3 * Copyright (c) 2003 Fabrice Bellard
5 * This file is part of FFmpeg.
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.
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.
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
24 #include "libavutil/bprint.h"
25 #include "libavutil/imgutils.h"
27 #include "bytestream.h"
35 typedef struct PNGDecContext {
37 AVCodecContext *avctx;
40 ThreadFrame last_picture;
56 uint32_t palette[256];
59 unsigned int last_row_size;
61 unsigned int tmp_row_size;
65 int crow_size; /* compressed row size (include filter type) */
66 int row_size; /* decompressed row size */
67 int pass_row_size; /* decompress row size of the current pass */
72 /* Mask to determine which pixels are valid in a pass */
73 static const uint8_t png_pass_mask[NB_PASSES] = {
74 0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff,
77 /* Mask to determine which y pixels can be written in a pass */
78 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
79 0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
82 /* Mask to determine which pixels to overwrite while displaying */
83 static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
84 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
87 /* NOTE: we try to construct a good looking image at each pass. width
88 is the original image width. We also do pixel format conversion at
90 static void png_put_interlaced_row(uint8_t *dst, int width,
91 int bits_per_pixel, int pass,
92 int color_type, const uint8_t *src)
94 int x, mask, dsp_mask, j, src_x, b, bpp;
98 mask = png_pass_mask[pass];
99 dsp_mask = png_pass_dsp_mask[pass];
101 switch (bits_per_pixel) {
104 for (x = 0; x < width; x++) {
106 if ((dsp_mask << j) & 0x80) {
107 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
108 dst[x >> 3] &= 0xFF7F>>j;
109 dst[x >> 3] |= b << (7 - j);
111 if ((mask << j) & 0x80)
117 for (x = 0; x < width; x++) {
118 int j2 = 2 * (x & 3);
120 if ((dsp_mask << j) & 0x80) {
121 b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3;
122 dst[x >> 2] &= 0xFF3F>>j2;
123 dst[x >> 2] |= b << (6 - j2);
125 if ((mask << j) & 0x80)
131 for (x = 0; x < width; x++) {
134 if ((dsp_mask << j) & 0x80) {
135 b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15;
136 dst[x >> 1] &= 0xFF0F>>j2;
137 dst[x >> 1] |= b << (4 - j2);
139 if ((mask << j) & 0x80)
144 bpp = bits_per_pixel >> 3;
147 for (x = 0; x < width; x++) {
149 if ((dsp_mask << j) & 0x80) {
153 if ((mask << j) & 0x80)
160 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
163 for (i = 0; i < w; i++) {
164 int a, b, c, p, pa, pb, pc;
177 if (pa <= pb && pa <= pc)
187 #define UNROLL1(bpp, op) {\
189 if(bpp >= 2) g = dst[1];\
190 if(bpp >= 3) b = dst[2];\
191 if(bpp >= 4) a = dst[3];\
192 for(; i <= size - bpp; i+=bpp) {\
193 dst[i+0] = r = op(r, src[i+0], last[i+0]);\
194 if(bpp == 1) continue;\
195 dst[i+1] = g = op(g, src[i+1], last[i+1]);\
196 if(bpp == 2) continue;\
197 dst[i+2] = b = op(b, src[i+2], last[i+2]);\
198 if(bpp == 3) continue;\
199 dst[i+3] = a = op(a, src[i+3], last[i+3]);\
203 #define UNROLL_FILTER(op)\
204 if(bpp == 1) UNROLL1(1, op)\
205 else if(bpp == 2) UNROLL1(2, op)\
206 else if(bpp == 3) UNROLL1(3, op)\
207 else if(bpp == 4) UNROLL1(4, op)\
208 for (; i < size; i++) {\
209 dst[i] = op(dst[i-bpp], src[i], last[i]);\
212 /* NOTE: 'dst' can be equal to 'last' */
213 static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
214 uint8_t *src, uint8_t *last, int size, int bpp)
216 int i, p, r, g, b, a;
218 switch (filter_type) {
219 case PNG_FILTER_VALUE_NONE:
220 memcpy(dst, src, size);
222 case PNG_FILTER_VALUE_SUB:
223 for (i = 0; i < bpp; i++) {
228 for (; i < size; i += bpp) {
229 int s = *(int*)(src + i);
230 p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
231 *(int*)(dst + i) = p;
234 #define OP_SUB(x,s,l) x+s
235 UNROLL_FILTER(OP_SUB);
238 case PNG_FILTER_VALUE_UP:
239 dsp->add_bytes_l2(dst, src, last, size);
241 case PNG_FILTER_VALUE_AVG:
242 for (i = 0; i < bpp; i++) {
246 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
247 UNROLL_FILTER(OP_AVG);
249 case PNG_FILTER_VALUE_PAETH:
250 for (i = 0; i < bpp; i++) {
254 if (bpp > 2 && size > 4) {
255 // would write off the end of the array if we let it process the last pixel with bpp=3
256 int w = bpp == 4 ? size : size - 3;
257 dsp->add_paeth_prediction(dst + i, src + i, last + i, w - i, bpp);
260 ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
265 /* This used to be called "deloco" in FFmpeg
266 * and is actually an inverse reversible colorspace transformation */
267 #define YUV2RGB(NAME, TYPE) \
268 static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
271 for (i = 0; i < size; i += 3 + alpha) { \
278 YUV2RGB(rgb8, uint8_t)
279 YUV2RGB(rgb16, uint16_t)
281 /* process exactly one decompressed row */
282 static void png_handle_row(PNGDecContext *s)
284 uint8_t *ptr, *last_row;
287 if (!s->interlace_type) {
288 ptr = s->image_buf + s->image_linesize * s->y;
290 last_row = s->last_row;
292 last_row = ptr - s->image_linesize;
294 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
295 last_row, s->row_size, s->bpp);
296 /* loco lags by 1 row so that it doesn't interfere with top prediction */
297 if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
298 if (s->bit_depth == 16) {
299 deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2,
300 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
302 deloco_rgb8(ptr - s->image_linesize, s->row_size,
303 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
307 if (s->y == s->height) {
308 s->state |= PNG_ALLIMAGE;
309 if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
310 if (s->bit_depth == 16) {
311 deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
312 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
314 deloco_rgb8(ptr, s->row_size,
315 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
322 ptr = s->image_buf + s->image_linesize * s->y;
323 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
324 /* if we already read one row, it is time to stop to
325 wait for the next one */
328 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
329 s->last_row, s->pass_row_size, s->bpp);
330 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
331 FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size);
334 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
335 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
336 s->color_type, s->last_row);
339 if (s->y == s->height) {
340 memset(s->last_row, 0, s->row_size);
342 if (s->pass == NB_PASSES - 1) {
343 s->state |= PNG_ALLIMAGE;
348 s->pass_row_size = ff_png_pass_row_size(s->pass,
351 s->crow_size = s->pass_row_size + 1;
352 if (s->pass_row_size != 0)
354 /* skip pass if empty row */
363 static int png_decode_idat(PNGDecContext *s, int length)
366 s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
367 s->zstream.next_in = (unsigned char *)s->gb.buffer;
368 bytestream2_skip(&s->gb, length);
370 /* decode one line if possible */
371 while (s->zstream.avail_in > 0) {
372 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
373 if (ret != Z_OK && ret != Z_STREAM_END) {
374 av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
375 return AVERROR_EXTERNAL;
377 if (s->zstream.avail_out == 0) {
378 if (!(s->state & PNG_ALLIMAGE)) {
381 s->zstream.avail_out = s->crow_size;
382 s->zstream.next_out = s->crow_buf;
388 static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
389 const uint8_t *data_end)
396 zstream.zalloc = ff_png_zalloc;
397 zstream.zfree = ff_png_zfree;
398 zstream.opaque = NULL;
399 if (inflateInit(&zstream) != Z_OK)
400 return AVERROR_EXTERNAL;
401 zstream.next_in = (unsigned char *)data;
402 zstream.avail_in = data_end - data;
403 av_bprint_init(bp, 0, -1);
405 while (zstream.avail_in > 0) {
406 av_bprint_get_buffer(bp, 1, &buf, &buf_size);
408 ret = AVERROR(ENOMEM);
411 zstream.next_out = buf;
412 zstream.avail_out = buf_size;
413 ret = inflate(&zstream, Z_PARTIAL_FLUSH);
414 if (ret != Z_OK && ret != Z_STREAM_END) {
415 ret = AVERROR_EXTERNAL;
418 bp->len += zstream.next_out - buf;
419 if (ret == Z_STREAM_END)
422 inflateEnd(&zstream);
423 bp->str[bp->len] = 0;
427 inflateEnd(&zstream);
428 av_bprint_finalize(bp, NULL);
432 static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
437 for (i = 0; i < size_in; i++)
438 extra += in[i] >= 0x80;
439 if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
441 q = out = av_malloc(size_in + extra + 1);
444 for (i = 0; i < size_in; i++) {
446 *(q++) = 0xC0 | (in[i] >> 6);
447 *(q++) = 0x80 | (in[i] & 0x3F);
456 static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed,
460 const uint8_t *data = s->gb.buffer;
461 const uint8_t *data_end = data + length;
462 const uint8_t *keyword = data;
463 const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
464 uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
469 return AVERROR_INVALIDDATA;
470 data = keyword_end + 1;
473 if (data == data_end)
474 return AVERROR_INVALIDDATA;
477 return AVERROR_INVALIDDATA;
478 if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
481 av_bprint_finalize(&bp, (char **)&text);
483 return AVERROR(ENOMEM);
485 text = (uint8_t *)data;
486 text_len = data_end - text;
489 kw_utf8 = iso88591_to_utf8(keyword, keyword_end - keyword);
490 txt_utf8 = iso88591_to_utf8(text, text_len);
493 if (!(kw_utf8 && txt_utf8)) {
496 return AVERROR(ENOMEM);
499 av_dict_set(dict, kw_utf8, txt_utf8,
500 AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
504 static int decode_frame(AVCodecContext *avctx,
505 void *data, int *got_frame,
508 PNGDecContext * const s = avctx->priv_data;
509 const uint8_t *buf = avpkt->data;
510 int buf_size = avpkt->size;
512 AVDictionary *metadata = NULL;
513 uint32_t tag, length;
517 ff_thread_release_buffer(avctx, &s->last_picture);
518 FFSWAP(ThreadFrame, s->picture, s->last_picture);
521 bytestream2_init(&s->gb, buf, buf_size);
523 /* check signature */
524 sig = bytestream2_get_be64(&s->gb);
527 av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
528 return AVERROR_INVALIDDATA;
534 s->zstream.zalloc = ff_png_zalloc;
535 s->zstream.zfree = ff_png_zfree;
536 s->zstream.opaque = NULL;
537 ret = inflateInit(&s->zstream);
539 av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
540 return AVERROR_EXTERNAL;
543 if (bytestream2_get_bytes_left(&s->gb) <= 0) {
544 av_log(avctx, AV_LOG_ERROR, "No bytes left\n");
548 length = bytestream2_get_be32(&s->gb);
549 if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) {
550 av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
553 tag = bytestream2_get_le32(&s->gb);
554 if (avctx->debug & FF_DEBUG_STARTCODE)
555 av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
558 ((tag >> 16) & 0xff),
559 ((tag >> 24) & 0xff), length);
561 case MKTAG('I', 'H', 'D', 'R'):
564 s->width = bytestream2_get_be32(&s->gb);
565 s->height = bytestream2_get_be32(&s->gb);
566 if (av_image_check_size(s->width, s->height, 0, avctx)) {
567 s->width = s->height = 0;
568 av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
571 s->bit_depth = bytestream2_get_byte(&s->gb);
572 s->color_type = bytestream2_get_byte(&s->gb);
573 s->compression_type = bytestream2_get_byte(&s->gb);
574 s->filter_type = bytestream2_get_byte(&s->gb);
575 s->interlace_type = bytestream2_get_byte(&s->gb);
576 bytestream2_skip(&s->gb, 4); /* crc */
577 s->state |= PNG_IHDR;
578 if (avctx->debug & FF_DEBUG_PICT_INFO)
579 av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d "
580 "compression_type=%d filter_type=%d interlace_type=%d\n",
581 s->width, s->height, s->bit_depth, s->color_type,
582 s->compression_type, s->filter_type, s->interlace_type);
584 case MKTAG('p', 'H', 'Y', 's'):
585 if (s->state & PNG_IDAT) {
586 av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
589 avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
590 avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
591 if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
592 avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
593 bytestream2_skip(&s->gb, 1); /* unit specifier */
594 bytestream2_skip(&s->gb, 4); /* crc */
596 case MKTAG('I', 'D', 'A', 'T'):
597 if (!(s->state & PNG_IHDR)) {
598 av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
601 if (!(s->state & PNG_IDAT)) {
602 /* init image info */
603 avctx->width = s->width;
604 avctx->height = s->height;
606 s->channels = ff_png_get_nb_channels(s->color_type);
607 s->bits_per_pixel = s->bit_depth * s->channels;
608 s->bpp = (s->bits_per_pixel + 7) >> 3;
609 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
611 if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
612 s->color_type == PNG_COLOR_TYPE_RGB) {
613 avctx->pix_fmt = AV_PIX_FMT_RGB24;
614 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
615 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
616 avctx->pix_fmt = AV_PIX_FMT_RGBA;
617 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
618 s->color_type == PNG_COLOR_TYPE_GRAY) {
619 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
620 } else if (s->bit_depth == 16 &&
621 s->color_type == PNG_COLOR_TYPE_GRAY) {
622 avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
623 } else if (s->bit_depth == 16 &&
624 s->color_type == PNG_COLOR_TYPE_RGB) {
625 avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
626 } else if (s->bit_depth == 16 &&
627 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
628 avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
629 } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
630 s->color_type == PNG_COLOR_TYPE_PALETTE) {
631 avctx->pix_fmt = AV_PIX_FMT_PAL8;
632 } else if (s->bit_depth == 1) {
633 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
634 } else if (s->bit_depth == 8 &&
635 s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
636 avctx->pix_fmt = AV_PIX_FMT_Y400A;
638 av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
639 "and color type %d\n",
640 s->bit_depth, s->color_type);
644 if (ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF) < 0)
646 ff_thread_finish_setup(avctx);
648 p->pict_type = AV_PICTURE_TYPE_I;
650 p->interlaced_frame = !!s->interlace_type;
652 /* compute the compressed row size */
653 if (!s->interlace_type) {
654 s->crow_size = s->row_size + 1;
657 s->pass_row_size = ff_png_pass_row_size(s->pass,
660 s->crow_size = s->pass_row_size + 1;
662 av_dlog(avctx, "row_size=%d crow_size =%d\n",
663 s->row_size, s->crow_size);
664 s->image_buf = p->data[0];
665 s->image_linesize = p->linesize[0];
666 /* copy the palette if needed */
667 if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
668 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
669 /* empty row is used if differencing to the first row */
670 av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
673 if (s->interlace_type ||
674 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
675 av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size);
680 av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
684 /* we want crow_buf+1 to be 16-byte aligned */
685 s->crow_buf = s->buffer + 15;
686 s->zstream.avail_out = s->crow_size;
687 s->zstream.next_out = s->crow_buf;
689 s->state |= PNG_IDAT;
690 if (png_decode_idat(s, length) < 0)
692 bytestream2_skip(&s->gb, 4); /* crc */
694 case MKTAG('P', 'L', 'T', 'E'):
698 if ((length % 3) != 0 || length > 256 * 3)
700 /* read the palette */
702 for (i = 0; i < n; i++) {
703 r = bytestream2_get_byte(&s->gb);
704 g = bytestream2_get_byte(&s->gb);
705 b = bytestream2_get_byte(&s->gb);
706 s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
708 for (; i < 256; i++) {
709 s->palette[i] = (0xFFU << 24);
711 s->state |= PNG_PLTE;
712 bytestream2_skip(&s->gb, 4); /* crc */
715 case MKTAG('t', 'R', 'N', 'S'):
719 /* read the transparency. XXX: Only palette mode supported */
720 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
722 !(s->state & PNG_PLTE))
724 for (i = 0; i < length; i++) {
725 v = bytestream2_get_byte(&s->gb);
726 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
728 bytestream2_skip(&s->gb, 4); /* crc */
731 case MKTAG('t', 'E', 'X', 't'):
732 if (decode_text_chunk(s, length, 0, &metadata) < 0)
733 av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
734 bytestream2_skip(&s->gb, length + 4);
736 case MKTAG('z', 'T', 'X', 't'):
737 if (decode_text_chunk(s, length, 1, &metadata) < 0)
738 av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
739 bytestream2_skip(&s->gb, length + 4);
741 case MKTAG('I', 'E', 'N', 'D'):
742 if (!(s->state & PNG_ALLIMAGE))
743 av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
744 if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
747 bytestream2_skip(&s->gb, 4); /* crc */
752 bytestream2_skip(&s->gb, length + 4);
758 if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE){
760 uint8_t *pd = p->data[0];
761 for (j = 0; j < s->height; j++) {
763 for (k = 7; k >= 1; k--)
764 if ((s->width&7) >= k)
765 pd[8*i + k - 1] = (pd[i]>>8-k) & 1;
766 for (i--; i >= 0; i--) {
767 pd[8*i + 7]= pd[i] & 1;
768 pd[8*i + 6]= (pd[i]>>1) & 1;
769 pd[8*i + 5]= (pd[i]>>2) & 1;
770 pd[8*i + 4]= (pd[i]>>3) & 1;
771 pd[8*i + 3]= (pd[i]>>4) & 1;
772 pd[8*i + 2]= (pd[i]>>5) & 1;
773 pd[8*i + 1]= (pd[i]>>6) & 1;
774 pd[8*i + 0]= pd[i]>>7;
776 pd += s->image_linesize;
779 if (s->bits_per_pixel == 2){
781 uint8_t *pd = p->data[0];
782 for (j = 0; j < s->height; j++) {
784 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
785 if ((s->width&3) >= 3) pd[4*i + 2]= (pd[i] >> 2) & 3;
786 if ((s->width&3) >= 2) pd[4*i + 1]= (pd[i] >> 4) & 3;
787 if ((s->width&3) >= 1) pd[4*i + 0]= pd[i] >> 6;
788 for (i--; i >= 0; i--) {
789 pd[4*i + 3]= pd[i] & 3;
790 pd[4*i + 2]= (pd[i]>>2) & 3;
791 pd[4*i + 1]= (pd[i]>>4) & 3;
792 pd[4*i + 0]= pd[i]>>6;
795 if ((s->width&3) >= 3) pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
796 if ((s->width&3) >= 2) pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
797 if ((s->width&3) >= 1) pd[4*i + 0]= ( pd[i]>>6 )*0x55;
798 for (i--; i >= 0; i--) {
799 pd[4*i + 3]= ( pd[i] & 3)*0x55;
800 pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
801 pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
802 pd[4*i + 0]= ( pd[i]>>6 )*0x55;
805 pd += s->image_linesize;
808 if (s->bits_per_pixel == 4){
810 uint8_t *pd = p->data[0];
811 for (j = 0; j < s->height; j++) {
813 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
814 if (s->width&1) pd[2*i+0]= pd[i]>>4;
815 for (i--; i >= 0; i--) {
816 pd[2*i + 1] = pd[i] & 15;
817 pd[2*i + 0] = pd[i] >> 4;
820 if (s->width & 1) pd[2*i + 0]= (pd[i] >> 4) * 0x11;
821 for (i--; i >= 0; i--) {
822 pd[2*i + 1] = (pd[i] & 15) * 0x11;
823 pd[2*i + 0] = (pd[i] >> 4) * 0x11;
826 pd += s->image_linesize;
830 /* handle p-frames only if a predecessor frame is available */
831 if (s->last_picture.f->data[0]) {
832 if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
833 && s->last_picture.f->width == p->width
834 && s->last_picture.f->height== p->height
835 && s->last_picture.f->format== p->format
838 uint8_t *pd = p->data[0];
839 uint8_t *pd_last = s->last_picture.f->data[0];
841 ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
842 for (j = 0; j < s->height; j++) {
843 for (i = 0; i < s->width * s->bpp; i++) {
846 pd += s->image_linesize;
847 pd_last += s->image_linesize;
851 ff_thread_report_progress(&s->picture, INT_MAX, 0);
853 av_frame_set_metadata(p, metadata);
856 if ((ret = av_frame_ref(data, s->picture.f)) < 0)
861 ret = bytestream2_tell(&s->gb);
863 inflateEnd(&s->zstream);
867 av_dict_free(&metadata);
868 ff_thread_report_progress(&s->picture, INT_MAX, 0);
869 ret = AVERROR_INVALIDDATA;
873 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
875 PNGDecContext *psrc = src->priv_data;
876 PNGDecContext *pdst = dst->priv_data;
881 ff_thread_release_buffer(dst, &pdst->picture);
882 if (psrc->picture.f->data[0])
883 return ff_thread_ref_frame(&pdst->picture, &psrc->picture);
888 static av_cold int png_dec_init(AVCodecContext *avctx)
890 PNGDecContext *s = avctx->priv_data;
893 s->last_picture.f = av_frame_alloc();
894 s->picture.f = av_frame_alloc();
895 if (!s->last_picture.f || !s->picture.f)
896 return AVERROR(ENOMEM);
898 if (!avctx->internal->is_copy) {
899 avctx->internal->allocate_progress = 1;
900 ff_pngdsp_init(&s->dsp);
906 static av_cold int png_dec_end(AVCodecContext *avctx)
908 PNGDecContext *s = avctx->priv_data;
910 ff_thread_release_buffer(avctx, &s->last_picture);
911 av_frame_free(&s->last_picture.f);
912 ff_thread_release_buffer(avctx, &s->picture);
913 av_frame_free(&s->picture.f);
914 av_freep(&s->buffer);
916 av_freep(&s->last_row);
917 s->last_row_size = 0;
918 av_freep(&s->tmp_row);
924 AVCodec ff_png_decoder = {
926 .type = AVMEDIA_TYPE_VIDEO,
927 .id = AV_CODEC_ID_PNG,
928 .priv_data_size = sizeof(PNGDecContext),
929 .init = png_dec_init,
930 .close = png_dec_end,
931 .decode = decode_frame,
932 .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
933 .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
934 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
935 .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),