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1 8809cfee Michael Niedermayer
/*
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
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
 
20
/**
21
 * @file 4xm.c
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 * 4XM codec.
23
 */
24
 
25
#include "avcodec.h"
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#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]={
38
  {   //{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},
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  { 2, 0, 0, 0},
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  { 2, 0, 0, 0},
54
};
55
56
static const int8_t mv[256][2]={
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{  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},
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{  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},
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{ -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},
80
{  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},
82
{  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},
84
{ 13,-20},{ 24, -2},{-15, 19},{-11, 22},{ 16, 19},{ 23,-10},{-18,-18},{ -9,-24},
85
{ 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},
88
{-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,
95
 18, 24, 27, 37, 52, 59, 49, 20,
96
 16, 28, 34, 40, 60, 80, 51, 20,
97
 18, 31, 48, 66, 68, 86, 56, 21,
98
 19, 38, 56, 59, 64, 64, 48, 20,
99
 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
    DCTELEM __align8 block[6][64];
125
    uint8_t *bitstream_buffer;
126
    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
    static int done = 0;
224
    int i;
225
226
    if (!done) {
227
        done = 1;
228
229
        for(i=0; i<4; i++){
230
            init_vlc(&block_type_vlc[i], BLOCK_TYPE_VLC_BITS, 7, 
231
                     &block_type_tab[i][0][1], 2, 1,
232
                     &block_type_tab[i][0][0], 2, 1);
233
        }
234
    }
235
}
236
237
static void init_mv(FourXContext *f){
238
    int i;
239
240
    for(i=0; i<256; i++){
241
        f->mv[i] = mv[i][0] + mv[i][1]*f->current_picture.linesize[0]/2;
242
    }
243
}
244
245
static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w, int h, int stride, int scale, int dc){
246
   int i;
247
   dc*= 0x10001;
248
249
   switch(log2w){
250
   case 0:
251
        for(i=0; i<h; i++){
252
            dst[0] = scale*src[0] + dc;
253
            if(scale) src += stride;
254
            dst += stride;
255
        }
256
        break;
257
    case 1:
258
        for(i=0; i<h; i++){
259
            ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
260
            if(scale) src += stride;
261
            dst += stride;
262
        }
263
        break;
264
    case 2:
265
        for(i=0; i<h; i++){
266
            ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
267
            ((uint32_t*)dst)[1] = scale*((uint32_t*)src)[1] + dc;
268
            if(scale) src += stride;
269
            dst += stride;
270
        }
271
        break;
272
    case 3:
273
        for(i=0; i<h; i++){
274
            ((uint32_t*)dst)[0] = scale*((uint32_t*)src)[0] + dc;
275
            ((uint32_t*)dst)[1] = scale*((uint32_t*)src)[1] + dc;
276
            ((uint32_t*)dst)[2] = scale*((uint32_t*)src)[2] + dc;
277
            ((uint32_t*)dst)[3] = scale*((uint32_t*)src)[3] + dc;
278
            if(scale) src += stride;
279
            dst += stride;
280
        }
281
        break;
282
    default: assert(0);
283
    }
284
}
285
286
static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src, int log2w, int log2h, int stride){
287
    const int index= size2index[log2h][log2w];
288
    const int h= 1<<log2h;
289
    int code= get_vlc2(&f->gb, block_type_vlc[index].table, BLOCK_TYPE_VLC_BITS, 1);
290
    
291
    assert(code>=0 && code<=6);
292
293
    if(code == 0){
294
        src += f->mv[ *f->bytestream++ ];
295
        mcdc(dst, src, log2w, h, stride, 1, 0);
296
    }else if(code == 1){
297
        log2h--;
298
        decode_p_block(f, dst                  , src                  , log2w, log2h, stride);
299
        decode_p_block(f, dst + (stride<<log2h), src + (stride<<log2h), log2w, log2h, stride);
300
    }else if(code == 2){
301
        log2w--;
302
        decode_p_block(f, dst             , src             , log2w, log2h, stride);
303
        decode_p_block(f, dst + (1<<log2w), src + (1<<log2w), log2w, log2h, stride);
304
    }else if(code == 4){
305
        src += f->mv[ *f->bytestream++ ];
306
        mcdc(dst, src, log2w, h, stride, 1, le2me_16(*f->wordstream++));
307
    }else if(code == 5){
308
        mcdc(dst, src, log2w, h, stride, 0, le2me_16(*f->wordstream++));
309
    }else if(code == 6){
310
        if(log2w){
311
            dst[0] = le2me_16(*f->wordstream++);
312
            dst[1] = le2me_16(*f->wordstream++);
313
        }else{
314
            dst[0     ] = le2me_16(*f->wordstream++);
315
            dst[stride] = le2me_16(*f->wordstream++);
316
        }
317
    }
318
}
319
320
static int get32(void *p){
321
    return le2me_32(*(uint32_t*)p);
322
}
323
324
static int decode_p_frame(FourXContext *f, uint8_t *buf, int length){
325
    int x, y;
326
    const int width= f->avctx->width;
327
    const int height= f->avctx->height;
328
    uint16_t *src= (uint16_t*)f->last_picture.data[0];
329
    uint16_t *dst= (uint16_t*)f->current_picture.data[0];
330
    const int stride= f->current_picture.linesize[0]>>1;
331
    const int bitstream_size= get32(buf+8);
332
    const int bytestream_size= get32(buf+16);
333
    const int wordstream_size= get32(buf+12);
334
    
335
    if(bitstream_size+ bytestream_size+ wordstream_size + 20 != length)
336 9b879566 Michel Bardiaux
        av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size, 
337 8809cfee Michael Niedermayer
        bitstream_size+ bytestream_size+ wordstream_size - length);
338
    
339
    f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
340
    f->dsp.bswap_buf((uint32_t*)f->bitstream_buffer, (uint32_t*)(buf + 20), bitstream_size/4);
341
    init_get_bits(&f->gb, f->bitstream_buffer, 8*bitstream_size);
342
343
    f->wordstream= (uint16_t*)(buf + 20 + bitstream_size);
344
    f->bytestream= buf + 20 + bitstream_size + wordstream_size;
345
    
346
    init_mv(f);
347
    
348
    for(y=0; y<height; y+=8){
349
        for(x=0; x<width; x+=8){
350
            decode_p_block(f, dst + x, src + x, 3, 3, stride);
351
        }
352
        src += 8*stride; 
353
        dst += 8*stride; 
354
    }
355
    
356
    if(bitstream_size != (get_bits_count(&f->gb)+31)/32*4)
357 6ce1a818 Alex Beregszaszi
        av_log(f->avctx, AV_LOG_ERROR, " %d %d %d bytes left\n", 
358 8809cfee Michael Niedermayer
            bitstream_size - (get_bits_count(&f->gb)+31)/32*4, 
359
            bytestream_size - (f->bytestream - (buf + 20 + bitstream_size + wordstream_size)),
360
            wordstream_size - (((uint8_t*)f->wordstream) - (buf + 20 + bitstream_size))
361
        );
362
    
363
    return 0;
364
}
365
366
/**
367
 * decode block and dequantize.
368
 * Note this is allmost identical to mjpeg
369
 */
370
static int decode_i_block(FourXContext *f, DCTELEM *block){
371
    int code, i, j, level, val;
372
373
    /* DC coef */
374
    val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
375
    if (val>>4){
376 9b879566 Michel Bardiaux
        av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");
377 8809cfee Michael Niedermayer
    }
378
379
    if(val)
380
        val = get_xbits(&f->gb, val);
381
382
    val = val * dequant_table[0] + f->last_dc;
383
    f->last_dc =
384
    block[0] = val;
385
    /* AC coefs */
386
    i = 1;
387
    for(;;) {
388
        code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
389
        
390
        /* EOB */
391
        if (code == 0)
392
            break;
393
        if (code == 0xf0) {
394
            i += 16;
395
        } else {
396
            level = get_xbits(&f->gb, code & 0xf);
397
            i += code >> 4;
398
            if (i >= 64) {
399 9b879566 Michel Bardiaux
                av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);
400 8809cfee Michael Niedermayer
                return 0;
401
            }
402
403
            j= ff_zigzag_direct[i];
404
            block[j] = level * dequant_table[j];
405
            i++;
406
            if (i >= 64)
407
                break;
408
        }
409
    }
410
411
    return 0;
412
}
413
414
static inline void idct_put(FourXContext *f, int x, int y){
415
    DCTELEM (*block)[64]= f->block;
416
    int stride= f->current_picture.linesize[0]>>1;
417
    int i;
418
    uint16_t *dst = ((uint16_t*)f->current_picture.data[0]) + y * stride + x;
419 b60ad448 Michael Niedermayer
    
420
    for(i=0; i<4; i++){
421
        block[i][0] += 0x80*8*8;
422
        idct(block[i]);
423
    }
424 8809cfee Michael Niedermayer
425 b60ad448 Michael Niedermayer
    if(!(f->avctx->flags&CODEC_FLAG_GRAY)){
426
        for(i=4; i<6; i++) idct(block[i]);
427
    }
428 8809cfee Michael Niedermayer
429 c9319f2e Michael Niedermayer
/* Note transform is:
430
y= ( 1b + 4g + 2r)/14
431
cb=( 3b - 2g - 1r)/14
432
cr=(-1b - 4g + 5r)/14
433
*/ 
434 8809cfee Michael Niedermayer
    for(y=0; y<8; y++){
435
        for(x=0; x<8; x++){
436
            DCTELEM *temp= block[(x>>2) + 2*(y>>2)] + 2*(x&3) + 2*8*(y&3); //FIXME optimize
437 b60ad448 Michael Niedermayer
            int cb= block[4][x + 8*y];
438
            int cr= block[5][x + 8*y];
439 8809cfee Michael Niedermayer
            int cg= (cb + cr)>>1;
440
            int y;
441
            
442 b60ad448 Michael Niedermayer
            cb+=cb;
443 8809cfee Michael Niedermayer
            
444
            y = temp[0];
445 b60ad448 Michael Niedermayer
            dst[0       ]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
446 8809cfee Michael Niedermayer
            y = temp[1];
447 b60ad448 Michael Niedermayer
            dst[1       ]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
448 8809cfee Michael Niedermayer
            y = temp[8];
449 b60ad448 Michael Niedermayer
            dst[  stride]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
450 8809cfee Michael Niedermayer
            y = temp[9];
451 b60ad448 Michael Niedermayer
            dst[1+stride]= ((y+cb)>>3) + (((y-cg)&0xFC)<<3) + (((y+cr)&0xF8)<<8);
452 8809cfee Michael Niedermayer
            dst += 2;
453
        }
454
        dst += 2*stride - 2*8;
455
    }
456
}
457
458
static int decode_i_mb(FourXContext *f){
459
    int i;
460
    
461
    f->dsp.clear_blocks(f->block[0]);
462
    
463
    for(i=0; i<6; i++){
464
        if(decode_i_block(f, f->block[i]) < 0)
465
            return -1;
466
    }
467
    
468
    return 0;
469
}
470
471
static uint8_t *read_huffman_tables(FourXContext *f, uint8_t * const buf){
472
    int frequency[512];
473
    uint8_t flag[512];
474
    int up[512];
475
    uint8_t len_tab[257];
476
    int bits_tab[257];
477
    int start, end;
478
    uint8_t *ptr= buf;
479
    int j;
480
    
481
    memset(frequency, 0, sizeof(frequency));
482
    memset(up, -1, sizeof(up));
483
484
    start= *ptr++;
485
    end= *ptr++;
486
    for(;;){
487
        int i;
488
        
489
        for(i=start; i<=end; i++){
490
            frequency[i]= *ptr++;
491
//            printf("%d %d %d\n", start, end, frequency[i]);
492
        }
493
        start= *ptr++;
494
        if(start==0) break;
495
        
496
        end= *ptr++;
497
    }
498
    frequency[256]=1;
499
500
    while((ptr - buf)&3) ptr++; // 4byte align 
501
502
//    for(j=0; j<16; j++)
503
//        printf("%2X", ptr[j]);
504
    
505
    for(j=257; j<512; j++){
506 5be8a373 Michael Niedermayer
        int min_freq[2]= {256*256, 256*256};
507
        int smallest[2]= {0, 0};
508 8809cfee Michael Niedermayer
        int i;
509
        for(i=0; i<j; i++){
510
            if(frequency[i] == 0) continue;
511 5be8a373 Michael Niedermayer
            if(frequency[i] < min_freq[1]){
512
                if(frequency[i] < min_freq[0]){
513
                    min_freq[1]= min_freq[0]; smallest[1]= smallest[0];
514
                    min_freq[0]= frequency[i];smallest[0]= i;
515
                }else{
516
                    min_freq[1]= frequency[i];smallest[1]= i;
517
                }
518 8809cfee Michael Niedermayer
            }
519
        }
520 5be8a373 Michael Niedermayer
        if(min_freq[1] == 256*256) break;
521 8809cfee Michael Niedermayer
        
522 5be8a373 Michael Niedermayer
        frequency[j]= min_freq[0] + min_freq[1];
523 8809cfee Michael Niedermayer
        flag[ smallest[0] ]= 0;
524
        flag[ smallest[1] ]= 1;
525
        up[ smallest[0] ]= 
526
        up[ smallest[1] ]= j;
527
        frequency[ smallest[0] ]= frequency[ smallest[1] ]= 0;
528
    }
529
530
    for(j=0; j<257; j++){
531
        int node;
532
        int len=0;
533
        int bits=0;
534
535
        for(node= j; up[node] != -1; node= up[node]){
536
            bits += flag[node]<<len;
537
            len++;
538 9b879566 Michel Bardiaux
            if(len > 31) av_log(f->avctx, AV_LOG_ERROR, "vlc length overflow\n"); //can this happen at all ?
539 8809cfee Michael Niedermayer
        }
540
        
541
        bits_tab[j]= bits;
542
        len_tab[j]= len;
543
    }
544
    
545
    init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, 
546
             len_tab , 1, 1,
547
             bits_tab, 4, 4);
548
             
549
    return ptr;
550
}
551
552
static int decode_i_frame(FourXContext *f, uint8_t *buf, int length){
553
    int x, y;
554
    const int width= f->avctx->width;
555
    const int height= f->avctx->height;
556
    uint16_t *dst= (uint16_t*)f->current_picture.data[0];
557
    const int stride= f->current_picture.linesize[0]>>1;
558
    const int bitstream_size= get32(buf);
559 e4e70d2e Falk H├╝ffner
    const int token_count __attribute__((unused)) = get32(buf + bitstream_size + 8);
560 8809cfee Michael Niedermayer
    int prestream_size= 4*get32(buf + bitstream_size + 4);
561
    uint8_t *prestream= buf + bitstream_size + 12;
562
    
563
    if(prestream_size + bitstream_size + 12 != length)
564 9b879566 Michel Bardiaux
        av_log(f->avctx, AV_LOG_ERROR, "size missmatch %d %d %d\n", prestream_size, bitstream_size, length);
565 8809cfee Michael Niedermayer
   
566
    prestream= read_huffman_tables(f, prestream);
567
568
    init_get_bits(&f->gb, buf + 4, 8*bitstream_size);
569
570
    prestream_size= length + buf - prestream;
571 5be8a373 Michael Niedermayer
572 8809cfee Michael Niedermayer
    f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
573
    f->dsp.bswap_buf((uint32_t*)f->bitstream_buffer, (uint32_t*)prestream, prestream_size/4);
574
    init_get_bits(&f->pre_gb, f->bitstream_buffer, 8*prestream_size);
575
576
    f->last_dc= 0*128*8*8;
577
    
578
    for(y=0; y<height; y+=16){
579
        for(x=0; x<width; x+=16){
580
            if(decode_i_mb(f) < 0)
581
                return -1;
582
583
            idct_put(f, x, y);
584
        }
585
        dst += 16*stride; 
586
    }
587
588
    if(get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
589 9b879566 Michel Bardiaux
        av_log(f->avctx, AV_LOG_ERROR, "end missmatch\n");
590 8809cfee Michael Niedermayer
    
591
    return 0;
592
}
593
594
static int decode_frame(AVCodecContext *avctx, 
595
                        void *data, int *data_size,
596
                        uint8_t *buf, int buf_size)
597
{
598
    FourXContext * const f = avctx->priv_data;
599
    AVFrame *picture = data;
600
    AVFrame *p, temp;
601
    int i, frame_4cc, frame_size;
602
603
    /* special case for last picture */
604
    if (buf_size == 0) {
605
        return 0;
606
    }
607
608
    frame_4cc= get32(buf);
609
    if(buf_size != get32(buf+4)+8){
610 9b879566 Michel Bardiaux
        av_log(f->avctx, AV_LOG_ERROR, "size missmatch %d %d\n", buf_size, get32(buf+4));
611 8809cfee Michael Niedermayer
    }
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 9b879566 Michel Bardiaux
                av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n", f->cfrm[i].id);
623 8809cfee Michael Niedermayer
        }
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 9b879566 Michel Bardiaux
                av_log(f->avctx, AV_LOG_ERROR, "cframe id missmatch %d %d\n", id, avctx->frame_number);
647 8809cfee Michael Niedermayer
            }
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 9b879566 Michel Bardiaux
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
673 8809cfee Michael Niedermayer
        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 9b879566 Michel Bardiaux
        av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n", buf_size);
686 8809cfee Michael Niedermayer
    }else{
687 9b879566 Michel Bardiaux
        av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n", buf_size);
688 8809cfee Michael Niedermayer
    }
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
};