/*
* 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 */