initial Interplay video decoder
[libav.git] / libavcodec / interplayvideo.c
1 /*
2 * Interplay MVE 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 interplayvideo.c
23 * Interplay MVE Video Decoder by Mike Melanson (melanson@pcisys.net)
24 * For more information about the Interplay MVE format, visit:
25 * http://www.pcisys.net/~melanson/codecs/interplay-mve.txt
26 * This code is written in such a way that the identifiers match up
27 * with the encoding descriptions in the document.
28 *
29 * This decoder presently only supports a PAL8 output colorspace.
30 *
31 * An Interplay video frame consists of 2 parts: The decoding map and
32 * the video data. A demuxer must load these 2 parts together in a single
33 * buffer before sending it through the stream to this decoder.
34 */
35
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40
41 #include "common.h"
42 #include "avcodec.h"
43 #include "dsputil.h"
44
45 #define PALETTE_COUNT 256
46
47 /* debugging support */
48 #define DEBUG_INTERPLAY 0
49 #if DEBUG_INTERPLAY
50 #define debug_interplay printf
51 #else
52 static inline void debug_interplay(const char *format, ...) { }
53 #endif
54
55 typedef struct IpvideoContext {
56
57 AVCodecContext *avctx;
58 DSPContext dsp;
59 AVFrame last_frame;
60 AVFrame current_frame;
61 int first_frame;
62 unsigned char *decoding_map;
63 int decoding_map_size;
64
65 unsigned char *buf;
66 int size;
67
68 unsigned char palette[PALETTE_COUNT * 4];
69
70 } IpvideoContext;
71
72 #define CHECK_STREAM_PTR(n) \
73 if ((sg_stream_ptr + n) > sg_stream_end) { \
74 printf ("Interplay video warning: stream_ptr out of bounds (%p >= %p)\n", \
75 sg_stream_ptr + n, sg_stream_end); \
76 return -1; \
77 }
78
79 static void ipvideo_new_palette(IpvideoContext *s, unsigned char *palette) {
80
81 int i;
82 unsigned char r, g, b;
83 unsigned int *palette32;
84
85 switch (s->avctx->pix_fmt) {
86
87 case PIX_FMT_PAL8:
88 palette32 = (unsigned int *)s->palette;
89 for (i = 0; i < PALETTE_COUNT; i++) {
90 r = *palette++;
91 g = *palette++;
92 b = *palette++;
93 palette32[i] = (r << 16) | (g << 8) | (b);
94 }
95 break;
96
97 default:
98 printf ("Interplay video: Unhandled video format\n");
99 break;
100 }
101 }
102
103 static unsigned char *sg_stream_ptr;
104 static unsigned char *sg_stream_end;
105 static unsigned char *sg_current_plane;
106 static unsigned char *sg_output_plane;
107 static unsigned char *sg_last_plane;
108 static int sg_line_inc;
109 static int sg_stride;
110 static int sg_upper_motion_limit_offset;
111 static DSPContext sg_dsp;
112
113 static int ipvideo_decode_block_opcode_0x0_0x1(void)
114 {
115 int x, y;
116 unsigned char *src_block;
117
118 /* skip block, which actually means to copy from previous frame */
119 src_block = sg_last_plane + (sg_output_plane - sg_current_plane);
120 for (y = 0; y < 8; y++) {
121 for (x = 0; x < 8; x++) {
122 *sg_output_plane++ = *src_block++;
123 }
124 sg_output_plane += sg_line_inc;
125 src_block += sg_line_inc;
126 }
127
128 /* report success */
129 return 0;
130 }
131
132 #define COPY_FROM_CURRENT() \
133 motion_offset = current_offset; \
134 motion_offset += y * sg_stride; \
135 motion_offset += x; \
136 if (motion_offset < 0) { \
137 printf (" Interplay video: motion offset < 0 (%d)\n", motion_offset); \
138 return -1; \
139 } else if (motion_offset > sg_upper_motion_limit_offset) { \
140 printf (" Interplay video: motion offset above limit (%d >= %d)\n", \
141 motion_offset, sg_upper_motion_limit_offset); \
142 return -1; \
143 } \
144 sg_dsp.put_pixels_tab[0][0](sg_output_plane, \
145 sg_current_plane + motion_offset, sg_stride, 8);
146
147 #define COPY_FROM_PREVIOUS() \
148 motion_offset = current_offset; \
149 motion_offset += y * sg_stride; \
150 motion_offset += x; \
151 if (motion_offset < 0) { \
152 printf (" Interplay video: motion offset < 0 (%d)\n", motion_offset); \
153 return -1; \
154 } else if (motion_offset > sg_upper_motion_limit_offset) { \
155 printf (" Interplay video: motion offset above limit (%d >= %d)\n", \
156 motion_offset, sg_upper_motion_limit_offset); \
157 return -1; \
158 } \
159 sg_dsp.put_pixels_tab[0][0](sg_output_plane, \
160 sg_last_plane + motion_offset, sg_stride, 8);
161
162 static int ipvideo_decode_block_opcode_0x2(void)
163 {
164 unsigned char B;
165 int x, y;
166 int motion_offset;
167 int current_offset = sg_output_plane - sg_current_plane;
168
169 /* This is the opcode which claims to copy data from within the same
170 * frame at a coordinate which has not been rendered yet. Assume that
171 * it is supposed to be copied from the previous frame. */
172
173 /* need 1 more byte for motion */
174 CHECK_STREAM_PTR(1);
175 B = *sg_stream_ptr++;
176
177 if (B < 56) {
178 x = 8 + (B % 7);
179 y = B / 7;
180 } else {
181 x = -14 + ((B - 56) % 29);
182 y = 8 + ((B - 56) / 29);
183 }
184
185 debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
186 COPY_FROM_PREVIOUS();
187
188 /* report success */
189 return 0;
190 }
191
192 static int ipvideo_decode_block_opcode_0x3(void)
193 {
194 unsigned char B;
195 int x, y;
196 int motion_offset;
197 int current_offset = sg_output_plane - sg_current_plane;
198
199 /* copy 8x8 block from current frame from an up/left block */
200
201 /* need 1 more byte for motion */
202 CHECK_STREAM_PTR(1);
203 B = *sg_stream_ptr++;
204
205 if (B < 56) {
206 x = -(8 + (B % 7));
207 y = -(B / 7);
208 } else {
209 x = -(-14 + ((B - 56) % 29));
210 y = -( 8 + ((B - 56) / 29));
211 }
212
213 debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
214 COPY_FROM_CURRENT();
215
216 /* report success */
217 return 0;
218 }
219
220 static int ipvideo_decode_block_opcode_0x4(void)
221 {
222 int x, y;
223 unsigned char B, BL, BH;
224 int motion_offset;
225 int current_offset = sg_output_plane - sg_current_plane;
226
227 /* copy a block from the previous frame; need 1 more byte */
228 CHECK_STREAM_PTR(1);
229
230 B = *sg_stream_ptr++;
231 BL = B & 0x0F;
232 BH = (B >> 4) & 0x0F;
233 x = -8 + BL;
234 y = -8 + BH;
235
236 debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
237 COPY_FROM_PREVIOUS();
238
239 /* report success */
240 return 0;
241 }
242
243 static int ipvideo_decode_block_opcode_0x5(void)
244 {
245 signed char x, y;
246 int motion_offset;
247 int current_offset = sg_output_plane - sg_current_plane;
248
249 /* copy a block from the previous frame using an expanded range;
250 * need 2 more bytes */
251 CHECK_STREAM_PTR(2);
252
253 x = *sg_stream_ptr++;
254 y = *sg_stream_ptr++;
255
256 debug_interplay (" motion bytes = %d, %d\n", x, y);
257 COPY_FROM_PREVIOUS();
258
259 /* report success */
260 return 0;
261 }
262
263 static int ipvideo_decode_block_opcode_0x6(void)
264 {
265 /* mystery opcode? skip multiple blocks? */
266 printf (" Interplay video: Help! Mystery opcode 0x6 seen\n");
267
268 /* report success */
269 return 0;
270 }
271
272 static int ipvideo_decode_block_opcode_0x7(void)
273 {
274 int x, y;
275 unsigned char P0, P1;
276 unsigned char B[8];
277 unsigned int flags;
278 int bitmask;
279
280 /* 2-color encoding */
281 CHECK_STREAM_PTR(2);
282
283 P0 = *sg_stream_ptr++;
284 P1 = *sg_stream_ptr++;
285
286 if (P0 <= P1) {
287
288 /* need 8 more bytes from the stream */
289 CHECK_STREAM_PTR(8);
290 for (y = 0; y < 8; y++)
291 B[y] = *sg_stream_ptr++;
292
293 for (y = 0; y < 8; y++) {
294 flags = B[y];
295 for (x = 0x80; x != 0; x >>= 1) {
296 if (flags & x)
297 *sg_output_plane++ = P1;
298 else
299 *sg_output_plane++ = P0;
300 }
301 sg_output_plane += sg_line_inc;
302 }
303
304 } else {
305
306 /* need 2 more bytes from the stream */
307 CHECK_STREAM_PTR(2);
308 B[0] = *sg_stream_ptr++;
309 B[1] = *sg_stream_ptr++;
310
311 flags = (B[0] << 8) | B[1];
312 bitmask = 0x8000;
313 for (y = 0; y < 8; y += 2) {
314 for (x = 0; x < 8; x += 2, bitmask >>= 1) {
315 if (flags & bitmask) {
316 *(sg_output_plane + x) = P0;
317 *(sg_output_plane + x + 1) = P0;
318 *(sg_output_plane + sg_stride + x) = P0;
319 *(sg_output_plane + sg_stride + x + 1) = P0;
320 } else {
321 *(sg_output_plane + x) = P1;
322 *(sg_output_plane + x + 1) = P1;
323 *(sg_output_plane + sg_stride + x) = P1;
324 *(sg_output_plane + sg_stride + x + 1) = P1;
325 }
326 }
327 sg_output_plane += sg_stride * 2;
328 }
329 }
330
331 /* report success */
332 return 0;
333 }
334
335 static int ipvideo_decode_block_opcode_0x8(void)
336 {
337 int x, y;
338 unsigned char P[8];
339 unsigned char B[8];
340 unsigned int flags = 0;
341 unsigned int bitmask = 0;
342 unsigned char P0 = 0, P1 = 0;
343 int lower_half = 0;
344
345 /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
346 * either top and bottom or left and right halves */
347 CHECK_STREAM_PTR(2);
348
349 P[0] = *sg_stream_ptr++;
350 P[1] = *sg_stream_ptr++;
351
352 if (P[0] <= P[1]) {
353
354 /* need 12 more bytes */
355 CHECK_STREAM_PTR(12);
356 B[0] = *sg_stream_ptr++; B[1] = *sg_stream_ptr++;
357 P[2] = *sg_stream_ptr++; P[3] = *sg_stream_ptr++;
358 B[2] = *sg_stream_ptr++; B[3] = *sg_stream_ptr++;
359 P[4] = *sg_stream_ptr++; P[5] = *sg_stream_ptr++;
360 B[4] = *sg_stream_ptr++; B[5] = *sg_stream_ptr++;
361 P[6] = *sg_stream_ptr++; P[7] = *sg_stream_ptr++;
362 B[6] = *sg_stream_ptr++; B[7] = *sg_stream_ptr++;
363
364 for (y = 0; y < 8; y++) {
365
366 /* time to reload flags? */
367 if (y == 0) {
368 flags =
369 ((B[0] & 0xF0) << 24) | ((B[4] & 0xF0) << 20) |
370 ((B[0] & 0x0F) << 20) | ((B[4] & 0x0F) << 16) |
371 ((B[1] & 0xF0) << 8) | ((B[5] & 0xF0) << 4) |
372 ((B[1] & 0x0F) << 4) | ((B[5] & 0x0F) << 0);
373 bitmask = 0x80000000;
374 lower_half = 0; /* still on top half */
375 } else if (y == 4) {
376 flags =
377 ((B[2] & 0xF0) << 24) | ((B[6] & 0xF0) << 20) |
378 ((B[2] & 0x0F) << 20) | ((B[6] & 0x0F) << 16) |
379 ((B[3] & 0xF0) << 8) | ((B[7] & 0xF0) << 4) |
380 ((B[3] & 0x0F) << 4) | ((B[7] & 0x0F) << 0);
381 bitmask = 0x80000000;
382 lower_half = 4;
383 }
384
385 for (x = 0; x < 8; x++, bitmask >>= 1) {
386 /* get the pixel values ready for this quadrant */
387 if (x == 0) {
388 P0 = P[lower_half + 0];
389 P1 = P[lower_half + 1];
390 } else if (x == 4) {
391 P0 = P[lower_half + 2];
392 P1 = P[lower_half + 3];
393 }
394
395 if (flags & bitmask)
396 *sg_output_plane++ = P1;
397 else
398 *sg_output_plane++ = P0;
399 }
400 sg_output_plane += sg_line_inc;
401 }
402
403 } else {
404
405 /* need 10 more bytes */
406 CHECK_STREAM_PTR(10);
407 B[0] = *sg_stream_ptr++; B[1] = *sg_stream_ptr++;
408 B[2] = *sg_stream_ptr++; B[3] = *sg_stream_ptr++;
409 P[2] = *sg_stream_ptr++; P[3] = *sg_stream_ptr++;
410 B[4] = *sg_stream_ptr++; B[5] = *sg_stream_ptr++;
411 B[6] = *sg_stream_ptr++; B[7] = *sg_stream_ptr++;
412
413 if (P[2] <= P[3]) {
414
415 /* vertical split; left & right halves are 2-color encoded */
416
417 for (y = 0; y < 8; y++) {
418
419 /* time to reload flags? */
420 if (y == 0) {
421 flags =
422 ((B[0] & 0xF0) << 24) | ((B[4] & 0xF0) << 20) |
423 ((B[0] & 0x0F) << 20) | ((B[4] & 0x0F) << 16) |
424 ((B[1] & 0xF0) << 8) | ((B[5] & 0xF0) << 4) |
425 ((B[1] & 0x0F) << 4) | ((B[5] & 0x0F) << 0);
426 bitmask = 0x80000000;
427 } else if (y == 4) {
428 flags =
429 ((B[2] & 0xF0) << 24) | ((B[6] & 0xF0) << 20) |
430 ((B[2] & 0x0F) << 20) | ((B[6] & 0x0F) << 16) |
431 ((B[3] & 0xF0) << 8) | ((B[7] & 0xF0) << 4) |
432 ((B[3] & 0x0F) << 4) | ((B[7] & 0x0F) << 0);
433 bitmask = 0x80000000;
434 }
435
436 for (x = 0; x < 8; x++, bitmask >>= 1) {
437 /* get the pixel values ready for this half */
438 if (x == 0) {
439 P0 = P[0];
440 P1 = P[1];
441 } else if (x == 4) {
442 P0 = P[2];
443 P1 = P[3];
444 }
445
446 if (flags & bitmask)
447 *sg_output_plane++ = P0;
448 else
449 *sg_output_plane++ = P1;
450 }
451 sg_output_plane += sg_line_inc;
452 }
453
454 } else {
455
456 /* horizontal split; top & bottom halves are 2-color encoded */
457
458 for (y = 0; y < 8; y++) {
459
460 flags = B[y];
461 if (y == 0) {
462 P0 = P[0];
463 P1 = P[1];
464 } else if (y == 4) {
465 P0 = P[2];
466 P1 = P[3];
467 }
468
469 for (bitmask = 0x80; bitmask != 0; bitmask >>= 1) {
470
471 if (flags & bitmask)
472 *sg_output_plane++ = P0;
473 else
474 *sg_output_plane++ = P1;
475 }
476 sg_output_plane += sg_line_inc;
477 }
478 }
479 }
480
481 /* report success */
482 return 0;
483 }
484
485 static int ipvideo_decode_block_opcode_0x9(void)
486 {
487 int x, y;
488 unsigned char P[4];
489 unsigned int flags = 0;
490 int shifter = 0;
491 unsigned char pix;
492
493 /* 4-color encoding */
494 CHECK_STREAM_PTR(4);
495
496 for (y = 0; y < 4; y++)
497 P[y] = *sg_stream_ptr++;
498
499 if ((P[0] <= P[1]) && (P[2] <= P[3])) {
500
501 /* 1 of 4 colors for each pixel, need 16 more bytes */
502 CHECK_STREAM_PTR(16);
503
504 for (y = 0; y < 8; y++) {
505 /* get the next set of 8 2-bit flags */
506 flags = (sg_stream_ptr[0] << 8) | sg_stream_ptr[1];
507 sg_stream_ptr += 2;
508 for (x = 0, shifter = 14; x < 8; x++, shifter -= 2) {
509 *sg_output_plane++ = P[(flags >> shifter) & 0x03];
510 }
511 sg_output_plane += sg_line_inc;
512 }
513
514 } else if ((P[0] <= P[1]) && (P[2] > P[3])) {
515
516 /* 1 of 4 colors for each 2x2 block, need 4 more bytes */
517 CHECK_STREAM_PTR(4);
518
519 flags = 0;
520 flags = (flags << 8) | *sg_stream_ptr++;
521 flags = (flags << 8) | *sg_stream_ptr++;
522 flags = (flags << 8) | *sg_stream_ptr++;
523 flags = (flags << 8) | *sg_stream_ptr++;
524 shifter = 30;
525
526 for (y = 0; y < 8; y += 2) {
527 for (x = 0; x < 8; x += 2, shifter -= 2) {
528 pix = P[(flags >> shifter) & 0x03];
529 *(sg_output_plane + x) = pix;
530 *(sg_output_plane + x + 1) = pix;
531 *(sg_output_plane + sg_stride + x) = pix;
532 *(sg_output_plane + sg_stride + x + 1) = pix;
533 }
534 sg_output_plane += sg_stride * 2;
535 }
536
537 } else if ((P[0] > P[1]) && (P[2] <= P[3])) {
538
539 /* 1 of 4 colors for each 2x1 block, need 8 more bytes */
540 CHECK_STREAM_PTR(8);
541
542 for (y = 0; y < 8; y++) {
543 /* time to reload flags? */
544 if ((y == 0) || (y == 4)) {
545 flags = 0;
546 flags = (flags << 8) | *sg_stream_ptr++;
547 flags = (flags << 8) | *sg_stream_ptr++;
548 flags = (flags << 8) | *sg_stream_ptr++;
549 flags = (flags << 8) | *sg_stream_ptr++;
550 shifter = 30;
551 }
552 for (x = 0; x < 8; x += 2, shifter -= 2) {
553 pix = P[(flags >> shifter) & 0x03];
554 *(sg_output_plane + x) = pix;
555 *(sg_output_plane + x + 1) = pix;
556 }
557 sg_output_plane += sg_stride;
558 }
559
560 } else {
561
562 /* 1 of 4 colors for each 1x2 block, need 8 more bytes */
563 CHECK_STREAM_PTR(8);
564
565 for (y = 0; y < 8; y += 2) {
566 /* time to reload flags? */
567 if ((y == 0) || (y == 4)) {
568 flags = 0;
569 flags = (flags << 8) | *sg_stream_ptr++;
570 flags = (flags << 8) | *sg_stream_ptr++;
571 flags = (flags << 8) | *sg_stream_ptr++;
572 flags = (flags << 8) | *sg_stream_ptr++;
573 shifter = 30;
574 }
575 for (x = 0; x < 8; x++, shifter -= 2) {
576 pix = P[(flags >> shifter) & 0x03];
577 *(sg_output_plane + x) = pix;
578 *(sg_output_plane + sg_stride + x) = pix;
579 }
580 sg_output_plane += sg_stride * 2;
581 }
582 }
583
584 /* report success */
585 return 0;
586 }
587
588 static int ipvideo_decode_block_opcode_0xA(void)
589 {
590 int x, y;
591 unsigned char P[16];
592 unsigned char B[16];
593 int flags = 0;
594 int shifter = 0;
595 int index;
596 int split;
597 int lower_half;
598
599 /* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
600 * either top and bottom or left and right halves */
601 CHECK_STREAM_PTR(4);
602
603 for (y = 0; y < 4; y++)
604 P[y] = *sg_stream_ptr++;
605
606 if (P[0] <= P[1]) {
607
608 /* 4-color encoding for each quadrant; need 28 more bytes */
609 CHECK_STREAM_PTR(28);
610
611 for (y = 0; y < 4; y++)
612 B[y] = *sg_stream_ptr++;
613 for (y = 4; y < 16; y += 4) {
614 for (x = y; x < y + 4; x++)
615 P[x] = *sg_stream_ptr++;
616 for (x = y; x < y + 4; x++)
617 B[x] = *sg_stream_ptr++;
618 }
619
620 for (y = 0; y < 8; y++) {
621
622 lower_half = (y >= 4) ? 4 : 0;
623 flags = (B[y] << 8) | B[y + 8];
624
625 for (x = 0, shifter = 14; x < 8; x++, shifter -= 2) {
626 split = (x >= 4) ? 8 : 0;
627 index = split + lower_half + ((flags >> shifter) & 0x03);
628 *sg_output_plane++ = P[index];
629 }
630
631 sg_output_plane += sg_line_inc;
632 }
633
634 } else {
635
636 /* 4-color encoding for either left and right or top and bottom
637 * halves; need 20 more bytes */
638 CHECK_STREAM_PTR(20);
639
640 for (y = 0; y < 8; y++)
641 B[y] = *sg_stream_ptr++;
642 for (y = 4; y < 8; y++)
643 P[y] = *sg_stream_ptr++;
644 for (y = 8; y < 16; y++)
645 B[y] = *sg_stream_ptr++;
646
647 if (P[4] <= P[5]) {
648
649 /* block is divided into left and right halves */
650 for (y = 0; y < 8; y++) {
651
652 flags = (B[y] << 8) | B[y + 8];
653 split = 0;
654
655 for (x = 0, shifter = 14; x < 8; x++, shifter -= 2) {
656 if (x == 4)
657 split = 4;
658 *sg_output_plane++ = P[split + ((flags >> shifter) & 0x03)];
659 }
660
661 sg_output_plane += sg_line_inc;
662 }
663
664 } else {
665
666 /* block is divided into top and bottom halves */
667 split = 0;
668 for (y = 0; y < 8; y++) {
669
670 flags = (B[y * 2] << 8) | B[y * 2 + 1];
671 if (y == 4)
672 split = 4;
673
674 for (x = 0, shifter = 14; x < 8; x++, shifter -= 2)
675 *sg_output_plane++ = P[split + ((flags >> shifter) & 0x03)];
676
677 sg_output_plane += sg_line_inc;
678 }
679 }
680 }
681
682 /* report success */
683 return 0;
684 }
685
686 static int ipvideo_decode_block_opcode_0xB(void)
687 {
688 int x, y;
689
690 /* 64-color encoding (each pixel in block is a different color) */
691 CHECK_STREAM_PTR(64);
692
693 for (y = 0; y < 8; y++) {
694 for (x = 0; x < 8; x++) {
695 *sg_output_plane++ = *sg_stream_ptr++;
696 }
697 sg_output_plane += sg_line_inc;
698 }
699
700 /* report success */
701 return 0;
702 }
703
704 static int ipvideo_decode_block_opcode_0xC(void)
705 {
706 int x, y;
707 unsigned char pix;
708
709 /* 16-color block encoding: each 2x2 block is a different color */
710 CHECK_STREAM_PTR(16);
711
712 for (y = 0; y < 8; y += 2) {
713 for (x = 0; x < 8; x += 2) {
714 pix = *sg_stream_ptr++;
715 *(sg_output_plane + x) = pix;
716 *(sg_output_plane + x + 1) = pix;
717 *(sg_output_plane + sg_stride + x) = pix;
718 *(sg_output_plane + sg_stride + x + 1) = pix;
719 }
720 sg_output_plane += sg_stride * 2;
721 }
722
723 /* report success */
724 return 0;
725 }
726
727 static int ipvideo_decode_block_opcode_0xD(void)
728 {
729 int x, y;
730 unsigned char P[4];
731 unsigned char index = 0;
732
733 /* 4-color block encoding: each 4x4 block is a different color */
734 CHECK_STREAM_PTR(4);
735
736 for (y = 0; y < 4; y++)
737 P[y] = *sg_stream_ptr++;
738
739 for (y = 0; y < 8; y++) {
740 if (y < 4)
741 index = 0;
742 else
743 index = 2;
744
745 for (x = 0; x < 8; x++) {
746 if (x == 4)
747 index++;
748 *sg_output_plane++ = P[index];
749 }
750 sg_output_plane += sg_line_inc;
751 }
752
753 /* report success */
754 return 0;
755 }
756
757 static int ipvideo_decode_block_opcode_0xE(void)
758 {
759 int x, y;
760 unsigned char pix;
761
762 /* 1-color encoding: the whole block is 1 solid color */
763 CHECK_STREAM_PTR(1);
764 pix = *sg_stream_ptr++;
765
766 for (y = 0; y < 8; y++) {
767 for (x = 0; x < 8; x++) {
768 *sg_output_plane++ = pix;
769 }
770 sg_output_plane += sg_line_inc;
771 }
772
773 /* report success */
774 return 0;
775 }
776
777 static int ipvideo_decode_block_opcode_0xF(void)
778 {
779 int x, y;
780 unsigned char sample0, sample1;
781
782 /* dithered encoding */
783 CHECK_STREAM_PTR(2);
784 sample0 = *sg_stream_ptr++;
785 sample1 = *sg_stream_ptr++;
786
787 for (y = 0; y < 8; y++) {
788 for (x = 0; x < 8; x += 2) {
789 if (y & 1) {
790 *sg_output_plane++ = sample1;
791 *sg_output_plane++ = sample0;
792 } else {
793 *sg_output_plane++ = sample0;
794 *sg_output_plane++ = sample1;
795 }
796 }
797 sg_output_plane += sg_line_inc;
798 }
799
800 /* report success */
801 return 0;
802 }
803
804 static int (*ipvideo_decode_block[16])(void);
805
806 static void ipvideo_decode_opcodes(IpvideoContext *s)
807 {
808 int x, y;
809 int index = 0;
810 unsigned char opcode;
811 int ret;
812 int code_counts[16];
813 static int frame = 0;
814
815 debug_interplay("------------------ frame %d\n", frame);
816 frame++;
817
818 for (x = 0; x < 16; x++)
819 code_counts[x] = 0;
820
821 /* this is PAL8, so make the palette available */
822 if (s->avctx->pix_fmt == PIX_FMT_PAL8)
823 memcpy(s->current_frame.data[1], s->palette, PALETTE_COUNT * 4);
824
825 switch (s->avctx->pix_fmt) {
826
827 case PIX_FMT_PAL8:
828 sg_stride = s->current_frame.linesize[0];
829 sg_stream_ptr = s->buf + 14; /* data starts 14 bytes in */
830 sg_stream_end = s->buf + s->size;
831 sg_line_inc = sg_stride - 8;
832 sg_current_plane = s->current_frame.data[0];
833 sg_last_plane = s->last_frame.data[0];
834 sg_upper_motion_limit_offset = (s->avctx->height - 8) * sg_stride
835 + s->avctx->width - 8;
836 sg_dsp = s->dsp;
837
838 for (y = 0; y < (sg_stride * s->avctx->height); y += sg_stride * 8) {
839 for (x = y; x < y + s->avctx->width; x += 8) {
840 /* bottom nibble first, then top nibble (which makes it
841 * hard to use a GetBitcontext) */
842 if (index & 1)
843 opcode = s->decoding_map[index >> 1] >> 4;
844 else
845 opcode = s->decoding_map[index >> 1] & 0xF;
846 index++;
847
848 debug_interplay(" block @ (%3d, %3d): encoding 0x%X, data ptr @ %p\n",
849 x - y, y / sg_stride, opcode, sg_stream_ptr);
850 code_counts[opcode]++;
851
852 sg_output_plane = sg_current_plane + x;
853 ret = ipvideo_decode_block[opcode]();
854 if (ret != 0) {
855 printf(" Interplay video: decode problem on frame %d, @ block (%d, %d)\n",
856 frame, x - y, y / sg_stride);
857 return;
858 }
859 }
860 }
861 if ((sg_stream_ptr != sg_stream_end) &&
862 (sg_stream_ptr + 1 != sg_stream_end)) {
863 printf (" Interplay video: decode finished with %d bytes left over\n",
864 sg_stream_end - sg_stream_ptr);
865 }
866 break;
867
868 default:
869 printf ("Interplay video: Unhandled video format\n");
870 break;
871 }
872
873 }
874
875 static int ipvideo_decode_init(AVCodecContext *avctx)
876 {
877 IpvideoContext *s = avctx->priv_data;
878
879 s->avctx = avctx;
880
881 if (s->avctx->extradata_size != sizeof(AVPaletteControl)) {
882 printf (" Interplay video: expected extradata_size of %d\n",
883 sizeof(AVPaletteControl));
884 return -1;
885 }
886
887 avctx->pix_fmt = PIX_FMT_PAL8;
888 avctx->has_b_frames = 0;
889 dsputil_init(&s->dsp, avctx);
890
891 s->first_frame = 1;
892
893 /* decoding map contains 4 bits of information per 8x8 block */
894 s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
895
896 /* assign block decode functions */
897 ipvideo_decode_block[0x0] = ipvideo_decode_block_opcode_0x0_0x1;
898 ipvideo_decode_block[0x1] = ipvideo_decode_block_opcode_0x0_0x1;
899 ipvideo_decode_block[0x2] = ipvideo_decode_block_opcode_0x2;
900 ipvideo_decode_block[0x3] = ipvideo_decode_block_opcode_0x3;
901 ipvideo_decode_block[0x4] = ipvideo_decode_block_opcode_0x4;
902 ipvideo_decode_block[0x5] = ipvideo_decode_block_opcode_0x5;
903 ipvideo_decode_block[0x6] = ipvideo_decode_block_opcode_0x6;
904 ipvideo_decode_block[0x7] = ipvideo_decode_block_opcode_0x7;
905 ipvideo_decode_block[0x8] = ipvideo_decode_block_opcode_0x8;
906 ipvideo_decode_block[0x9] = ipvideo_decode_block_opcode_0x9;
907 ipvideo_decode_block[0xA] = ipvideo_decode_block_opcode_0xA;
908 ipvideo_decode_block[0xB] = ipvideo_decode_block_opcode_0xB;
909 ipvideo_decode_block[0xC] = ipvideo_decode_block_opcode_0xC;
910 ipvideo_decode_block[0xD] = ipvideo_decode_block_opcode_0xD;
911 ipvideo_decode_block[0xE] = ipvideo_decode_block_opcode_0xE;
912 ipvideo_decode_block[0xF] = ipvideo_decode_block_opcode_0xF;
913
914 return 0;
915 }
916
917 static int ipvideo_decode_frame(AVCodecContext *avctx,
918 void *data, int *data_size,
919 uint8_t *buf, int buf_size)
920 {
921 IpvideoContext *s = avctx->priv_data;
922 AVPaletteControl *palette_control = (AVPaletteControl *)avctx->extradata;
923
924 if (palette_control->palette_changed) {
925 /* load the new palette and reset the palette control */
926 ipvideo_new_palette(s, palette_control->palette);
927 palette_control->palette_changed = 0;
928 }
929
930 s->decoding_map = buf;
931 s->buf = buf + s->decoding_map_size;
932 s->size = buf_size - s->decoding_map_size;
933
934 if (avctx->get_buffer(avctx, &s->current_frame)) {
935 printf (" Interplay Video: get_buffer() failed\n");
936 return -1;
937 }
938
939 ipvideo_decode_opcodes(s);
940
941 /* release the last frame if it is allocated */
942 if (s->first_frame)
943 s->first_frame = 0;
944 else
945 avctx->release_buffer(avctx, &s->last_frame);
946
947 /* shuffle frames */
948 s->last_frame = s->current_frame;
949
950 *data_size = sizeof(AVFrame);
951 *(AVFrame*)data = s->current_frame;
952
953 /* report that the buffer was completely consumed */
954 return buf_size;
955 }
956
957 static int ipvideo_decode_end(AVCodecContext *avctx)
958 {
959 IpvideoContext *s = avctx->priv_data;
960
961 /* release the last frame */
962 avctx->release_buffer(avctx, &s->last_frame);
963
964 return 0;
965 }
966
967 AVCodec interplay_video_decoder = {
968 "interplayvideo",
969 CODEC_TYPE_VIDEO,
970 CODEC_ID_INTERPLAY_VIDEO,
971 sizeof(IpvideoContext),
972 ipvideo_decode_init,
973 NULL,
974 ipvideo_decode_end,
975 ipvideo_decode_frame,
976 CODEC_CAP_DR1,
977 };