7c92eaace2
All cbs-functions to write units share a common pattern: 1. They check whether they have a write buffer (that is used to store the unit's data until the needed size becomes known after writing the unit when a dedicated buffer will be allocated). 2. They use this buffer for a PutBitContext. 3. The (codec-specific) writing takes place through the PutBitContext. 4. The return value is checked. AVERROR(ENOSPC) here always indicates that the buffer was too small and leads to a reallocation of said buffer. 5. The final buffer will be allocated and the data copied. This commit factors this common code out in a single function in cbs.c. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
118 lines
4.5 KiB
C
118 lines
4.5 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_INTERNAL_H
|
|
#define AVCODEC_CBS_INTERNAL_H
|
|
|
|
#include "avcodec.h"
|
|
#include "cbs.h"
|
|
#include "get_bits.h"
|
|
#include "put_bits.h"
|
|
|
|
|
|
typedef struct CodedBitstreamType {
|
|
enum AVCodecID codec_id;
|
|
|
|
size_t priv_data_size;
|
|
|
|
// Split frag->data into coded bitstream units, creating the
|
|
// frag->units array. Fill data but not content on each unit.
|
|
// The header argument should be set if the fragment came from
|
|
// a header block, which may require different parsing for some
|
|
// codecs (e.g. the AVCC header in H.264).
|
|
int (*split_fragment)(CodedBitstreamContext *ctx,
|
|
CodedBitstreamFragment *frag,
|
|
int header);
|
|
|
|
// Read the unit->data bitstream and decompose it, creating
|
|
// unit->content.
|
|
int (*read_unit)(CodedBitstreamContext *ctx,
|
|
CodedBitstreamUnit *unit);
|
|
|
|
// Write the data bitstream from unit->content into pbc.
|
|
// Return value AVERROR(ENOSPC) indicates that pbc was too small.
|
|
int (*write_unit)(CodedBitstreamContext *ctx,
|
|
CodedBitstreamUnit *unit,
|
|
PutBitContext *pbc);
|
|
|
|
// Read the data from all of frag->units and assemble it into
|
|
// a bitstream for the whole fragment.
|
|
int (*assemble_fragment)(CodedBitstreamContext *ctx,
|
|
CodedBitstreamFragment *frag);
|
|
|
|
// Free the codec internal state.
|
|
void (*close)(CodedBitstreamContext *ctx);
|
|
} CodedBitstreamType;
|
|
|
|
|
|
// Helper functions for trace output.
|
|
|
|
void ff_cbs_trace_header(CodedBitstreamContext *ctx,
|
|
const char *name);
|
|
|
|
void ff_cbs_trace_syntax_element(CodedBitstreamContext *ctx, int position,
|
|
const char *name, const int *subscripts,
|
|
const char *bitstring, int64_t value);
|
|
|
|
|
|
// Helper functions for read/write of common bitstream elements, including
|
|
// generation of trace output.
|
|
|
|
int ff_cbs_read_unsigned(CodedBitstreamContext *ctx, GetBitContext *gbc,
|
|
int width, const char *name,
|
|
const int *subscripts, uint32_t *write_to,
|
|
uint32_t range_min, uint32_t range_max);
|
|
|
|
int ff_cbs_write_unsigned(CodedBitstreamContext *ctx, PutBitContext *pbc,
|
|
int width, const char *name,
|
|
const int *subscripts, uint32_t value,
|
|
uint32_t range_min, uint32_t range_max);
|
|
|
|
int ff_cbs_read_signed(CodedBitstreamContext *ctx, GetBitContext *gbc,
|
|
int width, const char *name,
|
|
const int *subscripts, int32_t *write_to,
|
|
int32_t range_min, int32_t range_max);
|
|
|
|
int ff_cbs_write_signed(CodedBitstreamContext *ctx, PutBitContext *pbc,
|
|
int width, const char *name,
|
|
const int *subscripts, int32_t value,
|
|
int32_t range_min, int32_t range_max);
|
|
|
|
// The largest unsigned value representable in N bits, suitable for use as
|
|
// range_max in the above functions.
|
|
#define MAX_UINT_BITS(length) ((UINT64_C(1) << (length)) - 1)
|
|
|
|
// The largest signed value representable in N bits, suitable for use as
|
|
// range_max in the above functions.
|
|
#define MAX_INT_BITS(length) ((INT64_C(1) << ((length) - 1)) - 1)
|
|
|
|
// The smallest signed value representable in N bits, suitable for use as
|
|
// range_min in the above functions.
|
|
#define MIN_INT_BITS(length) (-(INT64_C(1) << ((length) - 1)))
|
|
|
|
|
|
extern const CodedBitstreamType ff_cbs_type_av1;
|
|
extern const CodedBitstreamType ff_cbs_type_h264;
|
|
extern const CodedBitstreamType ff_cbs_type_h265;
|
|
extern const CodedBitstreamType ff_cbs_type_jpeg;
|
|
extern const CodedBitstreamType ff_cbs_type_mpeg2;
|
|
extern const CodedBitstreamType ff_cbs_type_vp9;
|
|
|
|
|
|
#endif /* AVCODEC_CBS_INTERNAL_H */
|