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/*
* WAV encoder and decoder
* Copyright (c) 2001 Gerard Lantau.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "avformat.h"
#include "avi.h"
typedef struct {
offset_t data;
} WAVContext;
static int wav_write_header(AVFormatContext *s)
{
WAVContext *wav;
ByteIOContext *pb = &s->pb;
offset_t fmt;
wav = malloc(sizeof(WAVContext));
if (!wav)
return -1;
memset(wav, 0, sizeof(WAVContext));
s->priv_data = wav;
put_tag(pb, "RIFF");
put_le32(pb, 0); /* file length */
put_tag(pb, "WAVE");
/* format header */
fmt = start_tag(pb, "fmt ");
put_wav_header(pb, &s->streams[0]->codec);
end_tag(pb, fmt);
/* data header */
wav->data = start_tag(pb, "data");
put_flush_packet(pb);
return 0;
}
static int wav_write_packet(AVFormatContext *s, int stream_index_ptr,
UINT8 *buf, int size)
{
ByteIOContext *pb = &s->pb;
put_buffer(pb, buf, 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)(file_size - 8));
url_fseek(pb, file_size, SEEK_SET);
put_flush_packet(pb);
}
free(wav);
return 0;
}
/* return the size of the found tag */
/* XXX: > 2GB ? */
static int find_tag(ByteIOContext *pb, UINT32 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;
}
/* wav input */
static int wav_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
int size;
unsigned int tag;
ByteIOContext *pb = &s->pb;
unsigned int id, channels, rate, bit_rate, extra_size;
AVStream *st;
/* 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;
id = get_le16(pb);
channels = get_le16(pb);
rate = get_le32(pb);
bit_rate = get_le32(pb) * 8;
get_le16(pb); /* block align */
get_le16(pb); /* bits per sample */
if (size >= 18) {
/* wav_extra_size */
extra_size = get_le16(pb);
/* skip unused data */
url_fseek(pb, size - 18, SEEK_CUR);
}
size = find_tag(pb, MKTAG('d', 'a', 't', 'a'));
if (size < 0)
return -1;
/* now we are ready: build format streams */
st = malloc(sizeof(AVStream));
if (!st)
return -1;
s->nb_streams = 1;
s->streams[0] = st;
st->id = 0;
st->codec.codec_type = CODEC_TYPE_AUDIO;
st->codec.codec_tag = id;
st->codec.codec_id = codec_get_id(codec_wav_tags, id);
st->codec.channels = channels;
st->codec.sample_rate = rate;
return 0;
}
#define MAX_SIZE 4096
static int wav_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
int packet_size, n, ret;
if (url_feof(&s->pb))
return -EIO;
packet_size = url_get_packet_size(&s->pb);
n = MAX_SIZE / packet_size;
if (n <= 0)
return n = 1;
if (av_new_packet(pkt, n * packet_size))
return -EIO;
pkt->stream_index = 0;
ret = get_buffer(&s->pb, pkt->data, pkt->size);
if (ret < 0)
av_free_packet(pkt);
return ret;
}
static int wav_read_close(AVFormatContext *s)
{
return 0;
}
AVFormat wav_format = {
"wav",
"wav format",
"audio/x-wav",
"wav",
CODEC_ID_PCM,
CODEC_ID_NONE,
wav_write_header,
wav_write_packet,
wav_write_trailer,
wav_read_header,
wav_read_packet,
wav_read_close,
};
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