1 /*
2 * Gremlin Digital Video (GDV) decoder
3 * Copyright (c) 2017 Konstantin Shishkov
4 * Copyright (c) 2017 Paul B Mahol
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "libavutil/common.h"
24 #include "avcodec.h"
25 #include "bytestream.h"
26 #include "internal.h"
27
28 typedef struct GDVContext {
29 AVCodecContext *avctx;
30
31 GetByteContext gb;
32 GetByteContext g2;
33 PutByteContext pb;
34
35 uint32_t pal[256];
36 uint8_t *frame;
37 unsigned frame_size;
38 unsigned scale_h, scale_v;
39 } GDVContext;
40
41 typedef struct Bits8 {
42 uint8_t queue;
43 uint8_t fill;
44 } Bits8;
45
46 typedef struct Bits32 {
47 uint32_t queue;
48 uint8_t fill;
49 } Bits32;
50
51 #define PREAMBLE_SIZE 4096
52
gdv_decode_init(AVCodecContext * avctx)53 static av_cold int gdv_decode_init(AVCodecContext *avctx)
54 {
55 GDVContext *gdv = avctx->priv_data;
56 int i, j, k;
57
58 avctx->pix_fmt = AV_PIX_FMT_PAL8;
59 gdv->frame_size = avctx->width * avctx->height + PREAMBLE_SIZE;
60 gdv->frame = av_calloc(gdv->frame_size, 1);
61 if (!gdv->frame)
62 return AVERROR(ENOMEM);
63
64 for (i = 0; i < 2; i++) {
65 for (j = 0; j < 256; j++) {
66 for (k = 0; k < 8; k++) {
67 gdv->frame[i * 2048 + j * 8 + k] = j;
68 }
69 }
70 }
71
72 return 0;
73 }
74
scaleup(uint8_t * dst,const uint8_t * src,int w)75 static void scaleup(uint8_t *dst, const uint8_t *src, int w)
76 {
77 int x;
78 for (x = 0; x < w - 7; x+=8) {
79 dst[x + 0] =
80 dst[x + 1] = src[(x>>1) + 0];
81 dst[x + 2] =
82 dst[x + 3] = src[(x>>1) + 1];
83 dst[x + 4] =
84 dst[x + 5] = src[(x>>1) + 2];
85 dst[x + 6] =
86 dst[x + 7] = src[(x>>1) + 3];
87 }
88 for (; x < w; x++) {
89 dst[x] = src[(x>>1)];
90 }
91 }
92
scaleup_rev(uint8_t * dst,const uint8_t * src,int w)93 static void scaleup_rev(uint8_t *dst, const uint8_t *src, int w)
94 {
95 int x;
96
97 for (x = w - 1; (x+1) & 7; x--) {
98 dst[x] = src[(x>>1)];
99 }
100 for (x -= 7; x >= 0; x -= 8) {
101 dst[x + 6] =
102 dst[x + 7] = src[(x>>1) + 3];
103 dst[x + 4] =
104 dst[x + 5] = src[(x>>1) + 2];
105 dst[x + 2] =
106 dst[x + 3] = src[(x>>1) + 1];
107 dst[x + 0] =
108 dst[x + 1] = src[(x>>1) + 0];
109 }
110 }
111
scaledown(uint8_t * dst,const uint8_t * src,int w)112 static void scaledown(uint8_t *dst, const uint8_t *src, int w)
113 {
114 int x;
115 for (x = 0; x < w - 7; x+=8) {
116 dst[x + 0] = src[2*x + 0];
117 dst[x + 1] = src[2*x + 2];
118 dst[x + 2] = src[2*x + 4];
119 dst[x + 3] = src[2*x + 6];
120 dst[x + 4] = src[2*x + 8];
121 dst[x + 5] = src[2*x +10];
122 dst[x + 6] = src[2*x +12];
123 dst[x + 7] = src[2*x +14];
124 }
125 for (; x < w; x++) {
126 dst[x] = src[2*x];
127 }
128 }
129
rescale(GDVContext * gdv,uint8_t * dst,int w,int h,int scale_v,int scale_h)130 static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, int scale_h)
131 {
132 int j, y;
133
134 if ((gdv->scale_v == scale_v) && (gdv->scale_h == scale_h)) {
135 return;
136 }
137
138 if (gdv->scale_v) {
139 for (j = 0; j < h; j++) {
140 int y = h - j - 1;
141 uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
142 uint8_t *src1 = dst + PREAMBLE_SIZE + (y>>!!gdv->scale_h) * (w>>1);
143
144 scaleup_rev(dst1, src1, w);
145 }
146 } else if (gdv->scale_h) {
147 for (j = 0; j < h; j++) {
148 int y = h - j - 1;
149 uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
150 uint8_t *src1 = dst + PREAMBLE_SIZE + (y>>1) * w;
151 memcpy(dst1, src1, w);
152 }
153 }
154
155 if (scale_h && scale_v) {
156 for (y = 0; y < (h>>1); y++) {
157 uint8_t *dst1 = dst + PREAMBLE_SIZE + y * (w>>1);
158 uint8_t *src1 = dst + PREAMBLE_SIZE + y*2 * w;
159 scaledown(dst1, src1, w>>1);
160 }
161 } else if (scale_h) {
162 for (y = 0; y < (h>>1); y++) {
163 uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
164 uint8_t *src1 = dst + PREAMBLE_SIZE + y*2 * w;
165 memcpy(dst1, src1, w);
166 }
167 } else if (scale_v) {
168 for (y = 0; y < h; y++) {
169 uint8_t *dst1 = dst + PREAMBLE_SIZE + y * w;
170 scaledown(dst1, dst1, w>>1);
171 }
172 }
173
174 gdv->scale_v = scale_v;
175 gdv->scale_h = scale_h;
176 }
177
read_bits2(Bits8 * bits,GetByteContext * gb)178 static int read_bits2(Bits8 *bits, GetByteContext *gb)
179 {
180 int res;
181
182 if (bits->fill == 0) {
183 bits->queue |= bytestream2_get_byte(gb);
184 bits->fill = 8;
185 }
186 res = bits->queue >> 6;
187 bits->queue <<= 2;
188 bits->fill -= 2;
189
190 return res;
191 }
192
fill_bits32(Bits32 * bits,GetByteContext * gb)193 static void fill_bits32(Bits32 *bits, GetByteContext *gb)
194 {
195 bits->queue = bytestream2_get_le32(gb);
196 bits->fill = 32;
197 }
198
read_bits32(Bits32 * bits,GetByteContext * gb,int nbits)199 static int read_bits32(Bits32 *bits, GetByteContext *gb, int nbits)
200 {
201 int res = bits->queue & ((1 << nbits) - 1);
202
203 bits->queue >>= nbits;
204 bits->fill -= nbits;
205 if (bits->fill <= 16) {
206 bits->queue |= bytestream2_get_le16(gb) << bits->fill;
207 bits->fill += 16;
208 }
209
210 return res;
211 }
212
lz_copy(PutByteContext * pb,GetByteContext * g2,int offset,unsigned len)213 static void lz_copy(PutByteContext *pb, GetByteContext *g2, int offset, unsigned len)
214 {
215 int i;
216
217 if (offset == -1) {
218 int c;
219
220 bytestream2_seek(g2, bytestream2_tell_p(pb) - 1, SEEK_SET);
221 c = bytestream2_get_byte(g2);
222 for (i = 0; i < len; i++) {
223 bytestream2_put_byte(pb, c);
224 }
225 } else if (offset < 0) {
226 int start = bytestream2_tell_p(pb) - (-offset);
227
228 bytestream2_seek(g2, start, SEEK_SET);
229 for (i = 0; i < len; i++) {
230 bytestream2_put_byte(pb, bytestream2_get_byte(g2));
231 }
232 } else {
233 int start = bytestream2_tell_p(pb) + offset;
234
235 bytestream2_seek(g2, start, SEEK_SET);
236 for (i = 0; i < len; i++) {
237 bytestream2_put_byte(pb, bytestream2_get_byte(g2));
238 }
239 }
240 }
241
decompress_2(AVCodecContext * avctx)242 static int decompress_2(AVCodecContext *avctx)
243 {
244 GDVContext *gdv = avctx->priv_data;
245 GetByteContext *gb = &gdv->gb;
246 GetByteContext *g2 = &gdv->g2;
247 PutByteContext *pb = &gdv->pb;
248 Bits8 bits = { 0 };
249 int c, i;
250
251 bytestream2_init(g2, gdv->frame, gdv->frame_size);
252 bytestream2_skip_p(pb, PREAMBLE_SIZE);
253
254 for (c = 0; c < 256; c++) {
255 for (i = 0; i < 16; i++) {
256 gdv->frame[c * 16 + i] = c;
257 }
258 }
259
260 while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
261 int tag = read_bits2(&bits, gb);
262 if (tag == 0) {
263 bytestream2_put_byte(pb, bytestream2_get_byte(gb));
264 } else if (tag == 1) {
265 int b = bytestream2_get_byte(gb);
266 int len = (b & 0xF) + 3;
267 int top = (b >> 4) & 0xF;
268 int off = (bytestream2_get_byte(gb) << 4) + top - 4096;
269 lz_copy(pb, g2, off, len);
270 } else if (tag == 2) {
271 int len = (bytestream2_get_byte(gb)) + 2;
272 bytestream2_skip_p(pb, len);
273 } else {
274 break;
275 }
276 }
277
278 if (bytestream2_get_bytes_left_p(pb) > 0)
279 return AVERROR_INVALIDDATA;
280
281 return 0;
282 }
283
decompress_5(AVCodecContext * avctx,unsigned skip)284 static int decompress_5(AVCodecContext *avctx, unsigned skip)
285 {
286 GDVContext *gdv = avctx->priv_data;
287 GetByteContext *gb = &gdv->gb;
288 GetByteContext *g2 = &gdv->g2;
289 PutByteContext *pb = &gdv->pb;
290 Bits8 bits = { 0 };
291
292 bytestream2_init(g2, gdv->frame, gdv->frame_size);
293 bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
294
295 while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
296 int tag = read_bits2(&bits, gb);
297 if (bytestream2_get_bytes_left(gb) < 1)
298 return AVERROR_INVALIDDATA;
299 if (tag == 0) {
300 bytestream2_put_byte(pb, bytestream2_get_byte(gb));
301 } else if (tag == 1) {
302 int b = bytestream2_get_byte(gb);
303 int len = (b & 0xF) + 3;
304 int top = b >> 4;
305 int off = (bytestream2_get_byte(gb) << 4) + top - 4096;
306 lz_copy(pb, g2, off, len);
307 } else if (tag == 2) {
308 int len;
309 int b = bytestream2_get_byte(gb);
310 if (b == 0) {
311 return 0;
312 }
313 if (b != 0xFF) {
314 len = b;
315 } else {
316 len = bytestream2_get_le16(gb);
317 }
318 bytestream2_skip_p(pb, len + 1);
319 } else {
320 int b = bytestream2_get_byte(gb);
321 int len = (b & 0x3) + 2;
322 int off = -(b >> 2) - 1;
323 lz_copy(pb, g2, off, len);
324 }
325 }
326 if (bytestream2_get_bytes_left_p(pb) > 0)
327 return AVERROR_INVALIDDATA;
328 return 0;
329 }
330
decompress_68(AVCodecContext * avctx,unsigned skip,unsigned use8)331 static int decompress_68(AVCodecContext *avctx, unsigned skip, unsigned use8)
332 {
333 GDVContext *gdv = avctx->priv_data;
334 GetByteContext *gb = &gdv->gb;
335 GetByteContext *g2 = &gdv->g2;
336 PutByteContext *pb = &gdv->pb;
337 Bits32 bits;
338
339 bytestream2_init(g2, gdv->frame, gdv->frame_size);
340 bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
341 fill_bits32(&bits, gb);
342
343 while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
344 int tag = read_bits32(&bits, gb, 2);
345 if (tag == 0) {
346 int b = read_bits32(&bits, gb, 1);
347 if (b == 0) {
348 bytestream2_put_byte(pb, bytestream2_get_byte(gb));
349 } else {
350 int i, len = 2;
351 int lbits = 0;
352 while (1) {
353 int val;
354
355 lbits += 1;
356 val = read_bits32(&bits, gb, lbits);
357 len += val;
358 if (val != ((1 << lbits) - 1)) {
359 break;
360 }
361 if (lbits >= 16)
362 return AVERROR_INVALIDDATA;
363 }
364 for (i = 0; i < len; i++) {
365 bytestream2_put_byte(pb, bytestream2_get_byte(gb));
366 }
367 }
368 } else if (tag == 1) {
369 int b = read_bits32(&bits, gb, 1);
370 int len;
371
372 if (b == 0) {
373 len = (read_bits32(&bits, gb, 4)) + 2;
374 } else {
375 int bb = bytestream2_get_byte(gb);
376 if ((bb & 0x80) == 0) {
377 len = bb + 18;
378 } else {
379 int top = (bb & 0x7F) << 8;
380 len = top + bytestream2_get_byte(gb) + 146;
381 }
382 }
383 bytestream2_skip_p(pb, len);
384 } else if (tag == 2) {
385 int i, subtag = read_bits32(&bits, gb, 2);
386
387 if (subtag != 3) {
388 int top = (read_bits32(&bits, gb, 4)) << 8;
389 int offs = top + bytestream2_get_byte(gb);
390 if ((subtag != 0) || (offs <= 0xF80)) {
391 int len = (subtag) + 3;
392 lz_copy(pb, g2, (offs) - 4096, len);
393 } else {
394 int real_off, len, c1, c2;
395
396 if (offs == 0xFFF) {
397 return 0;
398 }
399
400 real_off = ((offs >> 4) & 0x7) + 1;
401 len = ((offs & 0xF) + 2) * 2;
402 c1 = gdv->frame[bytestream2_tell_p(pb) - real_off];
403 c2 = gdv->frame[bytestream2_tell_p(pb) - real_off + 1];
404 for (i = 0; i < len/2; i++) {
405 bytestream2_put_byte(pb, c1);
406 bytestream2_put_byte(pb, c2);
407 }
408 }
409 } else {
410 int b = bytestream2_get_byte(gb);
411 int off = ((b & 0x7F)) + 1;
412 int len = ((b & 0x80) == 0) ? 2 : 3;
413
414 lz_copy(pb, g2, -off, len);
415 }
416 } else {
417 int len;
418 int off;
419 if (use8) {
420 int q, b = bytestream2_get_byte(gb);
421 if ((b & 0xC0) == 0xC0) {
422 len = ((b & 0x3F)) + 8;
423 q = read_bits32(&bits, gb, 4);
424 off = (q << 8) + (bytestream2_get_byte(gb)) + 1;
425 } else {
426 int ofs1;
427 if ((b & 0x80) == 0) {
428 len = ((b >> 4)) + 6;
429 ofs1 = (b & 0xF);
430 } else {
431 len = ((b & 0x3F)) + 14;
432 ofs1 = read_bits32(&bits, gb, 4);
433 }
434 off = (ofs1 << 8) + (bytestream2_get_byte(gb)) - 4096;
435 }
436 } else {
437 int ofs1, b = bytestream2_get_byte(gb);
438
439 if ((b >> 4) == 0xF) {
440 len = bytestream2_get_byte(gb) + 21;
441 } else {
442 len = (b >> 4) + 6;
443 }
444 ofs1 = (b & 0xF);
445 off = (ofs1 << 8) + bytestream2_get_byte(gb) - 4096;
446 }
447 lz_copy(pb, g2, off, len);
448 }
449 }
450
451 if (bytestream2_get_bytes_left_p(pb) > 0)
452 return AVERROR_INVALIDDATA;
453
454 return 0;
455 }
456
gdv_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)457 static int gdv_decode_frame(AVCodecContext *avctx, void *data,
458 int *got_frame, AVPacket *avpkt)
459 {
460 GDVContext *gdv = avctx->priv_data;
461 GetByteContext *gb = &gdv->gb;
462 PutByteContext *pb = &gdv->pb;
463 AVFrame *frame = data;
464 int ret, i;
465 buffer_size_t pal_size;
466 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
467 int compression;
468 unsigned flags;
469 uint8_t *dst;
470
471 bytestream2_init(gb, avpkt->data, avpkt->size);
472 bytestream2_init_writer(pb, gdv->frame, gdv->frame_size);
473
474 flags = bytestream2_get_le32(gb);
475 compression = flags & 0xF;
476
477 if (compression == 4 || compression == 7 || compression > 8)
478 return AVERROR_INVALIDDATA;
479
480 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
481 return ret;
482 if (pal && pal_size == AVPALETTE_SIZE)
483 memcpy(gdv->pal, pal, AVPALETTE_SIZE);
484
485 if (compression < 2 && bytestream2_get_bytes_left(gb) < 256*3)
486 return AVERROR_INVALIDDATA;
487 rescale(gdv, gdv->frame, avctx->width, avctx->height,
488 !!(flags & 0x10), !!(flags & 0x20));
489
490 switch (compression) {
491 case 1:
492 memset(gdv->frame + PREAMBLE_SIZE, 0, gdv->frame_size - PREAMBLE_SIZE);
493 case 0:
494 for (i = 0; i < 256; i++) {
495 unsigned r = bytestream2_get_byte(gb);
496 unsigned g = bytestream2_get_byte(gb);
497 unsigned b = bytestream2_get_byte(gb);
498 gdv->pal[i] = 0xFFU << 24 | r << 18 | g << 10 | b << 2;
499 }
500 break;
501 case 2:
502 ret = decompress_2(avctx);
503 break;
504 case 3:
505 break;
506 case 5:
507 ret = decompress_5(avctx, flags >> 8);
508 break;
509 case 6:
510 ret = decompress_68(avctx, flags >> 8, 0);
511 break;
512 case 8:
513 ret = decompress_68(avctx, flags >> 8, 1);
514 break;
515 default:
516 av_assert0(0);
517 }
518 if (ret < 0)
519 return ret;
520
521 memcpy(frame->data[1], gdv->pal, AVPALETTE_SIZE);
522 dst = frame->data[0];
523
524 if (!gdv->scale_v && !gdv->scale_h) {
525 int sidx = PREAMBLE_SIZE, didx = 0;
526 int y;
527
528 for (y = 0; y < avctx->height; y++) {
529 memcpy(dst + didx, gdv->frame + sidx, avctx->width);
530 sidx += avctx->width;
531 didx += frame->linesize[0];
532 }
533 } else {
534 int sidx = PREAMBLE_SIZE, didx = 0;
535 int y;
536
537 for (y = 0; y < avctx->height; y++) {
538 if (!gdv->scale_v) {
539 memcpy(dst + didx, gdv->frame + sidx, avctx->width);
540 } else {
541 uint8_t *dst2 = dst + didx;
542 uint8_t *src2 = gdv->frame + sidx;
543
544 scaleup(dst2, src2, avctx->width);
545 }
546 if (!gdv->scale_h || ((y & 1) == 1)) {
547 sidx += !gdv->scale_v ? avctx->width : avctx->width/2;
548 }
549 didx += frame->linesize[0];
550 }
551 }
552
553 *got_frame = 1;
554
555 return avpkt->size;
556 }
557
gdv_decode_close(AVCodecContext * avctx)558 static av_cold int gdv_decode_close(AVCodecContext *avctx)
559 {
560 GDVContext *gdv = avctx->priv_data;
561 av_freep(&gdv->frame);
562 return 0;
563 }
564
565 AVCodec ff_gdv_decoder = {
566 .name = "gdv",
567 .long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
568 .type = AVMEDIA_TYPE_VIDEO,
569 .id = AV_CODEC_ID_GDV,
570 .priv_data_size = sizeof(GDVContext),
571 .init = gdv_decode_init,
572 .close = gdv_decode_close,
573 .decode = gdv_decode_frame,
574 .capabilities = AV_CODEC_CAP_DR1,
575 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
576 };
577