* commit '36ef5369ee9b336febc2c270f8718cec4476cb85': Replace all CODEC_ID_* with AV_CODEC_ID_* lavc: add AV prefix to codec ids. Conflicts: doc/APIchanges doc/examples/decoding_encoding.c doc/examples/muxing.c ffmpeg.c ffprobe.c ffserver.c libavcodec/8svx.c libavcodec/avcodec.h libavcodec/dnxhd_parser.c libavcodec/dvdsubdec.c libavcodec/error_resilience.c libavcodec/h263dec.c libavcodec/libvorbisenc.c libavcodec/mjpeg_parser.c libavcodec/mjpegenc.c libavcodec/mpeg12.c libavcodec/mpeg4videodec.c libavcodec/mpegvideo.c libavcodec/mpegvideo_enc.c libavcodec/pcm.c libavcodec/r210dec.c libavcodec/utils.c libavcodec/v210dec.c libavcodec/version.h libavdevice/alsa-audio-dec.c libavdevice/bktr.c libavdevice/v4l2.c libavformat/asfdec.c libavformat/asfenc.c libavformat/avformat.h libavformat/avidec.c libavformat/caf.c libavformat/electronicarts.c libavformat/flacdec.c libavformat/flvdec.c libavformat/flvenc.c libavformat/framecrcenc.c libavformat/img2.c libavformat/img2dec.c libavformat/img2enc.c libavformat/ipmovie.c libavformat/isom.c libavformat/matroska.c libavformat/matroskadec.c libavformat/matroskaenc.c libavformat/mov.c libavformat/movenc.c libavformat/mp3dec.c libavformat/mpeg.c libavformat/mpegts.c libavformat/mxf.c libavformat/mxfdec.c libavformat/mxfenc.c libavformat/nsvdec.c libavformat/nut.c libavformat/oggenc.c libavformat/pmpdec.c libavformat/rawdec.c libavformat/rawenc.c libavformat/riff.c libavformat/sdp.c libavformat/utils.c libavformat/vocenc.c libavformat/wtv.c libavformat/xmv.c Merged-by: Michael Niedermayer <michaelni@gmx.at>
		
			
				
	
	
		
			852 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			852 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Microsoft Screen 1 (aka Windows Media Video V7 Screen) decoder
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 * Copyright (c) 2012 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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 * @file
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 * Microsoft Screen 1 (aka Windows Media Video V7 Screen) decoder
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 */
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#include "libavutil/intfloat.h"
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#include "libavutil/intreadwrite.h"
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#include "avcodec.h"
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#include "get_bits.h"
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enum SplitMode {
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    SPLIT_VERT = 0,
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    SPLIT_HOR,
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    SPLIT_NONE
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};
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typedef struct ArithCoder {
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    int low, high, value;
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    GetBitContext *gb;
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} ArithCoder;
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#define MODEL_MIN_SYMS    2
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#define MODEL_MAX_SYMS  256
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#define THRESH_ADAPTIVE  -1
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#define THRESH_LOW       15
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#define THRESH_HIGH      50
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typedef struct Model {
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    int cum_prob[MODEL_MAX_SYMS + 1];
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    int weights[MODEL_MAX_SYMS + 1];
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    int idx2sym[MODEL_MAX_SYMS + 1];
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    int sym2idx[MODEL_MAX_SYMS + 1];
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    int num_syms;
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    int thr_weight, threshold;
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} Model;
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static const int sec_order_sizes[4] = { 1, 7, 6, 1 };
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enum ContextDirection {
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    TOP_LEFT = 0,
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    TOP,
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    TOP_RIGHT,
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    LEFT
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};
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typedef struct PixContext {
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    int cache_size, num_syms;
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    uint8_t cache[12];
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    Model cache_model, full_model;
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    Model sec_models[4][8][4];
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} PixContext;
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typedef struct MSS1Context {
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    AVCodecContext *avctx;
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    AVFrame        pic;
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    uint8_t        *pic_start;
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    int            pic_stride;
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    uint8_t        *mask;
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    int            mask_linesize;
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    uint32_t       pal[256];
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    int            free_colours;
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    Model          intra_region, inter_region;
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    Model          pivot, edge_mode, split_mode;
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    PixContext     intra_pix_ctx, inter_pix_ctx;
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    int            corrupted;
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} MSS1Context;
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static void arith_init(ArithCoder *c, GetBitContext *gb)
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{
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    c->low   = 0;
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    c->high  = 0xFFFF;
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    c->value = get_bits(gb, 16);
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    c->gb    = gb;
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}
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static void arith_normalise(ArithCoder *c)
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{
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    for (;;) {
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        if (c->high >= 0x8000) {
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            if (c->low < 0x8000) {
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                if (c->low >= 0x4000 && c->high < 0xC000) {
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                    c->value -= 0x4000;
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                    c->low   -= 0x4000;
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                    c->high  -= 0x4000;
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                } else {
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                    return;
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                }
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            } else {
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                c->value -= 0x8000;
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                c->low   -= 0x8000;
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                c->high  -= 0x8000;
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            }
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        }
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        c->value <<= 1;
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        c->low   <<= 1;
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        c->high  <<= 1;
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        c->high   |= 1;
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        c->value  |= get_bits1(c->gb);
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    }
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}
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static int arith_get_bit(ArithCoder *c)
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{
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    int range = c->high - c->low + 1;
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    int bit   = (((c->value - c->low) << 1) + 1) / range;
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    if (bit)
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        c->low += range >> 1;
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    else
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        c->high = c->low + (range >> 1) - 1;
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    arith_normalise(c);
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    return bit;
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}
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static int arith_get_bits(ArithCoder *c, int bits)
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{
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    int range = c->high - c->low + 1;
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    int val   = (((c->value - c->low + 1) << bits) - 1) / range;
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    int prob  = range * val;
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    c->high   = ((prob + range) >> bits) + c->low - 1;
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    c->low   += prob >> bits;
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    arith_normalise(c);
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    return val;
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}
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static int arith_get_number(ArithCoder *c, int mod_val)
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{
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    int range = c->high - c->low + 1;
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    int val   = ((c->value - c->low + 1) * mod_val - 1) / range;
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    int prob  = range * val;
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    c->high   = (prob + range) / mod_val + c->low - 1;
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    c->low   += prob / mod_val;
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    arith_normalise(c);
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    return val;
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}
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static int arith_get_prob(ArithCoder *c, int *probs)
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{
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    int range = c->high - c->low + 1;
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    int val   = ((c->value - c->low + 1) * probs[0] - 1) / range;
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    int sym   = 1;
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    while (probs[sym] > val)
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        sym++;
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    c->high = range * probs[sym - 1] / probs[0] + c->low - 1;
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    c->low += range * probs[sym]     / probs[0];
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    return sym;
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}
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static int model_calc_threshold(Model *m)
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{
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    int thr;
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    if (m->thr_weight == -1) {
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        thr = 2 * m->weights[m->num_syms] - 1;
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        thr = ((thr >> 1) + 4 * m->cum_prob[0]) / thr;
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    } else {
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        thr = m->num_syms * m->thr_weight;
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    }
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    return FFMIN(thr, 0x3FFF);
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}
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static void model_reset(Model *m)
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{
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    int i;
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    for (i = 0; i <= m->num_syms; i++) {
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        m->weights[i]  = 1;
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        m->cum_prob[i] = m->num_syms - i;
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    }
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    m->weights[0]           = -1;
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    m->idx2sym[0]           = -1;
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    m->sym2idx[m->num_syms] = -1;
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    for (i = 0; i < m->num_syms; i++) {
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        m->sym2idx[i]     = i + 1;
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        m->idx2sym[i + 1] = i;
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    }
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}
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static av_cold void model_init(Model *m, int num_syms, int thr_weight)
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{
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    m->num_syms   = num_syms;
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    m->thr_weight = thr_weight;
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    m->threshold  = model_calc_threshold(m);
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    model_reset(m);
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}
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static void model_rescale_weights(Model *m)
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{
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    int i;
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    int cum_prob;
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    if (m->thr_weight == -1)
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        m->threshold = model_calc_threshold(m);
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    while (m->cum_prob[0] > m->threshold) {
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        cum_prob = 0;
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        for (i = m->num_syms; i >= 0; i--) {
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            m->cum_prob[i] = cum_prob;
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            m->weights[i]  = (m->weights[i] + 1) >> 1;
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            cum_prob      += m->weights[i];
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        }
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    }
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}
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static void model_update(Model *m, int val)
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{
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    int i;
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    if (m->weights[val] == m->weights[val - 1]) {
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        for (i = val; m->weights[i - 1] == m->weights[val]; i--);
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        if (i != val) {
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            int sym1, sym2;
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            sym1 = m->idx2sym[val];
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            sym2 = m->idx2sym[i];
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            m->idx2sym[val]  = sym2;
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            m->idx2sym[i]    = sym1;
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            m->sym2idx[sym1] = i;
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            m->sym2idx[sym2] = val;
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            val = i;
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        }
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    }
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    m->weights[val]++;
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    for (i = val - 1; i >= 0; i--)
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        m->cum_prob[i]++;
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    model_rescale_weights(m);
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}
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static int arith_get_model_sym(ArithCoder *c, Model *m)
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{
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    int idx, val;
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    idx = arith_get_prob(c, m->cum_prob);
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    val = m->idx2sym[idx];
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    model_update(m, idx);
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    arith_normalise(c);
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    return val;
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}
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static void pixctx_reset(PixContext *ctx)
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{
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    int i, j, k;
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    for (i = 0; i < ctx->cache_size; i++)
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        ctx->cache[i] = i;
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    model_reset(&ctx->cache_model);
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    model_reset(&ctx->full_model);
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    for (i = 0; i < 4; i++)
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        for (j = 0; j < sec_order_sizes[i]; j++)
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            for (k = 0; k < 4; k++)
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                model_reset(&ctx->sec_models[i][j][k]);
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}
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static av_cold void pixctx_init(PixContext *ctx, int cache_size)
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{
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    int i, j, k;
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    ctx->cache_size = cache_size + 4;
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    ctx->num_syms   = cache_size;
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    for (i = 0; i < ctx->cache_size; i++)
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        ctx->cache[i] = i;
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    model_init(&ctx->cache_model, ctx->num_syms + 1, THRESH_LOW);
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    model_init(&ctx->full_model, 256, THRESH_HIGH);
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    for (i = 0; i < 4; i++) {
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        for (j = 0; j < sec_order_sizes[i]; j++) {
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            for (k = 0; k < 4; k++) {
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                model_init(&ctx->sec_models[i][j][k], 2 + i,
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                           i ? THRESH_LOW : THRESH_ADAPTIVE);
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            }
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        }
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    }
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}
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static int decode_top_left_pixel(ArithCoder *acoder, PixContext *pctx)
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{
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    int i, val, pix;
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    val = arith_get_model_sym(acoder, &pctx->cache_model);
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    if (val < pctx->num_syms) {
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        pix = pctx->cache[val];
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    } else {
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        pix = arith_get_model_sym(acoder, &pctx->full_model);
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        for (i = 0; i < pctx->cache_size - 1; i++)
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            if (pctx->cache[i] == pix)
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                break;
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        val = i;
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    }
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    if (val) {
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        for (i = val; i > 0; i--)
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            pctx->cache[i] = pctx->cache[i - 1];
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        pctx->cache[0] = pix;
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    }
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    return pix;
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}
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static int decode_pixel(ArithCoder *acoder, PixContext *pctx,
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                        uint8_t *ngb, int num_ngb)
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{
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    int i, val, pix;
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    val = arith_get_model_sym(acoder, &pctx->cache_model);
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    if (val < pctx->num_syms) {
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        int idx, j;
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        idx = 0;
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        for (i = 0; i < pctx->cache_size; i++) {
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            for (j = 0; j < num_ngb; j++)
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                if (pctx->cache[i] == ngb[j])
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                    break;
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            if (j == num_ngb) {
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                if (idx == val)
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                    break;
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                idx++;
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            }
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        }
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        val = FFMIN(i, pctx->cache_size - 1);
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        pix = pctx->cache[val];
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    } else {
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        pix = arith_get_model_sym(acoder, &pctx->full_model);
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        for (i = 0; i < pctx->cache_size - 1; i++)
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            if (pctx->cache[i] == pix)
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                break;
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        val = i;
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    }
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    if (val) {
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        for (i = val; i > 0; i--)
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            pctx->cache[i] = pctx->cache[i - 1];
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        pctx->cache[0] = pix;
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    }
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    return pix;
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}
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static int decode_pixel_in_context(ArithCoder *acoder, PixContext *pctx,
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                                   uint8_t *src, int stride, int x, int y,
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                                   int has_right)
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{
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    uint8_t neighbours[4];
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    uint8_t ref_pix[4];
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    int nlen;
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    int layer = 0, sub;
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    int pix;
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    int i, j;
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    if (!y) {
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        memset(neighbours, src[-1], 4);
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    } else {
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        neighbours[TOP] = src[-stride];
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        if (!x) {
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            neighbours[TOP_LEFT] = neighbours[LEFT] = neighbours[TOP];
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        } else {
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            neighbours[TOP_LEFT] = src[-stride - 1];
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            neighbours[    LEFT] = src[-1];
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        }
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        if (has_right)
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            neighbours[TOP_RIGHT] = src[-stride + 1];
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        else
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            neighbours[TOP_RIGHT] = neighbours[TOP];
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    }
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    sub = 0;
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    if (x >= 2 && src[-2] == neighbours[LEFT])
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        sub  = 1;
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    if (y >= 2 && src[-2 * stride] == neighbours[TOP])
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        sub |= 2;
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    nlen = 1;
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    ref_pix[0] = neighbours[0];
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    for (i = 1; i < 4; i++) {
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        for (j = 0; j < nlen; j++)
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            if (ref_pix[j] == neighbours[i])
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                break;
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        if (j == nlen)
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            ref_pix[nlen++] = neighbours[i];
 | 
						|
    }
 | 
						|
 | 
						|
    switch (nlen) {
 | 
						|
    case 1:
 | 
						|
    case 4:
 | 
						|
        layer = 0;
 | 
						|
        break;
 | 
						|
    case 2:
 | 
						|
        if (neighbours[TOP] == neighbours[TOP_LEFT]) {
 | 
						|
            if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT])
 | 
						|
                layer = 3;
 | 
						|
            else if (neighbours[LEFT] == neighbours[TOP_LEFT])
 | 
						|
                layer = 2;
 | 
						|
            else
 | 
						|
                layer = 4;
 | 
						|
        } else if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT]) {
 | 
						|
            if (neighbours[LEFT] == neighbours[TOP_LEFT])
 | 
						|
                layer = 1;
 | 
						|
            else
 | 
						|
                layer = 5;
 | 
						|
        } else if (neighbours[LEFT] == neighbours[TOP_LEFT]) {
 | 
						|
            layer = 6;
 | 
						|
        } else {
 | 
						|
            layer = 0;
 | 
						|
        }
 | 
						|
        break;
 | 
						|
    case 3:
 | 
						|
        if (neighbours[TOP] == neighbours[TOP_LEFT])
 | 
						|
            layer = 0;
 | 
						|
        else if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT])
 | 
						|
            layer = 1;
 | 
						|
        else if (neighbours[LEFT] == neighbours[TOP_LEFT])
 | 
						|
            layer = 2;
 | 
						|
        else if (neighbours[TOP_RIGHT] == neighbours[TOP])
 | 
						|
            layer = 3;
 | 
						|
        else if (neighbours[TOP] == neighbours[LEFT])
 | 
						|
            layer = 4;
 | 
						|
        else
 | 
						|
            layer = 5;
 | 
						|
        break;
 | 
						|
    }
 | 
						|
 | 
						|
    pix = arith_get_model_sym(acoder, &pctx->sec_models[nlen - 1][layer][sub]);
 | 
						|
    if (pix < nlen)
 | 
						|
        return ref_pix[pix];
 | 
						|
    else
 | 
						|
        return decode_pixel(acoder, pctx, ref_pix, nlen);
 | 
						|
}
 | 
						|
 | 
						|
static int decode_region(MSS1Context *ctx, ArithCoder *acoder, uint8_t *dst,
 | 
						|
                         int x, int y, int width, int height, int stride,
 | 
						|
                         PixContext *pctx)
 | 
						|
{
 | 
						|
    int i, j;
 | 
						|
 | 
						|
    dst += x + y * stride;
 | 
						|
 | 
						|
    dst[0] = decode_top_left_pixel(acoder, pctx);
 | 
						|
    for (j = 0; j < height; j++) {
 | 
						|
        for (i = 0; i < width; i++) {
 | 
						|
            if (!i && !j)
 | 
						|
                continue;
 | 
						|
 | 
						|
            dst[i] = decode_pixel_in_context(acoder, pctx, dst + i, stride,
 | 
						|
                                             i, j, width - i - 1);
 | 
						|
        }
 | 
						|
        dst += stride;
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_region_masked(MSS1Context *ctx, ArithCoder *acoder,
 | 
						|
                                uint8_t *dst, int stride, uint8_t *mask,
 | 
						|
                                int mask_stride, int x, int y,
 | 
						|
                                int width, int height,
 | 
						|
                                PixContext *pctx)
 | 
						|
{
 | 
						|
    int i, j;
 | 
						|
 | 
						|
    dst  += x + y * stride;
 | 
						|
    mask += x + y * mask_stride;
 | 
						|
 | 
						|
    if (mask[0] == 0xFF)
 | 
						|
        dst[0] = decode_top_left_pixel(acoder, pctx);
 | 
						|
    for (j = 0; j < height; j++) {
 | 
						|
        for (i = 0; i < width; i++) {
 | 
						|
            if (!i && !j || mask[i] != 0xFF)
 | 
						|
                continue;
 | 
						|
 | 
						|
            dst[i] = decode_pixel_in_context(acoder, pctx, dst + i, stride,
 | 
						|
                                             i, j, width - i - 1);
 | 
						|
        }
 | 
						|
        dst  += stride;
 | 
						|
        mask += mask_stride;
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static av_cold void codec_init(MSS1Context *ctx)
 | 
						|
{
 | 
						|
    model_init(&ctx->intra_region, 2, THRESH_ADAPTIVE);
 | 
						|
    model_init(&ctx->inter_region, 2, THRESH_ADAPTIVE);
 | 
						|
    model_init(&ctx->split_mode,   3, THRESH_HIGH);
 | 
						|
    model_init(&ctx->edge_mode,    2, THRESH_HIGH);
 | 
						|
    model_init(&ctx->pivot,        3, THRESH_LOW);
 | 
						|
    pixctx_init(&ctx->intra_pix_ctx, 8);
 | 
						|
    pixctx_init(&ctx->inter_pix_ctx, 2);
 | 
						|
    ctx->corrupted = 1;
 | 
						|
}
 | 
						|
 | 
						|
static void codec_reset(MSS1Context *ctx)
 | 
						|
{
 | 
						|
    model_reset(&ctx->intra_region);
 | 
						|
    model_reset(&ctx->inter_region);
 | 
						|
    model_reset(&ctx->split_mode);
 | 
						|
    model_reset(&ctx->edge_mode);
 | 
						|
    model_reset(&ctx->pivot);
 | 
						|
    pixctx_reset(&ctx->intra_pix_ctx);
 | 
						|
    pixctx_reset(&ctx->inter_pix_ctx);
 | 
						|
 | 
						|
    ctx->corrupted = 0;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_pal(MSS1Context *ctx, ArithCoder *acoder)
 | 
						|
{
 | 
						|
    int i, ncol, r, g, b;
 | 
						|
    uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
 | 
						|
 | 
						|
    if (!ctx->free_colours)
 | 
						|
        return 0;
 | 
						|
 | 
						|
    ncol = arith_get_number(acoder, ctx->free_colours + 1);
 | 
						|
    for (i = 0; i < ncol; i++) {
 | 
						|
        r = arith_get_bits(acoder, 8);
 | 
						|
        g = arith_get_bits(acoder, 8);
 | 
						|
        b = arith_get_bits(acoder, 8);
 | 
						|
        *pal++ = (0xFF << 24) | (r << 16) | (g << 8) | b;
 | 
						|
    }
 | 
						|
 | 
						|
    return !!ncol;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_pivot(MSS1Context *ctx, ArithCoder *acoder, int base)
 | 
						|
{
 | 
						|
    int val, inv;
 | 
						|
 | 
						|
    inv = arith_get_model_sym(acoder, &ctx->edge_mode);
 | 
						|
    val = arith_get_model_sym(acoder, &ctx->pivot) + 1;
 | 
						|
 | 
						|
    if (val > 2) {
 | 
						|
        if ((base + 1) / 2 - 2 <= 0) {
 | 
						|
            ctx->corrupted = 1;
 | 
						|
            return 0;
 | 
						|
        }
 | 
						|
        val = arith_get_number(acoder, (base + 1) / 2 - 2) + 3;
 | 
						|
    }
 | 
						|
 | 
						|
    if ((unsigned)val >= base) {
 | 
						|
        ctx->corrupted = 1;
 | 
						|
        return 0;
 | 
						|
    }
 | 
						|
 | 
						|
    return inv ? base - val : val;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_region_intra(MSS1Context *ctx, ArithCoder *acoder,
 | 
						|
                               int x, int y, int width, int height)
 | 
						|
{
 | 
						|
    int mode;
 | 
						|
 | 
						|
    mode = arith_get_model_sym(acoder, &ctx->intra_region);
 | 
						|
 | 
						|
    if (!mode) {
 | 
						|
        int i, pix;
 | 
						|
        int stride = ctx->pic_stride;
 | 
						|
        uint8_t *dst = ctx->pic_start + x + y * stride;
 | 
						|
 | 
						|
        pix = decode_top_left_pixel(acoder, &ctx->intra_pix_ctx);
 | 
						|
        for (i = 0; i < height; i++, dst += stride)
 | 
						|
            memset(dst, pix, width);
 | 
						|
    } else {
 | 
						|
        return decode_region(ctx, acoder, ctx->pic_start,
 | 
						|
                             x, y, width, height, ctx->pic_stride,
 | 
						|
                             &ctx->intra_pix_ctx);
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_intra(MSS1Context *ctx, ArithCoder *acoder,
 | 
						|
                        int x, int y, int width, int height)
 | 
						|
{
 | 
						|
    int mode, pivot;
 | 
						|
 | 
						|
    if (ctx->corrupted)
 | 
						|
        return -1;
 | 
						|
 | 
						|
    mode = arith_get_model_sym(acoder, &ctx->split_mode);
 | 
						|
 | 
						|
    switch (mode) {
 | 
						|
    case SPLIT_VERT:
 | 
						|
        pivot = decode_pivot(ctx, acoder, height);
 | 
						|
        if (ctx->corrupted)
 | 
						|
            return -1;
 | 
						|
        if (decode_intra(ctx, acoder, x, y, width, pivot))
 | 
						|
            return -1;
 | 
						|
        if (decode_intra(ctx, acoder, x, y + pivot, width, height - pivot))
 | 
						|
            return -1;
 | 
						|
        break;
 | 
						|
    case SPLIT_HOR:
 | 
						|
        pivot = decode_pivot(ctx, acoder, width);
 | 
						|
        if (ctx->corrupted)
 | 
						|
            return -1;
 | 
						|
        if (decode_intra(ctx, acoder, x, y, pivot, height))
 | 
						|
            return -1;
 | 
						|
        if (decode_intra(ctx, acoder, x + pivot, y, width - pivot, height))
 | 
						|
            return -1;
 | 
						|
        break;
 | 
						|
    case SPLIT_NONE:
 | 
						|
        return decode_region_intra(ctx, acoder, x, y, width, height);
 | 
						|
    default:
 | 
						|
        return -1;
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_region_inter(MSS1Context *ctx, ArithCoder *acoder,
 | 
						|
                               int x, int y, int width, int height)
 | 
						|
{
 | 
						|
    int mode;
 | 
						|
 | 
						|
    mode = arith_get_model_sym(acoder, &ctx->inter_region);
 | 
						|
 | 
						|
    if (!mode) {
 | 
						|
        mode = decode_top_left_pixel(acoder, &ctx->inter_pix_ctx);
 | 
						|
        if (mode != 0xFF) {
 | 
						|
            return 0;
 | 
						|
        } else {
 | 
						|
            return decode_region_intra(ctx, acoder, x, y, width, height);
 | 
						|
        }
 | 
						|
    } else {
 | 
						|
        if (decode_region(ctx, acoder, ctx->mask,
 | 
						|
                          x, y, width, height, ctx->mask_linesize,
 | 
						|
                          &ctx->inter_pix_ctx) < 0)
 | 
						|
            return -1;
 | 
						|
        return decode_region_masked(ctx, acoder, ctx->pic_start,
 | 
						|
                                    -ctx->pic.linesize[0], ctx->mask,
 | 
						|
                                    ctx->mask_linesize,
 | 
						|
                                    x, y, width, height,
 | 
						|
                                    &ctx->intra_pix_ctx);
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int decode_inter(MSS1Context *ctx, ArithCoder *acoder,
 | 
						|
                        int x, int y, int width, int height)
 | 
						|
{
 | 
						|
    int mode, pivot;
 | 
						|
 | 
						|
    if (ctx->corrupted)
 | 
						|
        return -1;
 | 
						|
 | 
						|
    mode = arith_get_model_sym(acoder, &ctx->split_mode);
 | 
						|
 | 
						|
    switch (mode) {
 | 
						|
    case SPLIT_VERT:
 | 
						|
        pivot = decode_pivot(ctx, acoder, height);
 | 
						|
        if (decode_inter(ctx, acoder, x, y, width, pivot))
 | 
						|
            return -1;
 | 
						|
        if (decode_inter(ctx, acoder, x, y + pivot, width, height - pivot))
 | 
						|
            return -1;
 | 
						|
        break;
 | 
						|
    case SPLIT_HOR:
 | 
						|
        pivot = decode_pivot(ctx, acoder, width);
 | 
						|
        if (decode_inter(ctx, acoder, x, y, pivot, height))
 | 
						|
            return -1;
 | 
						|
        if (decode_inter(ctx, acoder, x + pivot, y, width - pivot, height))
 | 
						|
            return -1;
 | 
						|
        break;
 | 
						|
    case SPLIT_NONE:
 | 
						|
        return decode_region_inter(ctx, acoder, x, y, width, height);
 | 
						|
    default:
 | 
						|
        return -1;
 | 
						|
    }
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static int mss1_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
 | 
						|
                             AVPacket *avpkt)
 | 
						|
{
 | 
						|
    const uint8_t *buf = avpkt->data;
 | 
						|
    int buf_size = avpkt->size;
 | 
						|
    MSS1Context *c = avctx->priv_data;
 | 
						|
    GetBitContext gb;
 | 
						|
    ArithCoder acoder;
 | 
						|
    int pal_changed = 0;
 | 
						|
    int ret;
 | 
						|
 | 
						|
    init_get_bits(&gb, buf, buf_size * 8);
 | 
						|
    arith_init(&acoder, &gb);
 | 
						|
 | 
						|
    c->pic.reference    = 3;
 | 
						|
    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
 | 
						|
                          FF_BUFFER_HINTS_REUSABLE;
 | 
						|
    if ((ret = avctx->reget_buffer(avctx, &c->pic)) < 0) {
 | 
						|
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 | 
						|
        return ret;
 | 
						|
    }
 | 
						|
 | 
						|
    c->pic_start  = c->pic.data[0] + c->pic.linesize[0] * (avctx->height - 1);
 | 
						|
    c->pic_stride = -c->pic.linesize[0];
 | 
						|
    if (!arith_get_bit(&acoder)) {
 | 
						|
        codec_reset(c);
 | 
						|
        pal_changed      = decode_pal(c, &acoder);
 | 
						|
        c->corrupted     = decode_intra(c, &acoder, 0, 0,
 | 
						|
                                        avctx->width, avctx->height);
 | 
						|
        c->pic.key_frame = 1;
 | 
						|
        c->pic.pict_type = AV_PICTURE_TYPE_I;
 | 
						|
    } else {
 | 
						|
        if (c->corrupted)
 | 
						|
            return AVERROR_INVALIDDATA;
 | 
						|
        c->corrupted     = decode_inter(c, &acoder, 0, 0,
 | 
						|
                                        avctx->width, avctx->height);
 | 
						|
        c->pic.key_frame = 0;
 | 
						|
        c->pic.pict_type = AV_PICTURE_TYPE_P;
 | 
						|
    }
 | 
						|
    if (c->corrupted)
 | 
						|
        return AVERROR_INVALIDDATA;
 | 
						|
    memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
 | 
						|
    c->pic.palette_has_changed = pal_changed;
 | 
						|
 | 
						|
    *data_size = sizeof(AVFrame);
 | 
						|
    *(AVFrame*)data = c->pic;
 | 
						|
 | 
						|
    /* always report that the buffer was completely consumed */
 | 
						|
    return buf_size;
 | 
						|
}
 | 
						|
 | 
						|
static av_cold int mss1_decode_init(AVCodecContext *avctx)
 | 
						|
{
 | 
						|
    MSS1Context * const c = avctx->priv_data;
 | 
						|
    int i;
 | 
						|
 | 
						|
    c->avctx = avctx;
 | 
						|
 | 
						|
    if (avctx->extradata_size < 52 + 256 * 3) {
 | 
						|
        av_log(avctx, AV_LOG_ERROR, "Insufficient extradata size %d\n",
 | 
						|
               avctx->extradata_size);
 | 
						|
        return AVERROR_INVALIDDATA;
 | 
						|
    }
 | 
						|
 | 
						|
    if (AV_RB32(avctx->extradata) < avctx->extradata_size) {
 | 
						|
        av_log(avctx, AV_LOG_ERROR,
 | 
						|
               "Insufficient extradata size: expected %d got %d\n",
 | 
						|
               AV_RB32(avctx->extradata),
 | 
						|
               avctx->extradata_size);
 | 
						|
        return AVERROR_INVALIDDATA;
 | 
						|
    }
 | 
						|
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Encoder version %d.%d\n",
 | 
						|
           AV_RB32(avctx->extradata + 4), AV_RB32(avctx->extradata + 8));
 | 
						|
    c->free_colours     = AV_RB32(avctx->extradata + 48);
 | 
						|
    if ((unsigned)c->free_colours > 256) {
 | 
						|
        av_log(avctx, AV_LOG_ERROR,
 | 
						|
               "Incorrect number of changeable palette entries: %d\n",
 | 
						|
               c->free_colours);
 | 
						|
        return AVERROR_INVALIDDATA;
 | 
						|
    }
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "%d free colour(s)\n", c->free_colours);
 | 
						|
    avctx->coded_width  = AV_RB32(avctx->extradata + 20);
 | 
						|
    avctx->coded_height = AV_RB32(avctx->extradata + 24);
 | 
						|
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Display dimensions %dx%d\n",
 | 
						|
           AV_RB32(avctx->extradata + 12), AV_RB32(avctx->extradata + 16));
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Coded dimensions %dx%d\n",
 | 
						|
           avctx->coded_width, avctx->coded_height);
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "%g frames per second\n",
 | 
						|
           av_int2float(AV_RB32(avctx->extradata + 28)));
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Bitrate %d bps\n",
 | 
						|
           AV_RB32(avctx->extradata + 32));
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Max. lead time %g ms\n",
 | 
						|
           av_int2float(AV_RB32(avctx->extradata + 36)));
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Max. lag time %g ms\n",
 | 
						|
           av_int2float(AV_RB32(avctx->extradata + 40)));
 | 
						|
    av_log(avctx, AV_LOG_DEBUG, "Max. seek time %g ms\n",
 | 
						|
           av_int2float(AV_RB32(avctx->extradata + 44)));
 | 
						|
 | 
						|
    for (i = 0; i < 256; i++)
 | 
						|
        c->pal[i] = 0xFF << 24 | AV_RB24(avctx->extradata + 52 + i * 3);
 | 
						|
 | 
						|
    avctx->pix_fmt = PIX_FMT_PAL8;
 | 
						|
 | 
						|
    c->mask_linesize = FFALIGN(avctx->width, 16);
 | 
						|
    c->mask          = av_malloc(c->mask_linesize * avctx->height);
 | 
						|
    if (!c->mask) {
 | 
						|
        av_log(avctx, AV_LOG_ERROR, "Cannot allocate mask plane\n");
 | 
						|
        return AVERROR(ENOMEM);
 | 
						|
    }
 | 
						|
 | 
						|
    avctx->coded_frame = &c->pic;
 | 
						|
 | 
						|
    codec_init(c);
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
static av_cold int mss1_decode_end(AVCodecContext *avctx)
 | 
						|
{
 | 
						|
    MSS1Context * const c = avctx->priv_data;
 | 
						|
 | 
						|
    if (c->pic.data[0])
 | 
						|
        avctx->release_buffer(avctx, &c->pic);
 | 
						|
    av_freep(&c->mask);
 | 
						|
 | 
						|
    return 0;
 | 
						|
}
 | 
						|
 | 
						|
AVCodec ff_mss1_decoder = {
 | 
						|
    .name           = "mss1",
 | 
						|
    .type           = AVMEDIA_TYPE_VIDEO,
 | 
						|
    .id             = AV_CODEC_ID_MSS1,
 | 
						|
    .priv_data_size = sizeof(MSS1Context),
 | 
						|
    .init           = mss1_decode_init,
 | 
						|
    .close          = mss1_decode_end,
 | 
						|
    .decode         = mss1_decode_frame,
 | 
						|
    .capabilities   = CODEC_CAP_DR1,
 | 
						|
    .long_name      = NULL_IF_CONFIG_SMALL("MS Screen 1"),
 | 
						|
};
 |