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/*
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 * CCITT Fax Group 3 and 4 decompression
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 * Copyright (c) 2008 Konstantin Shishkov
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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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 * CCITT Fax Group 3 and 4 decompression
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 * @file faxcompr.c
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 * @author Konstantin Shishkov
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 */
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#include "avcodec.h"
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#include "bitstream.h"
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#include "faxcompr.h"
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#define CCITT_SYMS 104
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static const uint16_t ccitt_syms[CCITT_SYMS] = {
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    0,    1,    2,    3,    4,    5,    6,    7,    8,    9,   10,   11,   12,
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   13,   14,   15,   16,   17,   18,   19,   20,   21,   22,   23,   24,   25,
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   26,   27,   28,   29,   30,   31,   32,   33,   34,   35,   36,   37,   38,
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   39,   40,   41,   42,   43,   44,   45,   46,   47,   48,   49,   50,   51,
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   52,   53,   54,   55,   56,   57,   58,   59,   60,   61,   62,   63,   64,
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  128,  192,  256,  320,  384,  448,  512,  576,  640,  704,  768,  832,  896,
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  960, 1024, 1088, 1152, 1216, 1280, 1344, 1408, 1472, 1536, 1600, 1664, 1728,
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 1792, 1856, 1920, 1984, 2048, 2112, 2176, 2240, 2304, 2368, 2432, 2496, 2560
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};
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static const uint8_t ccitt_codes_bits[2][CCITT_SYMS] =
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{
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  {
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    0x35, 0x07, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, 0x13, 0x14, 0x07, 0x08, 0x08,
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    0x03, 0x34, 0x35, 0x2A, 0x2B, 0x27, 0x0C, 0x08, 0x17, 0x03, 0x04, 0x28, 0x2B,
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    0x13, 0x24, 0x18, 0x02, 0x03, 0x1A, 0x1B, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
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    0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x04, 0x05, 0x0A, 0x0B, 0x52, 0x53, 0x54,
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    0x55, 0x24, 0x25, 0x58, 0x59, 0x5A, 0x5B, 0x4A, 0x4B, 0x32, 0x33, 0x34, 0x1B,
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    0x12, 0x17, 0x37, 0x36, 0x37, 0x64, 0x65, 0x68, 0x67, 0xCC, 0xCD, 0xD2, 0xD3,
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    0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0x98, 0x99, 0x9A, 0x18, 0x9B,
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    0x08, 0x0C, 0x0D, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x1C, 0x1D, 0x1E, 0x1F
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  },
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  {
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    0x37, 0x02, 0x03, 0x02, 0x03, 0x03, 0x02, 0x03, 0x05, 0x04, 0x04, 0x05, 0x07,
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    0x04, 0x07, 0x18, 0x17, 0x18, 0x08, 0x67, 0x68, 0x6C, 0x37, 0x28, 0x17, 0x18,
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    0xCA, 0xCB, 0xCC, 0xCD, 0x68, 0x69, 0x6A, 0x6B, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6,
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    0xD7, 0x6C, 0x6D, 0xDA, 0xDB, 0x54, 0x55, 0x56, 0x57, 0x64, 0x65, 0x52, 0x53,
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    0x24, 0x37, 0x38, 0x27, 0x28, 0x58, 0x59, 0x2B, 0x2C, 0x5A, 0x66, 0x67, 0x0F,
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    0xC8, 0xC9, 0x5B, 0x33, 0x34, 0x35, 0x6C, 0x6D, 0x4A, 0x4B, 0x4C, 0x4D, 0x72,
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    0x73, 0x74, 0x75, 0x76, 0x77, 0x52, 0x53, 0x54, 0x55, 0x5A, 0x5B, 0x64, 0x65,
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    0x08, 0x0C, 0x0D, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x1C, 0x1D, 0x1E, 0x1F
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  }
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};
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static const uint8_t ccitt_codes_lens[2][CCITT_SYMS] =
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{
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  {
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     8,  6,  4,  4,  4,  4,  4,  4,  5,  5,  5,  5,  6,  6,  6,  6,  6,  6,  7,  7,
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     7,  7,  7,  7,  7,  7,  7,  7,  7,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,
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     8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,  8,
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     8,  8,  8,  8,  5,  5,  6,  7,  8,  8,  8,  8,  8,  8,  9,  9,  9,  9,  9,  9,
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     9,  9,  9,  9,  9,  9,  9,  9,  9,  6,  9, 11, 11, 11, 12, 12, 12, 12, 12, 12,
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    12, 12, 12, 12
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  },
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  {
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    10,  3,  2,  2,  3,  4,  4,  5,  6,  6,  7,  7,  7,  8,  8,  9, 10, 10, 10, 11,
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    11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
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    12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
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    12, 12, 12, 12, 10, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13,
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    13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 11, 11, 11, 12, 12, 12, 12, 12, 12,
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    12, 12, 12, 12
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  }
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};
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static const uint8_t ccitt_group3_2d_bits[11] = {
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    1, 1, 2, 2, 2, 1, 3, 3, 3, 1, 1
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};
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static const uint8_t ccitt_group3_2d_lens[11] = {
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    4, 3, 7, 6, 3, 1, 3, 6, 7, 7, 9
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};
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static VLC ccitt_vlc[2], ccitt_group3_2d_vlc;
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av_cold void ff_ccitt_unpack_init()
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{
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    static VLC_TYPE code_table1[528][2];
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    static VLC_TYPE code_table2[648][2];
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    int i;
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    static int initialized = 0;
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    if(initialized)
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        return;
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    ccitt_vlc[0].table = code_table1;
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    ccitt_vlc[0].table_allocated = 528;
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    ccitt_vlc[1].table = code_table2;
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    ccitt_vlc[1].table_allocated = 648;
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    for(i = 0; i < 2; i++){
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        init_vlc_sparse(&ccitt_vlc[i], 9, CCITT_SYMS,
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                        ccitt_codes_lens[i], 1, 1,
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                        ccitt_codes_bits[i], 1, 1,
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                        ccitt_syms, 2, 2,
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                        INIT_VLC_USE_NEW_STATIC);
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    }
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    INIT_VLC_STATIC(&ccitt_group3_2d_vlc, 9, 11,
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                    ccitt_group3_2d_lens, 1, 1,
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                    ccitt_group3_2d_bits, 1, 1, 512);
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    initialized = 1;
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}
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static int decode_group3_1d_line(AVCodecContext *avctx, GetBitContext *gb,
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                                 int pix_left, int *runs)
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{
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    int mode = 0, run = 0;
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    unsigned int t;
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    for(;;){
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        t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
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        run += t;
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        if(t < 64){
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            pix_left -= run;
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            *runs++ = run;
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            if(pix_left <= 0){
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                if(!pix_left)
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                    break;
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                runs[-1] = 0;
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                av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
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                return -1;
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            }
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            run = 0;
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            mode = !mode;
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        }else if((int)t == -1){
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            av_log(avctx, AV_LOG_ERROR, "Incorrect code\n");
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            return -1;
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        }
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    }
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    *runs++ = 0;
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    return 0;
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}
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static int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb,
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                                 int pix_left, int *runs, const int *ref)
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{
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    int mode = 0, offs = 0, run = 0, saved_run = 0, t;
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    int run_off = *ref++;
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    int *run_start = runs;
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    while(pix_left > 0){
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        int cmode = get_vlc2(gb, ccitt_group3_2d_vlc.table, 9, 1);
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        if(cmode == -1){
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            av_log(avctx, AV_LOG_ERROR, "Incorrect mode VLC\n");
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            return -1;
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        }
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        //sync line pointers
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        if(runs != run_start)while(run_off <= offs && run_off < avctx->width){
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            run_off += *ref++;
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            run_off += *ref++;
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        }
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        if(!cmode){//pass mode
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            run_off += *ref++;
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            run = run_off - offs;
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            run_off += *ref++;
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            pix_left -= run;
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            if(pix_left < 0){
178
                av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
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                return -1;
180
            }
181
            offs += run;
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            saved_run += run;
183
        }else if(cmode == 1){//horizontal mode
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            int k;
185
            for(k = 0; k < 2; k++){
186
                run = 0;
187
                for(;;){
188
                    t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
189
                    if(t == -1){
190
                        av_log(avctx, AV_LOG_ERROR, "Incorrect code\n");
191
                        return -1;
192
                    }
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                    run += t;
194
                    if(t < 64)
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                        break;
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                }
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                *runs++ = run + saved_run;
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                saved_run = 0;
199
                if(pix_left < run){
200
                    av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
201
                    return -1;
202
                }
203
                pix_left -= run;
204
                offs += run;
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                mode = !mode;
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            }
207
        }else if(cmode == 9 || cmode == 10){
208
            av_log(avctx, AV_LOG_ERROR, "Special modes are not supported (yet)\n");
209
            return -1;
210
        }else{//vertical mode
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            run = run_off - offs + (cmode - 5);
212
            if(cmode >= 5)
213
                run_off += *ref++;
214
            else
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                run_off -= *--ref;
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            pix_left -= run;
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            if(pix_left < 0){
218
                av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n");
219
                return -1;
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            }
221
            offs += run;
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            *runs++ = run + saved_run;
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            saved_run = 0;
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            mode = !mode;
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        }
226
    }
227
    *runs++ = saved_run;
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    *runs++ = 0;
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    return 0;
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}
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static void put_line(uint8_t *dst, int size, int width, const int *runs)
233
{
234
    PutBitContext pb;
235
    int run, mode = 1, pix_left = width, run_idx = 0;
236

    
237
    init_put_bits(&pb, dst, size*8);
238
    while(pix_left > 0){
239
        run = runs[run_idx++];
240
        mode = !mode;
241
        if(!run){
242
            continue;
243
        }
244
        pix_left -= run;
245
        for(; run > 16; run -= 16)
246
            put_sbits(&pb, 16, -mode);
247
        put_sbits(&pb, run, -mode);
248
    }
249
}
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251
static int find_group3_syncmarker(GetBitContext *gb, int srcsize)
252
{
253
    unsigned int state = -1;
254
    srcsize -= get_bits_count(gb);
255
    while(srcsize-- > 0){
256
        state+= state + get_bits1(gb);
257
        if((state & 0xFFF) != 1)
258
            return 0;
259
    }
260
    return -1;
261
}
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263
int ff_ccitt_unpack_1d(AVCodecContext *avctx,
264
                       const uint8_t *src, int srcsize,
265
                       uint8_t *dst, int height, int stride)
266
{
267
    int j;
268
    GetBitContext gb;
269
    int *runs, *last;
270

    
271
    runs = av_malloc(avctx->width * sizeof(runs[0]));
272
    last = av_malloc(avctx->width * sizeof(last[0]));
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    init_get_bits(&gb, src, srcsize*8);
274
    for(j = 0; j < height; j++){
275
        if(find_group3_syncmarker(&gb, srcsize*8) < 0)
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            break;
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        if(decode_group3_1d_line(avctx, &gb, avctx->width, runs) < 0){
278
            put_line(dst, stride, avctx->width, last);
279
        }else{
280
            put_line(dst, stride, avctx->width, runs);
281
            FFSWAP(int*, last, runs);
282
        }
283
        dst += stride;
284
    }
285
    av_free(runs);
286
    av_free(last);
287
    return 0;
288
}
289

    
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int ff_ccitt_unpack_2d(AVCodecContext *avctx,
291
                       const uint8_t *src, int srcsize,
292
                       uint8_t *dst, int height, int stride, int g4)
293
{
294
    int j;
295
    GetBitContext gb;
296
    int *runs, *ref;
297
    int ret;
298

    
299
    runs = av_malloc((avctx->width + 2) * sizeof(runs[0]));
300
    ref  = av_malloc((avctx->width + 2) * sizeof(ref[0]));
301
    ref[0] = avctx->width;
302
    ref[1] = 0;
303
    ref[2] = 0;
304
    init_get_bits(&gb, src, srcsize*8);
305
    for(j = 0; j < height; j++){
306
        if(g4){
307
            ret = decode_group3_2d_line(avctx, &gb, avctx->width, runs, ref);
308
            if(ret < 0){
309
                av_free(runs);
310
                av_free(ref);
311
                return -1;
312
            }
313
        }else{
314
            if(find_group3_syncmarker(&gb, srcsize*8) < 0)
315
                break;
316
            if(get_bits1(&gb))
317
                ret = decode_group3_1d_line(avctx, &gb, avctx->width, runs);
318
            else
319
                ret = decode_group3_2d_line(avctx, &gb, avctx->width, runs, ref);
320
        }
321
        if(ret < 0){
322
            put_line(dst, stride, avctx->width, ref);
323
        }else{
324
            put_line(dst, stride, avctx->width, runs);
325
            FFSWAP(int*, runs, ref);
326
        }
327
        dst += stride;
328
    }
329
    av_free(runs);
330
    av_free(ref);
331
    return 0;
332
}