95 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * DNxHD/VC-3 parser
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|  * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
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|  *
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|  * This file is part of Libav.
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|  *
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|  * Libav 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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|  * Libav 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 Libav; 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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| /**
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|  * @file
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|  * DNxHD/VC-3 parser
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|  */
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| 
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| #include "parser.h"
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| 
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| #define DNXHD_HEADER_PREFIX 0x0000028001
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| 
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| static int dnxhd_find_frame_end(ParseContext *pc,
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|                                 const uint8_t *buf, int buf_size)
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| {
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|     uint64_t state = pc->state64;
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|     int pic_found = pc->frame_start_found;
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|     int i = 0;
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| 
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|     if (!pic_found) {
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|         for (i = 0; i < buf_size; i++) {
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|             state = (state<<8) | buf[i];
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|             if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) {
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|                 i++;
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|                 pic_found = 1;
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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 (pic_found) {
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|         if (!buf_size) /* EOF considered as end of frame */
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|             return 0;
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|         for (; i < buf_size; i++) {
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|             state = (state<<8) | buf[i];
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|             if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) {
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|                 pc->frame_start_found = 0;
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|                 pc->state64 = -1;
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|                 return i-4;
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|             }
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|         }
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|     }
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|     pc->frame_start_found = pic_found;
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|     pc->state64 = state;
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|     return END_NOT_FOUND;
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| }
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| 
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| static int dnxhd_parse(AVCodecParserContext *s,
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|                        AVCodecContext *avctx,
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|                        const uint8_t **poutbuf, int *poutbuf_size,
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|                        const uint8_t *buf, int buf_size)
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| {
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|     ParseContext *pc = s->priv_data;
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|     int next;
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| 
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|     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
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|         next = buf_size;
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|     } else {
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|         next = dnxhd_find_frame_end(pc, buf, buf_size);
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|         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
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|             *poutbuf = NULL;
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|             *poutbuf_size = 0;
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|             return buf_size;
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|         }
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|     }
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|     *poutbuf = buf;
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|     *poutbuf_size = buf_size;
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|     return next;
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| }
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| 
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| AVCodecParser ff_dnxhd_parser = {
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|     .codec_ids      = { AV_CODEC_ID_DNXHD },
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|     .priv_data_size = sizeof(ParseContext),
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|     .parser_parse   = dnxhd_parse,
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|     .parser_close   = ff_parse_close,
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| };
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