1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavcodec/h2645_parse.h
Andreas Rheinhardt aba4a4f080 avcodec/h2645_parse: Move ref_idc further up in H2645NAL
This puts it directly near the NALU type which is more natural
and furthermore reduces the size of the structure because it
can be placed in padding (on 64-bit systems).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2021-12-16 02:37:25 +01:00

140 lines
4.0 KiB
C

/*
* H.264/HEVC common parsing code
*
* 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_H2645_PARSE_H
#define AVCODEC_H2645_PARSE_H
#include <stdint.h>
#include "libavutil/buffer.h"
#include "libavutil/error.h"
#include "libavutil/log.h"
#include "codec_id.h"
#include "get_bits.h"
#define MAX_MBPAIR_SIZE (256*1024) // a tighter bound could be calculated if someone cares about a few bytes
typedef struct H2645NAL {
const uint8_t *data;
int size;
/**
* Size, in bits, of just the data, excluding the stop bit and any trailing
* padding. I.e. what HEVC calls SODB.
*/
int size_bits;
int raw_size;
const uint8_t *raw_data;
GetBitContext gb;
/**
* NAL unit type
*/
int type;
/**
* H.264 only, nal_ref_idc
*/
int ref_idc;
/**
* HEVC only, nuh_temporal_id_plus_1 - 1
*/
int temporal_id;
/*
* HEVC only, identifier of layer to which nal unit belongs
*/
int nuh_layer_id;
int skipped_bytes;
int skipped_bytes_pos_size;
int *skipped_bytes_pos;
} H2645NAL;
typedef struct H2645RBSP {
uint8_t *rbsp_buffer;
AVBufferRef *rbsp_buffer_ref;
int rbsp_buffer_alloc_size;
int rbsp_buffer_size;
} H2645RBSP;
/* an input packet split into unescaped NAL units */
typedef struct H2645Packet {
H2645NAL *nals;
H2645RBSP rbsp;
int nb_nals;
int nals_allocated;
unsigned nal_buffer_size;
} H2645Packet;
/**
* Extract the raw (unescaped) bitstream.
*/
int ff_h2645_extract_rbsp(const uint8_t *src, int length, H2645RBSP *rbsp,
H2645NAL *nal, int small_padding);
/**
* Split an input packet into NAL units.
*
* If data == raw_data holds true for a NAL unit of the returned pkt, then
* said NAL unit does not contain any emulation_prevention_three_byte and
* the data is contained in the input buffer pointed to by buf.
* Otherwise, the unescaped data is part of the rbsp_buffer described by the
* packet's H2645RBSP.
*
* If the packet's rbsp_buffer_ref is not NULL, the underlying AVBuffer must
* own rbsp_buffer. If not and rbsp_buffer is not NULL, use_ref must be 0.
* If use_ref is set, rbsp_buffer will be reference-counted and owned by
* the underlying AVBuffer of rbsp_buffer_ref.
*/
int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
void *logctx, int is_nalff, int nal_length_size,
enum AVCodecID codec_id, int small_padding, int use_ref);
/**
* Free all the allocated memory in the packet.
*/
void ff_h2645_packet_uninit(H2645Packet *pkt);
static inline int get_nalsize(int nal_length_size, const uint8_t *buf,
int buf_size, int *buf_index, void *logctx)
{
int i, nalsize = 0;
if (*buf_index >= buf_size - nal_length_size) {
// the end of the buffer is reached, refill it
return AVERROR(EAGAIN);
}
for (i = 0; i < nal_length_size; i++)
nalsize = ((unsigned)nalsize << 8) | buf[(*buf_index)++];
if (nalsize <= 0 || nalsize > buf_size - *buf_index) {
av_log(logctx, AV_LOG_ERROR,
"Invalid NAL unit size (%d > %d).\n", nalsize, buf_size - *buf_index);
return AVERROR_INVALIDDATA;
}
return nalsize;
}
#endif /* AVCODEC_H2645_PARSE_H */