#include <stddef.h>
#include <stdint.h>
#include "libavutil/buffer.h"
#include "codec_id.h"
#include "codec_par.h"
#include "defs.h"
#include "packet.h"

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...

typedef void(*	CBSTraceReadCallback) (void trace_context, struct GetBitContext gbc, int start_position, const char name, const int subscripts, int64_t value)
	Callback type for read tracing. More...

typedef void(*	CBSTraceWriteCallback) (void trace_context, struct PutBitContext pbc, int start_position, const char name, const int subscripts, int64_t value)
	Callback type for write tracing. More...

Enumerations
enum	CbsDiscardFlags { DISCARD_FLAG_NONE = 0, DISCARD_FLAG_KEEP_NON_VCL = 0x01 }

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_extradata_from_codec (CodedBitstreamContext ctx, CodedBitstreamFragment frag, const struct AVCodecContext *avctx)
	Read the extradata bitstream found in a codec context into a fragment, then split into units and decompose. More...

int	ff_cbs_read_packet_side_data (CodedBitstreamContext ctx, CodedBitstreamFragment frag, const AVPacket *pkt)

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 (CodedBitstreamContext ctx, CodedBitstreamUnit unit)
	Allocate a new internal content buffer matching the type of the unit. More...

int	ff_cbs_insert_unit_content (CodedBitstreamFragment frag, int position, CodedBitstreamUnitType type, void content, void *content_ref)
	Insert a new unit into a fragment with the given content. More...

int	ff_cbs_append_unit_data (CodedBitstreamFragment frag, CodedBitstreamUnitType type, uint8_t data, size_t data_size, AVBufferRef *data_buf)
	Add a new unit to 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...

void	ff_cbs_discard_units (CodedBitstreamContext ctx, CodedBitstreamFragment frag, enum AVDiscard skip, int flags)
	Discard units accroding to 'skip'. More...

void	ff_cbs_trace_read_log (void trace_context, struct GetBitContext gbc, int length, const char str, const int subscripts, int64_t value)
	Helper function for read tracing which formats the syntax element and logs the result. More...

void	ff_cbs_trace_write_log (void trace_context, struct PutBitContext pbc, int length, const char str, const int subscripts, int64_t value)
	Helper function for write tracing which formats the syntax element and logs the result. More...

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

Typedef Documentation

◆ CodedBitstreamUnitType

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 47 of file cbs.h.

◆ CBSTraceReadCallback

typedef void(* CBSTraceReadCallback) (void *trace_context, struct GetBitContext *gbc, int start_position, const char *name, const int *subscripts, int64_t value)

Callback type for read tracing.

Parameters

ctx	User-set trace context.
gbc	A GetBitContext set at the start of the syntax element. This is a copy, the callee does not need to preserve it.
length	Length in bits of the syntax element.
name	String name of the syntax elements.
subscripts	If the syntax element is an array, a pointer to an array of subscripts into the array.
value	Parsed value of the syntax element.

Definition at line 189 of file cbs.h.

◆ CBSTraceWriteCallback

typedef void(* CBSTraceWriteCallback) (void *trace_context, struct PutBitContext *pbc, int start_position, const char *name, const int *subscripts, int64_t value)

Callback type for write tracing.

Parameters

ctx	User-set trace context.
pbc	A PutBitContext set at the end of the syntax element. The user must not modify this, but may inspect it to determine state.
length	Length in bits of the syntax element.
name	String name of the syntax elements.
subscripts	If the syntax element is an array, a pointer to an array of subscripts into the array.
value	Written value of the syntax element.

Definition at line 209 of file cbs.h.

Enumeration Type Documentation

◆ CbsDiscardFlags

enum CbsDiscardFlags

Enumerator
DISCARD_FLAG_NONE
DISCARD_FLAG_KEEP_NON_VCL	keep non-vcl units even if the picture has been dropped.

Definition at line 501 of file cbs.h.

Function Documentation

◆ ff_cbs_init()

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

Create and initialise a new context for the given codec.

Definition at line 83 of file cbs.c.

Referenced by av1_decode_init(), av1_frame_merge_init(), av1_frame_split_init(), av1_parser_init(), dts2pts_init(), ff_cbs_bsf_generic_init(), filter_units_init(), trace_headers_init(), vaapi_encode_av1_configure(), vaapi_encode_h264_configure(), vaapi_encode_h265_configure(), vaapi_encode_mjpeg_configure(), vaapi_encode_mpeg2_configure(), and vvc_parser_init().

◆ ff_cbs_flush()

void ff_cbs_flush ( CodedBitstreamContext * ctx )

Reset all internal state in a context.

Definition at line 129 of file cbs.c.

Referenced by av1_decode_flush(), and dts2pts_flush().

◆ ff_cbs_close()

void ff_cbs_close ( CodedBitstreamContext ** ctx )

Close a context and free all internal state.

Definition at line 135 of file cbs.c.

Referenced by av1_decode_free(), av1_frame_merge_close(), av1_frame_split_close(), av1_parser_close(), dts2pts_close(), ff_cbs_bsf_generic_close(), filter_units_close(), trace_headers_close(), vaapi_encode_av1_close(), vaapi_encode_h264_close(), vaapi_encode_h265_close(), vaapi_encode_mjpeg_close(), vaapi_encode_mpeg2_close(), and vvc_parser_close().

◆ ff_cbs_read_extradata()

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 279 of file cbs.c.

Referenced by av1_frame_split_init(), dts2pts_init(), ff_cbs_bsf_generic_init(), filter_units_init(), and trace_headers_init().

◆ ff_cbs_read_extradata_from_codec()

int ff_cbs_read_extradata_from_codec	(	CodedBitstreamContext *	ctx,
		CodedBitstreamFragment *	frag,
		const struct AVCodecContext *	avctx
	)

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

This acts identical to ff_cbs_read_extradata() for the case where you already have a codec context.

◆ ff_cbs_read_packet_side_data()

int ff_cbs_read_packet_side_data	(	CodedBitstreamContext *	ctx,
		CodedBitstreamFragment *	frag,
		const AVPacket *	pkt
	)

Definition at line 305 of file cbs.c.

Referenced by cbs_bsf_update_side_data(), and trace_headers().

◆ ff_cbs_read_packet()

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 297 of file cbs.c.

Referenced by av1_frame_merge_filter(), av1_frame_split_filter(), av1_receive_frame(), ff_cbs_bsf_generic_filter(), filter_units_filter(), h264_filter(), and trace_headers().

◆ ff_cbs_read()

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 318 of file cbs.c.

Referenced by av1_parser_parse(), and parse_nal_units().

◆ ff_cbs_write_fragment_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 402 of file cbs.c.

Referenced by cbs_bsf_update_side_data(), ff_cbs_write_extradata(), ff_cbs_write_packet(), vaapi_encode_av1_write_obu(), vaapi_encode_h264_write_access_unit(), vaapi_encode_h265_write_access_unit(), vaapi_encode_mjpeg_write_image_header(), and vaapi_encode_mpeg2_write_fragment().

◆ ff_cbs_write_extradata()

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 438 of file cbs.c.

Referenced by ff_cbs_bsf_generic_init(), and filter_units_init().

◆ ff_cbs_write_packet()

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 467 of file cbs.c.

Referenced by av1_frame_merge_filter(), ff_cbs_bsf_generic_filter(), and filter_units_filter().

◆ ff_cbs_fragment_reset()

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.

Definition at line 165 of file cbs.c.

◆ ff_cbs_fragment_free()

void ff_cbs_fragment_free ( CodedBitstreamFragment * frag )

Free the units array of a fragment in addition to what ff_cbs_fragment_reset does.

Definition at line 179 of file cbs.c.

Referenced by av1_decode_free(), av1_frame_merge_close(), av1_frame_split_close(), av1_parser_close(), dts2pts_close(), ff_cbs_bsf_generic_close(), ff_cbs_discard_units(), filter_units_close(), trace_headers_close(), vaapi_encode_av1_close(), vaapi_encode_h264_close(), vaapi_encode_h265_close(), vaapi_encode_mjpeg_close(), vaapi_encode_mpeg2_close(), and vvc_parser_close().

◆ ff_cbs_alloc_unit_content()

int ff_cbs_alloc_unit_content	(	CodedBitstreamContext *	ctx,
		CodedBitstreamUnit *	unit
	)

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

The content will be zeroed.

Definition at line 916 of file cbs.c.

Referenced by cbs_av1_read_unit(), cbs_h264_read_nal_unit(), cbs_h265_read_nal_unit(), cbs_h266_read_nal_unit(), cbs_jpeg_read_unit(), cbs_mpeg2_read_unit(), cbs_sei_get_unit(), and cbs_vp9_read_unit().

◆ ff_cbs_insert_unit_content()

int ff_cbs_insert_unit_content	(	CodedBitstreamFragment *	frag,
		int	position,
		CodedBitstreamUnitType	type,
		void *	content,
		void *	content_ref
	)

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

If content_ref is supplied, it has to be a RefStruct reference backing content; the user keeps ownership of the supplied reference. The content structure continues to be owned by the caller if content_ref is not supplied.

Definition at line 776 of file cbs.c.

Referenced by av1_frame_merge_filter(), av1_metadata_update_fragment(), cbs_sei_get_unit(), h264_metadata_insert_aud(), h265_metadata_update_fragment(), h266_metadata_update_fragment(), mpeg2_metadata_update_fragment(), vaapi_encode_av1_add_obu(), vaapi_encode_h264_add_nal(), vaapi_encode_h265_add_nal(), vaapi_encode_mjpeg_write_image_header(), and vaapi_encode_mpeg2_add_header().

◆ ff_cbs_append_unit_data()

int ff_cbs_append_unit_data	(	CodedBitstreamFragment *	frag,
		CodedBitstreamUnitType	type,
		uint8_t *	data,
		size_t	data_size,
		AVBufferRef *	data_buf
	)

Add a new unit to 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 843 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().

◆ ff_cbs_delete_unit()

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 853 of file cbs.c.

Referenced by av1_metadata_update_fragment(), ff_cbs_discard_units(), filter_units_filter(), h264_metadata_update_fragment(), h265_metadata_update_fragment(), and h266_metadata_update_fragment().

◆ ff_cbs_make_unit_refcounted()

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 1028 of file cbs.c.

Referenced by cbs_av1_write_obu(), and cbs_h2645_replace_ps().

◆ 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 1037 of file cbs.c.

Referenced by h264_redundant_pps_fixup_pps().

◆ ff_cbs_discard_units()

void ff_cbs_discard_units	(	CodedBitstreamContext *	ctx,
		CodedBitstreamFragment *	frag,
		enum AVDiscard	skip,
		int	flags
	)

Discard units accroding to 'skip'.

Definition at line 1054 of file cbs.c.

Referenced by filter_units_filter().

◆ ff_cbs_trace_read_log()

void ff_cbs_trace_read_log	(	void *	trace_context,
		struct GetBitContext *	gbc,
		int	length,
		const char *	str,
		const int *	subscripts,
		int64_t	value
	)

Helper function for read tracing which formats the syntax element and logs the result.

Trace context should be set to the CodedBitstreamContext.

Definition at line 501 of file cbs.c.

Referenced by ff_cbs_trace_write_log(), and trace_headers_init().

◆ ff_cbs_trace_write_log()

void ff_cbs_trace_write_log	(	void *	trace_context,
		struct PutBitContext *	pbc,
		int	length,
		const char *	str,
		const int *	subscripts,
		int64_t	value
	)

Helper function for write tracing which formats the syntax element and logs the result.

Trace context should be set to the CodedBitstreamContext.

Definition at line 559 of file cbs.c.

Referenced by ff_cbs_bsf_generic_init().

Variable Documentation

◆ ff_cbs_all_codec_ids

enum AVCodecID ff_cbs_all_codec_ids[]

Table of all supported codec IDs.

Terminated by AV_CODEC_ID_NONE.

Definition at line 58 of file cbs.c.

Data Structures

Typedefs

Enumerations

Functions

Variables

Typedef Documentation

◆ CodedBitstreamUnitType

◆ CBSTraceReadCallback

◆ CBSTraceWriteCallback

Enumeration Type Documentation

◆ CbsDiscardFlags

Function Documentation

◆ ff_cbs_init()

◆ ff_cbs_flush()

◆ ff_cbs_close()

◆ ff_cbs_read_extradata()

◆ ff_cbs_read_extradata_from_codec()

◆ ff_cbs_read_packet_side_data()

◆ ff_cbs_read_packet()

◆ ff_cbs_read()

◆ ff_cbs_write_fragment_data()

◆ ff_cbs_write_extradata()

◆ ff_cbs_write_packet()

◆ ff_cbs_fragment_reset()

◆ ff_cbs_fragment_free()

◆ ff_cbs_alloc_unit_content()

◆ ff_cbs_insert_unit_content()

◆ ff_cbs_append_unit_data()

◆ ff_cbs_delete_unit()

◆ ff_cbs_make_unit_refcounted()

◆ ff_cbs_make_unit_writable()

◆ ff_cbs_discard_units()

◆ ff_cbs_trace_read_log()

◆ ff_cbs_trace_write_log()

Variable Documentation

◆ ff_cbs_all_codec_ids