mirror of https://git.ffmpeg.org/ffmpeg.git
126 lines
3.6 KiB
C
126 lines
3.6 KiB
C
/*
|
|
* Copyright (c) 2021 Paul B Mahol
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* AMR audio parser
|
|
*
|
|
* Splits packets into individual blocks.
|
|
*/
|
|
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "parser.h"
|
|
|
|
static const uint8_t amrnb_packed_size[16] = {
|
|
13, 14, 16, 18, 20, 21, 27, 32, 6, 1, 1, 1, 1, 1, 1, 1
|
|
};
|
|
static const uint8_t amrwb_packed_size[16] = {
|
|
18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 1, 1, 1, 1, 1, 1
|
|
};
|
|
|
|
typedef struct AMRParseContext {
|
|
ParseContext pc;
|
|
uint64_t cumulated_size;
|
|
uint64_t block_count;
|
|
int current_channel;
|
|
int remaining;
|
|
} AMRParseContext;
|
|
|
|
static av_cold int amr_parse_init(AVCodecParserContext *s1)
|
|
{
|
|
AMRParseContext *s = s1->priv_data;
|
|
s->remaining = -1;
|
|
return 0;
|
|
}
|
|
|
|
static int amr_parse(AVCodecParserContext *s1,
|
|
AVCodecContext *avctx,
|
|
const uint8_t **poutbuf, int *poutbuf_size,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
AMRParseContext *s = s1->priv_data;
|
|
ParseContext *pc = &s->pc;
|
|
int next = END_NOT_FOUND;
|
|
|
|
*poutbuf_size = 0;
|
|
*poutbuf = NULL;
|
|
|
|
if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
|
|
next = buf_size;
|
|
} else {
|
|
int ch, offset = 0;
|
|
|
|
for (ch = s->current_channel; ch < avctx->channels; ch++) {
|
|
if (s->remaining >= 0) {
|
|
next = s->remaining;
|
|
} else {
|
|
int mode = (buf[offset] >> 3) & 0x0F;
|
|
|
|
if (avctx->codec_id == AV_CODEC_ID_AMR_NB) {
|
|
next = amrnb_packed_size[mode];
|
|
} else if (avctx->codec_id == AV_CODEC_ID_AMR_WB) {
|
|
next = amrwb_packed_size[mode];
|
|
}
|
|
}
|
|
|
|
offset += next;
|
|
if (offset >= buf_size) {
|
|
s->remaining = offset - buf_size;
|
|
next = END_NOT_FOUND;
|
|
break;
|
|
} else {
|
|
s->remaining = -1;
|
|
}
|
|
}
|
|
|
|
s->current_channel = ch % avctx->channels;
|
|
if (s->remaining < 0)
|
|
next = offset;
|
|
|
|
if (next != END_NOT_FOUND) {
|
|
if (s->cumulated_size < UINT64_MAX - next) {
|
|
s->cumulated_size += next;
|
|
/* Both AMR formats have 50 frames per second */
|
|
avctx->bit_rate = s->cumulated_size / ++s->block_count * 8 * 50;
|
|
}
|
|
}
|
|
|
|
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
|
|
*poutbuf = NULL;
|
|
*poutbuf_size = 0;
|
|
return buf_size;
|
|
}
|
|
}
|
|
|
|
s1->duration = avctx->codec_id == AV_CODEC_ID_AMR_NB ? 160 : 320;
|
|
|
|
*poutbuf = buf;
|
|
*poutbuf_size = buf_size;
|
|
return next;
|
|
}
|
|
|
|
const AVCodecParser ff_amr_parser = {
|
|
.codec_ids = { AV_CODEC_ID_AMR_NB, AV_CODEC_ID_AMR_WB },
|
|
.priv_data_size = sizeof(AMRParseContext),
|
|
.parser_init = amr_parse_init,
|
|
.parser_parse = amr_parse,
|
|
.parser_close = ff_parse_close,
|
|
};
|