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	4d09bc9897
	
	
	
		
			
			Signed-off-by: Lukasz Marek <lukasz.m.luki2@gmail.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
		
			
				
	
	
		
			75 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * PCM common functions
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|  * Copyright (c) 2003 Fabrice Bellard
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #include "libavutil/mathematics.h"
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| #include "avformat.h"
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| #include "pcm.h"
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| 
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| #define RAW_SAMPLES     1024
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| 
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| int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
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| {
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|     int ret, size;
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| 
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|     size= RAW_SAMPLES*s->streams[0]->codec->block_align;
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|     if (size <= 0)
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|         return AVERROR(EINVAL);
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| 
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|     ret= av_get_packet(s->pb, pkt, size);
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| 
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|     pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
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|     pkt->stream_index = 0;
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| 
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|     return ret;
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| }
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| 
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| int ff_pcm_read_seek(AVFormatContext *s,
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|                      int stream_index, int64_t timestamp, int flags)
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| {
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|     AVStream *st;
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|     int block_align, byte_rate;
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|     int64_t pos, ret;
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| 
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|     st = s->streams[0];
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| 
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|     block_align = st->codec->block_align ? st->codec->block_align :
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|         (av_get_bits_per_sample(st->codec->codec_id) * st->codec->channels) >> 3;
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|     byte_rate = st->codec->bit_rate ? st->codec->bit_rate >> 3 :
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|         block_align * st->codec->sample_rate;
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| 
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|     if (block_align <= 0 || byte_rate <= 0)
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|         return -1;
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|     if (timestamp < 0) timestamp = 0;
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| 
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|     /* compute the position by aligning it to block_align */
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|     pos = av_rescale_rnd(timestamp * byte_rate,
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|                          st->time_base.num,
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|                          st->time_base.den * (int64_t)block_align,
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|                          (flags & AVSEEK_FLAG_BACKWARD) ? AV_ROUND_DOWN : AV_ROUND_UP);
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|     pos *= block_align;
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| 
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|     /* recompute exact position */
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|     st->cur_dts = av_rescale(pos, st->time_base.den, byte_rate * (int64_t)st->time_base.num);
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|     if ((ret = avio_seek(s->pb, pos + s->data_offset, SEEK_SET)) < 0)
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|         return ret;
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|     return 0;
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| }
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