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Diffstat (limited to 'ffmpeg/libavcodec/mss12.h')
| -rw-r--r-- | ffmpeg/libavcodec/mss12.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/mss12.h b/ffmpeg/libavcodec/mss12.h new file mode 100644 index 0000000..a3f9a7c --- /dev/null +++ b/ffmpeg/libavcodec/mss12.h @@ -0,0 +1,133 @@ +/* + * Copyright (c) 2012 Konstantin Shishkov + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * Common header for Microsoft Screen 1 and 2 + */ + +#ifndef AVCODEC_MSS12_H +#define AVCODEC_MSS12_H + +#include "libavutil/intreadwrite.h" +#include "avcodec.h" +#include "get_bits.h" +#include "bytestream.h" + +#define MODEL_MIN_SYMS 2 +#define MODEL_MAX_SYMS 256 +#define THRESH_ADAPTIVE -1 +#define THRESH_LOW 15 +#define THRESH_HIGH 50 + +typedef struct Model { + int16_t cum_prob[MODEL_MAX_SYMS + 1]; + int16_t weights[MODEL_MAX_SYMS + 1]; + uint8_t idx2sym[MODEL_MAX_SYMS + 1]; + int num_syms; + int thr_weight, threshold; +} Model; + +typedef struct ArithCoder { + int low, high, value; + union { + GetBitContext *gb; + GetByteContext *gB; + } gbc; + int (*get_model_sym)(struct ArithCoder *c, Model *m); + int (*get_number) (struct ArithCoder *c, int n); +} ArithCoder; + +typedef struct PixContext { + int cache_size, num_syms; + uint8_t cache[12]; + Model cache_model, full_model; + Model sec_models[15][4]; + int special_initial_cache; +} PixContext; + +struct MSS12Context; + +typedef struct SliceContext { + struct MSS12Context *c; + Model intra_region, inter_region; + Model pivot, edge_mode, split_mode; + PixContext intra_pix_ctx, inter_pix_ctx; +} SliceContext; + +typedef struct MSS12Context { + AVCodecContext *avctx; + uint32_t pal[256]; + uint8_t *pal_pic; + uint8_t *last_pal_pic; + int pal_stride; + uint8_t *mask; + int mask_stride; + uint8_t *rgb_pic; + uint8_t *last_rgb_pic; + int rgb_stride; + int free_colours; + int keyframe; + int mvX, mvY; + int corrupted; + int slice_split; + int full_model_syms; +} MSS12Context; + +int ff_mss12_decode_rect(SliceContext *ctx, ArithCoder *acoder, + int x, int y, int width, int height); +void ff_mss12_model_update(Model *m, int val); +void ff_mss12_slicecontext_reset(SliceContext *sc); +int ff_mss12_decode_init(MSS12Context *c, int version, + SliceContext *sc1, SliceContext *sc2); +int ff_mss12_decode_end(MSS12Context *ctx); + +#define ARITH_GET_BIT(VERSION) \ +static int arith ## VERSION ## _get_bit(ArithCoder *c) \ +{ \ + int range = c->high - c->low + 1; \ + int bit = 2 * c->value - c->low >= c->high; \ + \ + if (bit) \ + c->low += range >> 1; \ + else \ + c->high = c->low + (range >> 1) - 1; \ + \ + arith ## VERSION ## _normalise(c); \ + \ + return bit; \ +} + +#define ARITH_GET_MODEL_SYM(VERSION) \ +static int arith ## VERSION ## _get_model_sym(ArithCoder *c, Model *m) \ +{ \ + int idx, val; \ + \ + idx = arith ## VERSION ## _get_prob(c, m->cum_prob); \ + \ + val = m->idx2sym[idx]; \ + ff_mss12_model_update(m, idx); \ + \ + arith ## VERSION ## _normalise(c); \ + \ + return val; \ +} + +#endif /* AVCODEC_MSS12_H */ |