ffmpeg/libavformat/wav.c

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/*
* WAV encoder and decoder
* Copyright (c) 2001, 2002 Fabrice Bellard.
*
* 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 "avformat.h"
#include "allformats.h"
#include "riff.h"
typedef struct {
offset_t data;
offset_t data_end;
} WAVContext;
#ifdef CONFIG_MUXERS
static int wav_write_header(AVFormatContext *s)
{
WAVContext *wav = s->priv_data;
ByteIOContext *pb = &s->pb;
offset_t fmt;
put_tag(pb, "RIFF");
put_le32(pb, 0); /* file length */
put_tag(pb, "WAVE");
/* format header */
fmt = start_tag(pb, "fmt ");
if (put_wav_header(pb, s->streams[0]->codec) < 0) {
av_free(wav);
return -1;
}
end_tag(pb, fmt);
av_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
/* data header */
wav->data = start_tag(pb, "data");
put_flush_packet(pb);
return 0;
}
static int wav_write_packet(AVFormatContext *s, AVPacket *pkt)
{
ByteIOContext *pb = &s->pb;
put_buffer(pb, pkt->data, pkt->size);
return 0;
}
static int wav_write_trailer(AVFormatContext *s)
{
ByteIOContext *pb = &s->pb;
WAVContext *wav = s->priv_data;
offset_t file_size;
if (!url_is_streamed(&s->pb)) {
end_tag(pb, wav->data);
/* update file size */
file_size = url_ftell(pb);
url_fseek(pb, 4, SEEK_SET);
put_le32(pb, (uint32_t)(file_size - 8));
url_fseek(pb, file_size, SEEK_SET);
put_flush_packet(pb);
}
return 0;
}
#endif //CONFIG_MUXERS
/* return the size of the found tag */
/* XXX: > 2GB ? */
static int find_tag(ByteIOContext *pb, uint32_t tag1)
{
unsigned int tag;
int size;
for(;;) {
if (url_feof(pb))
return -1;
tag = get_le32(pb);
size = get_le32(pb);
if (tag == tag1)
break;
url_fseek(pb, size, SEEK_CUR);
}
if (size < 0)
size = 0x7fffffff;
return size;
}
static int wav_probe(AVProbeData *p)
{
/* check file header */
if (p->buf_size <= 32)
return 0;
if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
p->buf[2] == 'F' && p->buf[3] == 'F' &&
p->buf[8] == 'W' && p->buf[9] == 'A' &&
p->buf[10] == 'V' && p->buf[11] == 'E')
return AVPROBE_SCORE_MAX;
else
return 0;
}
/* wav input */
static int wav_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
int size;
unsigned int tag;
ByteIOContext *pb = &s->pb;
AVStream *st;
WAVContext *wav = s->priv_data;
/* check RIFF header */
tag = get_le32(pb);
if (tag != MKTAG('R', 'I', 'F', 'F'))
return -1;
get_le32(pb); /* file size */
tag = get_le32(pb);
if (tag != MKTAG('W', 'A', 'V', 'E'))
return -1;
/* parse fmt header */
size = find_tag(pb, MKTAG('f', 'm', 't', ' '));
if (size < 0)
return -1;
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
get_wav_header(pb, st->codec, size);
st->need_parsing = 1;
av_set_pts_info(st, 64, 1, st->codec->sample_rate);
size = find_tag(pb, MKTAG('d', 'a', 't', 'a'));
if (size < 0)
return -1;
wav->data_end= url_ftell(pb) + size;
return 0;
}
#define MAX_SIZE 4096
static int wav_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
int ret, size, left;
AVStream *st;
WAVContext *wav = s->priv_data;
if (url_feof(&s->pb))
return AVERROR_IO;
st = s->streams[0];
left= wav->data_end - url_ftell(&s->pb);
if(left <= 0){
left = find_tag(&(s->pb), MKTAG('d', 'a', 't', 'a'));
if (left < 0) {
return AVERROR_IO;
}
wav->data_end= url_ftell(&s->pb) + left;
}
size = MAX_SIZE;
if (st->codec->block_align > 1) {
if (size < st->codec->block_align)
size = st->codec->block_align;
size = (size / st->codec->block_align) * st->codec->block_align;
}
size= FFMIN(size, left);
if (av_new_packet(pkt, size))
return AVERROR_IO;
pkt->stream_index = 0;
ret = get_buffer(&s->pb, pkt->data, pkt->size);
if (ret < 0)
av_free_packet(pkt);
/* note: we need to modify the packet size here to handle the last
packet */
pkt->size = ret;
return ret;
}
static int wav_read_close(AVFormatContext *s)
{
return 0;
}
static int wav_read_seek(AVFormatContext *s,
int stream_index, int64_t timestamp, int flags)
{
AVStream *st;
st = s->streams[0];
switch(st->codec->codec_id) {
case CODEC_ID_MP2:
case CODEC_ID_MP3:
case CODEC_ID_AC3:
case CODEC_ID_DTS:
/* use generic seeking with dynamically generated indexes */
return -1;
default:
break;
}
return pcm_read_seek(s, stream_index, timestamp, flags);
}
#ifdef CONFIG_WAV_DEMUXER
AVInputFormat wav_demuxer = {
"wav",
"wav format",
sizeof(WAVContext),
wav_probe,
wav_read_header,
wav_read_packet,
wav_read_close,
wav_read_seek,
};
#endif
#ifdef CONFIG_WAV_MUXER
AVOutputFormat wav_muxer = {
"wav",
"wav format",
"audio/x-wav",
"wav",
sizeof(WAVContext),
CODEC_ID_PCM_S16LE,
CODEC_ID_NONE,
wav_write_header,
wav_write_packet,
wav_write_trailer,
};
#endif