FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/cdtoons.c
Date: 2022-07-04 00:18:54
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 "codec_internal.h"
35 #include "internal.h"
36
37 #define CDTOONS_HEADER_SIZE 44
38 #define CDTOONS_MAX_SPRITES 1200
39
40 typedef struct CDToonsSprite {
41 uint16_t flags;
42 uint16_t owner_frame;
43 uint16_t start_frame;
44 uint16_t end_frame;
45 unsigned int alloc_size;
46 uint32_t size;
47 uint8_t *data;
48 int active;
49 } CDToonsSprite;
50
51 typedef struct CDToonsContext {
52 AVFrame *frame;
53
54 uint16_t last_pal_id; ///< The index of the active palette sprite.
55 uint32_t pal[256]; ///< The currently-used palette data.
56 CDToonsSprite sprites[CDTOONS_MAX_SPRITES];
57 } CDToonsContext;
58
59 static int cdtoons_render_sprite(AVCodecContext *avctx, const uint8_t *data,
60 uint32_t data_size,
61 int dst_x, int dst_y, int width, int height)
62 {
63 CDToonsContext *c = avctx->priv_data;
64 const uint8_t *next_line = data;
65 const uint8_t *end = data + data_size;
66 uint16_t line_size;
67 uint8_t *dest;
68 int skip = 0, to_skip, x;
69
70 if (dst_x + width > avctx->width)
71 width = avctx->width - dst_x;
72 if (dst_y + height > avctx->height)
73 height = avctx->height - dst_y;
74
75 if (dst_x < 0) {
76 /* we need to skip the start of the scanlines */
77 skip = -dst_x;
78 if (width <= skip)
79 return 0;
80 dst_x = 0;
81 }
82
83 for (int y = 0; y < height; y++) {
84 /* one scanline at a time, size is provided */
85 data = next_line;
86 if (end - data < 2)
87 return 1;
88 line_size = bytestream_get_be16(&data);
89 if (end - data < line_size)
90 return 1;
91 next_line = data + line_size;
92 if (dst_y + y < 0)
93 continue;
94
95 dest = c->frame->data[0] + (dst_y + y) * c->frame->linesize[0] + dst_x;
96
97 to_skip = skip;
98 x = 0;
99 while (x < width - skip) {
100 int raw, size, step;
101 uint8_t val;
102
103 if (data >= end)
104 return 1;
105
106 val = bytestream_get_byte(&data);
107 raw = !(val & 0x80);
108 size = (int)(val & 0x7F) + 1;
109
110 /* skip the start of a scanline if it is off-screen */
111 if (to_skip >= size) {
112 to_skip -= size;
113 if (raw) {
114 step = size;
115 } else {
116 step = 1;
117 }
118 if (next_line - data < step)
119 return 1;
120 data += step;
121 continue;
122 } else if (to_skip) {
123 size -= to_skip;
124 if (raw) {
125 if (next_line - data < to_skip)
126 return 1;
127 data += to_skip;
128 }
129 to_skip = 0;
130 }
131
132 if (x + size >= width - skip)
133 size = width - skip - x;
134
135 /* either raw data, or a run of a single color */
136 if (raw) {
137 if (next_line - data < size)
138 return 1;
139 memcpy(dest + x, data, size);
140 data += size;
141 } else {
142 uint8_t color = bytestream_get_byte(&data);
143 /* ignore transparent runs */
144 if (color)
145 memset(dest + x, color, size);
146 }
147 x += size;
148 }
149 }
150
151 return 0;
152 }
153
154 static int cdtoons_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
155 int *got_frame, AVPacket *avpkt)
156 {
157 CDToonsContext *c = avctx->priv_data;
158 const uint8_t *buf = avpkt->data;
159 const uint8_t *eod = avpkt->data + avpkt->size;
160 const int buf_size = avpkt->size;
161 uint16_t frame_id;
162 uint8_t background_color;
163 uint16_t sprite_count, sprite_offset;
164 uint8_t referenced_count;
165 uint16_t palette_id;
166 uint8_t palette_set;
167 int ret;
168 int saw_embedded_sprites = 0;
169
170 if (buf_size < CDTOONS_HEADER_SIZE)
171 return AVERROR_INVALIDDATA;
172
173 if ((ret = ff_reget_buffer(avctx, c->frame, 0)) < 0)
174 return ret;
175
176 /* a lot of the header is useless junk in the absence of
177 * dirty rectangling etc */
178 buf += 2; /* version? (always 9?) */
179 frame_id = bytestream_get_be16(&buf);
180 buf += 2; /* blocks_valid_until */
181 buf += 1;
182 background_color = bytestream_get_byte(&buf);
183 buf += 16; /* clip rect, dirty rect */
184 buf += 4; /* flags */
185 sprite_count = bytestream_get_be16(&buf);
186 sprite_offset = bytestream_get_be16(&buf);
187 buf += 2; /* max block id? */
188 referenced_count = bytestream_get_byte(&buf);
189 buf += 1;
190 palette_id = bytestream_get_be16(&buf);
191 palette_set = bytestream_get_byte(&buf);
192 buf += 5;
193
194 if (sprite_offset > buf_size)
195 return AVERROR_INVALIDDATA;
196
197 /* read new sprites introduced in this frame */
198 buf = avpkt->data + sprite_offset;
199 while (sprite_count--) {
200 uint32_t size;
201 uint16_t sprite_id;
202
203 if (buf + 14 > eod)
204 return AVERROR_INVALIDDATA;
205
206 sprite_id = bytestream_get_be16(&buf);
207 if (sprite_id >= CDTOONS_MAX_SPRITES) {
208 av_log(avctx, AV_LOG_ERROR,
209 "Sprite ID %d is too high.\n", sprite_id);
210 return AVERROR_INVALIDDATA;
211 }
212 if (c->sprites[sprite_id].active) {
213 av_log(avctx, AV_LOG_ERROR,
214 "Sprite ID %d is a duplicate.\n", sprite_id);
215 return AVERROR_INVALIDDATA;
216 }
217
218 c->sprites[sprite_id].flags = bytestream_get_be16(&buf);
219 size = bytestream_get_be32(&buf);
220 if (size < 14) {
221 av_log(avctx, AV_LOG_ERROR,
222 "Sprite only has %d bytes of data.\n", size);
223 return AVERROR_INVALIDDATA;
224 }
225 size -= 14;
226 c->sprites[sprite_id].size = size;
227 c->sprites[sprite_id].owner_frame = frame_id;
228 c->sprites[sprite_id].start_frame = bytestream_get_be16(&buf);
229 c->sprites[sprite_id].end_frame = bytestream_get_be16(&buf);
230 buf += 2;
231
232 if (size > buf_size || buf + size > eod)
233 return AVERROR_INVALIDDATA;
234
235 av_fast_padded_malloc(&c->sprites[sprite_id].data, &c->sprites[sprite_id].alloc_size, size);
236 if (!c->sprites[sprite_id].data)
237 return AVERROR(ENOMEM);
238
239 c->sprites[sprite_id].active = 1;
240
241 bytestream_get_buffer(&buf, c->sprites[sprite_id].data, size);
242 }
243
244 /* render any embedded sprites */
245 while (buf < eod) {
246 uint32_t tag, size;
247 if (buf + 8 > eod) {
248 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for embedded sprites.\n");
249 return AVERROR_INVALIDDATA;
250 }
251 tag = bytestream_get_be32(&buf);
252 size = bytestream_get_be32(&buf);
253 if (tag == MKBETAG('D', 'i', 'f', 'f')) {
254 uint16_t diff_count;
255 if (buf + 10 > eod) {
256 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame.\n");
257 return AVERROR_INVALIDDATA;
258 }
259 diff_count = bytestream_get_be16(&buf);
260 buf += 8; /* clip rect? */
261 for (int i = 0; i < diff_count; i++) {
262 int16_t top, left;
263 uint16_t diff_size, width, height;
264
265 if (buf + 16 > eod) {
266 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame header.\n");
267 return AVERROR_INVALIDDATA;
268 }
269
270 top = bytestream_get_be16(&buf);
271 left = bytestream_get_be16(&buf);
272 buf += 4; /* bottom, right */
273 diff_size = bytestream_get_be32(&buf);
274 width = bytestream_get_be16(&buf);
275 height = bytestream_get_be16(&buf);
276 if (diff_size < 8 || diff_size - 4 > eod - buf) {
277 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame data.\n");
278 return AVERROR_INVALIDDATA;
279 }
280 if (cdtoons_render_sprite(avctx, buf + 4, diff_size - 8,
281 left, top, width, height)) {
282 av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
283 }
284 buf += diff_size - 4;
285 }
286 saw_embedded_sprites = 1;
287 } else {
288 /* we don't care about any other entries */
289 if (size < 8 || size - 8 > eod - buf) {
290 av_log(avctx, AV_LOG_WARNING, "Ran out of data for ignored entry (size %X, %d left).\n", size, (int)(eod - buf));
291 return AVERROR_INVALIDDATA;
292 }
293 buf += (size - 8);
294 }
295 }
296
297 /* was an intra frame? */
298 if (saw_embedded_sprites)
299 goto done;
300
301 /* render any referenced sprites */
302 buf = avpkt->data + CDTOONS_HEADER_SIZE;
303 eod = avpkt->data + sprite_offset;
304 for (int i = 0; i < referenced_count; i++) {
305 const uint8_t *block_data;
306 uint16_t sprite_id, width, height;
307 int16_t top, left, right;
308
309 if (buf + 10 > eod) {
310 av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data when rendering.\n");
311 return AVERROR_INVALIDDATA;
312 }
313
314 sprite_id = bytestream_get_be16(&buf);
315 top = bytestream_get_be16(&buf);
316 left = bytestream_get_be16(&buf);
317 buf += 2; /* bottom */
318 right = bytestream_get_be16(&buf);
319
320 if ((i == 0) && (sprite_id == 0)) {
321 /* clear background */
322 memset(c->frame->data[0], background_color,
323 c->frame->linesize[0] * avctx->height);
324 }
325
326 if (!right)
327 continue;
328 if (sprite_id >= CDTOONS_MAX_SPRITES) {
329 av_log(avctx, AV_LOG_ERROR,
330 "Sprite ID %d is too high.\n", sprite_id);
331 return AVERROR_INVALIDDATA;
332 }
333
334 block_data = c->sprites[sprite_id].data;
335 if (!c->sprites[sprite_id].active) {
336 /* this can happen when seeking around */
337 av_log(avctx, AV_LOG_WARNING, "Sprite %d is missing.\n", sprite_id);
338 continue;
339 }
340 if (c->sprites[sprite_id].size < 14) {
341 av_log(avctx, AV_LOG_ERROR, "Sprite %d is too small.\n", sprite_id);
342 continue;
343 }
344
345 height = bytestream_get_be16(&block_data);
346 width = bytestream_get_be16(&block_data);
347 block_data += 10;
348 if (cdtoons_render_sprite(avctx, block_data,
349 c->sprites[sprite_id].size - 14,
350 left, top, width, height)) {
351 av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
352 }
353 }
354
355 if (palette_id && (palette_id != c->last_pal_id)) {
356 if (palette_id >= CDTOONS_MAX_SPRITES) {
357 av_log(avctx, AV_LOG_ERROR,
358 "Palette ID %d is too high.\n", palette_id);
359 return AVERROR_INVALIDDATA;
360 }
361 if (!c->sprites[palette_id].active) {
362 /* this can happen when seeking around */
363 av_log(avctx, AV_LOG_WARNING,
364 "Palette ID %d is missing.\n", palette_id);
365 goto done;
366 }
367 if (c->sprites[palette_id].size != 256 * 2 * 3) {
368 av_log(avctx, AV_LOG_ERROR,
369 "Palette ID %d is wrong size (%d).\n",
370 palette_id, c->sprites[palette_id].size);
371 return AVERROR_INVALIDDATA;
372 }
373 c->last_pal_id = palette_id;
374 if (!palette_set) {
375 uint8_t *palette_data = c->sprites[palette_id].data;
376 for (int i = 0; i < 256; i++) {
377 /* QuickTime-ish palette: 16-bit RGB components */
378 unsigned r, g, b;
379 r = *palette_data;
380 g = *(palette_data + 2);
381 b = *(palette_data + 4);
382 c->pal[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
383 palette_data += 6;
384 }
385 /* first palette entry indicates transparency */
386 c->pal[0] = 0;
387 c->frame->palette_has_changed = 1;
388 }
389 }
390
391 done:
392 /* discard outdated blocks */
393 for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
394 if (c->sprites[i].end_frame > frame_id)
395 continue;
396 c->sprites[i].active = 0;
397 }
398
399 memcpy(c->frame->data[1], c->pal, AVPALETTE_SIZE);
400
401 if ((ret = av_frame_ref(rframe, c->frame)) < 0)
402 return ret;
403
404 *got_frame = 1;
405
406 /* always report that the buffer was completely consumed */
407 return buf_size;
408 }
409
410 static av_cold int cdtoons_decode_init(AVCodecContext *avctx)
411 {
412 CDToonsContext *c = avctx->priv_data;
413
414 avctx->pix_fmt = AV_PIX_FMT_PAL8;
415 c->last_pal_id = 0;
416 c->frame = av_frame_alloc();
417 if (!c->frame)
418 return AVERROR(ENOMEM);
419
420 return 0;
421 }
422
423 static void cdtoons_flush(AVCodecContext *avctx)
424 {
425 CDToonsContext *c = avctx->priv_data;
426
427 c->last_pal_id = 0;
428 for (int i = 0; i < CDTOONS_MAX_SPRITES; i++)
429 c->sprites[i].active = 0;
430 }
431
432 static av_cold int cdtoons_decode_end(AVCodecContext *avctx)
433 {
434 CDToonsContext *c = avctx->priv_data;
435
436 for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
437 av_freep(&c->sprites[i].data);
438 c->sprites[i].active = 0;
439 }
440
441 av_frame_free(&c->frame);
442
443 return 0;
444 }
445
446 const FFCodec ff_cdtoons_decoder = {
447 .p.name = "cdtoons",
448 .p.long_name = NULL_IF_CONFIG_SMALL("CDToons video"),
449 .p.type = AVMEDIA_TYPE_VIDEO,
450 .p.id = AV_CODEC_ID_CDTOONS,
451 .priv_data_size = sizeof(CDToonsContext),
452 .init = cdtoons_decode_init,
453 .close = cdtoons_decode_end,
454 FF_CODEC_DECODE_CB(cdtoons_decode_frame),
455 .p.capabilities = AV_CODEC_CAP_DR1,
456 .flush = cdtoons_flush,
457 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
458 };
459