static int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb, int width, int *runs, const int *runend, const int *ref) { int mode = 0, offs = 0, run = 0, saved_run = 0, t; int run_off = *ref++; int *run_start = runs; runend--; // for the last written 0 while(offs < width){ int cmode = get_vlc2(gb, ccitt_group3_2d_vlc.table, 9, 1); if(cmode == -1){ av_log(avctx, AV_LOG_ERROR, "Incorrect mode VLC\n"); return -1; } //sync line pointers if(runs != run_start)while(run_off <= offs){ run_off += *ref++; run_off += *ref++; } if(!cmode){//pass mode run_off += *ref++; run = run_off - offs; run_off += *ref++; offs += run; if(offs > width){ av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n"); return -1; } saved_run += run; }else if(cmode == 1){//horizontal mode int k; for(k = 0; k < 2; k++){ run = 0; for(;;){ t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2); if(t == -1){ av_log(avctx, AV_LOG_ERROR, "Incorrect code\n"); return -1; } run += t; if(t < 64) break; } *runs++ = run + saved_run; if(runs >= runend){ av_log(avctx, AV_LOG_ERROR, "Run overrun\n"); return -1; } saved_run = 0; offs += run; if(offs > width){ av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n"); return -1; } mode = !mode; } }else if(cmode == 9 || cmode == 10){ av_log(avctx, AV_LOG_ERROR, "Special modes are not supported (yet)\n"); return -1; }else{//vertical mode run = run_off - offs + (cmode - 5); if(cmode >= 5) run_off += *ref++; else run_off -= *--ref; offs += run; if(offs > width){ av_log(avctx, AV_LOG_ERROR, "Run went out of bounds\n"); return -1; } *runs++ = run + saved_run; if(runs >= runend){ av_log(avctx, AV_LOG_ERROR, "Run overrun\n"); return -1; } saved_run = 0; mode = !mode; } } *runs++ = saved_run; *runs++ = 0; return 0; }