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			91 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * CRYO APC audio format demuxer
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|  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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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 "avformat.h"
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| #include "string.h"
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| 
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| static int apc_probe(AVProbeData *p)
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| {
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|     if (!strncmp(p->buf, "CRYO_APC", 8))
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|         return AVPROBE_SCORE_MAX;
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| 
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|     return 0;
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| }
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| 
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| static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap)
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| {
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|     ByteIOContext *pb = &s->pb;
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|     AVStream *st;
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| 
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|     get_le32(pb); /* CRYO */
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|     get_le32(pb); /* _APC */
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|     get_le32(pb); /* 1.20 */
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| 
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|     st = av_new_stream(s, 0);
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|     if (!st)
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|         return AVERROR(ENOMEM);
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| 
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|     st->codec->codec_type = CODEC_TYPE_AUDIO;
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|     st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
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| 
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|     get_le32(pb); /* number of samples */
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|     st->codec->sample_rate = get_le32(pb);
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| 
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|     st->codec->extradata_size = 2 * 4;
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|     st->codec->extradata = av_malloc(st->codec->extradata_size +
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|                                      FF_INPUT_BUFFER_PADDING_SIZE);
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|     if (!st->codec->extradata)
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|         return AVERROR(ENOMEM);
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| 
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|     /* initial predictor values for adpcm decoder */
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|     get_buffer(pb, st->codec->extradata, 2 * 4);
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| 
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|     st->codec->channels = 1;
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|     if (get_le32(pb))
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|         st->codec->channels = 2;
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| 
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|     st->codec->bits_per_sample = 4;
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|     st->codec->bit_rate = st->codec->bits_per_sample * st->codec->channels
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|                           * st->codec->sample_rate;
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|     st->codec->block_align = 1;
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| 
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|     return 0;
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| }
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| 
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| #define MAX_READ_SIZE 4096
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| 
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| static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
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| {
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|     if (av_get_packet(&s->pb, pkt, MAX_READ_SIZE) <= 0)
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|         return AVERROR(EIO);
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|     pkt->stream_index = 0;
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|     return 0;
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| }
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| 
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| AVInputFormat apc_demuxer = {
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|     "apc",
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|     "CRYO APC format",
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|     0,
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|     apc_probe,
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|     apc_read_header,
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|     apc_read_packet,
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| };
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