82 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Micronas SC-4 parser
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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 "parser.h"
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| 
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| typedef struct MISC4Context {
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|     ParseContext pc;
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| } MISC4Context;
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| 
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| static int misc4_parse(AVCodecParserContext *s, 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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|     MISC4Context *ctx = s->priv_data;
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|     uint32_t state = ctx->pc.state;
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|     int next = END_NOT_FOUND, i = 0;
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| 
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|     *poutbuf_size = 0;
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|     *poutbuf = NULL;
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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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|         uint32_t marker = 0;
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| 
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|         switch (avctx->sample_rate) {
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|         case 8000:
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|         case 11025:
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|             marker = 0x11b;
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|             break;
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|         case 16000:
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|         case 32000:
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|             marker = 0x2b2;
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|             break;
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|         }
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| 
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|         for (; i < buf_size; i++) {
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|             state = (state << 8) | buf[i];
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|             if (state == marker && i > 3) {
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|                 next = i - 3;
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|                 break;
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|             }
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|         }
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| 
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|         ctx->pc.state = state;
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|         if (ff_combine_frame(&ctx->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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| 
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|     *poutbuf      = buf;
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|     *poutbuf_size = buf_size;
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| 
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|     return next;
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| }
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| 
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| const AVCodecParser ff_misc4_parser = {
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|     .codec_ids      = { AV_CODEC_ID_MISC4 },
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|     .priv_data_size = sizeof(MISC4Context),
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|     .parser_parse   = misc4_parse,
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|     .parser_close   = ff_parse_close,
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| };
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