FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/gdv.c
Date: 2021-09-24 20:55:06
Exec Total Coverage
Lines: 0 325 0.0%
Branches: 0 178 0.0%

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