FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/dfa.c
Date: 2025-10-29 00:48:36
Exec Total Coverage
Lines: 132 255 51.8%
Functions: 6 11 54.5%
Branches: 70 160 43.8%
Line Branch Exec Source
1 /*
2 * Chronomaster DFA Video Decoder
3 * Copyright (c) 2011 Konstantin Shishkov
4 * based on work by Vladimir "VAG" Gneushev
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 <inttypes.h>
24
25 #include "avcodec.h"
26 #include "bytestream.h"
27 #include "codec_internal.h"
28 #include "decode.h"
29
30 #include "libavutil/avassert.h"
31 #include "libavutil/imgutils.h"
32 #include "libavutil/mem.h"
33
34 typedef struct DfaContext {
35 uint32_t pal[256];
36 uint8_t *frame_buf;
37 } DfaContext;
38
39 22 static av_cold int dfa_decode_init(AVCodecContext *avctx)
40 {
41 22 DfaContext *s = avctx->priv_data;
42
43 22 avctx->pix_fmt = AV_PIX_FMT_PAL8;
44
45
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 22 if (!avctx->width || !avctx->height || FFMAX(avctx->width, avctx->height) >= (1<<16))
46 ✗ return AVERROR_INVALIDDATA;
47
48
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 22 av_assert0(av_image_check_size(avctx->width, avctx->height, 0, avctx) >= 0);
49
50 22 s->frame_buf = av_mallocz(avctx->width * avctx->height);
51
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 22 if (!s->frame_buf)
52 ✗ return AVERROR(ENOMEM);
53
54 22 return 0;
55 }
56
57 ✗ static int decode_copy(GetByteContext *gb, uint8_t *frame, int width, int height)
58 {
59 ✗ const int size = width * height;
60
61 ✗ if (bytestream2_get_buffer(gb, frame, size) != size)
62 ✗ return AVERROR_INVALIDDATA;
63 ✗ return 0;
64 }
65
66 35 static int decode_tsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
67 {
68 35 const uint8_t *frame_start = frame;
69 35 const uint8_t *frame_end = frame + width * height;
70 35 int mask = 0x10000, bitbuf = 0;
71 int v, count;
72 unsigned segments;
73 unsigned offset;
74
75 35 segments = bytestream2_get_le32(gb);
76 35 offset = bytestream2_get_le32(gb);
77
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 35 if (segments == 0 && offset == frame_end - frame)
78 1 return 0; // skip frame
79
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 34 if (frame_end - frame <= offset)
80 ✗ return AVERROR_INVALIDDATA;
81 34 frame += offset;
82
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 566915 while (segments--) {
83
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 566883 if (bytestream2_get_bytes_left(gb) < 2)
84 2 return AVERROR_INVALIDDATA;
85
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 566881 if (mask == 0x10000) {
86 35445 bitbuf = bytestream2_get_le16u(gb);
87 35445 mask = 1;
88 }
89
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 566881 if (frame_end - frame < 2)
90 ✗ return AVERROR_INVALIDDATA;
91
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 566881 if (bitbuf & mask) {
92 222937 v = bytestream2_get_le16(gb);
93 222937 offset = (v & 0x1FFF) << 1;
94 222937 count = ((v >> 13) + 2) << 1;
95
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 222937 if (frame - frame_start < offset || frame_end - frame < count)
96 ✗ return AVERROR_INVALIDDATA;
97 222937 av_memcpy_backptr(frame, offset, count);
98 222937 frame += count;
99 } else {
100 343944 *frame++ = bytestream2_get_byte(gb);
101 343944 *frame++ = bytestream2_get_byte(gb);
102 }
103 566881 mask <<= 1;
104 }
105
106 32 return 0;
107 }
108
109 121 static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
110 {
111 121 const uint8_t *frame_start = frame;
112 121 const uint8_t *frame_end = frame + width * height;
113 121 int mask = 0x10000, bitbuf = 0;
114 int v, offset, count, segments;
115
116 121 segments = bytestream2_get_le16(gb);
117
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 460962 while (segments--) {
118
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 460846 if (bytestream2_get_bytes_left(gb) < 2)
119 5 return AVERROR_INVALIDDATA;
120
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 460841 if (mask == 0x10000) {
121 57659 bitbuf = bytestream2_get_le16u(gb);
122 57659 mask = 1;
123 }
124
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 460841 if (frame_end - frame < 2)
125 ✗ return AVERROR_INVALIDDATA;
126
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 460841 if (bitbuf & mask) {
127 124238 v = bytestream2_get_le16(gb);
128 124238 offset = (v & 0x1FFF) << 1;
129 124238 count = ((v >> 13) + 2) << 1;
130
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 124238 if (frame - frame_start < offset || frame_end - frame < count)
131 ✗ return AVERROR_INVALIDDATA;
132 124238 av_memcpy_backptr(frame, offset, count);
133 124238 frame += count;
134
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 336603 } else if (bitbuf & (mask << 1)) {
135 70168 frame += bytestream2_get_le16(gb);
136 } else {
137 266435 *frame++ = bytestream2_get_byte(gb);
138 266435 *frame++ = bytestream2_get_byte(gb);
139 }
140 460841 mask <<= 2;
141 }
142
143 116 return 0;
144 }
145
146 ✗ static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
147 {
148 ✗ const uint8_t *frame_start = frame;
149 ✗ const uint8_t *frame_end = frame + width * height;
150 ✗ int mask = 0x10000, bitbuf = 0;
151 int i, v, offset, count, segments;
152
153 ✗ if ((width | height) & 1)
154 ✗ return AVERROR_INVALIDDATA;
155 ✗ segments = bytestream2_get_le16(gb);
156 ✗ while (segments--) {
157 ✗ if (bytestream2_get_bytes_left(gb) < 2)
158 ✗ return AVERROR_INVALIDDATA;
159 ✗ if (mask == 0x10000) {
160 ✗ bitbuf = bytestream2_get_le16u(gb);
161 ✗ mask = 1;
162 }
163
164 ✗ if (bitbuf & mask) {
165 ✗ v = bytestream2_get_le16(gb);
166 ✗ offset = (v & 0x1FFF) << 2;
167 ✗ count = ((v >> 13) + 2) << 1;
168 ✗ if (frame - frame_start < offset || frame_end - frame < count*2 + width)
169 ✗ return AVERROR_INVALIDDATA;
170 ✗ for (i = 0; i < count; i++) {
171 ✗ frame[0] = frame[1] =
172 ✗ frame[width] = frame[width + 1] = frame[-offset];
173
174 ✗ frame += 2;
175 }
176 ✗ } else if (bitbuf & (mask << 1)) {
177 ✗ v = bytestream2_get_le16(gb)*2;
178 ✗ if (frame - frame_end < v)
179 ✗ return AVERROR_INVALIDDATA;
180 ✗ frame += v;
181 } else {
182 ✗ if (width < 4 || frame_end - frame < width + 4)
183 ✗ return AVERROR_INVALIDDATA;
184 ✗ frame[0] = frame[1] =
185 ✗ frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
186 ✗ frame += 2;
187 ✗ frame[0] = frame[1] =
188 ✗ frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
189 ✗ frame += 2;
190 }
191 ✗ mask <<= 2;
192 }
193
194 ✗ return 0;
195 }
196
197 ✗ static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
198 {
199 uint8_t *line_ptr;
200 int count, lines, segments;
201
202 ✗ count = bytestream2_get_le16(gb);
203 ✗ if (count >= height)
204 ✗ return AVERROR_INVALIDDATA;
205 ✗ frame += width * count;
206 ✗ lines = bytestream2_get_le16(gb);
207 ✗ if (count + lines > height)
208 ✗ return AVERROR_INVALIDDATA;
209
210 ✗ while (lines--) {
211 ✗ if (bytestream2_get_bytes_left(gb) < 1)
212 ✗ return AVERROR_INVALIDDATA;
213 ✗ line_ptr = frame;
214 ✗ frame += width;
215 ✗ segments = bytestream2_get_byteu(gb);
216 ✗ while (segments--) {
217 ✗ if (frame - line_ptr <= bytestream2_peek_byte(gb))
218 ✗ return AVERROR_INVALIDDATA;
219 ✗ line_ptr += bytestream2_get_byte(gb);
220 ✗ count = (int8_t)bytestream2_get_byte(gb);
221 ✗ if (count >= 0) {
222 ✗ if (frame - line_ptr < count)
223 ✗ return AVERROR_INVALIDDATA;
224 ✗ if (bytestream2_get_buffer(gb, line_ptr, count) != count)
225 ✗ return AVERROR_INVALIDDATA;
226 } else {
227 ✗ count = -count;
228 ✗ if (frame - line_ptr < count)
229 ✗ return AVERROR_INVALIDDATA;
230 ✗ memset(line_ptr, bytestream2_get_byte(gb), count);
231 }
232 ✗ line_ptr += count;
233 }
234 }
235
236 ✗ return 0;
237 }
238
239 11 static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
240 {
241 11 const uint8_t *frame_end = frame + width * height;
242 uint8_t *line_ptr;
243 int count, i, v, lines, segments;
244 11 int y = 0;
245
246 11 lines = bytestream2_get_le16(gb);
247
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 11 if (lines > height)
248 ✗ return AVERROR_INVALIDDATA;
249
250
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 1448 while (lines--) {
251
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 1438 if (bytestream2_get_bytes_left(gb) < 2)
252 ✗ return AVERROR_INVALIDDATA;
253 1438 segments = bytestream2_get_le16u(gb);
254
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 1452 while ((segments & 0xC000) == 0xC000) {
255 14 unsigned skip_lines = -(int16_t)segments;
256 14 int64_t delta = -((int16_t)segments * (int64_t)width);
257
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 14 if (frame_end - frame <= delta || y + lines + skip_lines > height)
258 ✗ return AVERROR_INVALIDDATA;
259 14 frame += delta;
260 14 y += skip_lines;
261 14 segments = bytestream2_get_le16(gb);
262 }
263
264
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 1438 if (frame_end <= frame)
265 ✗ return AVERROR_INVALIDDATA;
266
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 1438 if (segments & 0x8000) {
267 ✗ frame[width - 1] = segments & 0xFF;
268 ✗ segments = bytestream2_get_le16(gb);
269 }
270 1438 line_ptr = frame;
271
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 1438 if (frame_end - frame < width)
272 ✗ return AVERROR_INVALIDDATA;
273 1438 frame += width;
274 1438 y++;
275
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 6577 while (segments--) {
276
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 5140 if (frame - line_ptr <= bytestream2_peek_byte(gb))
277 ✗ return AVERROR_INVALIDDATA;
278 5140 line_ptr += bytestream2_get_byte(gb);
279 5140 count = (int8_t)bytestream2_get_byte(gb);
280
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 5140 if (count >= 0) {
281
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 4691 if (frame - line_ptr < count * 2)
282 ✗ return AVERROR_INVALIDDATA;
283
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 4691 if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
284 1 return AVERROR_INVALIDDATA;
285 4690 line_ptr += count * 2;
286 } else {
287 449 count = -count;
288
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 449 if (frame - line_ptr < count * 2)
289 ✗ return AVERROR_INVALIDDATA;
290 449 v = bytestream2_get_le16(gb);
291
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 17044 for (i = 0; i < count; i++)
292 16595 bytestream_put_le16(&line_ptr, v);
293 }
294 }
295 }
296
297 10 return 0;
298 }
299
300 ✗ static int decode_tdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
301 {
302 ✗ const uint8_t *frame_end = frame + width * height;
303 ✗ uint32_t segments = bytestream2_get_le32(gb);
304 int skip, copy;
305
306 ✗ while (segments--) {
307 ✗ if (bytestream2_get_bytes_left(gb) < 2)
308 ✗ return AVERROR_INVALIDDATA;
309 ✗ copy = bytestream2_get_byteu(gb) * 2;
310 ✗ skip = bytestream2_get_byteu(gb) * 2;
311 ✗ if (frame_end - frame < copy + skip ||
312 ✗ bytestream2_get_bytes_left(gb) < copy)
313 ✗ return AVERROR_INVALIDDATA;
314 ✗ frame += skip;
315 ✗ bytestream2_get_buffer(gb, frame, copy);
316 ✗ frame += copy;
317 }
318
319 ✗ return 0;
320 }
321
322 ✗ static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
323 {
324 ✗ memset(frame, 0, width * height);
325 ✗ return 0;
326 }
327
328
329 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
330
331 static const chunk_decoder decoder[8] = {
332 decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
333 decode_tdlt, decode_dsw1, decode_blck, decode_dds1,
334 };
335
336 static const char chunk_name[8][5] = {
337 "COPY", "TSW1", "BDLT", "WDLT", "TDLT", "DSW1", "BLCK", "DDS1"
338 };
339
340 172 static int dfa_decode_frame(AVCodecContext *avctx, AVFrame *frame,
341 int *got_frame, AVPacket *avpkt)
342 {
343 172 DfaContext *s = avctx->priv_data;
344 GetByteContext gb;
345 172 const uint8_t *buf = avpkt->data;
346 uint32_t chunk_type, chunk_size;
347 uint8_t *dst;
348 int ret;
349 int i, pal_elems;
350
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 172 int version = avctx->extradata_size==2 ? AV_RL16(avctx->extradata) : 0;
351
352
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 172 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
353 ✗ return ret;
354
355 172 bytestream2_init(&gb, avpkt->data, avpkt->size);
356
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 343 while (bytestream2_get_bytes_left(&gb) > 0) {
357
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 343 if (bytestream2_get_bytes_left(&gb) < 12)
358 ✗ return AVERROR_INVALIDDATA;
359 343 bytestream2_skip(&gb, 4);
360 343 chunk_size = bytestream2_get_le32(&gb);
361 343 chunk_type = bytestream2_get_le32(&gb);
362
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 343 if (!chunk_type)
363 164 break;
364
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 179 if (chunk_type == 1) {
365
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 12 pal_elems = FFMIN(chunk_size / 3, 256);
366
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 3084 for (i = 0; i < pal_elems; i++) {
367 3072 s->pal[i] = bytestream2_get_be24(&gb) << 2;
368 3072 s->pal[i] |= 0xFFU << 24 | (s->pal[i] >> 6) & 0x30303;
369 }
370
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 167 } else if (chunk_type <= 9) {
371
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 167 if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
372 8 av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
373 8 chunk_name[chunk_type - 2]);
374 8 return AVERROR_INVALIDDATA;
375 }
376 } else {
377 ✗ av_log(avctx, AV_LOG_WARNING,
378 "Ignoring unknown chunk type %"PRIu32"\n",
379 chunk_type);
380 }
381 171 buf += chunk_size;
382 }
383
384 164 buf = s->frame_buf;
385 164 dst = frame->data[0];
386
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 164 if (version == 0x100) {
387 ✗ for (i = 0; i < avctx->height; i++) {
388 int j;
389 ✗ const uint8_t *buf1 = buf + (i&3)*(avctx->width/4) + (i/4)*avctx->width;
390 ✗ int stride = (avctx->height/4)*avctx->width;
391 ✗ for(j = 0; j < avctx->width/4; j++) {
392 ✗ dst[4*j+0] = buf1[j + 0*stride];
393 ✗ dst[4*j+1] = buf1[j + 1*stride];
394 ✗ dst[4*j+2] = buf1[j + 2*stride];
395 ✗ dst[4*j+3] = buf1[j + 3*stride];
396 }
397 ✗ j *= 4;
398 ✗ for(; j < avctx->width; j++) {
399 ✗ dst[j] = buf1[(j/4) + (j&3)*stride];
400 }
401 ✗ dst += frame->linesize[0];
402 }
403 } else
404 164 av_image_copy_plane(dst, frame->linesize[0], buf, avctx->width,
405 avctx->width, avctx->height);
406
407 164 memcpy(frame->data[1], s->pal, sizeof(s->pal));
408
409 164 *got_frame = 1;
410
411 164 return avpkt->size;
412 }
413
414 22 static av_cold int dfa_decode_end(AVCodecContext *avctx)
415 {
416 22 DfaContext *s = avctx->priv_data;
417
418 22 av_freep(&s->frame_buf);
419
420 22 return 0;
421 }
422
423 const FFCodec ff_dfa_decoder = {
424 .p.name = "dfa",
425 CODEC_LONG_NAME("Chronomaster DFA"),
426 .p.type = AVMEDIA_TYPE_VIDEO,
427 .p.id = AV_CODEC_ID_DFA,
428 .priv_data_size = sizeof(DfaContext),
429 .init = dfa_decode_init,
430 .close = dfa_decode_end,
431 FF_CODEC_DECODE_CB(dfa_decode_frame),
432 .p.capabilities = AV_CODEC_CAP_DR1,
433 };
434