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f6fa7814 DM |
1 | /* |
2 | * APNG demuxer | |
3 | * Copyright (c) 2014 Benoit Fouet | |
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 | * APNG demuxer. | |
25 | * @see https://wiki.mozilla.org/APNG_Specification | |
26 | * @see http://www.w3.org/TR/PNG | |
27 | */ | |
28 | ||
29 | #include "avformat.h" | |
30 | #include "avio_internal.h" | |
31 | #include "internal.h" | |
32 | #include "libavutil/imgutils.h" | |
33 | #include "libavutil/intreadwrite.h" | |
34 | #include "libavutil/opt.h" | |
35 | #include "libavcodec/apng.h" | |
36 | #include "libavcodec/png.h" | |
37 | #include "libavcodec/bytestream.h" | |
38 | ||
39 | #define DEFAULT_APNG_FPS 15 | |
40 | ||
41 | typedef struct APNGDemuxContext { | |
42 | const AVClass *class; | |
43 | ||
44 | int max_fps; | |
45 | int default_fps; | |
46 | ||
47 | int64_t pkt_pts; | |
48 | int pkt_duration; | |
49 | ||
50 | int is_key_frame; | |
51 | ||
52 | /* | |
53 | * loop options | |
54 | */ | |
55 | int ignore_loop; | |
56 | uint32_t num_frames; | |
57 | uint32_t num_play; | |
58 | uint32_t cur_loop; | |
59 | } APNGDemuxContext; | |
60 | ||
61 | /* | |
62 | * To be a valid APNG file, we mandate, in this order: | |
63 | * PNGSIG | |
64 | * IHDR | |
65 | * ... | |
66 | * acTL | |
67 | * ... | |
68 | * IDAT | |
69 | */ | |
70 | static int apng_probe(AVProbeData *p) | |
71 | { | |
72 | GetByteContext gb; | |
73 | int state = 0; | |
74 | uint32_t len, tag; | |
75 | ||
76 | bytestream2_init(&gb, p->buf, p->buf_size); | |
77 | ||
78 | if (bytestream2_get_be64(&gb) != PNGSIG) | |
79 | return 0; | |
80 | ||
81 | for (;;) { | |
82 | len = bytestream2_get_be32(&gb); | |
83 | if (len > 0x7fffffff) | |
84 | return 0; | |
85 | ||
86 | tag = bytestream2_get_le32(&gb); | |
87 | /* we don't check IDAT size, as this is the last tag | |
88 | * we check, and it may be larger than the probe buffer */ | |
89 | if (tag != MKTAG('I', 'D', 'A', 'T') && | |
90 | len + 4 > bytestream2_get_bytes_left(&gb)) | |
91 | return 0; | |
92 | ||
93 | switch (tag) { | |
94 | case MKTAG('I', 'H', 'D', 'R'): | |
95 | if (len != 13) | |
96 | return 0; | |
97 | if (av_image_check_size(bytestream2_get_be32(&gb), bytestream2_get_be32(&gb), 0, NULL)) | |
98 | return 0; | |
99 | bytestream2_skip(&gb, 9); | |
100 | state++; | |
101 | break; | |
102 | case MKTAG('a', 'c', 'T', 'L'): | |
103 | if (state != 1 || | |
104 | len != 8 || | |
105 | bytestream2_get_be32(&gb) == 0) /* 0 is not a valid value for number of frames */ | |
106 | return 0; | |
107 | bytestream2_skip(&gb, 8); | |
108 | state++; | |
109 | break; | |
110 | case MKTAG('I', 'D', 'A', 'T'): | |
111 | if (state != 2) | |
112 | return 0; | |
113 | goto end; | |
114 | default: | |
115 | /* skip other tags */ | |
116 | bytestream2_skip(&gb, len + 4); | |
117 | break; | |
118 | } | |
119 | } | |
120 | ||
121 | end: | |
122 | return AVPROBE_SCORE_MAX; | |
123 | } | |
124 | ||
125 | static int append_extradata(AVCodecContext *s, AVIOContext *pb, int len) | |
126 | { | |
127 | int previous_size = s->extradata_size; | |
128 | int new_size, ret; | |
129 | uint8_t *new_extradata; | |
130 | ||
131 | if (previous_size > INT_MAX - len) | |
132 | return AVERROR_INVALIDDATA; | |
133 | ||
134 | new_size = previous_size + len; | |
135 | new_extradata = av_realloc(s->extradata, new_size + FF_INPUT_BUFFER_PADDING_SIZE); | |
136 | if (!new_extradata) | |
137 | return AVERROR(ENOMEM); | |
138 | s->extradata = new_extradata; | |
139 | s->extradata_size = new_size; | |
140 | ||
141 | if ((ret = avio_read(pb, s->extradata + previous_size, len)) < 0) | |
142 | return ret; | |
143 | ||
144 | return previous_size; | |
145 | } | |
146 | ||
147 | static int apng_read_header(AVFormatContext *s) | |
148 | { | |
149 | APNGDemuxContext *ctx = s->priv_data; | |
150 | AVIOContext *pb = s->pb; | |
151 | uint32_t len, tag; | |
152 | AVStream *st; | |
153 | int ret = AVERROR_INVALIDDATA, acTL_found = 0; | |
154 | ||
155 | /* verify PNGSIG */ | |
156 | if (avio_rb64(pb) != PNGSIG) | |
157 | return ret; | |
158 | ||
159 | /* parse IHDR (must be first chunk) */ | |
160 | len = avio_rb32(pb); | |
161 | tag = avio_rl32(pb); | |
162 | if (len != 13 || tag != MKTAG('I', 'H', 'D', 'R')) | |
163 | return ret; | |
164 | ||
165 | st = avformat_new_stream(s, NULL); | |
166 | if (!st) | |
167 | return AVERROR(ENOMEM); | |
168 | ||
169 | /* set the timebase to something large enough (1/100,000 of second) | |
170 | * to hopefully cope with all sane frame durations */ | |
171 | avpriv_set_pts_info(st, 64, 1, 100000); | |
172 | st->codec->codec_type = AVMEDIA_TYPE_VIDEO; | |
173 | st->codec->codec_id = AV_CODEC_ID_APNG; | |
174 | st->codec->width = avio_rb32(pb); | |
175 | st->codec->height = avio_rb32(pb); | |
176 | if ((ret = av_image_check_size(st->codec->width, st->codec->height, 0, s)) < 0) | |
177 | return ret; | |
178 | ||
179 | /* extradata will contain every chunk up to the first fcTL (excluded) */ | |
180 | st->codec->extradata = av_malloc(len + 12 + FF_INPUT_BUFFER_PADDING_SIZE); | |
181 | if (!st->codec->extradata) | |
182 | return AVERROR(ENOMEM); | |
183 | st->codec->extradata_size = len + 12; | |
184 | AV_WB32(st->codec->extradata, len); | |
185 | AV_WL32(st->codec->extradata+4, tag); | |
186 | AV_WB32(st->codec->extradata+8, st->codec->width); | |
187 | AV_WB32(st->codec->extradata+12, st->codec->height); | |
188 | if ((ret = avio_read(pb, st->codec->extradata+16, 9)) < 0) | |
189 | goto fail; | |
190 | ||
191 | while (!avio_feof(pb)) { | |
192 | if (acTL_found && ctx->num_play != 1) { | |
193 | int64_t size = avio_size(pb); | |
194 | int64_t offset = avio_tell(pb); | |
195 | if (size < 0) { | |
196 | ret = size; | |
197 | goto fail; | |
198 | } else if (offset < 0) { | |
199 | ret = offset; | |
200 | goto fail; | |
201 | } else if ((ret = ffio_ensure_seekback(pb, size - offset)) < 0) { | |
202 | av_log(s, AV_LOG_WARNING, "Could not ensure seekback, will not loop\n"); | |
203 | ctx->num_play = 1; | |
204 | } | |
205 | } | |
206 | if ((ctx->num_play == 1 || !acTL_found) && | |
207 | ((ret = ffio_ensure_seekback(pb, 4 /* len */ + 4 /* tag */)) < 0)) | |
208 | goto fail; | |
209 | ||
210 | len = avio_rb32(pb); | |
211 | if (len > 0x7fffffff) { | |
212 | ret = AVERROR_INVALIDDATA; | |
213 | goto fail; | |
214 | } | |
215 | ||
216 | tag = avio_rl32(pb); | |
217 | switch (tag) { | |
218 | case MKTAG('a', 'c', 'T', 'L'): | |
219 | if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 || | |
220 | (ret = append_extradata(st->codec, pb, len + 12)) < 0) | |
221 | goto fail; | |
222 | acTL_found = 1; | |
223 | ctx->num_frames = AV_RB32(st->codec->extradata + ret + 8); | |
224 | ctx->num_play = AV_RB32(st->codec->extradata + ret + 12); | |
225 | av_log(s, AV_LOG_DEBUG, "num_frames: %"PRIu32", num_play: %"PRIu32"\n", | |
226 | ctx->num_frames, ctx->num_play); | |
227 | break; | |
228 | case MKTAG('f', 'c', 'T', 'L'): | |
229 | if (!acTL_found) { | |
230 | ret = AVERROR_INVALIDDATA; | |
231 | goto fail; | |
232 | } | |
233 | if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0) | |
234 | goto fail; | |
235 | return 0; | |
236 | default: | |
237 | if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 || | |
238 | (ret = append_extradata(st->codec, pb, len + 12)) < 0) | |
239 | goto fail; | |
240 | } | |
241 | } | |
242 | ||
243 | fail: | |
244 | if (st->codec->extradata_size) { | |
245 | av_freep(&st->codec->extradata); | |
246 | st->codec->extradata_size = 0; | |
247 | } | |
248 | return ret; | |
249 | } | |
250 | ||
251 | static int decode_fctl_chunk(AVFormatContext *s, APNGDemuxContext *ctx, AVPacket *pkt) | |
252 | { | |
253 | uint32_t sequence_number, width, height, x_offset, y_offset; | |
254 | uint16_t delay_num, delay_den; | |
255 | uint8_t dispose_op, blend_op; | |
256 | ||
257 | sequence_number = avio_rb32(s->pb); | |
258 | width = avio_rb32(s->pb); | |
259 | height = avio_rb32(s->pb); | |
260 | x_offset = avio_rb32(s->pb); | |
261 | y_offset = avio_rb32(s->pb); | |
262 | delay_num = avio_rb16(s->pb); | |
263 | delay_den = avio_rb16(s->pb); | |
264 | dispose_op = avio_r8(s->pb); | |
265 | blend_op = avio_r8(s->pb); | |
266 | avio_skip(s->pb, 4); /* crc */ | |
267 | ||
268 | /* default is hundredths of seconds */ | |
269 | if (!delay_den) | |
270 | delay_den = 100; | |
271 | if (!delay_num || delay_den / delay_num > ctx->max_fps) { | |
272 | delay_num = 1; | |
273 | delay_den = ctx->default_fps; | |
274 | } | |
275 | ctx->pkt_duration = av_rescale_q(delay_num, | |
276 | (AVRational){ 1, delay_den }, | |
277 | s->streams[0]->time_base); | |
278 | ||
279 | av_log(s, AV_LOG_DEBUG, "%s: " | |
280 | "sequence_number: %"PRId32", " | |
281 | "width: %"PRIu32", " | |
282 | "height: %"PRIu32", " | |
283 | "x_offset: %"PRIu32", " | |
284 | "y_offset: %"PRIu32", " | |
285 | "delay_num: %"PRIu16", " | |
286 | "delay_den: %"PRIu16", " | |
287 | "dispose_op: %d, " | |
288 | "blend_op: %d\n", | |
289 | __FUNCTION__, | |
290 | sequence_number, | |
291 | width, | |
292 | height, | |
293 | x_offset, | |
294 | y_offset, | |
295 | delay_num, | |
296 | delay_den, | |
297 | dispose_op, | |
298 | blend_op); | |
299 | ||
300 | if (width != s->streams[0]->codec->width || | |
301 | height != s->streams[0]->codec->height || | |
302 | x_offset != 0 || | |
303 | y_offset != 0) { | |
304 | if (sequence_number == 0 || | |
305 | x_offset >= s->streams[0]->codec->width || | |
306 | width > s->streams[0]->codec->width - x_offset || | |
307 | y_offset >= s->streams[0]->codec->height || | |
308 | height > s->streams[0]->codec->height - y_offset) | |
309 | return AVERROR_INVALIDDATA; | |
310 | ctx->is_key_frame = 0; | |
311 | } else { | |
312 | if (sequence_number == 0 && dispose_op == APNG_DISPOSE_OP_PREVIOUS) | |
313 | dispose_op = APNG_DISPOSE_OP_BACKGROUND; | |
314 | ctx->is_key_frame = dispose_op == APNG_DISPOSE_OP_BACKGROUND || | |
315 | blend_op == APNG_BLEND_OP_SOURCE; | |
316 | } | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
321 | static int apng_read_packet(AVFormatContext *s, AVPacket *pkt) | |
322 | { | |
323 | APNGDemuxContext *ctx = s->priv_data; | |
324 | int ret; | |
325 | int64_t size; | |
326 | AVIOContext *pb = s->pb; | |
327 | uint32_t len, tag; | |
328 | ||
329 | /* | |
330 | * fcTL chunk length, in bytes: | |
331 | * 4 (length) | |
332 | * 4 (tag) | |
333 | * 26 (actual chunk) | |
334 | * 4 (crc) bytes | |
335 | * and needed next: | |
336 | * 4 (length) | |
337 | * 4 (tag (must be fdAT or IDAT)) | |
338 | */ | |
339 | /* if num_play is not 1, then the seekback is already guaranteed */ | |
340 | if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 46)) < 0) | |
341 | return ret; | |
342 | ||
343 | len = avio_rb32(pb); | |
344 | tag = avio_rl32(pb); | |
345 | switch (tag) { | |
346 | case MKTAG('f', 'c', 'T', 'L'): | |
347 | if (len != 26) | |
348 | return AVERROR_INVALIDDATA; | |
349 | ||
350 | if ((ret = decode_fctl_chunk(s, ctx, pkt)) < 0) | |
351 | return ret; | |
352 | ||
353 | /* fcTL must precede fdAT or IDAT */ | |
354 | len = avio_rb32(pb); | |
355 | tag = avio_rl32(pb); | |
356 | if (len > 0x7fffffff || | |
357 | tag != MKTAG('f', 'd', 'A', 'T') && | |
358 | tag != MKTAG('I', 'D', 'A', 'T')) | |
359 | return AVERROR_INVALIDDATA; | |
360 | ||
361 | size = 38 /* fcTL */ + 8 /* len, tag */ + len + 4 /* crc */; | |
362 | if (size > INT_MAX) | |
363 | return AVERROR(EINVAL); | |
364 | ||
365 | if ((ret = avio_seek(pb, -46, SEEK_CUR)) < 0 || | |
366 | (ret = av_append_packet(pb, pkt, size)) < 0) | |
367 | return ret; | |
368 | ||
369 | if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 8)) < 0) | |
370 | return ret; | |
371 | ||
372 | len = avio_rb32(pb); | |
373 | tag = avio_rl32(pb); | |
374 | while (tag && | |
375 | tag != MKTAG('f', 'c', 'T', 'L') && | |
376 | tag != MKTAG('I', 'E', 'N', 'D')) { | |
377 | if (len > 0x7fffffff) | |
378 | return AVERROR_INVALIDDATA; | |
379 | if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 || | |
380 | (ret = av_append_packet(pb, pkt, len + 12)) < 0) | |
381 | return ret; | |
382 | if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 8)) < 0) | |
383 | return ret; | |
384 | len = avio_rb32(pb); | |
385 | tag = avio_rl32(pb); | |
386 | } | |
387 | if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0) | |
388 | return ret; | |
389 | ||
390 | if (ctx->is_key_frame) | |
391 | pkt->flags |= AV_PKT_FLAG_KEY; | |
392 | pkt->pts = ctx->pkt_pts; | |
393 | pkt->duration = ctx->pkt_duration; | |
394 | ctx->pkt_pts += ctx->pkt_duration; | |
395 | return ret; | |
396 | case MKTAG('I', 'E', 'N', 'D'): | |
397 | ctx->cur_loop++; | |
398 | if (ctx->ignore_loop || ctx->num_play >= 1 && ctx->cur_loop == ctx->num_play) { | |
399 | avio_seek(pb, -8, SEEK_CUR); | |
400 | return AVERROR_EOF; | |
401 | } | |
402 | if ((ret = avio_seek(pb, s->streams[0]->codec->extradata_size + 8, SEEK_SET)) < 0) | |
403 | return ret; | |
404 | return 0; | |
405 | default: | |
406 | { | |
092a9121 | 407 | char tag_buf[32]; |
f6fa7814 DM |
408 | |
409 | av_get_codec_tag_string(tag_buf, sizeof(tag_buf), tag); | |
410 | avpriv_request_sample(s, "In-stream tag=%s (0x%08X) len=%"PRIu32, tag_buf, tag, len); | |
411 | avio_skip(pb, len + 4); | |
412 | } | |
413 | } | |
414 | ||
415 | /* Handle the unsupported yet cases */ | |
416 | return AVERROR_PATCHWELCOME; | |
417 | } | |
418 | ||
419 | static const AVOption options[] = { | |
420 | { "ignore_loop", "ignore loop setting" , offsetof(APNGDemuxContext, ignore_loop), | |
421 | AV_OPT_TYPE_INT, { .i64 = 1 } , 0, 1 , AV_OPT_FLAG_DECODING_PARAM }, | |
422 | { "max_fps" , "maximum framerate (0 is no limit)" , offsetof(APNGDemuxContext, max_fps), | |
423 | AV_OPT_TYPE_INT, { .i64 = DEFAULT_APNG_FPS }, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM }, | |
424 | { "default_fps", "default framerate (0 is as fast as possible)", offsetof(APNGDemuxContext, default_fps), | |
425 | AV_OPT_TYPE_INT, { .i64 = DEFAULT_APNG_FPS }, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM }, | |
426 | { NULL }, | |
427 | }; | |
428 | ||
429 | static const AVClass demuxer_class = { | |
430 | .class_name = "APNG demuxer", | |
431 | .item_name = av_default_item_name, | |
432 | .option = options, | |
433 | .version = LIBAVUTIL_VERSION_INT, | |
434 | .category = AV_CLASS_CATEGORY_DEMUXER, | |
435 | }; | |
436 | ||
437 | AVInputFormat ff_apng_demuxer = { | |
438 | .name = "apng", | |
439 | .long_name = NULL_IF_CONFIG_SMALL("Animated Portable Network Graphics"), | |
440 | .priv_data_size = sizeof(APNGDemuxContext), | |
441 | .read_probe = apng_probe, | |
442 | .read_header = apng_read_header, | |
443 | .read_packet = apng_read_packet, | |
444 | .flags = AVFMT_GENERIC_INDEX, | |
445 | .priv_class = &demuxer_class, | |
446 | }; |