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1
/*
2
 * Wing Commander/Xan Video Decoder
3
 * Copyright (C) 2003 the ffmpeg project
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
16
 * 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
/**
22
 * @file xan.c
23
 * Xan video decoder for Wing Commander III & IV computer games
24
 * by Mario Brito (mbrito@student.dei.uc.pt)
25
 * and Mike Melanson (melanson@pcisys.net)
26
 *
27
 * The xan_wc3 decoder outputs the following colorspaces natively:
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 *   PAL8 (default), RGB555, RGB565, RGB24, BGR24, RGBA32, YUV444P
29
 */
30

    
31
#include <stdio.h>
32
#include <stdlib.h>
33
#include <string.h>
34
#include <unistd.h>
35

    
36
#include "common.h"
37
#include "avcodec.h"
38
#include "dsputil.h"
39

    
40
#define PALETTE_COUNT 256
41
#define PALETTE_CONTROL_SIZE ((256 * 3) + 1)
42

    
43
typedef struct XanContext {
44

    
45
    AVCodecContext *avctx;
46
    DSPContext dsp;
47
    AVFrame last_frame;
48
    AVFrame current_frame;
49

    
50
    unsigned char *buf;
51
    int size;
52

    
53
    unsigned char palette[PALETTE_COUNT * 4];
54

    
55
    /* scratch space */
56
    unsigned char *buffer1;
57
    unsigned char *buffer2;
58

    
59
} XanContext;
60

    
61
#define BE_16(x)  ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
62
#define LE_16(x)  ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
63
#define LE_32(x)  ((((uint8_t*)(x))[3] << 24) | \
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                   (((uint8_t*)(x))[2] << 16) | \
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                   (((uint8_t*)(x))[1] << 8) | \
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                    ((uint8_t*)(x))[0])
67

    
68
/* RGB -> YUV conversion stuff */
69
#define SCALEFACTOR 65536
70
#define CENTERSAMPLE 128
71

    
72
#define COMPUTE_Y(r, g, b) \
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  (unsigned char) \
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  ((y_r_table[r] + y_g_table[g] + y_b_table[b]) / SCALEFACTOR)
75
#define COMPUTE_U(r, g, b) \
76
  (unsigned char) \
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  ((u_r_table[r] + u_g_table[g] + u_b_table[b]) / SCALEFACTOR + CENTERSAMPLE)
78
#define COMPUTE_V(r, g, b) \
79
  (unsigned char) \
80
  ((v_r_table[r] + v_g_table[g] + v_b_table[b]) / SCALEFACTOR + CENTERSAMPLE)
81

    
82
#define Y_R (SCALEFACTOR *  0.29900)
83
#define Y_G (SCALEFACTOR *  0.58700)
84
#define Y_B (SCALEFACTOR *  0.11400)
85

    
86
#define U_R (SCALEFACTOR * -0.16874)
87
#define U_G (SCALEFACTOR * -0.33126)
88
#define U_B (SCALEFACTOR *  0.50000)
89

    
90
#define V_R (SCALEFACTOR *  0.50000)
91
#define V_G (SCALEFACTOR * -0.41869)
92
#define V_B (SCALEFACTOR * -0.08131)
93

    
94
/*
95
 * Precalculate all of the YUV tables since it requires fewer than
96
 * 10 kilobytes to store them.
97
 */
98
static int y_r_table[256];
99
static int y_g_table[256];
100
static int y_b_table[256];
101

    
102
static int u_r_table[256];
103
static int u_g_table[256];
104
static int u_b_table[256];
105

    
106
static int v_r_table[256];
107
static int v_g_table[256];
108
static int v_b_table[256];
109

    
110
static int xan_decode_init(AVCodecContext *avctx)
111
{
112
    XanContext *s = avctx->priv_data;
113
    int i;
114

    
115
    s->avctx = avctx;
116

    
117
    if ((avctx->codec->id == CODEC_ID_XAN_WC3) && 
118
        (s->avctx->extradata_size != sizeof(AVPaletteControl))) {
119
        printf (" WC3 Xan video: expected extradata_size of %d\n",
120
            sizeof(AVPaletteControl));
121
        return -1;
122
    }
123

    
124
    avctx->pix_fmt = PIX_FMT_PAL8;
125
    avctx->has_b_frames = 0;
126
    dsputil_init(&s->dsp, avctx);
127

    
128
    /* initialize the RGB -> YUV tables */
129
    for (i = 0; i < 256; i++) {
130
        y_r_table[i] = Y_R * i;
131
        y_g_table[i] = Y_G * i;
132
        y_b_table[i] = Y_B * i;
133

    
134
        u_r_table[i] = U_R * i;
135
        u_g_table[i] = U_G * i;
136
        u_b_table[i] = U_B * i;
137

    
138
        v_r_table[i] = V_R * i;
139
        v_g_table[i] = V_G * i;
140
        v_b_table[i] = V_B * i;
141
    }
142

    
143
    s->buffer1 = av_malloc(avctx->width * avctx->height);
144
    s->buffer2 = av_malloc(avctx->width * avctx->height);
145
    if (!s->buffer1 || !s->buffer2)
146
        return -1;
147

    
148
    return 0;
149
}
150

    
151
/* This function is used in lieu of memcpy(). This decoder can not use 
152
 * memcpy because the memory locations often overlap and
153
 * memcpy doesn't like that; it's not uncommon, for example, for
154
 * dest = src+1, to turn byte A into  pattern AAAAAAAA.
155
 * This was originally repz movsb in Intel x86 ASM. */
156
static inline void bytecopy(unsigned char *dest, unsigned char *src, int count)
157
{
158
    int i;
159

    
160
    for (i = 0; i < count; i++)
161
        dest[i] = src[i];
162
}
163

    
164
static int xan_huffman_decode(unsigned char *dest, unsigned char *src)
165
{
166
    unsigned char byte = *src++;
167
    unsigned char ival = byte + 0x16;
168
    unsigned char * ptr = src + byte*2;
169
    unsigned char val = ival;
170
    int counter = 0;
171

    
172
    unsigned char bits = *ptr++;
173

    
174
    while ( val != 0x16 ) {
175
        if ( (1 << counter) & bits )
176
            val = src[byte + val - 0x17];
177
        else
178
            val = src[val - 0x17];
179

    
180
        if ( val < 0x16 ) {
181
            *dest++ = val;
182
            val = ival;
183
        }
184

    
185
        if (counter++ == 7) {
186
            counter = 0;
187
            bits = *ptr++;
188
        }
189
    }
190

    
191
    return 0;
192
}
193

    
194
static void xan_unpack(unsigned char *dest, unsigned char *src)
195
{
196
    unsigned char opcode;
197
    int size;
198
    int offset;
199
    int byte1, byte2, byte3;
200

    
201
    for (;;) {
202
        opcode = *src++;
203

    
204
        if ( (opcode & 0x80) == 0 ) {
205

    
206
            offset = *src++;
207

    
208
            size = opcode & 3;
209
            bytecopy(dest, src, size);  dest += size;  src += size;
210

    
211
            size = ((opcode & 0x1c) >> 2) + 3;
212
            bytecopy (dest, dest - (((opcode & 0x60) << 3) + offset + 1), size);
213
            dest += size;
214

    
215
        } else if ( (opcode & 0x40) == 0 ) {
216

    
217
            byte1 = *src++;
218
            byte2 = *src++;
219

    
220
            size = byte1 >> 6;
221
            bytecopy (dest, src, size);  dest += size;  src += size;
222

    
223
            size = (opcode & 0x3f) + 4;
224
            bytecopy (dest, dest - (((byte1 & 0x3f) << 8) + byte2 + 1), size);
225
            dest += size;
226

    
227
        } else if ( (opcode & 0x20) == 0 ) {
228

    
229
            byte1 = *src++;
230
            byte2 = *src++;
231
            byte3 = *src++;
232

    
233
            size = opcode & 3;
234
            bytecopy (dest, src, size);  dest += size;  src += size;
235

    
236
            size = byte3 + 5 + ((opcode & 0xc) << 6);
237
            bytecopy (dest,
238
                dest - ((((opcode & 0x10) >> 4) << 0x10) + 1 + (byte1 << 8) + byte2),
239
                size);
240
            dest += size;
241
        } else {
242
            size = ((opcode & 0x1f) << 2) + 4;
243

    
244
            if (size > 0x70)
245
                break;
246

    
247
            bytecopy (dest, src, size);  dest += size;  src += size;
248
        }
249
    }
250

    
251
    size = opcode & 3;
252
    bytecopy(dest, src, size);  dest += size;  src += size;
253
}
254

    
255
static void inline xan_wc3_build_palette(XanContext *s, 
256
    unsigned char *palette_data)
257
{
258
    int i;
259
    unsigned char r, g, b;
260
    unsigned short *palette16;
261
    unsigned int *palette32;
262

    
263
    /* transform the palette passed through the palette control structure
264
     * into the necessary internal format depending on colorspace */
265

    
266
    switch (s->avctx->pix_fmt) {
267

    
268
    case PIX_FMT_RGB555:
269
        palette16 = (unsigned short *)s->palette;
270
        for (i = 0; i < PALETTE_COUNT; i++) {
271
            r = *palette_data++;
272
            g = *palette_data++;
273
            b = *palette_data++;
274
            palette16[i] = 
275
                ((r >> 3) << 10) |
276
                ((g >> 3) <<  5) |
277
                ((g >> 3) <<  0);
278
        }
279
        break;
280

    
281
    case PIX_FMT_RGB565:
282
        palette16 = (unsigned short *)s->palette;
283
        for (i = 0; i < PALETTE_COUNT; i++) {
284
            r = *palette_data++;
285
            g = *palette_data++;
286
            b = *palette_data++;
287
            palette16[i] = 
288
                ((r >> 3) << 11) |
289
                ((g >> 2) <<  5) |
290
                ((g >> 3) <<  0);
291
        }
292
        break;
293

    
294
    case PIX_FMT_RGB24:
295
        for (i = 0; i < PALETTE_COUNT; i++) {
296
            s->palette[i * 4 + 0] = *palette_data++;
297
            s->palette[i * 4 + 1] = *palette_data++;
298
            s->palette[i * 4 + 2] = *palette_data++;
299
        }
300
        break;
301

    
302
    case PIX_FMT_BGR24:
303
        for (i = 0; i < PALETTE_COUNT; i++) {
304
            r = *palette_data++;
305
            g = *palette_data++;
306
            b = *palette_data++;
307
            s->palette[i * 4 + 0] = b;
308
            s->palette[i * 4 + 1] = g;
309
            s->palette[i * 4 + 2] = r;
310
        }
311
        break;
312

    
313
    case PIX_FMT_PAL8:
314
    case PIX_FMT_RGBA32:
315
        palette32 = (unsigned int *)s->palette;
316
        for (i = 0; i < PALETTE_COUNT; i++) {
317
            r = *palette_data++;
318
            g = *palette_data++;
319
            b = *palette_data++;
320
            palette32[i] = (r << 16) | (g << 8) | (b);
321
        }
322
        break;
323

    
324
    case PIX_FMT_YUV444P:
325
        for (i = 0; i < PALETTE_COUNT; i++) {
326
            r = *palette_data++;
327
            g = *palette_data++;
328
            b = *palette_data++;
329
            s->palette[i * 4 + 0] = COMPUTE_Y(r, g, b);
330
            s->palette[i * 4 + 1] = COMPUTE_U(r, g, b);
331
            s->palette[i * 4 + 2] = COMPUTE_V(r, g, b);
332
        }
333
        break;
334

    
335
    default:
336
        printf (" Xan WC3: Unhandled colorspace\n");
337
        break;
338
    }
339
}
340

    
341
static void inline xan_wc3_output_pixel_run(XanContext *s, 
342
    unsigned char *pixel_buffer, int x, int y, int pixel_count)
343
{
344
    int stride;
345
    int line_inc;
346
    int index;
347
    int current_x;
348
    int width = s->avctx->width;
349
    unsigned char pixel;
350
    unsigned char *palette_plane;
351
    unsigned char *y_plane;
352
    unsigned char *u_plane;
353
    unsigned char *v_plane;
354
    unsigned char *rgb_plane;
355
    unsigned short *rgb16_plane;
356
    unsigned short *palette16;
357
    unsigned int *rgb32_plane;
358
    unsigned int *palette32;
359

    
360
    switch (s->avctx->pix_fmt) {
361

    
362
    case PIX_FMT_PAL8:
363
        palette_plane = s->current_frame.data[0];
364
        stride = s->current_frame.linesize[0];
365
        line_inc = stride - width;
366
        index = y * stride + x;
367
        current_x = x;
368
        while(pixel_count--) {
369

    
370
            /* don't do a memcpy() here; keyframes generally copy an entire
371
             * frame of data and the stride needs to be accounted for */
372
            palette_plane[index++] = *pixel_buffer++;
373

    
374
            current_x++;
375
            if (current_x >= width) {
376
                /* reset accounting variables */
377
                index += line_inc;
378
                current_x = 0;
379
            }
380
        }
381
        break;
382

    
383
    case PIX_FMT_RGB555:
384
    case PIX_FMT_RGB565:
385
        rgb16_plane = (unsigned short *)s->current_frame.data[0];
386
        palette16 = (unsigned short *)s->palette;
387
        stride = s->current_frame.linesize[0] / 2;
388
        line_inc = stride - width;
389
        index = y * stride + x;
390
        current_x = x;
391
        while(pixel_count--) {
392

    
393
            rgb16_plane[index++] = palette16[*pixel_buffer++];
394

    
395
            current_x++;
396
            if (current_x >= width) {
397
                /* reset accounting variables */
398
                index += line_inc;
399
                current_x = 0;
400
            }
401
        }
402
        break;
403

    
404
    case PIX_FMT_RGB24:
405
    case PIX_FMT_BGR24:
406
        rgb_plane = s->current_frame.data[0];
407
        stride = s->current_frame.linesize[0];
408
        line_inc = stride - width * 3;
409
        index = y * stride + x * 3;
410
        current_x = x;
411
        while(pixel_count--) {
412
            pixel = *pixel_buffer++;
413

    
414
            rgb_plane[index++] = s->palette[pixel * 4 + 0];
415
            rgb_plane[index++] = s->palette[pixel * 4 + 1];
416
            rgb_plane[index++] = s->palette[pixel * 4 + 2];
417

    
418
            current_x++;
419
            if (current_x >= width) {
420
                /* reset accounting variables */
421
                index += line_inc;
422
                current_x = 0;
423
            }
424
        }
425
        break;
426

    
427
    case PIX_FMT_RGBA32:
428
        rgb32_plane = (unsigned int *)s->current_frame.data[0];
429
        palette32 = (unsigned int *)s->palette;
430
        stride = s->current_frame.linesize[0] / 4;
431
        line_inc = stride - width;
432
        index = y * stride + x;
433
        current_x = x;
434
        while(pixel_count--) {
435

    
436
            rgb32_plane[index++] = palette32[*pixel_buffer++];
437

    
438
            current_x++;
439
            if (current_x >= width) {
440
                /* reset accounting variables */
441
                index += line_inc;
442
                current_x = 0;
443
            }
444
        }
445
        break;
446

    
447
    case PIX_FMT_YUV444P:
448
        y_plane = s->current_frame.data[0];
449
        u_plane = s->current_frame.data[1];
450
        v_plane = s->current_frame.data[2];
451
        stride = s->current_frame.linesize[0];
452
        line_inc = stride - width;
453
        index = y * stride + x;
454
        current_x = x;
455
        while(pixel_count--) {
456
            pixel = *pixel_buffer++;
457

    
458
            y_plane[index] = s->palette[pixel * 4 + 0];
459
            u_plane[index] = s->palette[pixel * 4 + 1];
460
            v_plane[index] = s->palette[pixel * 4 + 2];
461

    
462
            index++;
463
            current_x++;
464
            if (current_x >= width) {
465
                /* reset accounting variables */
466
                index += line_inc;
467
                current_x = 0;
468
            }
469
        }
470
        break;
471

    
472
    default:
473
        printf (" Xan WC3: Unhandled colorspace\n");
474
        break;
475
    }
476
}
477

    
478
static void inline xan_wc3_copy_pixel_run(XanContext *s, 
479
    int x, int y, int pixel_count, int motion_x, int motion_y)
480
{
481
    int stride;
482
    int line_inc;
483
    int curframe_index, prevframe_index;
484
    int curframe_x, prevframe_x;
485
    int width = s->avctx->width;
486
    unsigned char *palette_plane, *prev_palette_plane;
487
    unsigned char *y_plane, *u_plane, *v_plane;
488
    unsigned char *prev_y_plane, *prev_u_plane, *prev_v_plane;
489
    unsigned char *rgb_plane, *prev_rgb_plane;
490
    unsigned short *rgb16_plane, *prev_rgb16_plane;
491
    unsigned int *rgb32_plane, *prev_rgb32_plane;
492

    
493
    switch (s->avctx->pix_fmt) {
494

    
495
    case PIX_FMT_PAL8:
496
        palette_plane = s->current_frame.data[0];
497
        prev_palette_plane = s->last_frame.data[0];
498
        stride = s->current_frame.linesize[0];
499
        line_inc = stride - width;
500
        curframe_index = y * stride + x;
501
        curframe_x = x;
502
        prevframe_index = (y + motion_y) * stride + x + motion_x;
503
        prevframe_x = x + motion_x;
504
        while(pixel_count--) {
505

    
506
            palette_plane[curframe_index++] = 
507
                prev_palette_plane[prevframe_index++];
508

    
509
            curframe_x++;
510
            if (curframe_x >= width) {
511
                /* reset accounting variables */
512
                curframe_index += line_inc;
513
                curframe_x = 0;
514
            }
515

    
516
            prevframe_x++;
517
            if (prevframe_x >= width) {
518
                /* reset accounting variables */
519
                prevframe_index += line_inc;
520
                prevframe_x = 0;
521
            }
522
        }
523
        break;
524

    
525
    case PIX_FMT_RGB555:
526
    case PIX_FMT_RGB565:
527
        rgb16_plane = (unsigned short *)s->current_frame.data[0];
528
        prev_rgb16_plane = (unsigned short *)s->last_frame.data[0];
529
        stride = s->current_frame.linesize[0] / 2;
530
        line_inc = stride - width;
531
        curframe_index = y * stride + x;
532
        curframe_x = x;
533
        prevframe_index = (y + motion_y) * stride + x + motion_x;
534
        prevframe_x = x + motion_x;
535
        while(pixel_count--) {
536

    
537
            rgb16_plane[curframe_index++] = 
538
                prev_rgb16_plane[prevframe_index++];
539

    
540
            curframe_x++;
541
            if (curframe_x >= width) {
542
                /* reset accounting variables */
543
                curframe_index += line_inc;
544
                curframe_x = 0;
545
            }
546

    
547
            prevframe_x++;
548
            if (prevframe_x >= width) {
549
                /* reset accounting variables */
550
                prevframe_index += line_inc;
551
                prevframe_x = 0;
552
            }
553
        }
554
        break;
555

    
556
    case PIX_FMT_RGB24:
557
    case PIX_FMT_BGR24:
558
        rgb_plane = s->current_frame.data[0];
559
        prev_rgb_plane = s->last_frame.data[0];
560
        stride = s->current_frame.linesize[0];
561
        line_inc = stride - width * 3;
562
        curframe_index = y * stride + x * 3;
563
        curframe_x = x;
564
        prevframe_index = (y + motion_y) * stride + 
565
            (3 * (x + motion_x));
566
        prevframe_x = x + motion_x;
567
        while(pixel_count--) {
568

    
569
            rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
570
            rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
571
            rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
572

    
573
            curframe_x++;
574
            if (curframe_x >= width) {
575
                /* reset accounting variables */
576
                curframe_index += line_inc;
577
                curframe_x = 0;
578
            }
579

    
580
            prevframe_x++;
581
            if (prevframe_x >= width) {
582
                /* reset accounting variables */
583
                prevframe_index += line_inc;
584
                prevframe_x = 0;
585
            }
586
        }
587
        break;
588

    
589
    case PIX_FMT_RGBA32:
590
        rgb32_plane = (unsigned int *)s->current_frame.data[0];
591
        prev_rgb32_plane = (unsigned int *)s->last_frame.data[0];
592
        stride = s->current_frame.linesize[0] / 4;
593
        line_inc = stride - width;
594
        curframe_index = y * stride + x;
595
        curframe_x = x;
596
        prevframe_index = (y + motion_y) * stride + x + motion_x;
597
        prevframe_x = x + motion_x;
598
        while(pixel_count--) {
599

    
600
            rgb32_plane[curframe_index++] = 
601
                prev_rgb32_plane[prevframe_index++];
602

    
603
            curframe_x++;
604
            if (curframe_x >= width) {
605
                /* reset accounting variables */
606
                curframe_index += line_inc;
607
                curframe_x = 0;
608
            }
609

    
610
            prevframe_x++;
611
            if (prevframe_x >= width) {
612
                /* reset accounting variables */
613
                prevframe_index += line_inc;
614
                prevframe_x = 0;
615
            }
616
        }
617
        break;
618

    
619
    case PIX_FMT_YUV444P:
620
        y_plane = s->current_frame.data[0];
621
        u_plane = s->current_frame.data[1];
622
        v_plane = s->current_frame.data[2];
623
        prev_y_plane = s->last_frame.data[0];
624
        prev_u_plane = s->last_frame.data[1];
625
        prev_v_plane = s->last_frame.data[2];
626
        stride = s->current_frame.linesize[0];
627
        line_inc = stride - width;
628
        curframe_index = y * stride + x;
629
        curframe_x = x;
630
        prevframe_index = (y + motion_y) * stride + x + motion_x;
631
        prevframe_x = x + motion_x;
632
        while(pixel_count--) {
633

    
634
            y_plane[curframe_index] = prev_y_plane[prevframe_index];
635
            u_plane[curframe_index] = prev_u_plane[prevframe_index];
636
            v_plane[curframe_index] = prev_v_plane[prevframe_index];
637

    
638
            curframe_index++;
639
            curframe_x++;
640
            if (curframe_x >= width) {
641
                /* reset accounting variables */
642
                curframe_index += line_inc;
643
                curframe_x = 0;
644
            }
645

    
646
            prevframe_index++;
647
            prevframe_x++;
648
            if (prevframe_x >= width) {
649
                /* reset accounting variables */
650
                prevframe_index += line_inc;
651
                prevframe_x = 0;
652
            }
653
        }
654
        break;
655

    
656
    default:
657
        printf (" Xan WC3: Unhandled colorspace\n");
658
        break;
659
    }
660
}
661

    
662
static void xan_wc3_decode_frame(XanContext *s) {
663

    
664
    int width = s->avctx->width;
665
    int height = s->avctx->height;
666
    int total_pixels = width * height;
667
    unsigned char opcode;
668
    unsigned char flag = 0;
669
    int size = 0;
670
    int motion_x, motion_y;
671
    int x, y;
672

    
673
    unsigned char *opcode_buffer = s->buffer1;
674
    unsigned char *imagedata_buffer = s->buffer2;
675

    
676
    /* pointers to segments inside the compressed chunk */
677
    unsigned char *huffman_segment;
678
    unsigned char *size_segment;
679
    unsigned char *vector_segment;
680
    unsigned char *imagedata_segment;
681

    
682
    huffman_segment =   s->buf + LE_16(&s->buf[0]);
683
    size_segment =      s->buf + LE_16(&s->buf[2]);
684
    vector_segment =    s->buf + LE_16(&s->buf[4]);
685
    imagedata_segment = s->buf + LE_16(&s->buf[6]);
686

    
687
    xan_huffman_decode(opcode_buffer, huffman_segment);
688

    
689
    if (imagedata_segment[0] == 2)
690
        xan_unpack(imagedata_buffer, &imagedata_segment[1]);
691
    else
692
        imagedata_buffer = &imagedata_segment[1];
693

    
694
    /* use the decoded data segments to build the frame */
695
    x = y = 0;
696
    while (total_pixels) {
697

    
698
        opcode = *opcode_buffer++;
699
        size = 0;
700

    
701
        switch (opcode) {
702

    
703
        case 0:
704
            flag ^= 1;
705
            continue;
706

    
707
        case 1:
708
        case 2:
709
        case 3:
710
        case 4:
711
        case 5:
712
        case 6:
713
        case 7:
714
        case 8:
715
            size = opcode;
716
            break;
717

    
718
        case 12:
719
        case 13:
720
        case 14:
721
        case 15:
722
        case 16:
723
        case 17:
724
        case 18:
725
            size += (opcode - 10);
726
            break;
727

    
728
        case 9:
729
        case 19:
730
            size = *size_segment++;
731
            break;
732

    
733
        case 10:
734
        case 20:
735
            size = BE_16(&size_segment[0]);
736
            size_segment += 2;
737
            break;
738

    
739
        case 11:
740
        case 21:
741
            size = (size_segment[0] << 16) | (size_segment[1] << 8) |
742
                size_segment[2];
743
            size_segment += 3;
744
            break;
745
        }
746

    
747
        if (opcode < 12) {
748
            flag ^= 1;
749
            if (flag) {
750
                /* run of (size) pixels is unchanged from last frame */
751
                xan_wc3_copy_pixel_run(s, x, y, size, 0, 0);
752
            } else {
753
                /* output a run of pixels from imagedata_buffer */
754
                xan_wc3_output_pixel_run(s, imagedata_buffer, x, y, size);
755
                imagedata_buffer += size;
756
            }
757
        } else {
758
            /* run-based motion compensation from last frame */
759
            motion_x = (*vector_segment >> 4) & 0xF;
760
            motion_y = *vector_segment & 0xF;
761
            vector_segment++;
762

    
763
            /* sign extension */
764
            if (motion_x & 0x8)
765
                motion_x |= 0xFFFFFFF0;
766
            if (motion_y & 0x8)
767
                motion_y |= 0xFFFFFFF0;
768

    
769
            /* copy a run of pixels from the previous frame */
770
            xan_wc3_copy_pixel_run(s, x, y, size, motion_x, motion_y);
771

    
772
            flag = 0;
773
        }
774

    
775
        /* coordinate accounting */
776
        total_pixels -= size;
777
        while (size) {
778
            if (x + size >= width) {
779
                y++;
780
                size -= (width - x);
781
                x = 0;
782
            } else {
783
                x += size;
784
                size = 0;
785
            }
786
        }
787
    }
788

    
789
    /* for PAL8, make the palette available on the way out */
790
    if (s->avctx->pix_fmt == PIX_FMT_PAL8)
791
        memcpy(s->current_frame.data[1], s->palette, PALETTE_COUNT * 4);
792
}
793

    
794
static void xan_wc4_decode_frame(XanContext *s) {
795
}
796

    
797
static int xan_decode_frame(AVCodecContext *avctx,
798
                            void *data, int *data_size,
799
                            uint8_t *buf, int buf_size)
800
{
801
    XanContext *s = avctx->priv_data;
802
    AVPaletteControl *palette_control = (AVPaletteControl *)avctx->extradata;
803
    int keyframe = 0;
804

    
805
    if (palette_control->palette_changed) {
806
        /* load the new palette and reset the palette control */
807
        xan_wc3_build_palette(s, palette_control->palette);
808
        palette_control->palette_changed = 0;
809
        keyframe = 1;
810
    }
811

    
812
    if (avctx->get_buffer(avctx, &s->current_frame)) {
813
        printf ("  Xan Video: get_buffer() failed\n");
814
        return -1;
815
    }
816
    s->current_frame.reference = 3;
817

    
818
    s->buf = buf;
819
    s->size = buf_size;
820

    
821
    if (avctx->codec->id == CODEC_ID_XAN_WC3)
822
        xan_wc3_decode_frame(s);
823
    else if (avctx->codec->id == CODEC_ID_XAN_WC4)
824
        xan_wc4_decode_frame(s);
825

    
826
    /* release the last frame if it is allocated */
827
    if (s->last_frame.data[0])
828
        avctx->release_buffer(avctx, &s->last_frame);
829

    
830
    /* shuffle frames */
831
    s->last_frame = s->current_frame;
832

    
833
    *data_size = sizeof(AVFrame);
834
    *(AVFrame*)data = s->current_frame;
835

    
836
    /* always report that the buffer was completely consumed */
837
    return buf_size;
838
}
839

    
840
static int xan_decode_end(AVCodecContext *avctx)
841
{
842
    XanContext *s = avctx->priv_data;
843

    
844
    /* release the last frame */
845
    avctx->release_buffer(avctx, &s->last_frame);
846

    
847
    av_free(s->buffer1);
848
    av_free(s->buffer2);
849

    
850
    return 0;
851
}
852

    
853
AVCodec xan_wc3_decoder = {
854
    "xan_wc3",
855
    CODEC_TYPE_VIDEO,
856
    CODEC_ID_XAN_WC3,
857
    sizeof(XanContext),
858
    xan_decode_init,
859
    NULL,
860
    xan_decode_end,
861
    xan_decode_frame,
862
    CODEC_CAP_DR1,
863
};
864

    
865
/*
866
AVCodec xan_wc4_decoder = {
867
    "xan_wc4",
868
    CODEC_TYPE_VIDEO,
869
    CODEC_ID_XAN_WC4,
870
    sizeof(XanContext),
871
    xan_decode_init,
872
    NULL,
873
    xan_decode_end,
874
    xan_decode_frame,
875
    CODEC_CAP_DR1,
876
};
877
*/