition at line 213 of file codec_par.h.

◆ block_align

int AVCodecParameters::block_align

The number of bytes per coded audio frame, required by some formats.

Audio only.

Corresponds to nBlockAlign in WAVEFORMATEX.

Definition at line 221 of file codec_par.h.

◆ frame_size

int AVCodecParameters::frame_size

Audio frame size, if known.

Required by some formats to be static.

Audio only.

Definition at line 227 of file codec_par.h.

◆ initial_padding

int AVCodecParameters::initial_padding

Number of padding audio samples at the start.

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 to get the original audio without leading padding.

Audio only.

Definition at line 239 of file codec_par.h.

◆ trailing_padding

int AVCodecParameters::trailing_padding

Number of padding audio samples at the end.

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 from the end of the stream to get the original audio without any trailing padding.

Audio only.

Definition at line 250 of file codec_par.h.

◆ seek_preroll

int AVCodecParameters::seek_preroll

Number of audio samples to skip after a discontinuity.

Audio only.

Definition at line 256 of file codec_par.h.

◆ alpha_mode

enum AVAlphaMode AVCodecParameters::alpha_mode

Video with alpha channel only.

Alpha channel handling

Definition at line 261 of file codec_par.h.

The documentation for this struct was generated from the following files:

libavcodec/codec_par.h
libavcodec/avcodec.h

Data Fields

Related Symbols

Detailed Description

Field Documentation

◆ codec_type

◆ codec_id

◆ codec_tag

◆ extradata

◆ extradata_size

◆ coded_side_data

◆ nb_coded_side_data

◆ format

◆ bit_rate

◆ bits_per_coded_sample

◆ bits_per_raw_sample

◆ profile

◆ level

◆ width

◆ height

◆ sample_aspect_ratio

◆ framerate

◆ field_order

◆ color_range

◆ color_primaries

◆ color_trc

◆ color_space

◆ chroma_location

◆ video_delay

◆ ch_layout

◆ sample_rate

◆ block_align

◆ frame_size

◆ initial_padding

◆ trailing_padding

◆ seek_preroll

◆ alpha_mode