Reduce false positives for VVC files by adding additional checks in `vvc_probe`. Specifically, `nuh_temporal_id_plus1` is tested for valid values in extra cases depending on the NAL unit type, as per ITU-T H.266 section 7.4.2.2. Resolves trac #10703. Signed-off-by: Frank Plowman <post@frankplowman.com> Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
		
			
				
	
	
		
			78 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * RAW H.266 / VVC video demuxer
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|  * Copyright (c) 2020 Nuo Mi <nuomi2021@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 "libavcodec/vvc.h"
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| 
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| #include "avformat.h"
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| #include "rawdec.h"
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| 
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| static int check_temporal_id(uint8_t nuh_temporal_id_plus1, int type)
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| {
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|     if (nuh_temporal_id_plus1 == 0)
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|         return 0;
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| 
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|     if (nuh_temporal_id_plus1 != 1) {
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|         if (type >= VVC_IDR_W_RADL && type <= VVC_RSV_IRAP_11
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|                 || type == VVC_DCI_NUT || type == VVC_OPI_NUT
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|                 || type == VVC_VPS_NUT || type == VVC_SPS_NUT
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|                 || type == VVC_EOS_NUT || type == VVC_EOB_NUT)
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|             return 0;
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|     }
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| 
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|     return 1;
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| }
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| 
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| static int vvc_probe(const AVProbeData *p)
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| {
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|     uint32_t code = -1;
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|     int sps = 0, pps = 0, irap = 0;
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|     int i;
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| 
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|     for (i = 0; i < p->buf_size - 1; i++) {
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|         code = (code << 8) + p->buf[i];
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|         if ((code & 0xffffff00) == 0x100) {
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|             uint8_t nal2 = p->buf[i + 1];
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|             int type = (nal2 & 0xF8) >> 3;
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| 
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|             if (code & 0x80) // forbidden_zero_bit
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|                 return 0;
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| 
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|             if (!check_temporal_id(nal2 & 0x7, type))
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|                 return 0;
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| 
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|             switch (type) {
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|             case VVC_SPS_NUT:       sps++;  break;
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|             case VVC_PPS_NUT:       pps++;  break;
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|             case VVC_IDR_N_LP:
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|             case VVC_IDR_W_RADL:
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|             case VVC_CRA_NUT:
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|             case VVC_GDR_NUT:       irap++; break;
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|             }
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|         }
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|     }
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| 
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|     if (sps && pps && irap)
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|         return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg
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|     return 0;
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| }
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| 
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| FF_DEF_RAWVIDEO_DEMUXER(vvc, "raw H.266/VVC video", vvc_probe, "h266,266,vvc", AV_CODEC_ID_VVC)
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