400 lines
12 KiB
C
400 lines
12 KiB
C
|
/*
|
||
|
|
* 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_CBS_H
|
||
|
|
#define AVCODEC_CBS_H
|
||
|
|
|
||
|
|
#include <stddef.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
#include "libavutil/buffer.h"
|
||
|
|
|
||
|
|
#include "avcodec.h"
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This defines a framework for converting between a coded bitstream
|
||
|
|
* and structures defining all individual syntax elements found in
|
||
|
|
* such a stream.
|
||
|
|
*
|
||
|
|
* Conversion in both directions is possible. Given a coded bitstream
|
||
|
|
* (any meaningful fragment), it can be parsed and decomposed into
|
||
|
|
* syntax elements stored in a set of codec-specific structures.
|
||
|
|
* Similarly, given a set of those same codec-specific structures the
|
||
|
|
* syntax elements can be serialised and combined to create a coded
|
||
|
|
* bitstream.
|
||
|
|
*/
|
||
|
|
|
||
|
|
struct CodedBitstreamType;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The codec-specific type of a bitstream unit.
|
||
|
|
*
|
||
|
|
* H.264 / AVC: nal_unit_type
|
||
|
|
* H.265 / HEVC: nal_unit_type
|
||
|
|
* MPEG-2: start code value (without prefix)
|
||
|
|
* VP9: unused, set to zero (every unit is a frame)
|
||
|
|
*/
|
||
|
|
typedef uint32_t CodedBitstreamUnitType;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Coded bitstream unit structure.
|
||
|
|
*
|
||
|
|
* A bitstream unit the smallest element of a bitstream which
|
||
|
|
* is meaningful on its own. For example, an H.264 NAL unit.
|
||
|
|
*
|
||
|
|
* See the codec-specific header for the meaning of this for any
|
||
|
|
* particular codec.
|
||
|
|
*/
|
||
|
|
typedef struct CodedBitstreamUnit {
|
||
|
|
/**
|
||
|
|
* Codec-specific type of this unit.
|
||
|
|
*/
|
||
|
|
CodedBitstreamUnitType type;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Pointer to the directly-parsable bitstream form of this unit.
|
||
|
|
*
|
||
|
|
* May be NULL if the unit currently only exists in decomposed form.
|
||
|
|
*/
|
||
|
|
uint8_t *data;
|
||
|
|
/**
|
||
|
|
* The number of bytes in the bitstream (including any padding bits
|
||
|
|
* in the final byte).
|
||
|
|
*/
|
||
|
|
size_t data_size;
|
||
|
|
/**
|
||
|
|
* The number of bits which should be ignored in the final byte.
|
||
|
|
*
|
||
|
|
* This supports non-byte-aligned bitstreams.
|
||
|
|
*/
|
||
|
|
size_t data_bit_padding;
|
||
|
|
/**
|
||
|
|
* A reference to the buffer containing data.
|
||
|
|
*
|
||
|
|
* Must be set if data is not NULL.
|
||
|
|
*/
|
||
|
|
AVBufferRef *data_ref;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Pointer to the decomposed form of this unit.
|
||
|
|
*
|
||
|
|
* The type of this structure depends on both the codec and the
|
||
|
|
* type of this unit. May be NULL if the unit only exists in
|
||
|
|
* bitstream form.
|
||
|
|
*/
|
||
|
|
void *content;
|
||
|
|
/**
|
||
|
|
* If content is reference counted, a reference to the buffer containing
|
||
|
|
* content. Null if content is not reference counted.
|
||
|
|
*/
|
||
|
|
AVBufferRef *content_ref;
|
||
|
|
} CodedBitstreamUnit;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Coded bitstream fragment structure, combining one or more units.
|
||
|
|
*
|
||
|
|
* This is any sequence of units. It need not form some greater whole,
|
||
|
|
* though in many cases it will. For example, an H.264 access unit,
|
||
|
|
* which is composed of a sequence of H.264 NAL units.
|
||
|
|
*/
|
||
|
|
typedef struct CodedBitstreamFragment {
|
||
|
|
/**
|
||
|
|
* Pointer to the bitstream form of this fragment.
|
||
|
|
*
|
||
|
|
* May be NULL if the fragment only exists as component units.
|
||
|
|
*/
|
||
|
|
uint8_t *data;
|
||
|
|
/**
|
||
|
|
* The number of bytes in the bitstream.
|
||
|
|
*
|
||
|
|
* The number of bytes in the bitstream (including any padding bits
|
||
|
|
* in the final byte).
|
||
|
|
*/
|
||
|
|
size_t data_size;
|
||
|
|
/**
|
||
|
|
* The number of bits which should be ignored in the final byte.
|
||
|
|
*/
|
||
|
|
size_t data_bit_padding;
|
||
|
|
/**
|
||
|
|
* A reference to the buffer containing data.
|
||
|
|
*
|
||
|
|
* Must be set if data is not NULL.
|
||
|
|
*/
|
||
|
|
AVBufferRef *data_ref;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Number of units in this fragment.
|
||
|
|
*
|
||
|
|
* This may be zero if the fragment only exists in bitstream form
|
||
|
|
* and has not been decomposed.
|
||
|
|
*/
|
||
|
|
int nb_units;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Number of allocated units.
|
||
|
|
*
|
||
|
|
* Must always be >= nb_units; designed for internal use by cbs.
|
||
|
|
*/
|
||
|
|
int nb_units_allocated;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Pointer to an array of units of length nb_units_allocated.
|
||
|
|
* Only the first nb_units are valid.
|
||
|
|
*
|
||
|
|
* Must be NULL if nb_units_allocated is zero.
|
||
|
|
*/
|
||
|
|
CodedBitstreamUnit *units;
|
||
|
|
} CodedBitstreamFragment;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Context structure for coded bitstream operations.
|
||
|
|
*/
|
||
|
|
typedef struct CodedBitstreamContext {
|
||
|
|
/**
|
||
|
|
* Logging context to be passed to all av_log() calls associated
|
||
|
|
* with this context.
|
||
|
|
*/
|
||
|
|
void *log_ctx;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Internal codec-specific hooks.
|
||
|
|
*/
|
||
|
|
const struct CodedBitstreamType *codec;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Internal codec-specific data.
|
||
|
|
*
|
||
|
|
* This contains any information needed when reading/writing
|
||
|
|
* bitsteams which will not necessarily be present in a fragment.
|
||
|
|
* For example, for H.264 it contains all currently visible
|
||
|
|
* parameter sets - they are required to determine the bitstream
|
||
|
|
* syntax but need not be present in every access unit.
|
||
|
|
*/
|
||
|
|
void *priv_data;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Array of unit types which should be decomposed when reading.
|
||
|
|
*
|
||
|
|
* Types not in this list will be available in bitstream form only.
|
||
|
|
* If NULL, all supported types will be decomposed.
|
||
|
|
*/
|
||
|
|
CodedBitstreamUnitType *decompose_unit_types;
|
||
|
|
/**
|
||
|
|
* Length of the decompose_unit_types array.
|
||
|
|
*/
|
||
|
|
int nb_decompose_unit_types;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Enable trace output during read/write operations.
|
||
|
|
*/
|
||
|
|
int trace_enable;
|
||
|
|
/**
|
||
|
|
* Log level to use for trace output.
|
||
|
|
*
|
||
|
|
* From AV_LOG_*; defaults to AV_LOG_TRACE.
|
||
|
|
*/
|
||
|
|
int trace_level;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Write buffer. Used as intermediate buffer when writing units.
|
||
|
|
* For internal use of cbs only.
|
||
|
|
*/
|
||
|
|
uint8_t *write_buffer;
|
||
|
|
size_t write_buffer_size;
|
||
|
|
} CodedBitstreamContext;
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Table of all supported codec IDs.
|
||
|
|
*
|
||
|
|
* Terminated by AV_CODEC_ID_NONE.
|
||
|
|
*/
|
||
|
|
extern const enum AVCodecID ff_cbs_all_codec_ids[];
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Create and initialise a new context for the given codec.
|
||
|
|
*/
|
||
|
|
int ff_cbs_init(CodedBitstreamContext **ctx,
|
||
|
|
enum AVCodecID codec_id, void *log_ctx);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Close a context and free all internal state.
|
||
|
|
*/
|
||
|
|
void ff_cbs_close(CodedBitstreamContext **ctx);
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_read_extradata(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag,
|
||
|
|
const AVCodecParameters *par);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_read_packet(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag,
|
||
|
|
const AVPacket *pkt);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_read(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag,
|
||
|
|
const uint8_t *data, size_t size);
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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).
|
||
|
|
*/
|
||
|
|
int ff_cbs_write_fragment_data(CodedBitstreamContext *ctx,
|
||
|
|
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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
|
||
|
|
AVCodecParameters *par,
|
||
|
|
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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_write_packet(CodedBitstreamContext *ctx,
|
||
|
|
AVPacket *pkt,
|
||
|
|
CodedBitstreamFragment *frag);
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Free the units contained in a fragment as well as the fragment's
|
||
|
|
* own data buffer, but not the units array itself.
|
||
|
|
*/
|
||
|
|
void ff_cbs_fragment_reset(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Free the units array of a fragment in addition to what
|
||
|
|
* ff_cbs_fragment_reset does.
|
||
|
|
*/
|
||
|
|
void ff_cbs_fragment_free(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Allocate a new internal content buffer of the given size in the unit.
|
||
|
|
*
|
||
|
|
* The content will be zeroed.
|
||
|
|
*/
|
||
|
|
int ff_cbs_alloc_unit_content(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamUnit *unit,
|
||
|
|
size_t size,
|
||
|
|
void (*free)(void *opaque, uint8_t *content));
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Allocate a new internal data buffer of the given size in the unit.
|
||
|
|
*
|
||
|
|
* The data buffer will have input padding.
|
||
|
|
*/
|
||
|
|
int ff_cbs_alloc_unit_data(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamUnit *unit,
|
||
|
|
size_t size);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_insert_unit_content(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag,
|
||
|
|
int position,
|
||
|
|
CodedBitstreamUnitType type,
|
||
|
|
void *content,
|
||
|
|
AVBufferRef *content_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.
|
||
|
|
*/
|
||
|
|
int ff_cbs_insert_unit_data(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag,
|
||
|
|
int position,
|
||
|
|
CodedBitstreamUnitType type,
|
||
|
|
uint8_t *data, size_t data_size,
|
||
|
|
AVBufferRef *data_buf);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Delete a unit from a fragment and free all memory it uses.
|
||
|
|
*
|
||
|
|
* Requires position to be >= 0 and < frag->nb_units.
|
||
|
|
*/
|
||
|
|
void ff_cbs_delete_unit(CodedBitstreamContext *ctx,
|
||
|
|
CodedBitstreamFragment *frag,
|
||
|
|
int position);
|
||
|
|
|
||
|
|
|
||
|
|
#endif /* AVCODEC_CBS_H */
|