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FFmpeg/libavformat/wavarc.c
2023-09-02 16:34:25 +02:00

147 lines
4.3 KiB
C

/*
* WavArc demuxer
* Copyright (c) 2023 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
*/
#include "libavutil/channel_layout.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio_internal.h"
#include "demux.h"
#include "internal.h"
typedef struct WavArcContext {
int64_t data_end;
} WavArcContext;
static int wavarc_probe(const AVProbeData *p)
{
int len = p->buf[0];
uint32_t id;
if (len == 0 || len + 6 >= p->buf_size)
return 0;
if (p->buf[len + 1] != 0)
return 0;
id = AV_RL32(p->buf + len + 2);
if (id != MKTAG('0','C','P','Y') &&
id != MKTAG('1','D','I','F') &&
id != MKTAG('2','S','L','P') &&
id != MKTAG('3','N','L','P') &&
id != MKTAG('4','A','L','P') &&
id != MKTAG('5','E','L','P'))
return 0;
return AVPROBE_SCORE_MAX / 3 * 2;
}
static int wavarc_read_header(AVFormatContext *s)
{
WavArcContext *w = s->priv_data;
AVIOContext *pb = s->pb;
AVCodecParameters *par;
int filename_len, fmt_len, ret;
uint8_t data[36];
AVStream *st;
uint32_t id;
filename_len = avio_r8(pb);
if (filename_len == 0)
return AVERROR_INVALIDDATA;
avio_skip(pb, filename_len);
if (avio_r8(pb))
return AVERROR_INVALIDDATA;
id = avio_rl32(pb);
w->data_end = avio_tell(pb);
if (avio_read(pb, data, sizeof(data)) != sizeof(data))
return AVERROR(EIO);
w->data_end += 16LL + AV_RL32(data + 4);
fmt_len = AV_RL32(data + 32);
if (fmt_len < 12)
return AVERROR_INVALIDDATA;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
par = st->codecpar;
ret = ff_alloc_extradata(par, fmt_len + sizeof(data));
if (ret < 0)
return ret;
memcpy(par->extradata, data, sizeof(data));
ret = ffio_read_size(pb, par->extradata + sizeof(data), fmt_len);
if (ret < 0)
return ret;
par->codec_type = AVMEDIA_TYPE_AUDIO;
par->codec_id = AV_CODEC_ID_WAVARC;
par->codec_tag = id;
do {
id = avio_rl32(pb);
if (id != MKTAG('d','a','t','a'))
avio_skip(pb, avio_rl32(pb));
} while (id != MKTAG('d','a','t','a') && !avio_feof(pb));
avio_skip(pb, 4);
if (AV_RL32(par->extradata + 16) != MKTAG('R','I','F','F'))
return AVERROR_INVALIDDATA;
if (AV_RL32(par->extradata + 24) != MKTAG('W','A','V','E'))
return AVERROR_INVALIDDATA;
if (AV_RL32(par->extradata + 28) != MKTAG('f','m','t',' '))
return AVERROR_INVALIDDATA;
av_channel_layout_default(&par->ch_layout, AV_RL16(par->extradata + 38));
par->sample_rate = AV_RL32(par->extradata + 40);
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
st->start_time = 0;
return 0;
}
static int wavarc_read_packet(AVFormatContext *s, AVPacket *pkt)
{
WavArcContext *w = s->priv_data;
AVIOContext *pb = s->pb;
int64_t size, left = w->data_end - avio_tell(pb);
int ret;
size = FFMIN(left, 1024);
if (size <= 0)
return AVERROR_EOF;
ret = av_get_packet(pb, pkt, size);
pkt->stream_index = 0;
return ret;
}
const AVInputFormat ff_wavarc_demuxer = {
.name = "wavarc",
.long_name = NULL_IF_CONFIG_SMALL("Waveform Archiver"),
.priv_data_size = sizeof(WavArcContext),
.read_probe = wavarc_probe,
.read_packet = wavarc_read_packet,
.flags = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
.read_header = wavarc_read_header,
.extensions = "wa",
.raw_codec_id = AV_CODEC_ID_WAVARC,
};