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FFmpeg/libavformat/oggparseflac.c
Michael Niedermayer e900621074 avformat/oggparseflac: Replace skip_bits_long() by skip_bits() where possible
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2019-12-31 18:43:50 +01:00

141 lines
4.0 KiB
C

/*
* Copyright (C) 2005 Matthieu CASTET
*
* 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
*/
#include <stdlib.h>
#include "libavcodec/get_bits.h"
#include "libavcodec/flac.h"
#include "avformat.h"
#include "internal.h"
#include "oggdec.h"
#define OGG_FLAC_METADATA_TYPE_STREAMINFO 0x7F
static int
flac_header (AVFormatContext * s, int idx)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + idx;
AVStream *st = s->streams[idx];
GetBitContext gb;
int mdt, ret;
if (os->buf[os->pstart] == 0xff)
return 0;
init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
skip_bits1(&gb); /* metadata_last */
mdt = get_bits(&gb, 7);
if (mdt == OGG_FLAC_METADATA_TYPE_STREAMINFO) {
uint8_t *streaminfo_start = os->buf + os->pstart + 5 + 4 + 4 + 4;
uint32_t samplerate;
skip_bits_long(&gb, 4*8); /* "FLAC" */
if(get_bits(&gb, 8) != 1) /* unsupported major version */
return -1;
skip_bits(&gb, 8 + 16); /* minor version + header count */
skip_bits_long(&gb, 4*8); /* "fLaC" */
/* METADATA_BLOCK_HEADER */
if (get_bits_long(&gb, 32) != FLAC_STREAMINFO_SIZE)
return -1;
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_FLAC;
st->need_parsing = AVSTREAM_PARSE_HEADERS;
if ((ret = ff_alloc_extradata(st->codecpar, FLAC_STREAMINFO_SIZE)) < 0)
return ret;
memcpy(st->codecpar->extradata, streaminfo_start, st->codecpar->extradata_size);
samplerate = AV_RB24(st->codecpar->extradata + 10) >> 4;
if (!samplerate)
return AVERROR_INVALIDDATA;
avpriv_set_pts_info(st, 64, 1, samplerate);
} else if (mdt == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
ff_vorbis_stream_comment(s, st, os->buf + os->pstart + 4, os->psize - 4);
}
return 1;
}
static int
old_flac_header (AVFormatContext * s, int idx)
{
struct ogg *ogg = s->priv_data;
AVStream *st = s->streams[idx];
struct ogg_stream *os = ogg->streams + idx;
AVCodecParserContext *parser = av_parser_init(AV_CODEC_ID_FLAC);
AVCodecContext *avctx;
int size, ret;
uint8_t *data;
if (!parser)
return -1;
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_FLAC;
avctx = avcodec_alloc_context3(NULL);
if (!avctx) {
ret = AVERROR(ENOMEM);
goto fail;
}
ret = avcodec_parameters_to_context(avctx, st->codecpar);
if (ret < 0)
goto fail;
parser->flags = PARSER_FLAG_COMPLETE_FRAMES;
av_parser_parse2(parser, avctx,
&data, &size, os->buf + os->pstart, os->psize,
AV_NOPTS_VALUE, AV_NOPTS_VALUE, -1);
av_parser_close(parser);
if (avctx->sample_rate) {
avpriv_set_pts_info(st, 64, 1, avctx->sample_rate);
avcodec_free_context(&avctx);
return 0;
}
avcodec_free_context(&avctx);
return 1;
fail:
av_parser_close(parser);
avcodec_free_context(&avctx);
return ret;
}
const struct ogg_codec ff_flac_codec = {
.magic = "\177FLAC",
.magicsize = 5,
.header = flac_header,
.nb_header = 2,
};
const struct ogg_codec ff_old_flac_codec = {
.magic = "fLaC",
.magicsize = 4,
.header = old_flac_header,
.nb_header = 0,
};