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FFmpeg/libavcodec/ftr_parser.c
2022-09-24 14:03:59 +02:00

108 lines
3.1 KiB
C

/*
* FTR parser
* Copyright (c) 2022 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
* FTR parser
*/
#include "parser.h"
#include "get_bits.h"
#include "adts_header.h"
#include "adts_parser.h"
#include "mpeg4audio.h"
typedef struct FTRParseContext {
ParseContext pc;
int skip;
int split;
int frame_index;
} FTRParseContext;
static int ftr_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
uint8_t tmp[8 + AV_INPUT_BUFFER_PADDING_SIZE];
FTRParseContext *ftr = s->priv_data;
uint64_t state = ftr->pc.state64;
int next = END_NOT_FOUND;
GetBitContext bits;
AACADTSHeaderInfo hdr;
int size;
*poutbuf_size = 0;
*poutbuf = NULL;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
for (int i = 0; i < buf_size; i++) {
if (ftr->skip > 0) {
ftr->skip--;
if (ftr->skip == 0 && ftr->split) {
ftr->split = 0;
next = i;
s->duration = 1024;
s->key_frame = 1;
break;
} else if (ftr->skip > 0) {
continue;
}
}
state = (state << 8) | buf[i];
AV_WB64(tmp, state);
init_get_bits(&bits, tmp + 8 - AV_AAC_ADTS_HEADER_SIZE,
AV_AAC_ADTS_HEADER_SIZE * 8);
if ((size = ff_adts_header_parse(&bits, &hdr)) > 0) {
ftr->skip = size - 6;
ftr->frame_index += ff_mpeg4audio_channels[hdr.chan_config];
if (ftr->frame_index >= avctx->ch_layout.nb_channels) {
ftr->frame_index = 0;
ftr->split = 1;
}
}
}
ftr->pc.state64 = state;
if (ff_combine_frame(&ftr->pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
const AVCodecParser ff_ftr_parser = {
.codec_ids = { AV_CODEC_ID_FTR },
.priv_data_size = sizeof(FTRParseContext),
.parser_parse = ftr_parse,
.parser_close = ff_parse_close,
};