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			82 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * VC-1 demuxer
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|  * Copyright (c) 2015 Carl Eugen Hoyos
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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 "rawdec.h"
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| #include "libavutil/intreadwrite.h"
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| #include "libavcodec/vc1_common.h"
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| 
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| static int vc1_probe(AVProbeData *p)
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| {
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|     int seq = 0, entry = 0, frame = 0, i;
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| 
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|     for (i = 0; i < p->buf_size + 5; i++) {
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|         uint32_t code = AV_RB32(p->buf + i);
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|         if ((code & 0xffffffe0) == 0x100) {
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|             int type = code & 0x11f;
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|             i += 4;
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|             switch (type) {
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|             case VC1_CODE_SEQHDR: {
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|                 int profile, level, chromaformat;
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|                 profile = (p->buf[i] & 0xc0) >> 6;
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|                 if (profile != PROFILE_ADVANCED) {
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|                     seq = 0;
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|                     continue;
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|                 }
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|                 level = (p->buf[i] & 0x38) >> 3;
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|                 if (level >= 5) {
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|                     seq = 0;
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|                     continue;
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|                 }
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|                 chromaformat = (p->buf[i] & 0x6) >> 1;
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|                 if (chromaformat != 1) {
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|                     seq = 0;
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|                     continue;
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|                 }
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|                 seq++;
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|                 i += 6;
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|                 break;
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|             }
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|             case VC1_CODE_ENTRYPOINT:
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|                 if (!seq)
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|                     continue;
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|                 entry++;
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|                 i += 2;
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|                 break;
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|             case VC1_CODE_FRAME:
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|             case VC1_CODE_FIELD:
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|             case VC1_CODE_SLICE:
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|                 if (seq && entry)
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|                     frame++;
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|                 break;
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|             }
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|         }
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|     }
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| 
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|     if (frame > 1)
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|         return AVPROBE_SCORE_EXTENSION / 2 + 1;
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|     if (frame == 1)
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|         return AVPROBE_SCORE_EXTENSION / 4;
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|     return 0;
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| }
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| 
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| FF_DEF_RAWVIDEO_DEMUXER2(vc1, "raw VC-1", vc1_probe, "vc1", AV_CODEC_ID_VC1, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)
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