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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-02 03:06:28 +02:00
FFmpeg/libavformat/pcm.c
Michael Niedermayer 6cb2085278 Merge remote-tracking branch 'qatar/master'
* qatar/master: (27 commits)
  ppc: Add ff_ prefix to nonstatic symbols
  sh4: Add ff_ prefix to nonstatic symbols
  mpegvideo: Add ff_ prefix to nonstatic functions
  rtjpeg: Add ff_ prefix to nonstatic symbols
  rv: Add ff_ prefix to nonstatic symbols
  vp56: Add ff_ prefix to nonstatic symbols
  vorbis: Add ff_ prefix to nonstatic symbols
  msmpeg4: Add ff_ prefix to nonstatic symbols
  vc1: Add ff_ prefix to nonstatic symbols
  msmpeg4: Add ff_ prefixes to nonstatic symbols
  snow: Add ff_ prefix to nonstatic symbols
  mpeg12: Add ff_ prefix to nonstatic symbols
  mpeg4: Add ff_ prefixes to nonstatic symbols
  lagarith: Add ff_ prefix to lag_rac_init
  libavcodec: Add ff_ prefix to j_rev_dct*
  dsputil: Add ff_ prefix to inv_zigzag_direct16
  libavcodec: Prefix fdct_ifast, fdct_ifast248
  dsputil: Add ff_ prefix to the dsputil*_init* functions
  libavcodec: Add ff_ prefix to some nonstatic symbols
  vlc/rl: Add ff_ prefix to the nonstatic symbols
  ...

Conflicts:
	libavcodec/Makefile
	libavcodec/allcodecs.c
	libavcodec/dnxhddec.c
	libavcodec/ffv1.c
	libavcodec/h263.h
	libavcodec/h263dec.c
	libavcodec/h264.c
	libavcodec/mpegvideo.c
	libavcodec/mpegvideo_enc.c
	libavcodec/nuv.c
	libavcodec/ppc/dsputil_ppc.c
	libavcodec/proresdsp.c
	libavcodec/svq3.c
	libavcodec/version.h
	libavformat/dv.h
	libavformat/dvenc.c
	libavformat/matroskadec.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2012-02-16 01:34:37 +01:00

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 ff_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;
}