Statistics
| Branch: | Revision:

ffmpeg / libavcodec / xan.c @ 431f2172

History | View | Annotate | Download (22.3 KB)

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
17
 * 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:
28
 *   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) | \
64
                   (((uint8_t*)(x))[2] << 16) | \
65
                   (((uint8_t*)(x))[1] << 8) | \
66
                    ((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) \
73
  (unsigned char) \
74
  ((y_r_table[r] + y_g_table[g] + y_b_table[b]) / SCALEFACTOR)
75
#define COMPUTE_U(r, g, b) \
76
  (unsigned char) \
77
  ((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
                ((b >> 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
                ((b >> 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
/* advance current_x variable; reset accounting variables if current_x
342
 * moves beyond width */
343
#define ADVANCE_CURRENT_X() \
344
    current_x++; \
345
    if (current_x >= width) { \
346
        index += line_inc; \
347
        current_x = 0; \
348
    }
349

    
350
static void inline xan_wc3_output_pixel_run(XanContext *s, 
351
    unsigned char *pixel_buffer, int x, int y, int pixel_count)
352
{
353
    int stride;
354
    int line_inc;
355
    int index;
356
    int current_x;
357
    int width = s->avctx->width;
358
    unsigned char pix;
359
    unsigned char *palette_plane;
360
    unsigned char *y_plane;
361
    unsigned char *u_plane;
362
    unsigned char *v_plane;
363
    unsigned char *rgb_plane;
364
    unsigned short *rgb16_plane;
365
    unsigned short *palette16;
366
    unsigned int *rgb32_plane;
367
    unsigned int *palette32;
368

    
369
    switch (s->avctx->pix_fmt) {
370

    
371
    case PIX_FMT_PAL8:
372
        palette_plane = s->current_frame.data[0];
373
        stride = s->current_frame.linesize[0];
374
        line_inc = stride - width;
375
        index = y * stride + x;
376
        current_x = x;
377
        while(pixel_count--) {
378

    
379
            /* don't do a memcpy() here; keyframes generally copy an entire
380
             * frame of data and the stride needs to be accounted for */
381
            palette_plane[index++] = *pixel_buffer++;
382

    
383
            ADVANCE_CURRENT_X();
384
        }
385
        break;
386

    
387
    case PIX_FMT_RGB555:
388
    case PIX_FMT_RGB565:
389
        rgb16_plane = (unsigned short *)s->current_frame.data[0];
390
        palette16 = (unsigned short *)s->palette;
391
        stride = s->current_frame.linesize[0] / 2;
392
        line_inc = stride - width;
393
        index = y * stride + x;
394
        current_x = x;
395
        while(pixel_count--) {
396

    
397
            rgb16_plane[index++] = palette16[*pixel_buffer++];
398

    
399
            ADVANCE_CURRENT_X();
400
        }
401
        break;
402

    
403
    case PIX_FMT_RGB24:
404
    case PIX_FMT_BGR24:
405
        rgb_plane = s->current_frame.data[0];
406
        stride = s->current_frame.linesize[0];
407
        line_inc = stride - width * 3;
408
        index = y * stride + x * 3;
409
        current_x = x;
410
        while(pixel_count--) {
411
            pix = *pixel_buffer++;
412

    
413
            rgb_plane[index++] = s->palette[pix * 4 + 0];
414
            rgb_plane[index++] = s->palette[pix * 4 + 1];
415
            rgb_plane[index++] = s->palette[pix * 4 + 2];
416

    
417
            ADVANCE_CURRENT_X();
418
        }
419
        break;
420

    
421
    case PIX_FMT_RGBA32:
422
        rgb32_plane = (unsigned int *)s->current_frame.data[0];
423
        palette32 = (unsigned int *)s->palette;
424
        stride = s->current_frame.linesize[0] / 4;
425
        line_inc = stride - width;
426
        index = y * stride + x;
427
        current_x = x;
428
        while(pixel_count--) {
429

    
430
            rgb32_plane[index++] = palette32[*pixel_buffer++];
431

    
432
            ADVANCE_CURRENT_X();
433
        }
434
        break;
435

    
436
    case PIX_FMT_YUV444P:
437
        y_plane = s->current_frame.data[0];
438
        u_plane = s->current_frame.data[1];
439
        v_plane = s->current_frame.data[2];
440
        stride = s->current_frame.linesize[0];
441
        line_inc = stride - width;
442
        index = y * stride + x;
443
        current_x = x;
444
        while(pixel_count--) {
445
            pix = *pixel_buffer++;
446

    
447
            y_plane[index] = s->palette[pix * 4 + 0];
448
            u_plane[index] = s->palette[pix * 4 + 1];
449
            v_plane[index] = s->palette[pix * 4 + 2];
450

    
451
            index++;
452
            ADVANCE_CURRENT_X();
453
        }
454
        break;
455

    
456
    default:
457
        printf (" Xan WC3: Unhandled colorspace\n");
458
        break;
459
    }
460
}
461

    
462
#define ADVANCE_CURFRAME_X() \
463
    curframe_x++; \
464
    if (curframe_x >= width) { \
465
        curframe_index += line_inc; \
466
        curframe_x = 0; \
467
    }
468

    
469
#define ADVANCE_PREVFRAME_X() \
470
    prevframe_x++; \
471
    if (prevframe_x >= width) { \
472
        prevframe_index += line_inc; \
473
        prevframe_x = 0; \
474
    }
475

    
476
static void inline xan_wc3_copy_pixel_run(XanContext *s, 
477
    int x, int y, int pixel_count, int motion_x, int motion_y)
478
{
479
    int stride;
480
    int line_inc;
481
    int curframe_index, prevframe_index;
482
    int curframe_x, prevframe_x;
483
    int width = s->avctx->width;
484
    unsigned char *palette_plane, *prev_palette_plane;
485
    unsigned char *y_plane, *u_plane, *v_plane;
486
    unsigned char *prev_y_plane, *prev_u_plane, *prev_v_plane;
487
    unsigned char *rgb_plane, *prev_rgb_plane;
488
    unsigned short *rgb16_plane, *prev_rgb16_plane;
489
    unsigned int *rgb32_plane, *prev_rgb32_plane;
490

    
491
    switch (s->avctx->pix_fmt) {
492

    
493
    case PIX_FMT_PAL8:
494
        palette_plane = s->current_frame.data[0];
495
        prev_palette_plane = s->last_frame.data[0];
496
        stride = s->current_frame.linesize[0];
497
        line_inc = stride - width;
498
        curframe_index = y * stride + x;
499
        curframe_x = x;
500
        prevframe_index = (y + motion_y) * stride + x + motion_x;
501
        prevframe_x = x + motion_x;
502
        while(pixel_count--) {
503

    
504
            palette_plane[curframe_index++] = 
505
                prev_palette_plane[prevframe_index++];
506

    
507
            ADVANCE_CURFRAME_X();
508
            ADVANCE_PREVFRAME_X();
509
        }
510
        break;
511

    
512
    case PIX_FMT_RGB555:
513
    case PIX_FMT_RGB565:
514
        rgb16_plane = (unsigned short *)s->current_frame.data[0];
515
        prev_rgb16_plane = (unsigned short *)s->last_frame.data[0];
516
        stride = s->current_frame.linesize[0] / 2;
517
        line_inc = stride - width;
518
        curframe_index = y * stride + x;
519
        curframe_x = x;
520
        prevframe_index = (y + motion_y) * stride + x + motion_x;
521
        prevframe_x = x + motion_x;
522
        while(pixel_count--) {
523

    
524
            rgb16_plane[curframe_index++] = 
525
                prev_rgb16_plane[prevframe_index++];
526

    
527
            ADVANCE_CURFRAME_X();
528
            ADVANCE_PREVFRAME_X();
529
        }
530
        break;
531

    
532
    case PIX_FMT_RGB24:
533
    case PIX_FMT_BGR24:
534
        rgb_plane = s->current_frame.data[0];
535
        prev_rgb_plane = s->last_frame.data[0];
536
        stride = s->current_frame.linesize[0];
537
        line_inc = stride - width * 3;
538
        curframe_index = y * stride + x * 3;
539
        curframe_x = x;
540
        prevframe_index = (y + motion_y) * stride + 
541
            (3 * (x + motion_x));
542
        prevframe_x = x + motion_x;
543
        while(pixel_count--) {
544

    
545
            rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
546
            rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
547
            rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
548

    
549
            ADVANCE_CURFRAME_X();
550
            ADVANCE_PREVFRAME_X();
551
        }
552
        break;
553

    
554
    case PIX_FMT_RGBA32:
555
        rgb32_plane = (unsigned int *)s->current_frame.data[0];
556
        prev_rgb32_plane = (unsigned int *)s->last_frame.data[0];
557
        stride = s->current_frame.linesize[0] / 4;
558
        line_inc = stride - width;
559
        curframe_index = y * stride + x;
560
        curframe_x = x;
561
        prevframe_index = (y + motion_y) * stride + x + motion_x;
562
        prevframe_x = x + motion_x;
563
        while(pixel_count--) {
564

    
565
            rgb32_plane[curframe_index++] = 
566
                prev_rgb32_plane[prevframe_index++];
567

    
568
            ADVANCE_CURFRAME_X();
569
            ADVANCE_PREVFRAME_X();
570
        }
571
        break;
572

    
573
    case PIX_FMT_YUV444P:
574
        y_plane = s->current_frame.data[0];
575
        u_plane = s->current_frame.data[1];
576
        v_plane = s->current_frame.data[2];
577
        prev_y_plane = s->last_frame.data[0];
578
        prev_u_plane = s->last_frame.data[1];
579
        prev_v_plane = s->last_frame.data[2];
580
        stride = s->current_frame.linesize[0];
581
        line_inc = stride - width;
582
        curframe_index = y * stride + x;
583
        curframe_x = x;
584
        prevframe_index = (y + motion_y) * stride + x + motion_x;
585
        prevframe_x = x + motion_x;
586
        while(pixel_count--) {
587

    
588
            y_plane[curframe_index] = prev_y_plane[prevframe_index];
589
            u_plane[curframe_index] = prev_u_plane[prevframe_index];
590
            v_plane[curframe_index] = prev_v_plane[prevframe_index];
591

    
592
            curframe_index++;
593
            ADVANCE_CURFRAME_X();
594
            prevframe_index++;
595
            ADVANCE_PREVFRAME_X();
596
        }
597
        break;
598

    
599
    default:
600
        printf (" Xan WC3: Unhandled colorspace\n");
601
        break;
602
    }
603
}
604

    
605
static void xan_wc3_decode_frame(XanContext *s) {
606

    
607
    int width = s->avctx->width;
608
    int height = s->avctx->height;
609
    int total_pixels = width * height;
610
    unsigned char opcode;
611
    unsigned char flag = 0;
612
    int size = 0;
613
    int motion_x, motion_y;
614
    int x, y;
615

    
616
    unsigned char *opcode_buffer = s->buffer1;
617
    unsigned char *imagedata_buffer = s->buffer2;
618

    
619
    /* pointers to segments inside the compressed chunk */
620
    unsigned char *huffman_segment;
621
    unsigned char *size_segment;
622
    unsigned char *vector_segment;
623
    unsigned char *imagedata_segment;
624

    
625
    huffman_segment =   s->buf + LE_16(&s->buf[0]);
626
    size_segment =      s->buf + LE_16(&s->buf[2]);
627
    vector_segment =    s->buf + LE_16(&s->buf[4]);
628
    imagedata_segment = s->buf + LE_16(&s->buf[6]);
629

    
630
    xan_huffman_decode(opcode_buffer, huffman_segment);
631

    
632
    if (imagedata_segment[0] == 2)
633
        xan_unpack(imagedata_buffer, &imagedata_segment[1]);
634
    else
635
        imagedata_buffer = &imagedata_segment[1];
636

    
637
    /* use the decoded data segments to build the frame */
638
    x = y = 0;
639
    while (total_pixels) {
640

    
641
        opcode = *opcode_buffer++;
642
        size = 0;
643

    
644
        switch (opcode) {
645

    
646
        case 0:
647
            flag ^= 1;
648
            continue;
649

    
650
        case 1:
651
        case 2:
652
        case 3:
653
        case 4:
654
        case 5:
655
        case 6:
656
        case 7:
657
        case 8:
658
            size = opcode;
659
            break;
660

    
661
        case 12:
662
        case 13:
663
        case 14:
664
        case 15:
665
        case 16:
666
        case 17:
667
        case 18:
668
            size += (opcode - 10);
669
            break;
670

    
671
        case 9:
672
        case 19:
673
            size = *size_segment++;
674
            break;
675

    
676
        case 10:
677
        case 20:
678
            size = BE_16(&size_segment[0]);
679
            size_segment += 2;
680
            break;
681

    
682
        case 11:
683
        case 21:
684
            size = (size_segment[0] << 16) | (size_segment[1] << 8) |
685
                size_segment[2];
686
            size_segment += 3;
687
            break;
688
        }
689

    
690
        if (opcode < 12) {
691
            flag ^= 1;
692
            if (flag) {
693
                /* run of (size) pixels is unchanged from last frame */
694
                xan_wc3_copy_pixel_run(s, x, y, size, 0, 0);
695
            } else {
696
                /* output a run of pixels from imagedata_buffer */
697
                xan_wc3_output_pixel_run(s, imagedata_buffer, x, y, size);
698
                imagedata_buffer += size;
699
            }
700
        } else {
701
            /* run-based motion compensation from last frame */
702
            motion_x = (*vector_segment >> 4) & 0xF;
703
            motion_y = *vector_segment & 0xF;
704
            vector_segment++;
705

    
706
            /* sign extension */
707
            if (motion_x & 0x8)
708
                motion_x |= 0xFFFFFFF0;
709
            if (motion_y & 0x8)
710
                motion_y |= 0xFFFFFFF0;
711

    
712
            /* copy a run of pixels from the previous frame */
713
            xan_wc3_copy_pixel_run(s, x, y, size, motion_x, motion_y);
714

    
715
            flag = 0;
716
        }
717

    
718
        /* coordinate accounting */
719
        total_pixels -= size;
720
        while (size) {
721
            if (x + size >= width) {
722
                y++;
723
                size -= (width - x);
724
                x = 0;
725
            } else {
726
                x += size;
727
                size = 0;
728
            }
729
        }
730
    }
731

    
732
    /* for PAL8, make the palette available on the way out */
733
    if (s->avctx->pix_fmt == PIX_FMT_PAL8)
734
        memcpy(s->current_frame.data[1], s->palette, PALETTE_COUNT * 4);
735
}
736

    
737
static void xan_wc4_decode_frame(XanContext *s) {
738
}
739

    
740
static int xan_decode_frame(AVCodecContext *avctx,
741
                            void *data, int *data_size,
742
                            uint8_t *buf, int buf_size)
743
{
744
    XanContext *s = avctx->priv_data;
745
    AVPaletteControl *palette_control = (AVPaletteControl *)avctx->extradata;
746
    int keyframe = 0;
747

    
748
    if (palette_control->palette_changed) {
749
        /* load the new palette and reset the palette control */
750
        xan_wc3_build_palette(s, palette_control->palette);
751
        palette_control->palette_changed = 0;
752
        keyframe = 1;
753
    }
754

    
755
    if (avctx->get_buffer(avctx, &s->current_frame)) {
756
        printf ("  Xan Video: get_buffer() failed\n");
757
        return -1;
758
    }
759
    s->current_frame.reference = 3;
760

    
761
    s->buf = buf;
762
    s->size = buf_size;
763

    
764
    if (avctx->codec->id == CODEC_ID_XAN_WC3)
765
        xan_wc3_decode_frame(s);
766
    else if (avctx->codec->id == CODEC_ID_XAN_WC4)
767
        xan_wc4_decode_frame(s);
768

    
769
    /* release the last frame if it is allocated */
770
    if (s->last_frame.data[0])
771
        avctx->release_buffer(avctx, &s->last_frame);
772

    
773
    /* shuffle frames */
774
    s->last_frame = s->current_frame;
775

    
776
    *data_size = sizeof(AVFrame);
777
    *(AVFrame*)data = s->current_frame;
778

    
779
    /* always report that the buffer was completely consumed */
780
    return buf_size;
781
}
782

    
783
static int xan_decode_end(AVCodecContext *avctx)
784
{
785
    XanContext *s = avctx->priv_data;
786

    
787
    /* release the last frame */
788
    avctx->release_buffer(avctx, &s->last_frame);
789

    
790
    av_free(s->buffer1);
791
    av_free(s->buffer2);
792

    
793
    return 0;
794
}
795

    
796
AVCodec xan_wc3_decoder = {
797
    "xan_wc3",
798
    CODEC_TYPE_VIDEO,
799
    CODEC_ID_XAN_WC3,
800
    sizeof(XanContext),
801
    xan_decode_init,
802
    NULL,
803
    xan_decode_end,
804
    xan_decode_frame,
805
    CODEC_CAP_DR1,
806
};
807

    
808
/*
809
AVCodec xan_wc4_decoder = {
810
    "xan_wc4",
811
    CODEC_TYPE_VIDEO,
812
    CODEC_ID_XAN_WC4,
813
    sizeof(XanContext),
814
    xan_decode_init,
815
    NULL,
816
    xan_decode_end,
817
    xan_decode_frame,
818
    CODEC_CAP_DR1,
819
};
820
*/