142 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			142 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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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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| #include <stdint.h>
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| 
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| #include "libavutil/attributes.h"
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| #include "libavutil/mem.h"
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| 
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| #include "rl.h"
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| 
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| void ff_rl_free(RLTable *rl)
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| {
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|     int i;
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| 
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|     for (i = 0; i < 2; i++) {
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|         av_freep(&rl->max_run[i]);
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|         av_freep(&rl->max_level[i]);
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|         av_freep(&rl->index_run[i]);
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|     }
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| }
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| 
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| av_cold int ff_rl_init(RLTable *rl,
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|                        uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])
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| {
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|     int8_t  max_level[MAX_RUN + 1], max_run[MAX_LEVEL + 1];
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|     uint8_t index_run[MAX_RUN + 1];
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|     int last, run, level, start, end, i;
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| 
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|     /* If table is static, we can quit if rl->max_level[0] is not NULL */
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|     if (static_store && rl->max_level[0])
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|         return 0;
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| 
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|     /* compute max_level[], max_run[] and index_run[] */
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|     for (last = 0; last < 2; last++) {
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|         if (last == 0) {
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|             start = 0;
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|             end = rl->last;
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|         } else {
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|             start = rl->last;
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|             end = rl->n;
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|         }
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| 
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|         memset(max_level, 0, MAX_RUN + 1);
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|         memset(max_run, 0, MAX_LEVEL + 1);
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|         memset(index_run, rl->n, MAX_RUN + 1);
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|         for (i = start; i < end; i++) {
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|             run   = rl->table_run[i];
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|             level = rl->table_level[i];
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|             if (index_run[run] == rl->n)
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|                 index_run[run] = i;
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|             if (level > max_level[run])
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|                 max_level[run] = level;
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|             if (run > max_run[level])
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|                 max_run[level] = run;
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|         }
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|         if (static_store)
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|             rl->max_level[last] = static_store[last];
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|         else {
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|             rl->max_level[last] = av_malloc(MAX_RUN + 1);
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|             if (!rl->max_level[last])
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|                 goto fail;
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|         }
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|         memcpy(rl->max_level[last], max_level, MAX_RUN + 1);
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|         if (static_store)
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|             rl->max_run[last]   = static_store[last] + MAX_RUN + 1;
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|         else {
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|             rl->max_run[last]   = av_malloc(MAX_LEVEL + 1);
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|             if (!rl->max_run[last])
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|                 goto fail;
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|         }
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|         memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1);
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|         if (static_store)
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|             rl->index_run[last] = static_store[last] + MAX_RUN + MAX_LEVEL + 2;
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|         else {
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|             rl->index_run[last] = av_malloc(MAX_RUN + 1);
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|             if (!rl->index_run[last])
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|                 goto fail;
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|         }
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|         memcpy(rl->index_run[last], index_run, MAX_RUN + 1);
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|     }
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|     return 0;
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| 
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| fail:
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|     ff_rl_free(rl);
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|     return AVERROR(ENOMEM);
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| }
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| 
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| av_cold void ff_rl_init_vlc(RLTable *rl)
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| {
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|     int i, q;
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| 
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|     for (q = 0; q < 32; q++) {
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|         int qmul = q * 2;
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|         int qadd = (q - 1) | 1;
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| 
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|         if (q == 0) {
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|             qmul = 1;
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|             qadd = 0;
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|         }
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|         for (i = 0; i < rl->vlc.table_size; i++) {
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|             int code = rl->vlc.table[i][0];
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|             int len  = rl->vlc.table[i][1];
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|             int level, run;
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| 
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|             if (len == 0) { // illegal code
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|                 run   = 66;
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|                 level = MAX_LEVEL;
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|             } else if (len < 0) { // more bits needed
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|                 run   = 0;
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|                 level = code;
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|             } else {
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|                 if (code == rl->n) { // esc
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|                     run   = 66;
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|                     level =  0;
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|                 } else {
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|                     run   = rl->table_run[code] + 1;
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|                     level = rl->table_level[code] * qmul + qadd;
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|                     if (code >= rl->last) run += 192;
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|                 }
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|             }
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|             rl->rl_vlc[q][i].len   = len;
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|             rl->rl_vlc[q][i].level = level;
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|             rl->rl_vlc[q][i].run   = run;
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|         }
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|     }
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| }
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