1 /*
2 * PNG image format
3 * Copyright (c) 2003 Fabrice Bellard
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 //#define DEBUG
23
24 #include "libavutil/avassert.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/crc.h"
27 #include "libavutil/imgutils.h"
28 #include "libavutil/intreadwrite.h"
29 #include "libavutil/stereo3d.h"
30 #include "libavutil/mastering_display_metadata.h"
31
32 #include "avcodec.h"
33 #include "bytestream.h"
34 #include "internal.h"
35 #include "apng.h"
36 #include "png.h"
37 #include "pngdsp.h"
38 #include "thread.h"
39
40 #include <zlib.h>
41
42 enum PNGHeaderState {
43 PNG_IHDR = 1 << 0,
44 PNG_PLTE = 1 << 1,
45 };
46
47 enum PNGImageState {
48 PNG_IDAT = 1 << 0,
49 PNG_ALLIMAGE = 1 << 1,
50 };
51
52 typedef struct PNGDecContext {
53 PNGDSPContext dsp;
54 AVCodecContext *avctx;
55
56 GetByteContext gb;
57 ThreadFrame last_picture;
58 ThreadFrame picture;
59
60 AVDictionary *frame_metadata;
61
62 uint8_t iccp_name[82];
63 uint8_t *iccp_data;
64 size_t iccp_data_len;
65
66 int stereo_mode;
67
68 int have_chrm;
69 uint32_t white_point[2];
70 uint32_t display_primaries[3][2];
71
72 enum PNGHeaderState hdr_state;
73 enum PNGImageState pic_state;
74 int width, height;
75 int cur_w, cur_h;
76 int last_w, last_h;
77 int x_offset, y_offset;
78 int last_x_offset, last_y_offset;
79 uint8_t dispose_op, blend_op;
80 uint8_t last_dispose_op;
81 int bit_depth;
82 int color_type;
83 int compression_type;
84 int interlace_type;
85 int filter_type;
86 int channels;
87 int bits_per_pixel;
88 int bpp;
89 int has_trns;
90 uint8_t transparent_color_be[6];
91
92 uint8_t *background_buf;
93 unsigned background_buf_allocated;
94 uint32_t palette[256];
95 uint8_t *crow_buf;
96 uint8_t *last_row;
97 unsigned int last_row_size;
98 uint8_t *tmp_row;
99 unsigned int tmp_row_size;
100 uint8_t *buffer;
101 int buffer_size;
102 int pass;
103 int crow_size; /* compressed row size (include filter type) */
104 int row_size; /* decompressed row size */
105 int pass_row_size; /* decompress row size of the current pass */
106 int y;
107 z_stream zstream;
108 } PNGDecContext;
109
110 /* Mask to determine which pixels are valid in a pass */
111 static const uint8_t png_pass_mask[NB_PASSES] = {
112 0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff,
113 };
114
115 /* Mask to determine which y pixels can be written in a pass */
116 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
117 0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
118 };
119
120 /* Mask to determine which pixels to overwrite while displaying */
121 static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
122 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
123 };
124
125 /* NOTE: we try to construct a good looking image at each pass. width
126 * is the original image width. We also do pixel format conversion at
127 * this stage */
png_put_interlaced_row(uint8_t * dst,int width,int bits_per_pixel,int pass,int color_type,const uint8_t * src)128 static void png_put_interlaced_row(uint8_t *dst, int width,
129 int bits_per_pixel, int pass,
130 int color_type, const uint8_t *src)
131 {
132 int x, mask, dsp_mask, j, src_x, b, bpp;
133 uint8_t *d;
134 const uint8_t *s;
135
136 mask = png_pass_mask[pass];
137 dsp_mask = png_pass_dsp_mask[pass];
138
139 switch (bits_per_pixel) {
140 case 1:
141 src_x = 0;
142 for (x = 0; x < width; x++) {
143 j = (x & 7);
144 if ((dsp_mask << j) & 0x80) {
145 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
146 dst[x >> 3] &= 0xFF7F>>j;
147 dst[x >> 3] |= b << (7 - j);
148 }
149 if ((mask << j) & 0x80)
150 src_x++;
151 }
152 break;
153 case 2:
154 src_x = 0;
155 for (x = 0; x < width; x++) {
156 int j2 = 2 * (x & 3);
157 j = (x & 7);
158 if ((dsp_mask << j) & 0x80) {
159 b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3;
160 dst[x >> 2] &= 0xFF3F>>j2;
161 dst[x >> 2] |= b << (6 - j2);
162 }
163 if ((mask << j) & 0x80)
164 src_x++;
165 }
166 break;
167 case 4:
168 src_x = 0;
169 for (x = 0; x < width; x++) {
170 int j2 = 4*(x&1);
171 j = (x & 7);
172 if ((dsp_mask << j) & 0x80) {
173 b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15;
174 dst[x >> 1] &= 0xFF0F>>j2;
175 dst[x >> 1] |= b << (4 - j2);
176 }
177 if ((mask << j) & 0x80)
178 src_x++;
179 }
180 break;
181 default:
182 bpp = bits_per_pixel >> 3;
183 d = dst;
184 s = src;
185 for (x = 0; x < width; x++) {
186 j = x & 7;
187 if ((dsp_mask << j) & 0x80) {
188 memcpy(d, s, bpp);
189 }
190 d += bpp;
191 if ((mask << j) & 0x80)
192 s += bpp;
193 }
194 break;
195 }
196 }
197
ff_add_png_paeth_prediction(uint8_t * dst,uint8_t * src,uint8_t * top,int w,int bpp)198 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top,
199 int w, int bpp)
200 {
201 int i;
202 for (i = 0; i < w; i++) {
203 int a, b, c, p, pa, pb, pc;
204
205 a = dst[i - bpp];
206 b = top[i];
207 c = top[i - bpp];
208
209 p = b - c;
210 pc = a - c;
211
212 pa = abs(p);
213 pb = abs(pc);
214 pc = abs(p + pc);
215
216 if (pa <= pb && pa <= pc)
217 p = a;
218 else if (pb <= pc)
219 p = b;
220 else
221 p = c;
222 dst[i] = p + src[i];
223 }
224 }
225
226 #define UNROLL1(bpp, op) \
227 { \
228 r = dst[0]; \
229 if (bpp >= 2) \
230 g = dst[1]; \
231 if (bpp >= 3) \
232 b = dst[2]; \
233 if (bpp >= 4) \
234 a = dst[3]; \
235 for (; i <= size - bpp; i += bpp) { \
236 dst[i + 0] = r = op(r, src[i + 0], last[i + 0]); \
237 if (bpp == 1) \
238 continue; \
239 dst[i + 1] = g = op(g, src[i + 1], last[i + 1]); \
240 if (bpp == 2) \
241 continue; \
242 dst[i + 2] = b = op(b, src[i + 2], last[i + 2]); \
243 if (bpp == 3) \
244 continue; \
245 dst[i + 3] = a = op(a, src[i + 3], last[i + 3]); \
246 } \
247 }
248
249 #define UNROLL_FILTER(op) \
250 if (bpp == 1) { \
251 UNROLL1(1, op) \
252 } else if (bpp == 2) { \
253 UNROLL1(2, op) \
254 } else if (bpp == 3) { \
255 UNROLL1(3, op) \
256 } else if (bpp == 4) { \
257 UNROLL1(4, op) \
258 } \
259 for (; i < size; i++) { \
260 dst[i] = op(dst[i - bpp], src[i], last[i]); \
261 }
262
263 /* NOTE: 'dst' can be equal to 'last' */
ff_png_filter_row(PNGDSPContext * dsp,uint8_t * dst,int filter_type,uint8_t * src,uint8_t * last,int size,int bpp)264 void ff_png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
265 uint8_t *src, uint8_t *last, int size, int bpp)
266 {
267 int i, p, r, g, b, a;
268
269 switch (filter_type) {
270 case PNG_FILTER_VALUE_NONE:
271 memcpy(dst, src, size);
272 break;
273 case PNG_FILTER_VALUE_SUB:
274 for (i = 0; i < bpp; i++)
275 dst[i] = src[i];
276 if (bpp == 4) {
277 p = *(int *)dst;
278 for (; i < size; i += bpp) {
279 unsigned s = *(int *)(src + i);
280 p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
281 *(int *)(dst + i) = p;
282 }
283 } else {
284 #define OP_SUB(x, s, l) ((x) + (s))
285 UNROLL_FILTER(OP_SUB);
286 }
287 break;
288 case PNG_FILTER_VALUE_UP:
289 dsp->add_bytes_l2(dst, src, last, size);
290 break;
291 case PNG_FILTER_VALUE_AVG:
292 for (i = 0; i < bpp; i++) {
293 p = (last[i] >> 1);
294 dst[i] = p + src[i];
295 }
296 #define OP_AVG(x, s, l) (((((x) + (l)) >> 1) + (s)) & 0xff)
297 UNROLL_FILTER(OP_AVG);
298 break;
299 case PNG_FILTER_VALUE_PAETH:
300 for (i = 0; i < bpp; i++) {
301 p = last[i];
302 dst[i] = p + src[i];
303 }
304 if (bpp > 2 && size > 4) {
305 /* would write off the end of the array if we let it process
306 * the last pixel with bpp=3 */
307 int w = (bpp & 3) ? size - 3 : size;
308
309 if (w > i) {
310 dsp->add_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
311 i = w;
312 }
313 }
314 ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
315 break;
316 }
317 }
318
319 /* This used to be called "deloco" in FFmpeg
320 * and is actually an inverse reversible colorspace transformation */
321 #define YUV2RGB(NAME, TYPE) \
322 static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
323 { \
324 int i; \
325 for (i = 0; i < size; i += 3 + alpha) { \
326 int g = dst [i + 1]; \
327 dst[i + 0] += g; \
328 dst[i + 2] += g; \
329 } \
330 }
331
YUV2RGB(rgb8,uint8_t)332 YUV2RGB(rgb8, uint8_t)
333 YUV2RGB(rgb16, uint16_t)
334
335 static int percent_missing(PNGDecContext *s)
336 {
337 if (s->interlace_type) {
338 return 100 - 100 * s->pass / (NB_PASSES - 1);
339 } else {
340 return 100 - 100 * s->y / s->cur_h;
341 }
342 }
343
344 /* process exactly one decompressed row */
png_handle_row(PNGDecContext * s,uint8_t * dst,ptrdiff_t dst_stride)345 static void png_handle_row(PNGDecContext *s, uint8_t *dst, ptrdiff_t dst_stride)
346 {
347 uint8_t *ptr, *last_row;
348 int got_line;
349
350 if (!s->interlace_type) {
351 ptr = dst + dst_stride * (s->y + s->y_offset) + s->x_offset * s->bpp;
352 if (s->y == 0)
353 last_row = s->last_row;
354 else
355 last_row = ptr - dst_stride;
356
357 ff_png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
358 last_row, s->row_size, s->bpp);
359 /* loco lags by 1 row so that it doesn't interfere with top prediction */
360 if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
361 if (s->bit_depth == 16) {
362 deloco_rgb16((uint16_t *)(ptr - dst_stride), s->row_size / 2,
363 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
364 } else {
365 deloco_rgb8(ptr - dst_stride, s->row_size,
366 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
367 }
368 }
369 s->y++;
370 if (s->y == s->cur_h) {
371 s->pic_state |= PNG_ALLIMAGE;
372 if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
373 if (s->bit_depth == 16) {
374 deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
375 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
376 } else {
377 deloco_rgb8(ptr, s->row_size,
378 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
379 }
380 }
381 }
382 } else {
383 got_line = 0;
384 for (;;) {
385 ptr = dst + dst_stride * (s->y + s->y_offset) + s->x_offset * s->bpp;
386 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
387 /* if we already read one row, it is time to stop to
388 * wait for the next one */
389 if (got_line)
390 break;
391 ff_png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
392 s->last_row, s->pass_row_size, s->bpp);
393 FFSWAP(uint8_t *, s->last_row, s->tmp_row);
394 FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size);
395 got_line = 1;
396 }
397 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
398 png_put_interlaced_row(ptr, s->cur_w, s->bits_per_pixel, s->pass,
399 s->color_type, s->last_row);
400 }
401 s->y++;
402 if (s->y == s->cur_h) {
403 memset(s->last_row, 0, s->row_size);
404 for (;;) {
405 if (s->pass == NB_PASSES - 1) {
406 s->pic_state |= PNG_ALLIMAGE;
407 goto the_end;
408 } else {
409 s->pass++;
410 s->y = 0;
411 s->pass_row_size = ff_png_pass_row_size(s->pass,
412 s->bits_per_pixel,
413 s->cur_w);
414 s->crow_size = s->pass_row_size + 1;
415 if (s->pass_row_size != 0)
416 break;
417 /* skip pass if empty row */
418 }
419 }
420 }
421 }
422 the_end:;
423 }
424 }
425
png_decode_idat(PNGDecContext * s,int length,uint8_t * dst,ptrdiff_t dst_stride)426 static int png_decode_idat(PNGDecContext *s, int length,
427 uint8_t *dst, ptrdiff_t dst_stride)
428 {
429 int ret;
430 s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
431 s->zstream.next_in = s->gb.buffer;
432 bytestream2_skip(&s->gb, length);
433
434 /* decode one line if possible */
435 while (s->zstream.avail_in > 0) {
436 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
437 if (ret != Z_OK && ret != Z_STREAM_END) {
438 av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
439 return AVERROR_EXTERNAL;
440 }
441 if (s->zstream.avail_out == 0) {
442 if (!(s->pic_state & PNG_ALLIMAGE)) {
443 png_handle_row(s, dst, dst_stride);
444 }
445 s->zstream.avail_out = s->crow_size;
446 s->zstream.next_out = s->crow_buf;
447 }
448 if (ret == Z_STREAM_END && s->zstream.avail_in > 0) {
449 av_log(s->avctx, AV_LOG_WARNING,
450 "%d undecompressed bytes left in buffer\n", s->zstream.avail_in);
451 return 0;
452 }
453 }
454 return 0;
455 }
456
decode_zbuf(AVBPrint * bp,const uint8_t * data,const uint8_t * data_end)457 static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
458 const uint8_t *data_end)
459 {
460 z_stream zstream;
461 unsigned char *buf;
462 unsigned buf_size;
463 int ret;
464
465 zstream.zalloc = ff_png_zalloc;
466 zstream.zfree = ff_png_zfree;
467 zstream.opaque = NULL;
468 if (inflateInit(&zstream) != Z_OK)
469 return AVERROR_EXTERNAL;
470 zstream.next_in = data;
471 zstream.avail_in = data_end - data;
472 av_bprint_init(bp, 0, AV_BPRINT_SIZE_UNLIMITED);
473
474 while (zstream.avail_in > 0) {
475 av_bprint_get_buffer(bp, 2, &buf, &buf_size);
476 if (buf_size < 2) {
477 ret = AVERROR(ENOMEM);
478 goto fail;
479 }
480 zstream.next_out = buf;
481 zstream.avail_out = buf_size - 1;
482 ret = inflate(&zstream, Z_PARTIAL_FLUSH);
483 if (ret != Z_OK && ret != Z_STREAM_END) {
484 ret = AVERROR_EXTERNAL;
485 goto fail;
486 }
487 bp->len += zstream.next_out - buf;
488 if (ret == Z_STREAM_END)
489 break;
490 }
491 inflateEnd(&zstream);
492 bp->str[bp->len] = 0;
493 return 0;
494
495 fail:
496 inflateEnd(&zstream);
497 av_bprint_finalize(bp, NULL);
498 return ret;
499 }
500
iso88591_to_utf8(const uint8_t * in,size_t size_in)501 static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
502 {
503 size_t extra = 0, i;
504 uint8_t *out, *q;
505
506 for (i = 0; i < size_in; i++)
507 extra += in[i] >= 0x80;
508 if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
509 return NULL;
510 q = out = av_malloc(size_in + extra + 1);
511 if (!out)
512 return NULL;
513 for (i = 0; i < size_in; i++) {
514 if (in[i] >= 0x80) {
515 *(q++) = 0xC0 | (in[i] >> 6);
516 *(q++) = 0x80 | (in[i] & 0x3F);
517 } else {
518 *(q++) = in[i];
519 }
520 }
521 *(q++) = 0;
522 return out;
523 }
524
decode_text_chunk(PNGDecContext * s,uint32_t length,int compressed)525 static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed)
526 {
527 int ret, method;
528 const uint8_t *data = s->gb.buffer;
529 const uint8_t *data_end = data + length;
530 const uint8_t *keyword = data;
531 const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
532 uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
533 unsigned text_len;
534 AVBPrint bp;
535
536 if (!keyword_end)
537 return AVERROR_INVALIDDATA;
538 data = keyword_end + 1;
539
540 if (compressed) {
541 if (data == data_end)
542 return AVERROR_INVALIDDATA;
543 method = *(data++);
544 if (method)
545 return AVERROR_INVALIDDATA;
546 if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
547 return ret;
548 text_len = bp.len;
549 ret = av_bprint_finalize(&bp, (char **)&text);
550 if (ret < 0)
551 return ret;
552 } else {
553 text = (uint8_t *)data;
554 text_len = data_end - text;
555 }
556
557 kw_utf8 = iso88591_to_utf8(keyword, keyword_end - keyword);
558 txt_utf8 = iso88591_to_utf8(text, text_len);
559 if (text != data)
560 av_free(text);
561 if (!(kw_utf8 && txt_utf8)) {
562 av_free(kw_utf8);
563 av_free(txt_utf8);
564 return AVERROR(ENOMEM);
565 }
566
567 av_dict_set(&s->frame_metadata, kw_utf8, txt_utf8,
568 AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
569 return 0;
570 }
571
decode_ihdr_chunk(AVCodecContext * avctx,PNGDecContext * s,uint32_t length)572 static int decode_ihdr_chunk(AVCodecContext *avctx, PNGDecContext *s,
573 uint32_t length)
574 {
575 if (length != 13)
576 return AVERROR_INVALIDDATA;
577
578 if (s->pic_state & PNG_IDAT) {
579 av_log(avctx, AV_LOG_ERROR, "IHDR after IDAT\n");
580 return AVERROR_INVALIDDATA;
581 }
582
583 if (s->hdr_state & PNG_IHDR) {
584 av_log(avctx, AV_LOG_ERROR, "Multiple IHDR\n");
585 return AVERROR_INVALIDDATA;
586 }
587
588 s->width = s->cur_w = bytestream2_get_be32(&s->gb);
589 s->height = s->cur_h = bytestream2_get_be32(&s->gb);
590 if (av_image_check_size(s->width, s->height, 0, avctx)) {
591 s->cur_w = s->cur_h = s->width = s->height = 0;
592 av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
593 return AVERROR_INVALIDDATA;
594 }
595 s->bit_depth = bytestream2_get_byte(&s->gb);
596 if (s->bit_depth != 1 && s->bit_depth != 2 && s->bit_depth != 4 &&
597 s->bit_depth != 8 && s->bit_depth != 16) {
598 av_log(avctx, AV_LOG_ERROR, "Invalid bit depth\n");
599 goto error;
600 }
601 s->color_type = bytestream2_get_byte(&s->gb);
602 s->compression_type = bytestream2_get_byte(&s->gb);
603 if (s->compression_type) {
604 av_log(avctx, AV_LOG_ERROR, "Invalid compression method %d\n", s->compression_type);
605 goto error;
606 }
607 s->filter_type = bytestream2_get_byte(&s->gb);
608 s->interlace_type = bytestream2_get_byte(&s->gb);
609 bytestream2_skip(&s->gb, 4); /* crc */
610 s->hdr_state |= PNG_IHDR;
611 if (avctx->debug & FF_DEBUG_PICT_INFO)
612 av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d "
613 "compression_type=%d filter_type=%d interlace_type=%d\n",
614 s->width, s->height, s->bit_depth, s->color_type,
615 s->compression_type, s->filter_type, s->interlace_type);
616
617 return 0;
618 error:
619 s->cur_w = s->cur_h = s->width = s->height = 0;
620 s->bit_depth = 8;
621 return AVERROR_INVALIDDATA;
622 }
623
decode_phys_chunk(AVCodecContext * avctx,PNGDecContext * s)624 static int decode_phys_chunk(AVCodecContext *avctx, PNGDecContext *s)
625 {
626 if (s->pic_state & PNG_IDAT) {
627 av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
628 return AVERROR_INVALIDDATA;
629 }
630 avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
631 avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
632 if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
633 avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
634 bytestream2_skip(&s->gb, 1); /* unit specifier */
635 bytestream2_skip(&s->gb, 4); /* crc */
636
637 return 0;
638 }
639
decode_idat_chunk(AVCodecContext * avctx,PNGDecContext * s,uint32_t length,AVFrame * p)640 static int decode_idat_chunk(AVCodecContext *avctx, PNGDecContext *s,
641 uint32_t length, AVFrame *p)
642 {
643 int ret;
644 size_t byte_depth = s->bit_depth > 8 ? 2 : 1;
645
646 if (!(s->hdr_state & PNG_IHDR)) {
647 av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
648 return AVERROR_INVALIDDATA;
649 }
650 if (!(s->pic_state & PNG_IDAT)) {
651 /* init image info */
652 ret = ff_set_dimensions(avctx, s->width, s->height);
653 if (ret < 0)
654 return ret;
655
656 s->channels = ff_png_get_nb_channels(s->color_type);
657 s->bits_per_pixel = s->bit_depth * s->channels;
658 s->bpp = (s->bits_per_pixel + 7) >> 3;
659 s->row_size = (s->cur_w * s->bits_per_pixel + 7) >> 3;
660
661 if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
662 s->color_type == PNG_COLOR_TYPE_RGB) {
663 avctx->pix_fmt = AV_PIX_FMT_RGB24;
664 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
665 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
666 avctx->pix_fmt = AV_PIX_FMT_RGBA;
667 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
668 s->color_type == PNG_COLOR_TYPE_GRAY) {
669 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
670 } else if (s->bit_depth == 16 &&
671 s->color_type == PNG_COLOR_TYPE_GRAY) {
672 avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
673 } else if (s->bit_depth == 16 &&
674 s->color_type == PNG_COLOR_TYPE_RGB) {
675 avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
676 } else if (s->bit_depth == 16 &&
677 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
678 avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
679 } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
680 s->color_type == PNG_COLOR_TYPE_PALETTE) {
681 avctx->pix_fmt = AV_PIX_FMT_PAL8;
682 } else if (s->bit_depth == 1 && s->bits_per_pixel == 1 && avctx->codec_id != AV_CODEC_ID_APNG) {
683 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
684 } else if (s->bit_depth == 8 &&
685 s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
686 avctx->pix_fmt = AV_PIX_FMT_YA8;
687 } else if (s->bit_depth == 16 &&
688 s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
689 avctx->pix_fmt = AV_PIX_FMT_YA16BE;
690 } else {
691 avpriv_report_missing_feature(avctx,
692 "Bit depth %d color type %d",
693 s->bit_depth, s->color_type);
694 return AVERROR_PATCHWELCOME;
695 }
696
697 if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE) {
698 switch (avctx->pix_fmt) {
699 case AV_PIX_FMT_RGB24:
700 avctx->pix_fmt = AV_PIX_FMT_RGBA;
701 break;
702
703 case AV_PIX_FMT_RGB48BE:
704 avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
705 break;
706
707 case AV_PIX_FMT_GRAY8:
708 avctx->pix_fmt = AV_PIX_FMT_YA8;
709 break;
710
711 case AV_PIX_FMT_GRAY16BE:
712 avctx->pix_fmt = AV_PIX_FMT_YA16BE;
713 break;
714
715 default:
716 avpriv_request_sample(avctx, "bit depth %d "
717 "and color type %d with TRNS",
718 s->bit_depth, s->color_type);
719 return AVERROR_INVALIDDATA;
720 }
721
722 s->bpp += byte_depth;
723 }
724
725 ff_thread_release_buffer(avctx, &s->picture);
726 if ((ret = ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF)) < 0)
727 return ret;
728
729 p->pict_type = AV_PICTURE_TYPE_I;
730 p->key_frame = 1;
731 p->interlaced_frame = !!s->interlace_type;
732
733 ff_thread_finish_setup(avctx);
734
735 /* compute the compressed row size */
736 if (!s->interlace_type) {
737 s->crow_size = s->row_size + 1;
738 } else {
739 s->pass = 0;
740 s->pass_row_size = ff_png_pass_row_size(s->pass,
741 s->bits_per_pixel,
742 s->cur_w);
743 s->crow_size = s->pass_row_size + 1;
744 }
745 ff_dlog(avctx, "row_size=%d crow_size =%d\n",
746 s->row_size, s->crow_size);
747
748 /* copy the palette if needed */
749 if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
750 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
751 /* empty row is used if differencing to the first row */
752 av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
753 if (!s->last_row)
754 return AVERROR_INVALIDDATA;
755 if (s->interlace_type ||
756 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
757 av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size);
758 if (!s->tmp_row)
759 return AVERROR_INVALIDDATA;
760 }
761 /* compressed row */
762 av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
763 if (!s->buffer)
764 return AVERROR(ENOMEM);
765
766 /* we want crow_buf+1 to be 16-byte aligned */
767 s->crow_buf = s->buffer + 15;
768 s->zstream.avail_out = s->crow_size;
769 s->zstream.next_out = s->crow_buf;
770 }
771
772 s->pic_state |= PNG_IDAT;
773
774 /* set image to non-transparent bpp while decompressing */
775 if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE)
776 s->bpp -= byte_depth;
777
778 ret = png_decode_idat(s, length, p->data[0], p->linesize[0]);
779
780 if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE)
781 s->bpp += byte_depth;
782
783 if (ret < 0)
784 return ret;
785
786 bytestream2_skip(&s->gb, 4); /* crc */
787
788 return 0;
789 }
790
decode_plte_chunk(AVCodecContext * avctx,PNGDecContext * s,uint32_t length)791 static int decode_plte_chunk(AVCodecContext *avctx, PNGDecContext *s,
792 uint32_t length)
793 {
794 int n, i, r, g, b;
795
796 if ((length % 3) != 0 || length > 256 * 3)
797 return AVERROR_INVALIDDATA;
798 /* read the palette */
799 n = length / 3;
800 for (i = 0; i < n; i++) {
801 r = bytestream2_get_byte(&s->gb);
802 g = bytestream2_get_byte(&s->gb);
803 b = bytestream2_get_byte(&s->gb);
804 s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
805 }
806 for (; i < 256; i++)
807 s->palette[i] = (0xFFU << 24);
808 s->hdr_state |= PNG_PLTE;
809 bytestream2_skip(&s->gb, 4); /* crc */
810
811 return 0;
812 }
813
decode_trns_chunk(AVCodecContext * avctx,PNGDecContext * s,uint32_t length)814 static int decode_trns_chunk(AVCodecContext *avctx, PNGDecContext *s,
815 uint32_t length)
816 {
817 int v, i;
818
819 if (!(s->hdr_state & PNG_IHDR)) {
820 av_log(avctx, AV_LOG_ERROR, "trns before IHDR\n");
821 return AVERROR_INVALIDDATA;
822 }
823
824 if (s->pic_state & PNG_IDAT) {
825 av_log(avctx, AV_LOG_ERROR, "trns after IDAT\n");
826 return AVERROR_INVALIDDATA;
827 }
828
829 if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
830 if (length > 256 || !(s->hdr_state & PNG_PLTE))
831 return AVERROR_INVALIDDATA;
832
833 for (i = 0; i < length; i++) {
834 unsigned v = bytestream2_get_byte(&s->gb);
835 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
836 }
837 } else if (s->color_type == PNG_COLOR_TYPE_GRAY || s->color_type == PNG_COLOR_TYPE_RGB) {
838 if ((s->color_type == PNG_COLOR_TYPE_GRAY && length != 2) ||
839 (s->color_type == PNG_COLOR_TYPE_RGB && length != 6) ||
840 s->bit_depth == 1)
841 return AVERROR_INVALIDDATA;
842
843 for (i = 0; i < length / 2; i++) {
844 /* only use the least significant bits */
845 v = av_mod_uintp2(bytestream2_get_be16(&s->gb), s->bit_depth);
846
847 if (s->bit_depth > 8)
848 AV_WB16(&s->transparent_color_be[2 * i], v);
849 else
850 s->transparent_color_be[i] = v;
851 }
852 } else {
853 return AVERROR_INVALIDDATA;
854 }
855
856 bytestream2_skip(&s->gb, 4); /* crc */
857 s->has_trns = 1;
858
859 return 0;
860 }
861
decode_iccp_chunk(PNGDecContext * s,int length,AVFrame * f)862 static int decode_iccp_chunk(PNGDecContext *s, int length, AVFrame *f)
863 {
864 int ret, cnt = 0;
865 AVBPrint bp;
866
867 while ((s->iccp_name[cnt++] = bytestream2_get_byte(&s->gb)) && cnt < 81);
868 if (cnt > 80) {
869 av_log(s->avctx, AV_LOG_ERROR, "iCCP with invalid name!\n");
870 ret = AVERROR_INVALIDDATA;
871 goto fail;
872 }
873
874 length = FFMAX(length - cnt, 0);
875
876 if (bytestream2_get_byte(&s->gb) != 0) {
877 av_log(s->avctx, AV_LOG_ERROR, "iCCP with invalid compression!\n");
878 ret = AVERROR_INVALIDDATA;
879 goto fail;
880 }
881
882 length = FFMAX(length - 1, 0);
883
884 if ((ret = decode_zbuf(&bp, s->gb.buffer, s->gb.buffer + length)) < 0)
885 return ret;
886
887 av_freep(&s->iccp_data);
888 ret = av_bprint_finalize(&bp, (char **)&s->iccp_data);
889 if (ret < 0)
890 return ret;
891 s->iccp_data_len = bp.len;
892
893 /* ICC compressed data and CRC */
894 bytestream2_skip(&s->gb, length + 4);
895
896 return 0;
897 fail:
898 s->iccp_name[0] = 0;
899 return ret;
900 }
901
handle_small_bpp(PNGDecContext * s,AVFrame * p)902 static void handle_small_bpp(PNGDecContext *s, AVFrame *p)
903 {
904 if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE) {
905 int i, j, k;
906 uint8_t *pd = p->data[0];
907 for (j = 0; j < s->height; j++) {
908 i = s->width / 8;
909 for (k = 7; k >= 1; k--)
910 if ((s->width&7) >= k)
911 pd[8*i + k - 1] = (pd[i]>>8-k) & 1;
912 for (i--; i >= 0; i--) {
913 pd[8*i + 7]= pd[i] & 1;
914 pd[8*i + 6]= (pd[i]>>1) & 1;
915 pd[8*i + 5]= (pd[i]>>2) & 1;
916 pd[8*i + 4]= (pd[i]>>3) & 1;
917 pd[8*i + 3]= (pd[i]>>4) & 1;
918 pd[8*i + 2]= (pd[i]>>5) & 1;
919 pd[8*i + 1]= (pd[i]>>6) & 1;
920 pd[8*i + 0]= pd[i]>>7;
921 }
922 pd += p->linesize[0];
923 }
924 } else if (s->bits_per_pixel == 2) {
925 int i, j;
926 uint8_t *pd = p->data[0];
927 for (j = 0; j < s->height; j++) {
928 i = s->width / 4;
929 if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
930 if ((s->width&3) >= 3) pd[4*i + 2]= (pd[i] >> 2) & 3;
931 if ((s->width&3) >= 2) pd[4*i + 1]= (pd[i] >> 4) & 3;
932 if ((s->width&3) >= 1) pd[4*i + 0]= pd[i] >> 6;
933 for (i--; i >= 0; i--) {
934 pd[4*i + 3]= pd[i] & 3;
935 pd[4*i + 2]= (pd[i]>>2) & 3;
936 pd[4*i + 1]= (pd[i]>>4) & 3;
937 pd[4*i + 0]= pd[i]>>6;
938 }
939 } else {
940 if ((s->width&3) >= 3) pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
941 if ((s->width&3) >= 2) pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
942 if ((s->width&3) >= 1) pd[4*i + 0]= ( pd[i]>>6 )*0x55;
943 for (i--; i >= 0; i--) {
944 pd[4*i + 3]= ( pd[i] & 3)*0x55;
945 pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
946 pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
947 pd[4*i + 0]= ( pd[i]>>6 )*0x55;
948 }
949 }
950 pd += p->linesize[0];
951 }
952 } else if (s->bits_per_pixel == 4) {
953 int i, j;
954 uint8_t *pd = p->data[0];
955 for (j = 0; j < s->height; j++) {
956 i = s->width/2;
957 if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
958 if (s->width&1) pd[2*i+0]= pd[i]>>4;
959 for (i--; i >= 0; i--) {
960 pd[2*i + 1] = pd[i] & 15;
961 pd[2*i + 0] = pd[i] >> 4;
962 }
963 } else {
964 if (s->width & 1) pd[2*i + 0]= (pd[i] >> 4) * 0x11;
965 for (i--; i >= 0; i--) {
966 pd[2*i + 1] = (pd[i] & 15) * 0x11;
967 pd[2*i + 0] = (pd[i] >> 4) * 0x11;
968 }
969 }
970 pd += p->linesize[0];
971 }
972 }
973 }
974
decode_fctl_chunk(AVCodecContext * avctx,PNGDecContext * s,uint32_t length)975 static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s,
976 uint32_t length)
977 {
978 uint32_t sequence_number;
979 int cur_w, cur_h, x_offset, y_offset, dispose_op, blend_op;
980
981 if (length != 26)
982 return AVERROR_INVALIDDATA;
983
984 if (!(s->hdr_state & PNG_IHDR)) {
985 av_log(avctx, AV_LOG_ERROR, "fctl before IHDR\n");
986 return AVERROR_INVALIDDATA;
987 }
988
989 if (s->pic_state & PNG_IDAT) {
990 av_log(avctx, AV_LOG_ERROR, "fctl after IDAT\n");
991 return AVERROR_INVALIDDATA;
992 }
993
994 s->last_w = s->cur_w;
995 s->last_h = s->cur_h;
996 s->last_x_offset = s->x_offset;
997 s->last_y_offset = s->y_offset;
998 s->last_dispose_op = s->dispose_op;
999
1000 sequence_number = bytestream2_get_be32(&s->gb);
1001 cur_w = bytestream2_get_be32(&s->gb);
1002 cur_h = bytestream2_get_be32(&s->gb);
1003 x_offset = bytestream2_get_be32(&s->gb);
1004 y_offset = bytestream2_get_be32(&s->gb);
1005 bytestream2_skip(&s->gb, 4); /* delay_num (2), delay_den (2) */
1006 dispose_op = bytestream2_get_byte(&s->gb);
1007 blend_op = bytestream2_get_byte(&s->gb);
1008 bytestream2_skip(&s->gb, 4); /* crc */
1009
1010 if (sequence_number == 0 &&
1011 (cur_w != s->width ||
1012 cur_h != s->height ||
1013 x_offset != 0 ||
1014 y_offset != 0) ||
1015 cur_w <= 0 || cur_h <= 0 ||
1016 x_offset < 0 || y_offset < 0 ||
1017 cur_w > s->width - x_offset|| cur_h > s->height - y_offset)
1018 return AVERROR_INVALIDDATA;
1019
1020 if (blend_op != APNG_BLEND_OP_OVER && blend_op != APNG_BLEND_OP_SOURCE) {
1021 av_log(avctx, AV_LOG_ERROR, "Invalid blend_op %d\n", blend_op);
1022 return AVERROR_INVALIDDATA;
1023 }
1024
1025 if ((sequence_number == 0 || !s->last_picture.f->data[0]) &&
1026 dispose_op == APNG_DISPOSE_OP_PREVIOUS) {
1027 // No previous frame to revert to for the first frame
1028 // Spec says to just treat it as a APNG_DISPOSE_OP_BACKGROUND
1029 dispose_op = APNG_DISPOSE_OP_BACKGROUND;
1030 }
1031
1032 if (blend_op == APNG_BLEND_OP_OVER && !s->has_trns && (
1033 avctx->pix_fmt == AV_PIX_FMT_RGB24 ||
1034 avctx->pix_fmt == AV_PIX_FMT_RGB48BE ||
1035 avctx->pix_fmt == AV_PIX_FMT_PAL8 ||
1036 avctx->pix_fmt == AV_PIX_FMT_GRAY8 ||
1037 avctx->pix_fmt == AV_PIX_FMT_GRAY16BE ||
1038 avctx->pix_fmt == AV_PIX_FMT_MONOBLACK
1039 )) {
1040 // APNG_BLEND_OP_OVER is the same as APNG_BLEND_OP_SOURCE when there is no alpha channel
1041 blend_op = APNG_BLEND_OP_SOURCE;
1042 }
1043
1044 s->cur_w = cur_w;
1045 s->cur_h = cur_h;
1046 s->x_offset = x_offset;
1047 s->y_offset = y_offset;
1048 s->dispose_op = dispose_op;
1049 s->blend_op = blend_op;
1050
1051 return 0;
1052 }
1053
handle_p_frame_png(PNGDecContext * s,AVFrame * p)1054 static void handle_p_frame_png(PNGDecContext *s, AVFrame *p)
1055 {
1056 int i, j;
1057 uint8_t *pd = p->data[0];
1058 uint8_t *pd_last = s->last_picture.f->data[0];
1059 int ls = FFMIN(av_image_get_linesize(p->format, s->width, 0), s->width * s->bpp);
1060
1061 ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
1062 for (j = 0; j < s->height; j++) {
1063 for (i = 0; i < ls; i++)
1064 pd[i] += pd_last[i];
1065 pd += p->linesize[0];
1066 pd_last += s->last_picture.f->linesize[0];
1067 }
1068 }
1069
1070 // divide by 255 and round to nearest
1071 // apply a fast variant: (X+127)/255 = ((X+127)*257+257)>>16 = ((X+128)*257)>>16
1072 #define FAST_DIV255(x) ((((x) + 128) * 257) >> 16)
1073
handle_p_frame_apng(AVCodecContext * avctx,PNGDecContext * s,AVFrame * p)1074 static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
1075 AVFrame *p)
1076 {
1077 uint8_t *dst = p->data[0];
1078 ptrdiff_t dst_stride = p->linesize[0];
1079 const uint8_t *src = s->last_picture.f->data[0];
1080 ptrdiff_t src_stride = s->last_picture.f->linesize[0];
1081
1082 size_t x, y;
1083
1084 if (s->blend_op == APNG_BLEND_OP_OVER &&
1085 avctx->pix_fmt != AV_PIX_FMT_RGBA &&
1086 avctx->pix_fmt != AV_PIX_FMT_GRAY8A &&
1087 avctx->pix_fmt != AV_PIX_FMT_PAL8) {
1088 avpriv_request_sample(avctx, "Blending with pixel format %s",
1089 av_get_pix_fmt_name(avctx->pix_fmt));
1090 return AVERROR_PATCHWELCOME;
1091 }
1092
1093 ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
1094
1095 // need to reset a rectangle to background:
1096 if (s->last_dispose_op == APNG_DISPOSE_OP_BACKGROUND) {
1097 av_fast_malloc(&s->background_buf, &s->background_buf_allocated,
1098 src_stride * p->height);
1099 if (!s->background_buf)
1100 return AVERROR(ENOMEM);
1101
1102 memcpy(s->background_buf, src, src_stride * p->height);
1103
1104 for (y = s->last_y_offset; y < s->last_y_offset + s->last_h; y++) {
1105 memset(s->background_buf + src_stride * y +
1106 s->bpp * s->last_x_offset, 0, s->bpp * s->last_w);
1107 }
1108
1109 src = s->background_buf;
1110 }
1111
1112 // copy unchanged rectangles from the last frame
1113 for (y = 0; y < s->y_offset; y++)
1114 memcpy(dst + y * dst_stride, src + y * src_stride, p->width * s->bpp);
1115 for (y = s->y_offset; y < s->y_offset + s->cur_h; y++) {
1116 memcpy(dst + y * dst_stride, src + y * src_stride, s->x_offset * s->bpp);
1117 memcpy(dst + y * dst_stride + (s->x_offset + s->cur_w) * s->bpp,
1118 src + y * src_stride + (s->x_offset + s->cur_w) * s->bpp,
1119 (p->width - s->cur_w - s->x_offset) * s->bpp);
1120 }
1121 for (y = s->y_offset + s->cur_h; y < p->height; y++)
1122 memcpy(dst + y * dst_stride, src + y * src_stride, p->width * s->bpp);
1123
1124 if (s->blend_op == APNG_BLEND_OP_OVER) {
1125 // Perform blending
1126 for (y = s->y_offset; y < s->y_offset + s->cur_h; ++y) {
1127 uint8_t *foreground = dst + dst_stride * y + s->bpp * s->x_offset;
1128 const uint8_t *background = src + src_stride * y + s->bpp * s->x_offset;
1129 for (x = s->x_offset; x < s->x_offset + s->cur_w; ++x, foreground += s->bpp, background += s->bpp) {
1130 size_t b;
1131 uint8_t foreground_alpha, background_alpha, output_alpha;
1132 uint8_t output[10];
1133
1134 // Since we might be blending alpha onto alpha, we use the following equations:
1135 // output_alpha = foreground_alpha + (1 - foreground_alpha) * background_alpha
1136 // output = (foreground_alpha * foreground + (1 - foreground_alpha) * background_alpha * background) / output_alpha
1137
1138 switch (avctx->pix_fmt) {
1139 case AV_PIX_FMT_RGBA:
1140 foreground_alpha = foreground[3];
1141 background_alpha = background[3];
1142 break;
1143
1144 case AV_PIX_FMT_GRAY8A:
1145 foreground_alpha = foreground[1];
1146 background_alpha = background[1];
1147 break;
1148
1149 case AV_PIX_FMT_PAL8:
1150 foreground_alpha = s->palette[foreground[0]] >> 24;
1151 background_alpha = s->palette[background[0]] >> 24;
1152 break;
1153 }
1154
1155 if (foreground_alpha == 255)
1156 continue;
1157
1158 if (foreground_alpha == 0) {
1159 memcpy(foreground, background, s->bpp);
1160 continue;
1161 }
1162
1163 if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
1164 // TODO: Alpha blending with PAL8 will likely need the entire image converted over to RGBA first
1165 avpriv_request_sample(avctx, "Alpha blending palette samples");
1166 continue;
1167 }
1168
1169 output_alpha = foreground_alpha + FAST_DIV255((255 - foreground_alpha) * background_alpha);
1170
1171 av_assert0(s->bpp <= 10);
1172
1173 for (b = 0; b < s->bpp - 1; ++b) {
1174 if (output_alpha == 0) {
1175 output[b] = 0;
1176 } else if (background_alpha == 255) {
1177 output[b] = FAST_DIV255(foreground_alpha * foreground[b] + (255 - foreground_alpha) * background[b]);
1178 } else {
1179 output[b] = (255 * foreground_alpha * foreground[b] + (255 - foreground_alpha) * background_alpha * background[b]) / (255 * output_alpha);
1180 }
1181 }
1182 output[b] = output_alpha;
1183 memcpy(foreground, output, s->bpp);
1184 }
1185 }
1186 }
1187
1188 return 0;
1189 }
1190
decode_frame_common(AVCodecContext * avctx,PNGDecContext * s,AVFrame * p,const AVPacket * avpkt)1191 static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
1192 AVFrame *p, const AVPacket *avpkt)
1193 {
1194 const AVCRC *crc_tab = av_crc_get_table(AV_CRC_32_IEEE_LE);
1195 uint32_t tag, length;
1196 int decode_next_dat = 0;
1197 int i, ret;
1198
1199 for (;;) {
1200 length = bytestream2_get_bytes_left(&s->gb);
1201 if (length <= 0) {
1202
1203 if (avctx->codec_id == AV_CODEC_ID_PNG &&
1204 avctx->skip_frame == AVDISCARD_ALL) {
1205 return 0;
1206 }
1207
1208 if (CONFIG_APNG_DECODER && avctx->codec_id == AV_CODEC_ID_APNG && length == 0) {
1209 if (!(s->pic_state & PNG_IDAT))
1210 return 0;
1211 else
1212 goto exit_loop;
1213 }
1214 av_log(avctx, AV_LOG_ERROR, "%d bytes left\n", length);
1215 if ( s->pic_state & PNG_ALLIMAGE
1216 && avctx->strict_std_compliance <= FF_COMPLIANCE_NORMAL)
1217 goto exit_loop;
1218 ret = AVERROR_INVALIDDATA;
1219 goto fail;
1220 }
1221
1222 length = bytestream2_get_be32(&s->gb);
1223 if (length > 0x7fffffff || length + 8 > bytestream2_get_bytes_left(&s->gb)) {
1224 av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
1225 ret = AVERROR_INVALIDDATA;
1226 goto fail;
1227 }
1228 if (avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_IGNORE_ERR)) {
1229 uint32_t crc_sig = AV_RB32(s->gb.buffer + length + 4);
1230 uint32_t crc_cal = ~av_crc(crc_tab, UINT32_MAX, s->gb.buffer, length + 4);
1231 if (crc_sig ^ crc_cal) {
1232 av_log(avctx, AV_LOG_ERROR, "CRC mismatch in chunk");
1233 if (avctx->err_recognition & AV_EF_EXPLODE) {
1234 av_log(avctx, AV_LOG_ERROR, ", quitting\n");
1235 ret = AVERROR_INVALIDDATA;
1236 goto fail;
1237 }
1238 av_log(avctx, AV_LOG_ERROR, ", skipping\n");
1239 bytestream2_skip(&s->gb, 4); /* tag */
1240 goto skip_tag;
1241 }
1242 }
1243 tag = bytestream2_get_le32(&s->gb);
1244 if (avctx->debug & FF_DEBUG_STARTCODE)
1245 av_log(avctx, AV_LOG_DEBUG, "png: tag=%s length=%u\n",
1246 av_fourcc2str(tag), length);
1247
1248 if (avctx->codec_id == AV_CODEC_ID_PNG &&
1249 avctx->skip_frame == AVDISCARD_ALL) {
1250 switch(tag) {
1251 case MKTAG('I', 'H', 'D', 'R'):
1252 case MKTAG('p', 'H', 'Y', 's'):
1253 case MKTAG('t', 'E', 'X', 't'):
1254 case MKTAG('I', 'D', 'A', 'T'):
1255 case MKTAG('t', 'R', 'N', 'S'):
1256 break;
1257 default:
1258 goto skip_tag;
1259 }
1260 }
1261
1262 switch (tag) {
1263 case MKTAG('I', 'H', 'D', 'R'):
1264 if ((ret = decode_ihdr_chunk(avctx, s, length)) < 0)
1265 goto fail;
1266 break;
1267 case MKTAG('p', 'H', 'Y', 's'):
1268 if ((ret = decode_phys_chunk(avctx, s)) < 0)
1269 goto fail;
1270 break;
1271 case MKTAG('f', 'c', 'T', 'L'):
1272 if (!CONFIG_APNG_DECODER || avctx->codec_id != AV_CODEC_ID_APNG)
1273 goto skip_tag;
1274 if ((ret = decode_fctl_chunk(avctx, s, length)) < 0)
1275 goto fail;
1276 decode_next_dat = 1;
1277 break;
1278 case MKTAG('f', 'd', 'A', 'T'):
1279 if (!CONFIG_APNG_DECODER || avctx->codec_id != AV_CODEC_ID_APNG)
1280 goto skip_tag;
1281 if (!decode_next_dat || length < 4) {
1282 ret = AVERROR_INVALIDDATA;
1283 goto fail;
1284 }
1285 bytestream2_get_be32(&s->gb);
1286 length -= 4;
1287 /* fallthrough */
1288 case MKTAG('I', 'D', 'A', 'T'):
1289 if (CONFIG_APNG_DECODER && avctx->codec_id == AV_CODEC_ID_APNG && !decode_next_dat)
1290 goto skip_tag;
1291 if ((ret = decode_idat_chunk(avctx, s, length, p)) < 0)
1292 goto fail;
1293 break;
1294 case MKTAG('P', 'L', 'T', 'E'):
1295 if (decode_plte_chunk(avctx, s, length) < 0)
1296 goto skip_tag;
1297 break;
1298 case MKTAG('t', 'R', 'N', 'S'):
1299 if (decode_trns_chunk(avctx, s, length) < 0)
1300 goto skip_tag;
1301 break;
1302 case MKTAG('t', 'E', 'X', 't'):
1303 if (decode_text_chunk(s, length, 0) < 0)
1304 av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
1305 bytestream2_skip(&s->gb, length + 4);
1306 break;
1307 case MKTAG('z', 'T', 'X', 't'):
1308 if (decode_text_chunk(s, length, 1) < 0)
1309 av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
1310 bytestream2_skip(&s->gb, length + 4);
1311 break;
1312 case MKTAG('s', 'T', 'E', 'R'): {
1313 int mode = bytestream2_get_byte(&s->gb);
1314
1315 if (mode == 0 || mode == 1) {
1316 s->stereo_mode = mode;
1317 } else {
1318 av_log(avctx, AV_LOG_WARNING,
1319 "Unknown value in sTER chunk (%d)\n", mode);
1320 }
1321 bytestream2_skip(&s->gb, 4); /* crc */
1322 break;
1323 }
1324 case MKTAG('i', 'C', 'C', 'P'): {
1325 if ((ret = decode_iccp_chunk(s, length, p)) < 0)
1326 goto fail;
1327 break;
1328 }
1329 case MKTAG('c', 'H', 'R', 'M'): {
1330 s->have_chrm = 1;
1331
1332 s->white_point[0] = bytestream2_get_be32(&s->gb);
1333 s->white_point[1] = bytestream2_get_be32(&s->gb);
1334
1335 /* RGB Primaries */
1336 for (i = 0; i < 3; i++) {
1337 s->display_primaries[i][0] = bytestream2_get_be32(&s->gb);
1338 s->display_primaries[i][1] = bytestream2_get_be32(&s->gb);
1339 }
1340
1341 bytestream2_skip(&s->gb, 4); /* crc */
1342 break;
1343 }
1344 case MKTAG('g', 'A', 'M', 'A'): {
1345 AVBPrint bp;
1346 char *gamma_str;
1347 int num = bytestream2_get_be32(&s->gb);
1348
1349 av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
1350 av_bprintf(&bp, "%i/%i", num, 100000);
1351 ret = av_bprint_finalize(&bp, &gamma_str);
1352 if (ret < 0)
1353 return ret;
1354
1355 av_dict_set(&s->frame_metadata, "gamma", gamma_str, AV_DICT_DONT_STRDUP_VAL);
1356
1357 bytestream2_skip(&s->gb, 4); /* crc */
1358 break;
1359 }
1360 case MKTAG('I', 'E', 'N', 'D'):
1361 if (!(s->pic_state & PNG_ALLIMAGE))
1362 av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
1363 if (!(s->pic_state & (PNG_ALLIMAGE|PNG_IDAT))) {
1364 ret = AVERROR_INVALIDDATA;
1365 goto fail;
1366 }
1367 bytestream2_skip(&s->gb, 4); /* crc */
1368 goto exit_loop;
1369 default:
1370 /* skip tag */
1371 skip_tag:
1372 bytestream2_skip(&s->gb, length + 4);
1373 break;
1374 }
1375 }
1376 exit_loop:
1377
1378 if (avctx->codec_id == AV_CODEC_ID_PNG &&
1379 avctx->skip_frame == AVDISCARD_ALL) {
1380 return 0;
1381 }
1382
1383 if (percent_missing(s) > avctx->discard_damaged_percentage)
1384 return AVERROR_INVALIDDATA;
1385
1386 if (s->bits_per_pixel <= 4)
1387 handle_small_bpp(s, p);
1388
1389 /* apply transparency if needed */
1390 if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE) {
1391 size_t byte_depth = s->bit_depth > 8 ? 2 : 1;
1392 size_t raw_bpp = s->bpp - byte_depth;
1393 unsigned x, y;
1394
1395 av_assert0(s->bit_depth > 1);
1396
1397 for (y = 0; y < s->height; ++y) {
1398 uint8_t *row = &p->data[0][p->linesize[0] * y];
1399
1400 if (s->bpp == 2 && byte_depth == 1) {
1401 uint8_t *pixel = &row[2 * s->width - 1];
1402 uint8_t *rowp = &row[1 * s->width - 1];
1403 int tcolor = s->transparent_color_be[0];
1404 for (x = s->width; x > 0; --x) {
1405 *pixel-- = *rowp == tcolor ? 0 : 0xff;
1406 *pixel-- = *rowp--;
1407 }
1408 } else if (s->bpp == 4 && byte_depth == 1) {
1409 uint8_t *pixel = &row[4 * s->width - 1];
1410 uint8_t *rowp = &row[3 * s->width - 1];
1411 int tcolor = AV_RL24(s->transparent_color_be);
1412 for (x = s->width; x > 0; --x) {
1413 *pixel-- = AV_RL24(rowp-2) == tcolor ? 0 : 0xff;
1414 *pixel-- = *rowp--;
1415 *pixel-- = *rowp--;
1416 *pixel-- = *rowp--;
1417 }
1418 } else {
1419 /* since we're updating in-place, we have to go from right to left */
1420 for (x = s->width; x > 0; --x) {
1421 uint8_t *pixel = &row[s->bpp * (x - 1)];
1422 memmove(pixel, &row[raw_bpp * (x - 1)], raw_bpp);
1423
1424 if (!memcmp(pixel, s->transparent_color_be, raw_bpp)) {
1425 memset(&pixel[raw_bpp], 0, byte_depth);
1426 } else {
1427 memset(&pixel[raw_bpp], 0xff, byte_depth);
1428 }
1429 }
1430 }
1431 }
1432 }
1433
1434 /* handle P-frames only if a predecessor frame is available */
1435 if (s->last_picture.f->data[0]) {
1436 if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
1437 && s->last_picture.f->width == p->width
1438 && s->last_picture.f->height== p->height
1439 && s->last_picture.f->format== p->format
1440 ) {
1441 if (CONFIG_PNG_DECODER && avctx->codec_id != AV_CODEC_ID_APNG)
1442 handle_p_frame_png(s, p);
1443 else if (CONFIG_APNG_DECODER &&
1444 avctx->codec_id == AV_CODEC_ID_APNG &&
1445 (ret = handle_p_frame_apng(avctx, s, p)) < 0)
1446 goto fail;
1447 }
1448 }
1449 ff_thread_report_progress(&s->picture, INT_MAX, 0);
1450
1451 return 0;
1452
1453 fail:
1454 ff_thread_report_progress(&s->picture, INT_MAX, 0);
1455 return ret;
1456 }
1457
clear_frame_metadata(PNGDecContext * s)1458 static void clear_frame_metadata(PNGDecContext *s)
1459 {
1460 av_freep(&s->iccp_data);
1461 s->iccp_data_len = 0;
1462 s->iccp_name[0] = 0;
1463
1464 s->stereo_mode = -1;
1465
1466 s->have_chrm = 0;
1467
1468 av_dict_free(&s->frame_metadata);
1469 }
1470
output_frame(PNGDecContext * s,AVFrame * f,const AVFrame * src)1471 static int output_frame(PNGDecContext *s, AVFrame *f,
1472 const AVFrame *src)
1473 {
1474 int ret;
1475
1476 ret = av_frame_ref(f, src);
1477 if (ret < 0)
1478 return ret;
1479
1480 if (s->iccp_data) {
1481 AVFrameSideData *sd = av_frame_new_side_data(f, AV_FRAME_DATA_ICC_PROFILE, s->iccp_data_len);
1482 if (!sd) {
1483 ret = AVERROR(ENOMEM);
1484 goto fail;
1485 }
1486 memcpy(sd->data, s->iccp_data, s->iccp_data_len);
1487
1488 av_dict_set(&sd->metadata, "name", s->iccp_name, 0);
1489 }
1490
1491 if (s->stereo_mode >= 0) {
1492 AVStereo3D *stereo3d = av_stereo3d_create_side_data(f);
1493 if (!stereo3d) {
1494 ret = AVERROR(ENOMEM);
1495 goto fail;
1496 }
1497
1498 stereo3d->type = AV_STEREO3D_SIDEBYSIDE;
1499 stereo3d->flags = s->stereo_mode ? 0 : AV_STEREO3D_FLAG_INVERT;
1500 }
1501
1502 if (s->have_chrm) {
1503 AVMasteringDisplayMetadata *mdm = av_mastering_display_metadata_create_side_data(f);
1504 if (!mdm) {
1505 ret = AVERROR(ENOMEM);
1506 goto fail;
1507 }
1508
1509 mdm->white_point[0] = av_make_q(s->white_point[0], 100000);
1510 mdm->white_point[1] = av_make_q(s->white_point[1], 100000);
1511
1512 /* RGB Primaries */
1513 for (int i = 0; i < 3; i++) {
1514 mdm->display_primaries[i][0] = av_make_q(s->display_primaries[i][0], 100000);
1515 mdm->display_primaries[i][1] = av_make_q(s->display_primaries[i][1], 100000);
1516 }
1517
1518 mdm->has_primaries = 1;
1519 }
1520
1521 FFSWAP(AVDictionary*, f->metadata, s->frame_metadata);
1522
1523 return 0;
1524 fail:
1525 av_frame_unref(f);
1526 return ret;
1527 }
1528
1529 #if CONFIG_PNG_DECODER
decode_frame_png(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)1530 static int decode_frame_png(AVCodecContext *avctx,
1531 void *data, int *got_frame,
1532 AVPacket *avpkt)
1533 {
1534 PNGDecContext *const s = avctx->priv_data;
1535 const uint8_t *buf = avpkt->data;
1536 int buf_size = avpkt->size;
1537 AVFrame *dst_frame = data;
1538 AVFrame *p = s->picture.f;
1539 int64_t sig;
1540 int ret;
1541
1542 clear_frame_metadata(s);
1543
1544 bytestream2_init(&s->gb, buf, buf_size);
1545
1546 /* check signature */
1547 sig = bytestream2_get_be64(&s->gb);
1548 if (sig != PNGSIG &&
1549 sig != MNGSIG) {
1550 av_log(avctx, AV_LOG_ERROR, "Invalid PNG signature 0x%08"PRIX64".\n", sig);
1551 return AVERROR_INVALIDDATA;
1552 }
1553
1554 s->y = s->has_trns = 0;
1555 s->hdr_state = 0;
1556 s->pic_state = 0;
1557
1558 /* init the zlib */
1559 s->zstream.zalloc = ff_png_zalloc;
1560 s->zstream.zfree = ff_png_zfree;
1561 s->zstream.opaque = NULL;
1562 ret = inflateInit(&s->zstream);
1563 if (ret != Z_OK) {
1564 av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
1565 return AVERROR_EXTERNAL;
1566 }
1567
1568 if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
1569 goto the_end;
1570
1571 if (avctx->skip_frame == AVDISCARD_ALL) {
1572 *got_frame = 0;
1573 ret = bytestream2_tell(&s->gb);
1574 goto the_end;
1575 }
1576
1577 ret = output_frame(s, dst_frame, s->picture.f);
1578 if (ret < 0)
1579 goto the_end;
1580
1581 if (!(avctx->active_thread_type & FF_THREAD_FRAME)) {
1582 ff_thread_release_buffer(avctx, &s->last_picture);
1583 FFSWAP(ThreadFrame, s->picture, s->last_picture);
1584 }
1585
1586 *got_frame = 1;
1587
1588 ret = bytestream2_tell(&s->gb);
1589 the_end:
1590 inflateEnd(&s->zstream);
1591 s->crow_buf = NULL;
1592 return ret;
1593 }
1594 #endif
1595
1596 #if CONFIG_APNG_DECODER
decode_frame_apng(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)1597 static int decode_frame_apng(AVCodecContext *avctx,
1598 void *data, int *got_frame,
1599 AVPacket *avpkt)
1600 {
1601 PNGDecContext *const s = avctx->priv_data;
1602 AVFrame *dst_frame = data;
1603 int ret;
1604 AVFrame *p = s->picture.f;
1605
1606 clear_frame_metadata(s);
1607
1608 if (!(s->hdr_state & PNG_IHDR)) {
1609 if (!avctx->extradata_size)
1610 return AVERROR_INVALIDDATA;
1611
1612 /* only init fields, there is no zlib use in extradata */
1613 s->zstream.zalloc = ff_png_zalloc;
1614 s->zstream.zfree = ff_png_zfree;
1615
1616 bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
1617 if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
1618 goto end;
1619 }
1620
1621 /* reset state for a new frame */
1622 if ((ret = inflateInit(&s->zstream)) != Z_OK) {
1623 av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
1624 ret = AVERROR_EXTERNAL;
1625 goto end;
1626 }
1627 s->y = 0;
1628 s->pic_state = 0;
1629 bytestream2_init(&s->gb, avpkt->data, avpkt->size);
1630 if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
1631 goto end;
1632
1633 if (!(s->pic_state & PNG_ALLIMAGE))
1634 av_log(avctx, AV_LOG_WARNING, "Frame did not contain a complete image\n");
1635 if (!(s->pic_state & (PNG_ALLIMAGE|PNG_IDAT))) {
1636 ret = AVERROR_INVALIDDATA;
1637 goto end;
1638 }
1639
1640 ret = output_frame(s, dst_frame, s->picture.f);
1641 if (ret < 0)
1642 goto end;
1643
1644 if (!(avctx->active_thread_type & FF_THREAD_FRAME)) {
1645 if (s->dispose_op == APNG_DISPOSE_OP_PREVIOUS) {
1646 ff_thread_release_buffer(avctx, &s->picture);
1647 } else if (s->dispose_op == APNG_DISPOSE_OP_NONE) {
1648 ff_thread_release_buffer(avctx, &s->last_picture);
1649 FFSWAP(ThreadFrame, s->picture, s->last_picture);
1650 }
1651 }
1652
1653 *got_frame = 1;
1654 ret = bytestream2_tell(&s->gb);
1655
1656 end:
1657 inflateEnd(&s->zstream);
1658 return ret;
1659 }
1660 #endif
1661
1662 #if HAVE_THREADS
update_thread_context(AVCodecContext * dst,const AVCodecContext * src)1663 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
1664 {
1665 PNGDecContext *psrc = src->priv_data;
1666 PNGDecContext *pdst = dst->priv_data;
1667 ThreadFrame *src_frame = NULL;
1668 int ret;
1669
1670 if (dst == src)
1671 return 0;
1672
1673 if (CONFIG_APNG_DECODER && dst->codec_id == AV_CODEC_ID_APNG) {
1674
1675 pdst->width = psrc->width;
1676 pdst->height = psrc->height;
1677 pdst->bit_depth = psrc->bit_depth;
1678 pdst->color_type = psrc->color_type;
1679 pdst->compression_type = psrc->compression_type;
1680 pdst->interlace_type = psrc->interlace_type;
1681 pdst->filter_type = psrc->filter_type;
1682 pdst->cur_w = psrc->cur_w;
1683 pdst->cur_h = psrc->cur_h;
1684 pdst->x_offset = psrc->x_offset;
1685 pdst->y_offset = psrc->y_offset;
1686 pdst->has_trns = psrc->has_trns;
1687 memcpy(pdst->transparent_color_be, psrc->transparent_color_be, sizeof(pdst->transparent_color_be));
1688
1689 pdst->dispose_op = psrc->dispose_op;
1690
1691 memcpy(pdst->palette, psrc->palette, sizeof(pdst->palette));
1692
1693 pdst->hdr_state |= psrc->hdr_state;
1694 }
1695
1696 src_frame = psrc->dispose_op == APNG_DISPOSE_OP_NONE ?
1697 &psrc->picture : &psrc->last_picture;
1698
1699 ff_thread_release_buffer(dst, &pdst->last_picture);
1700 if (src_frame && src_frame->f->data[0]) {
1701 ret = ff_thread_ref_frame(&pdst->last_picture, src_frame);
1702 if (ret < 0)
1703 return ret;
1704 }
1705
1706 return 0;
1707 }
1708 #endif
1709
png_dec_init(AVCodecContext * avctx)1710 static av_cold int png_dec_init(AVCodecContext *avctx)
1711 {
1712 PNGDecContext *s = avctx->priv_data;
1713
1714 avctx->color_range = AVCOL_RANGE_JPEG;
1715
1716 s->avctx = avctx;
1717 s->last_picture.f = av_frame_alloc();
1718 s->picture.f = av_frame_alloc();
1719 if (!s->last_picture.f || !s->picture.f) {
1720 av_frame_free(&s->last_picture.f);
1721 av_frame_free(&s->picture.f);
1722 return AVERROR(ENOMEM);
1723 }
1724
1725 ff_pngdsp_init(&s->dsp);
1726
1727 return 0;
1728 }
1729
png_dec_end(AVCodecContext * avctx)1730 static av_cold int png_dec_end(AVCodecContext *avctx)
1731 {
1732 PNGDecContext *s = avctx->priv_data;
1733
1734 ff_thread_release_buffer(avctx, &s->last_picture);
1735 av_frame_free(&s->last_picture.f);
1736 ff_thread_release_buffer(avctx, &s->picture);
1737 av_frame_free(&s->picture.f);
1738 av_freep(&s->buffer);
1739 s->buffer_size = 0;
1740 av_freep(&s->last_row);
1741 s->last_row_size = 0;
1742 av_freep(&s->tmp_row);
1743 s->tmp_row_size = 0;
1744 av_freep(&s->background_buf);
1745
1746 av_freep(&s->iccp_data);
1747 av_dict_free(&s->frame_metadata);
1748
1749 return 0;
1750 }
1751
1752 #if CONFIG_APNG_DECODER
1753 AVCodec ff_apng_decoder = {
1754 .name = "apng",
1755 .long_name = NULL_IF_CONFIG_SMALL("APNG (Animated Portable Network Graphics) image"),
1756 .type = AVMEDIA_TYPE_VIDEO,
1757 .id = AV_CODEC_ID_APNG,
1758 .priv_data_size = sizeof(PNGDecContext),
1759 .init = png_dec_init,
1760 .close = png_dec_end,
1761 .decode = decode_frame_apng,
1762 .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
1763 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
1764 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
1765 FF_CODEC_CAP_ALLOCATE_PROGRESS,
1766 };
1767 #endif
1768
1769 #if CONFIG_PNG_DECODER
1770 AVCodec ff_png_decoder = {
1771 .name = "png",
1772 .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
1773 .type = AVMEDIA_TYPE_VIDEO,
1774 .id = AV_CODEC_ID_PNG,
1775 .priv_data_size = sizeof(PNGDecContext),
1776 .init = png_dec_init,
1777 .close = png_dec_end,
1778 .decode = decode_frame_png,
1779 .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
1780 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/,
1781 .caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM | FF_CODEC_CAP_INIT_THREADSAFE |
1782 FF_CODEC_CAP_ALLOCATE_PROGRESS,
1783 };
1784 #endif
1785