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FFmpeg/libavformat/oggparseflac.c
James Almer da23151eaf avformat/oggparseflac: use the GetByteContext API
All but one read are byte aligned, so there's no point in using the
GetBitContext API.

Signed-off-by: James Almer <jamrial@gmail.com>
2023-06-01 19:51:06 -03:00

142 lines
4.1 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/avcodec.h"
#include "libavcodec/bytestream.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];
GetByteContext gb;
int mdt, ret;
if (os->buf[os->pstart] == 0xff)
return 0;
bytestream2_init(&gb, os->buf + os->pstart, os->psize);
mdt = bytestream2_get_byte(&gb) & 0x7F;
if (mdt == OGG_FLAC_METADATA_TYPE_STREAMINFO) {
uint32_t samplerate;
if (bytestream2_get_bytes_left(&gb) < 4 + 4 + 4 + 4 + FLAC_STREAMINFO_SIZE)
return AVERROR_INVALIDDATA;
bytestream2_skipu(&gb, 4); /* "FLAC" */
if (bytestream2_get_byteu(&gb) != 1) /* unsupported major version */
return -1;
bytestream2_skipu(&gb, 1 + 2); /* minor version + header count */
bytestream2_skipu(&gb, 4); /* "fLaC" */
/* METADATA_BLOCK_HEADER */
if (bytestream2_get_be32u(&gb) != FLAC_STREAMINFO_SIZE)
return -1;
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_FLAC;
ffstream(st)->need_parsing = AVSTREAM_PARSE_HEADERS;
if ((ret = ff_alloc_extradata(st->codecpar, FLAC_STREAMINFO_SIZE)) < 0)
return ret;
bytestream2_get_bufferu(&gb, st->codecpar->extradata, FLAC_STREAMINFO_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,
};