FFmpeg
Data Structures | Typedefs | Functions | Variables
cbs.h File Reference
#include <stddef.h>
#include <stdint.h>
#include "libavutil/buffer.h"
#include "avcodec.h"

Go to the source code of this file.

Data Structures

struct  CodedBitstreamUnit
 Coded bitstream unit structure. More...
 
struct  CodedBitstreamFragment
 Coded bitstream fragment structure, combining one or more units. More...
 
struct  CodedBitstreamContext
 Context structure for coded bitstream operations. More...
 

Typedefs

typedef uint32_t CodedBitstreamUnitType
 The codec-specific type of a bitstream unit. More...
 

Functions

int ff_cbs_init (CodedBitstreamContext **ctx, enum AVCodecID codec_id, void *log_ctx)
 Create and initialise a new context for the given codec. More...
 
void ff_cbs_flush (CodedBitstreamContext *ctx)
 Reset all internal state in a context. More...
 
void ff_cbs_close (CodedBitstreamContext **ctx)
 Close a context and free all internal state. More...
 
int ff_cbs_read_extradata (CodedBitstreamContext *ctx, CodedBitstreamFragment *frag, const AVCodecParameters *par)
 Read the extradata bitstream found in codec parameters into a fragment, then split into units and decompose. More...
 
int ff_cbs_read_packet (CodedBitstreamContext *ctx, CodedBitstreamFragment *frag, const AVPacket *pkt)
 Read the data bitstream from a packet into a fragment, then split into units and decompose. More...
 
int ff_cbs_read (CodedBitstreamContext *ctx, CodedBitstreamFragment *frag, const uint8_t *data, size_t size)
 Read a bitstream from a memory region into a fragment, then split into units and decompose. More...
 
int ff_cbs_write_fragment_data (CodedBitstreamContext *ctx, CodedBitstreamFragment *frag)
 Write the content of the fragment to its own internal buffer. More...
 
int ff_cbs_write_extradata (CodedBitstreamContext *ctx, AVCodecParameters *par, CodedBitstreamFragment *frag)
 Write the bitstream of a fragment to the extradata in codec parameters. More...
 
int ff_cbs_write_packet (CodedBitstreamContext *ctx, AVPacket *pkt, CodedBitstreamFragment *frag)
 Write the bitstream of a fragment to a packet. More...
 
void ff_cbs_fragment_reset (CodedBitstreamFragment *frag)
 Free the units contained in a fragment as well as the fragment's own data buffer, but not the units array itself. More...
 
void ff_cbs_fragment_free (CodedBitstreamFragment *frag)
 Free the units array of a fragment in addition to what ff_cbs_fragment_reset does. More...
 
int ff_cbs_alloc_unit_content (CodedBitstreamUnit *unit, size_t size, void(*free)(void *opaque, uint8_t *content))
 Allocate a new internal content buffer of the given size in the unit. More...
 
int ff_cbs_alloc_unit_content2 (CodedBitstreamContext *ctx, CodedBitstreamUnit *unit)
 Allocate a new internal content buffer matching the type of the unit. More...
 
int ff_cbs_alloc_unit_data (CodedBitstreamUnit *unit, size_t size)
 Allocate a new internal data buffer of the given size in the unit. More...
 
int ff_cbs_insert_unit_content (CodedBitstreamFragment *frag, int position, CodedBitstreamUnitType type, void *content, AVBufferRef *content_buf)
 Insert a new unit into a fragment with the given content. More...
 
int ff_cbs_insert_unit_data (CodedBitstreamFragment *frag, int position, CodedBitstreamUnitType type, uint8_t *data, size_t data_size, AVBufferRef *data_buf)
 Insert a new unit into a fragment with the given data bitstream. More...
 
void ff_cbs_delete_unit (CodedBitstreamFragment *frag, int position)
 Delete a unit from a fragment and free all memory it uses. More...
 
int ff_cbs_make_unit_refcounted (CodedBitstreamContext *ctx, CodedBitstreamUnit *unit)
 Make the content of a unit refcounted. More...
 
int ff_cbs_make_unit_writable (CodedBitstreamContext *ctx, CodedBitstreamUnit *unit)
 Make the content of a unit writable so that internal fields can be modified. More...
 

Variables

enum AVCodecID ff_cbs_all_codec_ids []
 Table of all supported codec IDs. More...
 

Typedef Documentation

typedef uint32_t CodedBitstreamUnitType

The codec-specific type of a bitstream unit.

AV1: obu_type H.264 / AVC: nal_unit_type H.265 / HEVC: nal_unit_type JPEG: marker value (without 0xff prefix) MPEG-2: start code value (without prefix) VP9: unused, set to zero (every unit is a frame)

Definition at line 43 of file cbs.h.

Function Documentation

int ff_cbs_init ( CodedBitstreamContext **  ctx,
enum AVCodecID  codec_id,
void log_ctx 
)
void ff_cbs_flush ( CodedBitstreamContext ctx)

Reset all internal state in a context.

Definition at line 115 of file cbs.c.

Referenced by av1_decode_flush().

void ff_cbs_close ( CodedBitstreamContext **  ctx)
int ff_cbs_read_extradata ( CodedBitstreamContext ctx,
CodedBitstreamFragment frag,
const AVCodecParameters par 
)

Read the extradata bitstream found in codec parameters into a fragment, then split into units and decompose.

This also updates the internal state, so will need to be called for codecs with extradata to read parameter sets necessary for further parsing even if the fragment itself is not desired.

The fragment must have been zeroed or reset via ff_cbs_fragment_reset before use.

Definition at line 226 of file cbs.c.

Referenced by av1_frame_split_init(), av1_metadata_init(), filter_units_init(), h264_metadata_init(), h264_redundant_pps_init(), h265_metadata_init(), mpeg2_metadata_init(), and trace_headers_init().

int ff_cbs_read_packet ( CodedBitstreamContext ctx,
CodedBitstreamFragment frag,
const AVPacket pkt 
)

Read the data bitstream from a packet into a fragment, then split into units and decompose.

This also updates the internal state of the coded bitstream context with any persistent data from the fragment which may be required to read following fragments (e.g. parameter sets).

The fragment must have been zeroed or reset via ff_cbs_fragment_reset before use.

Definition at line 244 of file cbs.c.

Referenced by av1_decode_frame(), av1_frame_merge_filter(), av1_frame_split_filter(), av1_metadata_filter(), filter_units_filter(), h264_metadata_filter(), h264_redundant_pps_filter(), h265_metadata_filter(), mpeg2_metadata_filter(), trace_headers(), and vp9_metadata_filter().

int ff_cbs_read ( CodedBitstreamContext ctx,
CodedBitstreamFragment frag,
const uint8_t data,
size_t  size 
)

Read a bitstream from a memory region into a fragment, then split into units and decompose.

This also updates the internal state of the coded bitstream context with any persistent data from the fragment which may be required to read following fragments (e.g. parameter sets).

The fragment must have been zeroed or reset via ff_cbs_fragment_reset before use.

Definition at line 271 of file cbs.c.

Referenced by av1_decode_init(), av1_metadata_update_side_data(), av1_parser_parse(), h264_metadata_update_side_data(), and h265_metadata_update_side_data().

int ff_cbs_write_fragment_data ( CodedBitstreamContext ctx,
CodedBitstreamFragment frag 
)

Write the content of the fragment to its own internal buffer.

Writes the content of all units and then assembles them into a new data buffer. When modifying the content of decomposed units, this can be used to regenerate the bitstream form of units or the whole fragment so that it can be extracted for other use.

This also updates the internal state of the coded bitstream context with any persistent data from the fragment which may be required to write following fragments (e.g. parameter sets).

Definition at line 342 of file cbs.c.

Referenced by av1_metadata_update_side_data(), ff_cbs_write_extradata(), ff_cbs_write_packet(), h264_metadata_update_side_data(), h265_metadata_update_side_data(), vaapi_encode_h264_write_access_unit(), vaapi_encode_h265_write_access_unit(), vaapi_encode_mjpeg_write_image_header(), and vaapi_encode_mpeg2_write_fragment().

int ff_cbs_write_extradata ( CodedBitstreamContext ctx,
AVCodecParameters par,
CodedBitstreamFragment frag 
)

Write the bitstream of a fragment to the extradata in codec parameters.

Modifies context and fragment as ff_cbs_write_fragment_data does and replaces any existing extradata in the structure.

Definition at line 378 of file cbs.c.

Referenced by av1_metadata_init(), filter_units_init(), h264_metadata_init(), h264_redundant_pps_init(), h265_metadata_init(), and mpeg2_metadata_init().

int ff_cbs_write_packet ( CodedBitstreamContext ctx,
AVPacket pkt,
CodedBitstreamFragment frag 
)

Write the bitstream of a fragment to a packet.

Modifies context and fragment as ff_cbs_write_fragment_data does.

On success, the packet's buf is unreferenced and its buf, data and size fields are set to the corresponding values from the newly updated fragment; other fields are not touched. On failure, the packet is not touched at all.

Definition at line 403 of file cbs.c.

Referenced by av1_frame_merge_filter(), av1_metadata_filter(), filter_units_filter(), h264_metadata_filter(), h264_redundant_pps_filter(), h265_metadata_filter(), mpeg2_metadata_filter(), and vp9_metadata_filter().

void ff_cbs_fragment_reset ( CodedBitstreamFragment frag)
void ff_cbs_fragment_free ( CodedBitstreamFragment frag)
int ff_cbs_alloc_unit_content ( CodedBitstreamUnit unit,
size_t  size,
void(*)(void *opaque, uint8_t *content)  free 
)

Allocate a new internal content buffer of the given size in the unit.

The content will be zeroed.

int ff_cbs_alloc_unit_content2 ( CodedBitstreamContext ctx,
CodedBitstreamUnit unit 
)

Allocate a new internal content buffer matching the type of the unit.

The content will be zeroed.

Definition at line 853 of file cbs.c.

Referenced by cbs_av1_read_unit(), cbs_h2645_replace_ps(), cbs_h265_read_nal_unit(), cbs_mpeg2_read_unit(), and cbs_vp9_read_unit().

int ff_cbs_alloc_unit_data ( CodedBitstreamUnit unit,
size_t  size 
)

Allocate a new internal data buffer of the given size in the unit.

The data buffer will have input padding.

Definition at line 666 of file cbs.c.

Referenced by cbs_write_unit_data().

int ff_cbs_insert_unit_content ( CodedBitstreamFragment frag,
int  position,
CodedBitstreamUnitType  type,
void content,
AVBufferRef content_buf 
)

Insert a new unit into a fragment with the given content.

The content structure continues to be owned by the caller if content_buf is not supplied.

Definition at line 721 of file cbs.c.

Referenced by av1_frame_merge_filter(), av1_metadata_filter(), ff_cbs_h264_add_sei_message(), h264_metadata_filter(), h265_metadata_filter(), mpeg2_metadata_update_fragment(), vaapi_encode_h264_add_nal(), vaapi_encode_h265_add_nal(), vaapi_encode_mjpeg_write_image_header(), and vaapi_encode_mpeg2_add_header().

int ff_cbs_insert_unit_data ( CodedBitstreamFragment frag,
int  position,
CodedBitstreamUnitType  type,
uint8_t data,
size_t  data_size,
AVBufferRef data_buf 
)

Insert a new unit into a fragment with the given data bitstream.

If data_buf is not supplied then data must have been allocated with av_malloc() and will on success become owned by the unit after this call or freed on error.

Definition at line 757 of file cbs.c.

Referenced by cbs_av1_split_fragment(), cbs_h2645_fragment_add_nals(), cbs_jpeg_split_fragment(), cbs_mpeg2_split_fragment(), and cbs_vp9_split_fragment().

void ff_cbs_delete_unit ( CodedBitstreamFragment frag,
int  position 
)

Delete a unit from a fragment and free all memory it uses.

Requires position to be >= 0 and < frag->nb_units.

Definition at line 796 of file cbs.c.

Referenced by av1_metadata_filter(), ff_cbs_h264_delete_sei_message(), filter_units_filter(), h264_metadata_filter(), h264_redundant_pps_filter(), and h265_metadata_filter().

int ff_cbs_make_unit_refcounted ( CodedBitstreamContext ctx,
CodedBitstreamUnit unit 
)

Make the content of a unit refcounted.

If the unit is not refcounted, this will do a deep copy of the unit content to new refcounted buffers.

It is not valid to call this function on a unit which does not have decomposed content.

Definition at line 947 of file cbs.c.

Referenced by ff_cbs_make_unit_writable().

int ff_cbs_make_unit_writable ( CodedBitstreamContext ctx,
CodedBitstreamUnit unit 
)

Make the content of a unit writable so that internal fields can be modified.

If it is known that there are no other references to the content of the unit, does nothing and returns success. Otherwise (including the case where the unit content is not refcounted), it does a full clone of the content (including any internal buffers) to make a new copy, and replaces the existing references inside the unit with that.

It is not valid to call this function on a unit which does not have decomposed content.

Definition at line 995 of file cbs.c.

Referenced by h264_redundant_pps_fixup_pps().

Variable Documentation

enum AVCodecID ff_cbs_all_codec_ids[]

Table of all supported codec IDs.

Terminated by AV_CODEC_ID_NONE.

Definition at line 52 of file cbs.c.