FFmpeg/libavformat/pcm.c
Michael Niedermayer 976a8b2179 Merge remote-tracking branch 'qatar/master'
* qatar/master: (40 commits)
  H.264: template left MB handling
  H.264: faster fill_decode_caches
  H.264: faster write_back_*
  H.264: faster fill_filter_caches
  H.264: make filter_mb_fast support the case of unavailable top mb
  Do not include log.h in avutil.h
  Do not include pixfmt.h in avutil.h
  Do not include rational.h in avutil.h
  Do not include mathematics.h in avutil.h
  Do not include intfloat_readwrite.h in avutil.h
  Remove return statements following infinite loops without break
  RTSP: Doxygen comment cleanup
  doxygen: Escape '\' in Doxygen documentation.
  md5: cosmetics
  md5: use AV_WL32 to write result
  md5: add fate test
  md5: include correct headers
  md5: fix test program
  doxygen: Drop array size declarations from Doxygen parameter names.
  doxygen: Fix parameter names to match the function prototypes.
  ...

Conflicts:
	libavcodec/x86/dsputil_mmx.c
	libavformat/flvenc.c
	libavformat/oggenc.c
	libavformat/wtv.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2011-07-04 00:45:21 +02:00

57 lines
2.0 KiB
C

/*
* PCM common functions
* Copyright (c) 2003 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 "libavutil/mathematics.h"
#include "avformat.h"
#include "pcm.h"
int pcm_read_seek(AVFormatContext *s,
int stream_index, int64_t timestamp, int flags)
{
AVStream *st;
int block_align, byte_rate;
int64_t pos, ret;
st = s->streams[0];
block_align = st->codec->block_align ? st->codec->block_align :
(av_get_bits_per_sample(st->codec->codec_id) * st->codec->channels) >> 3;
byte_rate = st->codec->bit_rate ? st->codec->bit_rate >> 3 :
block_align * st->codec->sample_rate;
if (block_align <= 0 || byte_rate <= 0)
return -1;
if (timestamp < 0) timestamp = 0;
/* compute the position by aligning it to block_align */
pos = av_rescale_rnd(timestamp * byte_rate,
st->time_base.num,
st->time_base.den * (int64_t)block_align,
(flags & AVSEEK_FLAG_BACKWARD) ? AV_ROUND_DOWN : AV_ROUND_UP);
pos *= block_align;
/* recompute exact position */
st->cur_dts = av_rescale(pos, st->time_base.den, byte_rate * (int64_t)st->time_base.num);
if ((ret = avio_seek(s->pb, pos + s->data_offset, SEEK_SET)) < 0)
return ret;
return 0;
}