3 * Copyright (c) 2003 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/mathematics.h"
26 #define RAW_SAMPLES 1024
28 int ff_pcm_read_packet(AVFormatContext
*s
, AVPacket
*pkt
)
32 size
= RAW_SAMPLES
*s
->streams
[0]->codec
->block_align
;
34 return AVERROR(EINVAL
);
36 ret
= av_get_packet(s
->pb
, pkt
, size
);
38 pkt
->flags
&= ~AV_PKT_FLAG_CORRUPT
;
39 pkt
->stream_index
= 0;
44 int ff_pcm_read_seek(AVFormatContext
*s
,
45 int stream_index
, int64_t timestamp
, int flags
)
48 int block_align
, byte_rate
;
53 block_align
= st
->codec
->block_align
? st
->codec
->block_align
:
54 (av_get_bits_per_sample(st
->codec
->codec_id
) * st
->codec
->channels
) >> 3;
55 byte_rate
= st
->codec
->bit_rate
? st
->codec
->bit_rate
>> 3 :
56 block_align
* st
->codec
->sample_rate
;
58 if (block_align
<= 0 || byte_rate
<= 0)
60 if (timestamp
< 0) timestamp
= 0;
62 /* compute the position by aligning it to block_align */
63 pos
= av_rescale_rnd(timestamp
* byte_rate
,
65 st
->time_base
.den
* (int64_t)block_align
,
66 (flags
& AVSEEK_FLAG_BACKWARD
) ? AV_ROUND_DOWN
: AV_ROUND_UP
);
69 /* recompute exact position */
70 st
->cur_dts
= av_rescale(pos
, st
->time_base
.den
, byte_rate
* (int64_t)st
->time_base
.num
);
71 if ((ret
= avio_seek(s
->pb
, pos
+ s
->data_offset
, SEEK_SET
)) < 0)