FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/cdtoons.c
Date: 2021-09-22 05:58:22
Exec Total Coverage
Lines: 0 235 0.0%
Branches: 0 130 0.0%

Line Branch Exec Source
1 /*
2 * CDToons video decoder
3 * Copyright (C) 2020 Alyssa Milburn <amilburn@zall.org>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * CDToons video decoder
25 * @author Alyssa Milburn <amilburn@zall.org>
26 */
27
28 #include <stdint.h>
29
30 #include "libavutil/attributes.h"
31 #include "libavutil/internal.h"
32 #include "avcodec.h"
33 #include "bytestream.h"
34 #include "internal.h"
35
36 #define CDTOONS_HEADER_SIZE 44
37 #define CDTOONS_MAX_SPRITES 1200
38
39 typedef struct CDToonsSprite {
40 uint16_t flags;
41 uint16_t owner_frame;
42 uint16_t start_frame;
43 uint16_t end_frame;
44 unsigned int alloc_size;
45 uint32_t size;
46 uint8_t *data;
47 int active;
48 } CDToonsSprite;
49
50 typedef struct CDToonsContext {
51 AVFrame *frame;
52
53 uint16_t last_pal_id; ///< The index of the active palette sprite.
54 uint32_t pal[256]; ///< The currently-used palette data.
55 CDToonsSprite sprites[CDTOONS_MAX_SPRITES];
56 } CDToonsContext;
57
58 static int cdtoons_render_sprite(AVCodecContext *avctx, const uint8_t *data,
59 uint32_t data_size,
60 int dst_x, int dst_y, int width, int height)
61 {
62 CDToonsContext *c = avctx->priv_data;
63 const uint8_t *next_line = data;
64 const uint8_t *end = data + data_size;
65 uint16_t line_size;
66 uint8_t *dest;
67 int skip = 0, to_skip, x;
68
69 if (dst_x + width > avctx->width)
70 width = avctx->width - dst_x;
71 if (dst_y + height > avctx->height)
72 height = avctx->height - dst_y;
73
74 if (dst_x < 0) {
75 /* we need to skip the start of the scanlines */
76 skip = -dst_x;
77 if (width <= skip)
78 return 0;
79 dst_x = 0;
80 }
81
82 for (int y = 0; y < height; y++) {
83 /* one scanline at a time, size is provided */
84 data = next_line;
85 if (end - data < 2)
86 return 1;
87 line_size = bytestream_get_be16(&data);
88 if (end - data < line_size)
89 return 1;
90 next_line = data + line_size;
91 if (dst_y + y < 0)
92 continue;
93
94 dest = c->frame->data[0] + (dst_y + y) * c->frame->linesize[0] + dst_x;
95
96 to_skip = skip;
97 x = 0;
98 while (x < width - skip) {
99 int raw, size, step;
100 uint8_t val;
101
102 if (data >= end)
103 return 1;
104
105 val = bytestream_get_byte(&data);
106 raw = !(val & 0x80);
107 size = (int)(val & 0x7F) + 1;
108
109 /* skip the start of a scanline if it is off-screen */
110 if (to_skip >= size) {
111 to_skip -= size;
112 if (raw) {
113 step = size;
114 } else {
115 step = 1;
116 }
117 if (next_line - data < step)
118 return 1;
119 data += step;
120 continue;
121 } else if (to_skip) {
122 size -= to_skip;
123 if (raw) {
124 if (next_line - data < to_skip)
125 return 1;
126 data += to_skip;
127 }
128 to_skip = 0;
129 }
130
131 if (x + size >= width - skip)
132 size = width - skip - x;
133
134 /* either raw data, or a run of a single color */
135 if (raw) {
136 if (next_line - data < size)
137 return 1;
138 memcpy(dest + x, data, size);
139 data += size;
140 } else {
141 uint8_t color = bytestream_get_byte(&data);
142 /* ignore transparent runs */
143 if (color)
144 memset(dest + x, color, size);
145 }
146 x += size;
147 }
148 }
149
150 return 0;
151 }
152
153 static int cdtoons_decode_frame(AVCodecContext *avctx, void *data,
154 int *got_frame, AVPacket *avpkt)
155 {
156 CDToonsContext *c = avctx->priv_data;
157 const uint8_t *buf = avpkt->data;
158 const uint8_t *eod = avpkt->data + avpkt->size;
159 const int buf_size = avpkt->size;
160 uint16_t frame_id;
161 uint8_t background_color;
162 uint16_t sprite_count, sprite_offset;
163 uint8_t referenced_count;
164 uint16_t palette_id;
165 uint8_t palette_set;
166 int ret;
167 int saw_embedded_sprites = 0;
168
169 if (buf_size < CDTOONS_HEADER_SIZE)
170 return AVERROR_INVALIDDATA;
171
172 if ((ret = ff_reget_buffer(avctx, c->frame, 0)) < 0)
173 return ret;
174
175 /* a lot of the header is useless junk in the absence of
176 * dirty rectangling etc */
177 buf += 2; /* version? (always 9?) */
178 frame_id = bytestream_get_be16(&buf);
179 buf += 2; /* blocks_valid_until */
180 buf += 1;
181 background_color = bytestream_get_byte(&buf);
182 buf += 16; /* clip rect, dirty rect */
183 buf += 4; /* flags */
184 sprite_count = bytestream_get_be16(&buf);
185 sprite_offset = bytestream_get_be16(&buf);
186 buf += 2; /* max block id? */
187 referenced_count = bytestream_get_byte(&buf);
188 buf += 1;
189 palette_id = bytestream_get_be16(&buf);
190 palette_set = bytestream_get_byte(&buf);
191 buf += 5;
192
193 if (sprite_offset > buf_size)
194 return AVERROR_INVALIDDATA;
195
196 /* read new sprites introduced in this frame */
197 buf = avpkt->data + sprite_offset;
198 while (sprite_count--) {
199 uint32_t size;
200 uint16_t sprite_id;
201
202 if (buf + 14 > eod)
203 return AVERROR_INVALIDDATA;
204
205 sprite_id = bytestream_get_be16(&buf);
206 if (sprite_id >= CDTOONS_MAX_SPRITES) {
207 av_log(avctx, AV_LOG_ERROR,
208 "Sprite ID %d is too high.\n", sprite_id);
209 return AVERROR_INVALIDDATA;
210 }
211 if (c->sprites[sprite_id].active) {
212 av_log(avctx, AV_LOG_ERROR,
213 "Sprite ID %d is a duplicate.\n", sprite_id);
214 return AVERROR_INVALIDDATA;
215 }
216
217 c->sprites[sprite_id].flags = bytestream_get_be16(&buf);
218 size = bytestream_get_be32(&buf);
219 if (size < 14) {
220 av_log(avctx, AV_LOG_ERROR,
221 "Sprite only has %d bytes of data.\n", size);
222 return AVERROR_INVALIDDATA;
223 }
224 size -= 14;
225 c->sprites[sprite_id].size = size;
226 c->sprites[sprite_id].owner_frame = frame_id;
227 c->sprites[sprite_id].start_frame = bytestream_get_be16(&buf);
228 c->sprites[sprite_id].end_frame = bytestream_get_be16(&buf);
229 buf += 2;
230
231 if (size > buf_size || buf + size > eod)
232 return AVERROR_INVALIDDATA;
233
234 av_fast_padded_malloc(&c->sprites[sprite_id].data, &c->sprites[sprite_id].alloc_size, size);
235 if (!c->sprites[sprite_id].data)
236 return AVERROR(ENOMEM);
237
238 c->sprites[sprite_id].active = 1;
239
240 bytestream_get_buffer(&buf, c->sprites[sprite_id].data, size);
241 }
242
243 /* render any embedded sprites */
244 while (buf < eod) {
245 uint32_t tag, size;
246 if (buf + 8 > eod) {
247 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for embedded sprites.\n");
248 return AVERROR_INVALIDDATA;
249 }
250 tag = bytestream_get_be32(&buf);
251 size = bytestream_get_be32(&buf);
252 if (tag == MKBETAG('D', 'i', 'f', 'f')) {
253 uint16_t diff_count;
254 if (buf + 10 > eod) {
255 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame.\n");
256 return AVERROR_INVALIDDATA;
257 }
258 diff_count = bytestream_get_be16(&buf);
259 buf += 8; /* clip rect? */
260 for (int i = 0; i < diff_count; i++) {
261 int16_t top, left;
262 uint16_t diff_size, width, height;
263
264 if (buf + 16 > eod) {
265 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame header.\n");
266 return AVERROR_INVALIDDATA;
267 }
268
269 top = bytestream_get_be16(&buf);
270 left = bytestream_get_be16(&buf);
271 buf += 4; /* bottom, right */
272 diff_size = bytestream_get_be32(&buf);
273 width = bytestream_get_be16(&buf);
274 height = bytestream_get_be16(&buf);
275 if (diff_size < 8 || diff_size - 4 > eod - buf) {
276 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame data.\n");
277 return AVERROR_INVALIDDATA;
278 }
279 if (cdtoons_render_sprite(avctx, buf + 4, diff_size - 8,
280 left, top, width, height)) {
281 av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
282 }
283 buf += diff_size - 4;
284 }
285 saw_embedded_sprites = 1;
286 } else {
287 /* we don't care about any other entries */
288 if (size < 8 || size - 8 > eod - buf) {
289 av_log(avctx, AV_LOG_WARNING, "Ran out of data for ignored entry (size %X, %d left).\n", size, (int)(eod - buf));
290 return AVERROR_INVALIDDATA;
291 }
292 buf += (size - 8);
293 }
294 }
295
296 /* was an intra frame? */
297 if (saw_embedded_sprites)
298 goto done;
299
300 /* render any referenced sprites */
301 buf = avpkt->data + CDTOONS_HEADER_SIZE;
302 eod = avpkt->data + sprite_offset;
303 for (int i = 0; i < referenced_count; i++) {
304 const uint8_t *block_data;
305 uint16_t sprite_id, width, height;
306 int16_t top, left, right;
307
308 if (buf + 10 > eod) {
309 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data when rendering.\n");
310 return AVERROR_INVALIDDATA;
311 }
312
313 sprite_id = bytestream_get_be16(&buf);
314 top = bytestream_get_be16(&buf);
315 left = bytestream_get_be16(&buf);
316 buf += 2; /* bottom */
317 right = bytestream_get_be16(&buf);
318
319 if ((i == 0) && (sprite_id == 0)) {
320 /* clear background */
321 memset(c->frame->data[0], background_color,
322 c->frame->linesize[0] * avctx->height);
323 }
324
325 if (!right)
326 continue;
327 if (sprite_id >= CDTOONS_MAX_SPRITES) {
328 av_log(avctx, AV_LOG_ERROR,
329 "Sprite ID %d is too high.\n", sprite_id);
330 return AVERROR_INVALIDDATA;
331 }
332
333 block_data = c->sprites[sprite_id].data;
334 if (!c->sprites[sprite_id].active) {
335 /* this can happen when seeking around */
336 av_log(avctx, AV_LOG_WARNING, "Sprite %d is missing.\n", sprite_id);
337 continue;
338 }
339 if (c->sprites[sprite_id].size < 14) {
340 av_log(avctx, AV_LOG_ERROR, "Sprite %d is too small.\n", sprite_id);
341 continue;
342 }
343
344 height = bytestream_get_be16(&block_data);
345 width = bytestream_get_be16(&block_data);
346 block_data += 10;
347 if (cdtoons_render_sprite(avctx, block_data,
348 c->sprites[sprite_id].size - 14,
349 left, top, width, height)) {
350 av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
351 }
352 }
353
354 if (palette_id && (palette_id != c->last_pal_id)) {
355 if (palette_id >= CDTOONS_MAX_SPRITES) {
356 av_log(avctx, AV_LOG_ERROR,
357 "Palette ID %d is too high.\n", palette_id);
358 return AVERROR_INVALIDDATA;
359 }
360 if (!c->sprites[palette_id].active) {
361 /* this can happen when seeking around */
362 av_log(avctx, AV_LOG_WARNING,
363 "Palette ID %d is missing.\n", palette_id);
364 goto done;
365 }
366 if (c->sprites[palette_id].size != 256 * 2 * 3) {
367 av_log(avctx, AV_LOG_ERROR,
368 "Palette ID %d is wrong size (%d).\n",
369 palette_id, c->sprites[palette_id].size);
370 return AVERROR_INVALIDDATA;
371 }
372 c->last_pal_id = palette_id;
373 if (!palette_set) {
374 uint8_t *palette_data = c->sprites[palette_id].data;
375 for (int i = 0; i < 256; i++) {
376 /* QuickTime-ish palette: 16-bit RGB components */
377 unsigned r, g, b;
378 r = *palette_data;
379 g = *(palette_data + 2);
380 b = *(palette_data + 4);
381 c->pal[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
382 palette_data += 6;
383 }
384 /* first palette entry indicates transparency */
385 c->pal[0] = 0;
386 c->frame->palette_has_changed = 1;
387 }
388 }
389
390 done:
391 /* discard outdated blocks */
392 for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
393 if (c->sprites[i].end_frame > frame_id)
394 continue;
395 c->sprites[i].active = 0;
396 }
397
398 memcpy(c->frame->data[1], c->pal, AVPALETTE_SIZE);
399
400 if ((ret = av_frame_ref(data, c->frame)) < 0)
401 return ret;
402
403 *got_frame = 1;
404
405 /* always report that the buffer was completely consumed */
406 return buf_size;
407 }
408
409 static av_cold int cdtoons_decode_init(AVCodecContext *avctx)
410 {
411 CDToonsContext *c = avctx->priv_data;
412
413 avctx->pix_fmt = AV_PIX_FMT_PAL8;
414 c->last_pal_id = 0;
415 c->frame = av_frame_alloc();
416 if (!c->frame)
417 return AVERROR(ENOMEM);
418
419 return 0;
420 }
421
422 static void cdtoons_flush(AVCodecContext *avctx)
423 {
424 CDToonsContext *c = avctx->priv_data;
425
426 c->last_pal_id = 0;
427 for (int i = 0; i < CDTOONS_MAX_SPRITES; i++)
428 c->sprites[i].active = 0;
429 }
430
431 static av_cold int cdtoons_decode_end(AVCodecContext *avctx)
432 {
433 CDToonsContext *c = avctx->priv_data;
434
435 for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
436 av_freep(&c->sprites[i].data);
437 c->sprites[i].active = 0;
438 }
439
440 av_frame_free(&c->frame);
441
442 return 0;
443 }
444
445 const AVCodec ff_cdtoons_decoder = {
446 .name = "cdtoons",
447 .long_name = NULL_IF_CONFIG_SMALL("CDToons video"),
448 .type = AVMEDIA_TYPE_VIDEO,
449 .id = AV_CODEC_ID_CDTOONS,
450 .priv_data_size = sizeof(CDToonsContext),
451 .init = cdtoons_decode_init,
452 .close = cdtoons_decode_end,
453 .decode = cdtoons_decode_frame,
454 .capabilities = AV_CODEC_CAP_DR1,
455 .flush = cdtoons_flush,
456 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
457 };
458