479 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			479 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Quicktime Graphics (SMC) Video Decoder
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|  * Copyright (C) 2003 the ffmpeg project
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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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|  * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
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|  * For more information about the SMC format, visit:
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|  *   http://www.pcisys.net/~melanson/codecs/
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|  *
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|  * The SMC decoder outputs PAL8 colorspace data.
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|  */
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| 
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| 
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| #include "libavutil/intreadwrite.h"
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| #include "avcodec.h"
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| #include "bytestream.h"
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| #include "internal.h"
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| 
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| #define CPAIR 2
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| #define CQUAD 4
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| #define COCTET 8
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| 
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| #define COLORS_PER_TABLE 256
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| 
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| typedef struct SmcContext {
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| 
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|     AVCodecContext *avctx;
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|     AVFrame *frame;
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| 
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|     GetByteContext gb;
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| 
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|     /* SMC color tables */
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|     unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
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|     unsigned char color_quads[COLORS_PER_TABLE * CQUAD];
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|     unsigned char color_octets[COLORS_PER_TABLE * COCTET];
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| 
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|     uint32_t pal[256];
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| } SmcContext;
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| 
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| #define GET_BLOCK_COUNT() \
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|   (opcode & 0x10) ? (1 + bytestream2_get_byte(&s->gb)) : 1 + (opcode & 0x0F);
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| 
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| #define ADVANCE_BLOCK() \
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| { \
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|     pixel_ptr += 4; \
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|     if (pixel_ptr >= width) \
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|     { \
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|         pixel_ptr = 0; \
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|         row_ptr += stride * 4; \
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|     } \
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|     total_blocks--; \
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|     if (total_blocks < 0) \
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|     { \
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|         av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \
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|         return; \
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|     } \
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| }
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| 
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| static void smc_decode_stream(SmcContext *s)
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| {
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|     int width = s->avctx->width;
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|     int height = s->avctx->height;
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|     int stride = s->frame->linesize[0];
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|     int i;
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|     int chunk_size;
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|     int buf_size = (int) (s->gb.buffer_end - s->gb.buffer_start);
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|     unsigned char opcode;
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|     int n_blocks;
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|     unsigned int color_flags;
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|     unsigned int color_flags_a;
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|     unsigned int color_flags_b;
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|     unsigned int flag_mask;
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| 
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|     unsigned char *pixels = s->frame->data[0];
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| 
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|     int image_size = height * s->frame->linesize[0];
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|     int row_ptr = 0;
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|     int pixel_ptr = 0;
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|     int pixel_x, pixel_y;
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|     int row_inc = stride - 4;
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|     int block_ptr;
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|     int prev_block_ptr;
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|     int prev_block_ptr1, prev_block_ptr2;
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|     int prev_block_flag;
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|     int total_blocks;
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|     int color_table_index;  /* indexes to color pair, quad, or octet tables */
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|     int pixel;
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| 
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|     int color_pair_index = 0;
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|     int color_quad_index = 0;
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|     int color_octet_index = 0;
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| 
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|     /* make the palette available */
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|     memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
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| 
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|     bytestream2_skip(&s->gb, 1);
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|     chunk_size = bytestream2_get_be24(&s->gb);
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|     if (chunk_size != buf_size)
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|         av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
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|             chunk_size, buf_size);
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| 
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|     chunk_size = buf_size;
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|     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
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| 
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|     /* traverse through the blocks */
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|     while (total_blocks) {
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|         /* sanity checks */
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|         /* make sure the row pointer hasn't gone wild */
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|         if (row_ptr >= image_size) {
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|             av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",
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|                 row_ptr, image_size);
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|             return;
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|         }
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| 
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|         opcode = bytestream2_get_byte(&s->gb);
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|         switch (opcode & 0xF0) {
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|         /* skip n blocks */
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|         case 0x00:
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|         case 0x10:
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|             n_blocks = GET_BLOCK_COUNT();
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|             while (n_blocks--) {
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* repeat last block n times */
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|         case 0x20:
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|         case 0x30:
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|             n_blocks = GET_BLOCK_COUNT();
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| 
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|             /* sanity check */
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|             if ((row_ptr == 0) && (pixel_ptr == 0)) {
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|                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",
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|                     opcode & 0xF0);
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|                 return;
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|             }
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| 
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|             /* figure out where the previous block started */
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|             if (pixel_ptr == 0)
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|                 prev_block_ptr1 =
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|                     (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
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|             else
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|                 prev_block_ptr1 = row_ptr + pixel_ptr - 4;
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| 
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|             while (n_blocks--) {
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 prev_block_ptr = prev_block_ptr1;
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         pixels[block_ptr++] = pixels[prev_block_ptr++];
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|                     }
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|                     block_ptr += row_inc;
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|                     prev_block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* repeat previous pair of blocks n times */
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|         case 0x40:
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|         case 0x50:
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|             n_blocks = GET_BLOCK_COUNT();
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|             n_blocks *= 2;
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| 
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|             /* sanity check */
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|             if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {
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|                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
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|                     opcode & 0xF0);
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|                 return;
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|             }
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| 
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|             /* figure out where the previous 2 blocks started */
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|             if (pixel_ptr == 0)
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|                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +
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|                     s->avctx->width - 4 * 2;
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|             else if (pixel_ptr == 4)
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|                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
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|             else
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|                 prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
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| 
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|             if (pixel_ptr == 0)
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|                 prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
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|             else
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|                 prev_block_ptr2 = row_ptr + pixel_ptr - 4;
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| 
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|             prev_block_flag = 0;
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|             while (n_blocks--) {
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 if (prev_block_flag)
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|                     prev_block_ptr = prev_block_ptr2;
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|                 else
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|                     prev_block_ptr = prev_block_ptr1;
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|                 prev_block_flag = !prev_block_flag;
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| 
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         pixels[block_ptr++] = pixels[prev_block_ptr++];
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|                     }
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|                     block_ptr += row_inc;
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|                     prev_block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* 1-color block encoding */
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|         case 0x60:
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|         case 0x70:
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|             n_blocks = GET_BLOCK_COUNT();
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|             pixel = bytestream2_get_byte(&s->gb);
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| 
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|             while (n_blocks--) {
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         pixels[block_ptr++] = pixel;
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|                     }
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|                     block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* 2-color block encoding */
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|         case 0x80:
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|         case 0x90:
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|             n_blocks = (opcode & 0x0F) + 1;
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| 
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|             /* figure out which color pair to use to paint the 2-color block */
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|             if ((opcode & 0xF0) == 0x80) {
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|                 /* fetch the next 2 colors from bytestream and store in next
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|                  * available entry in the color pair table */
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|                 for (i = 0; i < CPAIR; i++) {
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|                     pixel = bytestream2_get_byte(&s->gb);
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|                     color_table_index = CPAIR * color_pair_index + i;
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|                     s->color_pairs[color_table_index] = pixel;
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|                 }
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|                 /* this is the base index to use for this block */
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|                 color_table_index = CPAIR * color_pair_index;
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|                 color_pair_index++;
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|                 /* wraparound */
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|                 if (color_pair_index == COLORS_PER_TABLE)
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|                     color_pair_index = 0;
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|             } else
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|                 color_table_index = CPAIR * bytestream2_get_byte(&s->gb);
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| 
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|             while (n_blocks--) {
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|                 color_flags = bytestream2_get_be16(&s->gb);
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|                 flag_mask = 0x8000;
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         if (color_flags & flag_mask)
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|                             pixel = color_table_index + 1;
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|                         else
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|                             pixel = color_table_index;
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|                         flag_mask >>= 1;
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|                         pixels[block_ptr++] = s->color_pairs[pixel];
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|                     }
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|                     block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* 4-color block encoding */
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|         case 0xA0:
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|         case 0xB0:
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|             n_blocks = (opcode & 0x0F) + 1;
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| 
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|             /* figure out which color quad to use to paint the 4-color block */
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|             if ((opcode & 0xF0) == 0xA0) {
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|                 /* fetch the next 4 colors from bytestream and store in next
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|                  * available entry in the color quad table */
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|                 for (i = 0; i < CQUAD; i++) {
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|                     pixel = bytestream2_get_byte(&s->gb);
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|                     color_table_index = CQUAD * color_quad_index + i;
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|                     s->color_quads[color_table_index] = pixel;
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|                 }
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|                 /* this is the base index to use for this block */
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|                 color_table_index = CQUAD * color_quad_index;
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|                 color_quad_index++;
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|                 /* wraparound */
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|                 if (color_quad_index == COLORS_PER_TABLE)
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|                     color_quad_index = 0;
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|             } else
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|                 color_table_index = CQUAD * bytestream2_get_byte(&s->gb);
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| 
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|             while (n_blocks--) {
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|                 color_flags = bytestream2_get_be32(&s->gb);
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|                 /* flag mask actually acts as a bit shift count here */
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|                 flag_mask = 30;
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         pixel = color_table_index +
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|                             ((color_flags >> flag_mask) & 0x03);
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|                         flag_mask -= 2;
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|                         pixels[block_ptr++] = s->color_quads[pixel];
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|                     }
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|                     block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* 8-color block encoding */
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|         case 0xC0:
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|         case 0xD0:
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|             n_blocks = (opcode & 0x0F) + 1;
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| 
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|             /* figure out which color octet to use to paint the 8-color block */
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|             if ((opcode & 0xF0) == 0xC0) {
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|                 /* fetch the next 8 colors from bytestream and store in next
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|                  * available entry in the color octet table */
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|                 for (i = 0; i < COCTET; i++) {
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|                     pixel = bytestream2_get_byte(&s->gb);
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|                     color_table_index = COCTET * color_octet_index + i;
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|                     s->color_octets[color_table_index] = pixel;
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|                 }
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|                 /* this is the base index to use for this block */
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|                 color_table_index = COCTET * color_octet_index;
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|                 color_octet_index++;
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|                 /* wraparound */
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|                 if (color_octet_index == COLORS_PER_TABLE)
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|                     color_octet_index = 0;
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|             } else
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|                 color_table_index = COCTET * bytestream2_get_byte(&s->gb);
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| 
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|             while (n_blocks--) {
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|                 /*
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|                   For this input of 6 hex bytes:
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|                     01 23 45 67 89 AB
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|                   Mangle it to this output:
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|                     flags_a = xx012456, flags_b = xx89A37B
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|                 */
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|                 /* build the color flags */
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|                 int val1 = bytestream2_get_be16(&s->gb);
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|                 int val2 = bytestream2_get_be16(&s->gb);
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|                 int val3 = bytestream2_get_be16(&s->gb);
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|                 color_flags_a = ((val1 & 0xFFF0) << 8) | (val2 >> 4);
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|                 color_flags_b = ((val3 & 0xFFF0) << 8) |
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|                     ((val1 & 0x0F) << 8) | ((val2 & 0x0F) << 4) | (val3 & 0x0F);
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| 
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|                 color_flags = color_flags_a;
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|                 /* flag mask actually acts as a bit shift count here */
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|                 flag_mask = 21;
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     /* reload flags at third row (iteration pixel_y == 2) */
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|                     if (pixel_y == 2) {
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|                         color_flags = color_flags_b;
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|                         flag_mask = 21;
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|                     }
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         pixel = color_table_index +
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|                             ((color_flags >> flag_mask) & 0x07);
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|                         flag_mask -= 3;
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|                         pixels[block_ptr++] = s->color_octets[pixel];
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|                     }
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|                     block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         /* 16-color block encoding (every pixel is a different color) */
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|         case 0xE0:
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|             n_blocks = (opcode & 0x0F) + 1;
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| 
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|             while (n_blocks--) {
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|                 block_ptr = row_ptr + pixel_ptr;
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|                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
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|                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
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|                         pixels[block_ptr++] = bytestream2_get_byte(&s->gb);
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|                     }
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|                     block_ptr += row_inc;
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|                 }
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|                 ADVANCE_BLOCK();
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|             }
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|             break;
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| 
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|         case 0xF0:
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|             avpriv_request_sample(s->avctx, "0xF0 opcode");
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|             break;
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|         }
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|     }
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| 
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|     return;
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| }
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| 
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| static av_cold int smc_decode_init(AVCodecContext *avctx)
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| {
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|     SmcContext *s = avctx->priv_data;
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| 
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|     s->avctx = avctx;
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|     avctx->pix_fmt = AV_PIX_FMT_PAL8;
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| 
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|     s->frame = av_frame_alloc();
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|     if (!s->frame)
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|         return AVERROR(ENOMEM);
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| 
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|     return 0;
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| }
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| 
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| static int smc_decode_frame(AVCodecContext *avctx,
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|                              void *data, int *got_frame,
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|                              AVPacket *avpkt)
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| {
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|     const uint8_t *buf = avpkt->data;
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|     int buf_size = avpkt->size;
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|     SmcContext *s = avctx->priv_data;
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|     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
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|     int ret;
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| 
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|     bytestream2_init(&s->gb, buf, buf_size);
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| 
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|     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
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|         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
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|         return ret;
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|     }
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| 
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|     if (pal) {
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|         s->frame->palette_has_changed = 1;
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|         memcpy(s->pal, pal, AVPALETTE_SIZE);
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|     }
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| 
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|     smc_decode_stream(s);
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| 
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|     *got_frame      = 1;
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|     if ((ret = av_frame_ref(data, s->frame)) < 0)
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|         return ret;
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| 
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|     /* always report that the buffer was completely consumed */
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|     return buf_size;
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| }
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| 
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| static av_cold int smc_decode_end(AVCodecContext *avctx)
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| {
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|     SmcContext *s = avctx->priv_data;
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| 
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|     av_frame_free(&s->frame);
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| 
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|     return 0;
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| }
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| 
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| AVCodec ff_smc_decoder = {
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|     .name           = "smc",
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|     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"),
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|     .type           = AVMEDIA_TYPE_VIDEO,
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|     .id             = AV_CODEC_ID_SMC,
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|     .priv_data_size = sizeof(SmcContext),
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|     .init           = smc_decode_init,
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|     .close          = smc_decode_end,
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|     .decode         = smc_decode_frame,
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|     .capabilities   = CODEC_CAP_DR1,
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| };
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