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by Sérgio Benjamim
FFmpeg 2.7.1 source for ppsspp. |
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/*
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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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* Common header for Microsoft Screen 1 and 2
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*/
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#ifndef AVCODEC_MSS12_H
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#define AVCODEC_MSS12_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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#include "bytestream.h" |
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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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int16_t cum_prob[MODEL_MAX_SYMS + 1]; |
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int16_t weights[MODEL_MAX_SYMS + 1]; |
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uint8_t idx2sym[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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typedef struct ArithCoder { |
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int low, high, value; |
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union { |
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GetBitContext *gb; |
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GetByteContext *gB; |
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} gbc; |
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int (*get_model_sym)(struct ArithCoder *c, Model *m); |
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int (*get_number) (struct ArithCoder *c, int n); |
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} ArithCoder; |
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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[15][4]; |
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int special_initial_cache; |
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} PixContext; |
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struct MSS12Context; |
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typedef struct SliceContext { |
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struct MSS12Context *c; |
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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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} SliceContext; |
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typedef struct MSS12Context { |
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AVCodecContext *avctx; |
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uint32_t pal[256]; |
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uint8_t *pal_pic; |
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uint8_t *last_pal_pic; |
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int pal_stride; |
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uint8_t *mask; |
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int mask_stride; |
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uint8_t *rgb_pic; |
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uint8_t *last_rgb_pic; |
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int rgb_stride; |
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int free_colours; |
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int keyframe; |
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int mvX, mvY; |
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int corrupted; |
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int slice_split; |
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int full_model_syms; |
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} MSS12Context; |
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int ff_mss12_decode_rect(SliceContext *ctx, ArithCoder *acoder, |
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int x, int y, int width, int height); |
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void ff_mss12_model_update(Model *m, int val); |
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void ff_mss12_slicecontext_reset(SliceContext *sc); |
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int ff_mss12_decode_init(MSS12Context *c, int version, |
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SliceContext *sc1, SliceContext *sc2); |
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int ff_mss12_decode_end(MSS12Context *ctx); |
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#define ARITH_GET_BIT(prefix) \
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static int prefix ## _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 = 2 * c->value - c->low >= c->high; \
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\
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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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\
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prefix ## _normalise(c); \
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\
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return bit; \
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}
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#define ARITH_GET_MODEL_SYM(prefix) \
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static int prefix ## _get_model_sym(ArithCoder *c, Model *m) \
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{ \
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int idx, val; \
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\
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idx = prefix ## _get_prob(c, m->cum_prob); \
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\
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val = m->idx2sym[idx]; \
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ff_mss12_model_update(m, idx); \
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\
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prefix ## _normalise(c); \
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\
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return val; \
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}
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#endif /* AVCODEC_MSS12_H */ |