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	 cef28b5602
			
		
	
	cef28b5602
	
	
	
		
			
			Mostly cosmetics changes, but also makes decoding little faster here. Signed-off-by: Paul B Mahol <onemda@gmail.com>
		
			
				
	
	
		
			129 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * TAK parser
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|  * Copyright (c) 2012 Michael Niedermayer
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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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| /**
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|  * @file
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|  * TAK parser
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|  **/
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| 
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| #include "tak.h"
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| #include "parser.h"
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| 
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| typedef struct TAKParseContext {
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|     ParseContext  pc;
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|     TAKStreamInfo ti;
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|     int           index;
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| } TAKParseContext;
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| 
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| static av_cold int tak_init(AVCodecParserContext *s)
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| {
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|     ff_tak_init_crc();
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|     return 0;
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| }
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| 
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| static int tak_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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|     TAKParseContext *t = s->priv_data;
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|     ParseContext *pc   = &t->pc;
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|     int next           = END_NOT_FOUND;
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|     GetBitContext gb;
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|     int consumed = 0;
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|     int needed   = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
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| 
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|     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
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|         TAKStreamInfo ti;
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|         init_get_bits(&gb, buf, buf_size);
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|         if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
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|             s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
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|                                                    : t->ti.frame_samples;
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|         *poutbuf      = buf;
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|         *poutbuf_size = buf_size;
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|         return buf_size;
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|     }
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| 
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|     while (buf_size || t->index + needed <= pc->index) {
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|         if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
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|             int tmp_buf_size       = FFMIN(2 * TAK_MAX_FRAME_HEADER_BYTES,
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|                                            buf_size);
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|             const uint8_t *tmp_buf = buf;
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| 
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|             if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
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|                 return AVERROR(ENOMEM);
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|             consumed += tmp_buf_size;
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|             buf      += tmp_buf_size;
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|             buf_size -= tmp_buf_size;
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|         }
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| 
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|         for (; t->index + needed <= pc->index; t->index++) {
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|             if (pc->buffer[ t->index     ] == 0xFF &&
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|                 pc->buffer[ t->index + 1 ] == 0xA0) {
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|                 TAKStreamInfo ti;
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| 
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|                 init_get_bits(&gb, pc->buffer + t->index,
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|                               8 * (pc->index - t->index));
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|                 if (!ff_tak_decode_frame_header(avctx, &gb,
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|                         pc->frame_start_found ? &ti : &t->ti, 127) &&
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|                     !ff_tak_check_crc(pc->buffer + t->index,
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|                                       get_bits_count(&gb) / 8)) {
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|                     if (!pc->frame_start_found) {
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|                         pc->frame_start_found = 1;
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|                         s->duration           = t->ti.last_frame_samples ?
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|                                                 t->ti.last_frame_samples :
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|                                                 t->ti.frame_samples;
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|                     } else {
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|                         pc->frame_start_found = 0;
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|                         next                  = t->index - pc->index;
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|                         t->index              = 0;
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|                         goto found;
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|                     }
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|                 }
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|             }
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|         }
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|     }
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| found:
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| 
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|     if (consumed && !buf_size && next == END_NOT_FOUND ||
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|         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 + consumed;
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|     }
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| 
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|     if (next != END_NOT_FOUND) {
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|         next        += consumed;
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|         pc->overread = FFMAX(0, -next);
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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_tak_parser = {
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|     .codec_ids      = { AV_CODEC_ID_TAK },
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|     .priv_data_size = sizeof(TAKParseContext),
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|     .parser_init    = tak_init,
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|     .parser_parse   = tak_parse,
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|     .parser_close   = ff_parse_close,
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| };
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