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1
/*
2
 * 4XM codec
3
 * Copyright (c) 2003 Michael Niedermayer
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * 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 of the License, or (at your option) any later version.
9
 *
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 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; 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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 */
19

    
20
/**
21
 * @file 4xm.c
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 * 4XM codec.
23
 */
24

    
25
#include "avcodec.h"
26
#include "dsputil.h"
27
#include "mpegvideo.h"
28

    
29
//#undef NDEBUG
30
//#include <assert.h>
31

    
32
#define BLOCK_TYPE_VLC_BITS 5
33
#define ACDC_VLC_BITS 9
34

    
35
#define CFRAME_BUFFER_COUNT 100
36

    
37
static const uint8_t block_type_tab[4][8][2]={
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  {   //{8,4,2}x{8,4,2}
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    { 0,1}, { 2,2}, { 6,3}, {14,4}, {30,5}, {31,5}, { 0,0}
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  },{ //{8,4}x1
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    { 0,1}, { 0,0}, { 2,2}, { 6,3}, {14,4}, {15,4}, { 0,0}
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  },{ //1x{8,4}
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    { 0,1}, { 2,2}, { 0,0}, { 6,3}, {14,4}, {15,4}, { 0,0}
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  },{ //1x2, 2x1
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    { 0,1}, { 0,0}, { 0,0}, { 2,2}, { 6,3}, {14,4}, {15,4}
46
  }
47
};
48

    
49
static const uint8_t size2index[4][4]={
50
  {-1, 3, 1, 1},
51
  { 3, 0, 0, 0},
52
  { 2, 0, 0, 0},
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  { 2, 0, 0, 0},
54
};
55

    
56
static const int8_t mv[256][2]={
57
{  0,  0},{  0, -1},{ -1,  0},{  1,  0},{  0,  1},{ -1, -1},{  1, -1},{ -1,  1},
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{  1,  1},{  0, -2},{ -2,  0},{  2,  0},{  0,  2},{ -1, -2},{  1, -2},{ -2, -1},
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{  2, -1},{ -2,  1},{  2,  1},{ -1,  2},{  1,  2},{ -2, -2},{  2, -2},{ -2,  2},
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{  2,  2},{  0, -3},{ -3,  0},{  3,  0},{  0,  3},{ -1, -3},{  1, -3},{ -3, -1},
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{  3, -1},{ -3,  1},{  3,  1},{ -1,  3},{  1,  3},{ -2, -3},{  2, -3},{ -3, -2},
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{  3, -2},{ -3,  2},{  3,  2},{ -2,  3},{  2,  3},{  0, -4},{ -4,  0},{  4,  0},
63
{  0,  4},{ -1, -4},{  1, -4},{ -4, -1},{  4, -1},{  4,  1},{ -1,  4},{  1,  4},
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{ -3, -3},{ -3,  3},{  3,  3},{ -2, -4},{ -4, -2},{  4, -2},{ -4,  2},{ -2,  4},
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{  2,  4},{ -3, -4},{  3, -4},{  4, -3},{ -5,  0},{ -4,  3},{ -3,  4},{  3,  4},
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{ -1, -5},{ -5, -1},{ -5,  1},{ -1,  5},{ -2, -5},{  2, -5},{  5, -2},{  5,  2},
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{ -4, -4},{ -4,  4},{ -3, -5},{ -5, -3},{ -5,  3},{  3,  5},{ -6,  0},{  0,  6},
68
{ -6, -1},{ -6,  1},{  1,  6},{  2, -6},{ -6,  2},{  2,  6},{ -5, -4},{  5,  4},
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{  4,  5},{ -6, -3},{  6,  3},{ -7,  0},{ -1, -7},{  5, -5},{ -7,  1},{ -1,  7},
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{  4, -6},{  6,  4},{ -2, -7},{ -7,  2},{ -3, -7},{  7, -3},{  3,  7},{  6, -5},
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{  0, -8},{ -1, -8},{ -7, -4},{ -8,  1},{  4,  7},{  2, -8},{ -2,  8},{  6,  6},
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{ -8,  3},{  5, -7},{ -5,  7},{  8, -4},{  0, -9},{ -9, -1},{  1,  9},{  7, -6},
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{ -7,  6},{ -5, -8},{ -5,  8},{ -9,  3},{  9, -4},{  7, -7},{  8, -6},{  6,  8},
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{ 10,  1},{-10,  2},{  9, -5},{ 10, -3},{ -8, -7},{-10, -4},{  6, -9},{-11,  0},
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{ 11,  1},{-11, -2},{ -2, 11},{  7, -9},{ -7,  9},{ 10,  6},{ -4, 11},{  8, -9},
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{  8,  9},{  5, 11},{  7,-10},{ 12, -3},{ 11,  6},{ -9, -9},{  8, 10},{  5, 12},
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{-11,  7},{ 13,  2},{  6,-12},{ 10,  9},{-11,  8},{ -7, 12},{  0, 14},{ 14, -2},
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{ -9, 11},{ -6, 13},{-14, -4},{ -5,-14},{  5, 14},{-15, -1},{-14, -6},{  3,-15},
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{ 11,-11},{ -7, 14},{ -5, 15},{  8,-14},{ 15,  6},{  3, 16},{  7,-15},{-16,  5},
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{  0, 17},{-16, -6},{-10, 14},{-16,  7},{ 12, 13},{-16,  8},{-17,  6},{-18,  3},
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{ -7, 17},{ 15, 11},{ 16, 10},{  2,-19},{  3,-19},{-11,-16},{-18,  8},{-19, -6},
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{  2,-20},{-17,-11},{-10,-18},{  8, 19},{-21, -1},{-20,  7},{ -4, 21},{ 21,  5},
83
{ 15, 16},{  2,-22},{-10,-20},{-22,  5},{ 20,-11},{ -7,-22},{-12, 20},{ 23, -5},
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{ 13,-20},{ 24, -2},{-15, 19},{-11, 22},{ 16, 19},{ 23,-10},{-18,-18},{ -9,-24},
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{ 24,-10},{ -3, 26},{-23, 13},{-18,-20},{ 17, 21},{ -4, 27},{ 27,  6},{  1,-28},
86
{-11, 26},{-17,-23},{  7, 28},{ 11,-27},{ 29,  5},{-23,-19},{-28,-11},{-21, 22},
87
{-30,  7},{-17, 26},{-27, 16},{ 13, 29},{ 19,-26},{ 10,-31},{-14,-30},{ 20,-27},
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{-29, 18},{-16,-31},{-28,-22},{ 21,-30},{-25, 28},{ 26,-29},{ 25,-32},{-32,-32}
89
};
90

    
91
// this is simply the scaled down elementwise product of the standard jpeg quantizer table and the AAN premul table
92
static const uint8_t dequant_table[64]={
93
 16, 15, 13, 19, 24, 31, 28, 17,
94
 17, 23, 25, 31, 36, 63, 45, 21,
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 18, 24, 27, 37, 52, 59, 49, 20,
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 16, 28, 34, 40, 60, 80, 51, 20,
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 18, 31, 48, 66, 68, 86, 56, 21,
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 19, 38, 56, 59, 64, 64, 48, 20,
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 27, 48, 55, 55, 56, 51, 35, 15,
100
 20, 35, 34, 32, 31, 22, 15,  8,
101
};
102

    
103
static VLC block_type_vlc[4];
104

    
105

    
106
typedef struct CFrameBuffer{
107
    int allocated_size;
108
    int size;
109
    int id;
110
    uint8_t *data;
111
}CFrameBuffer;
112

    
113
typedef struct FourXContext{
114
    AVCodecContext *avctx;
115
    DSPContext dsp;
116
    AVFrame current_picture, last_picture;
117
    GetBitContext pre_gb;          ///< ac/dc prefix
118
    GetBitContext gb;
119
    uint8_t *bytestream;
120
    uint16_t *wordstream;
121
    int mv[256];
122
    VLC pre_vlc;
123
    int last_dc;
124
    DECLARE_ALIGNED_8(DCTELEM, block[6][64]);
125
    uint8_t *bitstream_buffer;
126
    unsigned int bitstream_buffer_size;
127
    CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];
128
} FourXContext;
129

    
130

    
131
#define FIX_1_082392200  70936
132
#define FIX_1_414213562  92682
133
#define FIX_1_847759065 121095
134
#define FIX_2_613125930 171254
135

    
136
#define MULTIPLY(var,const)  (((var)*(const)) >> 16)
137

    
138
static void idct(DCTELEM block[64]){
139
    int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
140
    int tmp10, tmp11, tmp12, tmp13;
141
    int z5, z10, z11, z12, z13;
142
    int i;
143
    int temp[64];
144

    
145
    for(i=0; i<8; i++){
146
        tmp10 = block[8*0 + i] + block[8*4 + i];
147
        tmp11 = block[8*0 + i] - block[8*4 + i];
148

    
149
        tmp13 =          block[8*2 + i] + block[8*6 + i];
150
        tmp12 = MULTIPLY(block[8*2 + i] - block[8*6 + i], FIX_1_414213562) - tmp13;
151

    
152
        tmp0 = tmp10 + tmp13;
153
        tmp3 = tmp10 - tmp13;
154
        tmp1 = tmp11 + tmp12;
155
        tmp2 = tmp11 - tmp12;
156

    
157
        z13 = block[8*5 + i] + block[8*3 + i];
158
        z10 = block[8*5 + i] - block[8*3 + i];
159
        z11 = block[8*1 + i] + block[8*7 + i];
160
        z12 = block[8*1 + i] - block[8*7 + i];
161

    
162
        tmp7  =          z11 + z13;
163
        tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
164

    
165
        z5    = MULTIPLY(z10 + z12, FIX_1_847759065);
166
        tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
167
        tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5;
168

    
169
        tmp6 = tmp12 - tmp7;
170
        tmp5 = tmp11 - tmp6;
171
        tmp4 = tmp10 + tmp5;
172

    
173
        temp[8*0 + i] = tmp0 + tmp7;
174
        temp[8*7 + i] = tmp0 - tmp7;
175
        temp[8*1 + i] = tmp1 + tmp6;
176
        temp[8*6 + i] = tmp1 - tmp6;
177
        temp[8*2 + i] = tmp2 + tmp5;
178
        temp[8*5 + i] = tmp2 - tmp5;
179
        temp[8*4 + i] = tmp3 + tmp4;
180
        temp[8*3 + i] = tmp3 - tmp4;
181
    }
182

    
183
    for(i=0; i<8*8; i+=8){
184
        tmp10 = temp[0 + i] + temp[4 + i];
185
        tmp11 = temp[0 + i] - temp[4 + i];
186

    
187
        tmp13 = temp[2 + i] + temp[6 + i];
188
        tmp12 = MULTIPLY(temp[2 + i] - temp[6 + i], FIX_1_414213562) - tmp13;
189

    
190
        tmp0 = tmp10 + tmp13;
191
        tmp3 = tmp10 - tmp13;
192
        tmp1 = tmp11 + tmp12;
193
        tmp2 = tmp11 - tmp12;
194

    
195
        z13 = temp[5 + i] + temp[3 + i];
196
        z10 = temp[5 + i] - temp[3 + i];
197
        z11 = temp[1 + i] + temp[7 + i];
198
        z12 = temp[1 + i] - temp[7 + i];
199

    
200
        tmp7 = z11 + z13;
201
        tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
202

    
203
        z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
204
        tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
205
        tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5;
206

    
207
        tmp6 = tmp12 - tmp7;
208
        tmp5 = tmp11 - tmp6;
209
        tmp4 = tmp10 + tmp5;
210

    
211
        block[0 + i] = (tmp0 + tmp7)>>6;
212
        block[7 + i] = (tmp0 - tmp7)>>6;
213
        block[1 + i] = (tmp1 + tmp6)>>6;
214
        block[6 + i] = (tmp1 - tmp6)>>6;
215
        block[2 + i] = (tmp2 + tmp5)>>6;
216
        block[5 + i] = (tmp2 - tmp5)>>6;
217
        block[4 + i] = (tmp3 + tmp4)>>6;
218
        block[3 + i] = (tmp3 - tmp4)>>6;
219
    }
220
}
221

    
222
static void init_vlcs(FourXContext *f){
223
    int i;
224

    
225
    for(i=0; i<4; i++){
226
        init_vlc(&block_type_vlc[i], BLOCK_TYPE_VLC_BITS, 7,
227
                 &block_type_tab[i][0][1], 2, 1,
228
                 &block_type_tab[i][0][0], 2, 1, 1);
229
    }
230
}
231

    
232
static void init_mv(FourXContext *f){
233
    int i;
234

    
235
    for(i=0; i<256; i++){
236
        f->mv[i] = mv[i][0] + mv[i][1]*f->current_picture.linesize[0]/2;
237
    }
238
}
239

    
240
static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w, int h, int stride, int scale, int dc){
241
   int i;
242
   dc*= 0x10001;
243

    
244
   switch(log2w){
245
   case 0:
246
        for(i=0; i<h; i++){
247
            dst[0] = scale*src[0] + dc;
248
            if(scale) src += stride;
249
            dst += stride;
250
        }
251
        break;
252
    case 1:
253
        for(i=0; i<h; i++){
254
            ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
255
            if(scale) src += stride;
256
            dst += stride;
257
        }
258
        break;
259
    case 2:
260
        for(i=0; i<h; i++){
261
            ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
262
            ((uint32_t*)dst)[1] = scale*((uint32_t*)src)[1] + dc;
263
            if(scale) src += stride;
264
            dst += stride;
265
        }
266
        break;
267
    case 3:
268
        for(i=0; i<h; i++){
269
            ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
270
            ((uint32_t*)dst)[1] = scale*((uint32_t*)src)[1] + dc;
271
            ((uint32_t*)dst)[2] = scale*((uint32_t*)src)[2] + dc;
272
            ((uint32_t*)dst)[3] = scale*((uint32_t*)src)[3] + dc;
273
            if(scale) src += stride;
274
            dst += stride;
275
        }
276
        break;
277
    default: assert(0);
278
    }
279
}
280

    
281
static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src, int log2w, int log2h, int stride){
282
    const int index= size2index[log2h][log2w];
283
    const int h= 1<<log2h;
284
    int code= get_vlc2(&f->gb, block_type_vlc[index].table, BLOCK_TYPE_VLC_BITS, 1);
285

    
286
    assert(code>=0 && code<=6);
287

    
288
    if(code == 0){
289
        src += f->mv[ *f->bytestream++ ];
290
        mcdc(dst, src, log2w, h, stride, 1, 0);
291
    }else if(code == 1){
292
        log2h--;
293
        decode_p_block(f, dst                  , src                  , log2w, log2h, stride);
294
        decode_p_block(f, dst + (stride<<log2h), src + (stride<<log2h), log2w, log2h, stride);
295
    }else if(code == 2){
296
        log2w--;
297
        decode_p_block(f, dst             , src             , log2w, log2h, stride);
298
        decode_p_block(f, dst + (1<<log2w), src + (1<<log2w), log2w, log2h, stride);
299
    }else if(code == 4){
300
        src += f->mv[ *f->bytestream++ ];
301
        mcdc(dst, src, log2w, h, stride, 1, le2me_16(*f->wordstream++));
302
    }else if(code == 5){
303
        mcdc(dst, src, log2w, h, stride, 0, le2me_16(*f->wordstream++));
304
    }else if(code == 6){
305
        if(log2w){
306
            dst[0] = le2me_16(*f->wordstream++);
307
            dst[1] = le2me_16(*f->wordstream++);
308
        }else{
309
            dst[0     ] = le2me_16(*f->wordstream++);
310
            dst[stride] = le2me_16(*f->wordstream++);
311
        }
312
    }
313
}
314

    
315
static int get32(void *p){
316
    return le2me_32(*(uint32_t*)p);
317
}
318

    
319
static int decode_p_frame(FourXContext *f, uint8_t *buf, int length){
320
    int x, y;
321
    const int width= f->avctx->width;
322
    const int height= f->avctx->height;
323
    uint16_t *src= (uint16_t*)f->last_picture.data[0];
324
    uint16_t *dst= (uint16_t*)f->current_picture.data[0];
325
    const int stride= f->current_picture.linesize[0]>>1;
326
    const unsigned int bitstream_size= get32(buf+8);
327
    const unsigned int bytestream_size= get32(buf+16);
328
    const unsigned int wordstream_size= get32(buf+12);
329

    
330
    if(bitstream_size+ bytestream_size+ wordstream_size + 20 != length
331
       || bitstream_size  > (1<<26)
332
       || bytestream_size > (1<<26)
333
       || wordstream_size > (1<<26)
334
       ){
335
        av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size,
336
        bitstream_size+ bytestream_size+ wordstream_size - length);
337
        return -1;
338
    }
339

    
340
    f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
341
    f->dsp.bswap_buf((uint32_t*)f->bitstream_buffer, (uint32_t*)(buf + 20), bitstream_size/4);
342
    init_get_bits(&f->gb, f->bitstream_buffer, 8*bitstream_size);
343

    
344
    f->wordstream= (uint16_t*)(buf + 20 + bitstream_size);
345
    f->bytestream= buf + 20 + bitstream_size + wordstream_size;
346

    
347
    init_mv(f);
348

    
349
    for(y=0; y<height; y+=8){
350
        for(x=0; x<width; x+=8){
351
            decode_p_block(f, dst + x, src + x, 3, 3, stride);
352
        }
353
        src += 8*stride;
354
        dst += 8*stride;
355
    }
356

    
357
    if(bitstream_size != (get_bits_count(&f->gb)+31)/32*4)
358
        av_log(f->avctx, AV_LOG_ERROR, " %d %td %td bytes left\n",
359
            bitstream_size - (get_bits_count(&f->gb)+31)/32*4,
360
            bytestream_size - (f->bytestream - (buf + 20 + bitstream_size + wordstream_size)),
361
            wordstream_size - (((uint8_t*)f->wordstream) - (buf + 20 + bitstream_size))
362
        );
363

    
364
    return 0;
365
}
366

    
367
/**
368
 * decode block and dequantize.
369
 * Note this is allmost identical to mjpeg
370
 */
371
static int decode_i_block(FourXContext *f, DCTELEM *block){
372
    int code, i, j, level, val;
373

    
374
    /* DC coef */
375
    val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
376
    if (val>>4){
377
        av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");
378
    }
379

    
380
    if(val)
381
        val = get_xbits(&f->gb, val);
382

    
383
    val = val * dequant_table[0] + f->last_dc;
384
    f->last_dc =
385
    block[0] = val;
386
    /* AC coefs */
387
    i = 1;
388
    for(;;) {
389
        code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
390

    
391
        /* EOB */
392
        if (code == 0)
393
            break;
394
        if (code == 0xf0) {
395
            i += 16;
396
        } else {
397
            level = get_xbits(&f->gb, code & 0xf);
398
            i += code >> 4;
399
            if (i >= 64) {
400
                av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);
401
                return 0;
402
            }
403

    
404
            j= ff_zigzag_direct[i];
405
            block[j] = level * dequant_table[j];
406
            i++;
407
            if (i >= 64)
408
                break;
409
        }
410
    }
411

    
412
    return 0;
413
}
414

    
415
static inline void idct_put(FourXContext *f, int x, int y){
416
    DCTELEM (*block)[64]= f->block;
417
    int stride= f->current_picture.linesize[0]>>1;
418
    int i;
419
    uint16_t *dst = ((uint16_t*)f->current_picture.data[0]) + y * stride + x;
420

    
421
    for(i=0; i<4; i++){
422
        block[i][0] += 0x80*8*8;
423
        idct(block[i]);
424
    }
425

    
426
    if(!(f->avctx->flags&CODEC_FLAG_GRAY)){
427
        for(i=4; i<6; i++) idct(block[i]);
428
    }
429

    
430
/* Note transform is:
431
y= ( 1b + 4g + 2r)/14
432
cb=( 3b - 2g - 1r)/14
433
cr=(-1b - 4g + 5r)/14
434
*/
435
    for(y=0; y<8; y++){
436
        for(x=0; x<8; x++){
437
            DCTELEM *temp= block[(x>>2) + 2*(y>>2)] + 2*(x&3) + 2*8*(y&3); //FIXME optimize
438
            int cb= block[4][x + 8*y];
439
            int cr= block[5][x + 8*y];
440
            int cg= (cb + cr)>>1;
441
            int y;
442

    
443
            cb+=cb;
444

    
445
            y = temp[0];
446
            dst[0       ]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
447
            y = temp[1];
448
            dst[1       ]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
449
            y = temp[8];
450
            dst[  stride]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
451
            y = temp[9];
452
            dst[1+stride]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
453
            dst += 2;
454
        }
455
        dst += 2*stride - 2*8;
456
    }
457
}
458

    
459
static int decode_i_mb(FourXContext *f){
460
    int i;
461

    
462
    f->dsp.clear_blocks(f->block[0]);
463

    
464
    for(i=0; i<6; i++){
465
        if(decode_i_block(f, f->block[i]) < 0)
466
            return -1;
467
    }
468

    
469
    return 0;
470
}
471

    
472
static uint8_t *read_huffman_tables(FourXContext *f, uint8_t * const buf){
473
    int frequency[512];
474
    uint8_t flag[512];
475
    int up[512];
476
    uint8_t len_tab[257];
477
    int bits_tab[257];
478
    int start, end;
479
    uint8_t *ptr= buf;
480
    int j;
481

    
482
    memset(frequency, 0, sizeof(frequency));
483
    memset(up, -1, sizeof(up));
484

    
485
    start= *ptr++;
486
    end= *ptr++;
487
    for(;;){
488
        int i;
489

    
490
        for(i=start; i<=end; i++){
491
            frequency[i]= *ptr++;
492
//            printf("%d %d %d\n", start, end, frequency[i]);
493
        }
494
        start= *ptr++;
495
        if(start==0) break;
496

    
497
        end= *ptr++;
498
    }
499
    frequency[256]=1;
500

    
501
    while((ptr - buf)&3) ptr++; // 4byte align
502

    
503
//    for(j=0; j<16; j++)
504
//        printf("%2X", ptr[j]);
505

    
506
    for(j=257; j<512; j++){
507
        int min_freq[2]= {256*256, 256*256};
508
        int smallest[2]= {0, 0};
509
        int i;
510
        for(i=0; i<j; i++){
511
            if(frequency[i] == 0) continue;
512
            if(frequency[i] < min_freq[1]){
513
                if(frequency[i] < min_freq[0]){
514
                    min_freq[1]= min_freq[0]; smallest[1]= smallest[0];
515
                    min_freq[0]= frequency[i];smallest[0]= i;
516
                }else{
517
                    min_freq[1]= frequency[i];smallest[1]= i;
518
                }
519
            }
520
        }
521
        if(min_freq[1] == 256*256) break;
522

    
523
        frequency[j]= min_freq[0] + min_freq[1];
524
        flag[ smallest[0] ]= 0;
525
        flag[ smallest[1] ]= 1;
526
        up[ smallest[0] ]=
527
        up[ smallest[1] ]= j;
528
        frequency[ smallest[0] ]= frequency[ smallest[1] ]= 0;
529
    }
530

    
531
    for(j=0; j<257; j++){
532
        int node;
533
        int len=0;
534
        int bits=0;
535

    
536
        for(node= j; up[node] != -1; node= up[node]){
537
            bits += flag[node]<<len;
538
            len++;
539
            if(len > 31) av_log(f->avctx, AV_LOG_ERROR, "vlc length overflow\n"); //can this happen at all ?
540
        }
541

    
542
        bits_tab[j]= bits;
543
        len_tab[j]= len;
544
    }
545

    
546
    init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257,
547
             len_tab , 1, 1,
548
             bits_tab, 4, 4, 0);
549

    
550
    return ptr;
551
}
552

    
553
static int decode_i_frame(FourXContext *f, uint8_t *buf, int length){
554
    int x, y;
555
    const int width= f->avctx->width;
556
    const int height= f->avctx->height;
557
    uint16_t *dst= (uint16_t*)f->current_picture.data[0];
558
    const int stride= f->current_picture.linesize[0]>>1;
559
    const unsigned int bitstream_size= get32(buf);
560
    const int token_count __attribute__((unused)) = get32(buf + bitstream_size + 8);
561
    unsigned int prestream_size= 4*get32(buf + bitstream_size + 4);
562
    uint8_t *prestream= buf + bitstream_size + 12;
563

    
564
    if(prestream_size + bitstream_size + 12 != length
565
       || bitstream_size > (1<<26)
566
       || prestream_size > (1<<26)){
567
        av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n", prestream_size, bitstream_size, length);
568
        return -1;
569
    }
570

    
571
    prestream= read_huffman_tables(f, prestream);
572

    
573
    init_get_bits(&f->gb, buf + 4, 8*bitstream_size);
574

    
575
    prestream_size= length + buf - prestream;
576

    
577
    f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
578
    f->dsp.bswap_buf((uint32_t*)f->bitstream_buffer, (uint32_t*)prestream, prestream_size/4);
579
    init_get_bits(&f->pre_gb, f->bitstream_buffer, 8*prestream_size);
580

    
581
    f->last_dc= 0*128*8*8;
582

    
583
    for(y=0; y<height; y+=16){
584
        for(x=0; x<width; x+=16){
585
            if(decode_i_mb(f) < 0)
586
                return -1;
587

    
588
            idct_put(f, x, y);
589
        }
590
        dst += 16*stride;
591
    }
592

    
593
    if(get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
594
        av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");
595

    
596
    return 0;
597
}
598

    
599
static int decode_frame(AVCodecContext *avctx,
600
                        void *data, int *data_size,
601
                        uint8_t *buf, int buf_size)
602
{
603
    FourXContext * const f = avctx->priv_data;
604
    AVFrame *picture = data;
605
    AVFrame *p, temp;
606
    int i, frame_4cc, frame_size;
607

    
608
    frame_4cc= get32(buf);
609
    if(buf_size != get32(buf+4)+8){
610
        av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n", buf_size, get32(buf+4));
611
    }
612

    
613
    if(frame_4cc == ff_get_fourcc("cfrm")){
614
        int free_index=-1;
615
        const int data_size= buf_size - 20;
616
        const int id= get32(buf+12);
617
        const int whole_size= get32(buf+16);
618
        CFrameBuffer *cfrm;
619

    
620
        for(i=0; i<CFRAME_BUFFER_COUNT; i++){
621
            if(f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
622
                av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n", f->cfrm[i].id);
623
        }
624

    
625
        for(i=0; i<CFRAME_BUFFER_COUNT; i++){
626
            if(f->cfrm[i].id   == id) break;
627
            if(f->cfrm[i].size == 0 ) free_index= i;
628
        }
629

    
630
        if(i>=CFRAME_BUFFER_COUNT){
631
            i= free_index;
632
            f->cfrm[i].id= id;
633
        }
634
        cfrm= &f->cfrm[i];
635

    
636
        cfrm->data= av_fast_realloc(cfrm->data, &cfrm->allocated_size, cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
637

    
638
        memcpy(cfrm->data + cfrm->size, buf+20, data_size);
639
        cfrm->size += data_size;
640

    
641
        if(cfrm->size >= whole_size){
642
            buf= cfrm->data;
643
            frame_size= cfrm->size;
644

    
645
            if(id != avctx->frame_number){
646
                av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n", id, avctx->frame_number);
647
            }
648

    
649
            cfrm->size= cfrm->id= 0;
650
            frame_4cc= ff_get_fourcc("pfrm");
651
        }else
652
            return buf_size;
653
    }else{
654
        buf= buf + 12;
655
        frame_size= buf_size - 12;
656
    }
657

    
658
    temp= f->current_picture;
659
    f->current_picture= f->last_picture;
660
    f->last_picture= temp;
661

    
662
    p= &f->current_picture;
663
    avctx->coded_frame= p;
664

    
665
    avctx->flags |= CODEC_FLAG_EMU_EDGE; // alternatively we would have to use our own buffer management
666

    
667
    if(p->data[0])
668
        avctx->release_buffer(avctx, p);
669

    
670
    p->reference= 1;
671
    if(avctx->get_buffer(avctx, p) < 0){
672
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
673
        return -1;
674
    }
675

    
676
    if(frame_4cc == ff_get_fourcc("ifrm")){
677
        p->pict_type= I_TYPE;
678
        if(decode_i_frame(f, buf, frame_size) < 0)
679
            return -1;
680
    }else if(frame_4cc == ff_get_fourcc("pfrm")){
681
        p->pict_type= P_TYPE;
682
        if(decode_p_frame(f, buf, frame_size) < 0)
683
            return -1;
684
    }else if(frame_4cc == ff_get_fourcc("snd_")){
685
        av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n", buf_size);
686
    }else{
687
        av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n", buf_size);
688
    }
689

    
690
#if 0
691
for(i=0; i<20; i++){
692
    printf("%2X %c ", buf[i], clip(buf[i],16,126));
693
}
694
#endif
695

    
696
    p->key_frame= p->pict_type == I_TYPE;
697

    
698
    *picture= *p;
699
    *data_size = sizeof(AVPicture);
700

    
701
    emms_c();
702

    
703
    return buf_size;
704
}
705

    
706

    
707
static void common_init(AVCodecContext *avctx){
708
    FourXContext * const f = avctx->priv_data;
709

    
710
    dsputil_init(&f->dsp, avctx);
711

    
712
    f->avctx= avctx;
713
}
714

    
715
static int decode_init(AVCodecContext *avctx){
716
    FourXContext * const f = avctx->priv_data;
717

    
718
    common_init(avctx);
719
    init_vlcs(f);
720

    
721
    avctx->pix_fmt= PIX_FMT_RGB565;
722

    
723
    return 0;
724
}
725

    
726

    
727
static int decode_end(AVCodecContext *avctx){
728
    FourXContext * const f = avctx->priv_data;
729
    int i;
730

    
731
    av_freep(&f->bitstream_buffer);
732
    f->bitstream_buffer_size=0;
733
    for(i=0; i<CFRAME_BUFFER_COUNT; i++){
734
        av_freep(&f->cfrm[i].data);
735
        f->cfrm[i].allocated_size= 0;
736
    }
737
    free_vlc(&f->pre_vlc);
738

    
739
    return 0;
740
}
741

    
742
AVCodec fourxm_decoder = {
743
    "4xm",
744
    CODEC_TYPE_VIDEO,
745
    CODEC_ID_4XM,
746
    sizeof(FourXContext),
747
    decode_init,
748
    NULL,
749
    decode_end,
750
    decode_frame,
751
    /*CODEC_CAP_DR1,*/
752
};
753