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"
32 * - add 16 bit depth support
39 typedef struct PNGDecContext {
41 AVCodecContext *avctx;
44 AVFrame picture1, picture2;
45 AVFrame *current_picture, *last_picture;
60 uint32_t palette[256];
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];
100 switch(bits_per_pixel) {
103 for(x = 0; x < width; x++) {
105 if ((dsp_mask << j) & 0x80) {
106 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
107 dst[x >> 3] &= 0xFF7F>>j;
108 dst[x >> 3] |= b << (7 - j);
110 if ((mask << j) & 0x80)
116 for(x = 0; x < width; x++) {
119 if ((dsp_mask << j) & 0x80) {
120 b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3;
121 dst[x >> 2] &= 0xFF3F>>j2;
122 dst[x >> 2] |= b << (6 - j2);
124 if ((mask << j) & 0x80)
130 for(x = 0; x < width; x++) {
133 if ((dsp_mask << j) & 0x80) {
134 b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15;
135 dst[x >> 1] &= 0xFF0F>>j2;
136 dst[x >> 1] |= b << (4 - j2);
138 if ((mask << j) & 0x80)
143 bpp = bits_per_pixel >> 3;
146 for(x = 0; x < width; x++) {
148 if ((dsp_mask << j) & 0x80) {
152 if ((mask << j) & 0x80)
159 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
162 for(i = 0; i < w; i++) {
163 int a, b, c, p, pa, pb, pc;
176 if (pa <= pb && pa <= pc)
186 #define UNROLL1(bpp, op) {\
188 if(bpp >= 2) g = dst[1];\
189 if(bpp >= 3) b = dst[2];\
190 if(bpp >= 4) a = dst[3];\
191 for(; i < size; i+=bpp) {\
192 dst[i+0] = r = op(r, src[i+0], last[i+0]);\
193 if(bpp == 1) continue;\
194 dst[i+1] = g = op(g, src[i+1], last[i+1]);\
195 if(bpp == 2) continue;\
196 dst[i+2] = b = op(b, src[i+2], last[i+2]);\
197 if(bpp == 3) continue;\
198 dst[i+3] = a = op(a, src[i+3], last[i+3]);\
202 #define UNROLL_FILTER(op)\
203 if(bpp == 1) UNROLL1(1, op)\
204 else if(bpp == 2) UNROLL1(2, op)\
205 else if(bpp == 3) UNROLL1(3, op)\
206 else if(bpp == 4) UNROLL1(4, op)\
208 for (; i < size; i += bpp) {\
210 for (j = 0; j < bpp; j++)\
211 dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\
215 /* NOTE: 'dst' can be equal to 'last' */
216 static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
217 uint8_t *src, uint8_t *last, int size, int bpp)
219 int i, p, r, g, b, a;
221 switch(filter_type) {
222 case PNG_FILTER_VALUE_NONE:
223 memcpy(dst, src, size);
225 case PNG_FILTER_VALUE_SUB:
226 for(i = 0; i < bpp; i++) {
231 for(; i < size; i+=bpp) {
232 int s = *(int*)(src+i);
233 p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080);
237 #define OP_SUB(x,s,l) x+s
238 UNROLL_FILTER(OP_SUB);
241 case PNG_FILTER_VALUE_UP:
242 dsp->add_bytes_l2(dst, src, last, size);
244 case PNG_FILTER_VALUE_AVG:
245 for(i = 0; i < bpp; i++) {
249 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
250 UNROLL_FILTER(OP_AVG);
252 case PNG_FILTER_VALUE_PAETH:
253 for(i = 0; i < bpp; i++) {
257 if(bpp > 2 && size > 4) {
258 // would write off the end of the array if we let it process the last pixel with bpp=3
259 int w = bpp==4 ? size : size-3;
260 dsp->add_paeth_prediction(dst+i, src+i, last+i, w-i, bpp);
263 ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp);
268 /* This used to be called "deloco" in FFmpeg
269 * and is actually an inverse reversible colorspace transformation */
270 #define YUV2RGB(NAME, TYPE) \
271 static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
274 for (i = 0; i < size; i += 3 + alpha) { \
281 YUV2RGB(rgb8, uint8_t)
282 YUV2RGB(rgb16, uint16_t)
284 /* process exactly one decompressed row */
285 static void png_handle_row(PNGDecContext *s)
287 uint8_t *ptr, *last_row;
290 if (!s->interlace_type) {
291 ptr = s->image_buf + s->image_linesize * s->y;
293 last_row = s->last_row;
295 last_row = ptr - s->image_linesize;
297 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
298 last_row, s->row_size, s->bpp);
299 /* loco lags by 1 row so that it doesn't interfere with top prediction */
300 if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
301 if (s->bit_depth == 16) {
302 deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2,
303 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
305 deloco_rgb8(ptr - s->image_linesize, s->row_size,
306 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
310 if (s->y == s->height) {
311 s->state |= PNG_ALLIMAGE;
312 if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
313 if (s->bit_depth == 16) {
314 deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
315 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
317 deloco_rgb8(ptr, s->row_size,
318 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
325 ptr = s->image_buf + s->image_linesize * s->y;
326 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
327 /* if we already read one row, it is time to stop to
328 wait for the next one */
331 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
332 s->last_row, s->pass_row_size, s->bpp);
333 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
336 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
337 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
338 s->color_type, s->last_row);
341 if (s->y == s->height) {
342 memset(s->last_row, 0, s->row_size);
344 if (s->pass == NB_PASSES - 1) {
345 s->state |= PNG_ALLIMAGE;
350 s->pass_row_size = ff_png_pass_row_size(s->pass,
353 s->crow_size = s->pass_row_size + 1;
354 if (s->pass_row_size != 0)
356 /* skip pass if empty row */
365 static int png_decode_idat(PNGDecContext *s, int length)
368 s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
369 s->zstream.next_in = (unsigned char *)s->gb.buffer;
370 bytestream2_skip(&s->gb, length);
372 /* decode one line if possible */
373 while (s->zstream.avail_in > 0) {
374 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
375 if (ret != Z_OK && ret != Z_STREAM_END) {
376 av_log(s->avctx, AV_LOG_ERROR, "inflate returned %d\n", ret);
379 if (s->zstream.avail_out == 0) {
380 if (!(s->state & PNG_ALLIMAGE)) {
383 s->zstream.avail_out = s->crow_size;
384 s->zstream.next_out = s->crow_buf;
390 static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
391 const uint8_t *data_end)
398 zstream.zalloc = ff_png_zalloc;
399 zstream.zfree = ff_png_zfree;
400 zstream.opaque = NULL;
401 if (inflateInit(&zstream) != Z_OK)
402 return AVERROR_EXTERNAL;
403 zstream.next_in = (unsigned char *)data;
404 zstream.avail_in = data_end - data;
405 av_bprint_init(bp, 0, -1);
407 while (zstream.avail_in > 0) {
408 av_bprint_get_buffer(bp, 1, &buf, &buf_size);
410 ret = AVERROR(ENOMEM);
413 zstream.next_out = buf;
414 zstream.avail_out = buf_size;
415 ret = inflate(&zstream, Z_PARTIAL_FLUSH);
416 if (ret != Z_OK && ret != Z_STREAM_END) {
417 ret = AVERROR_EXTERNAL;
420 bp->len += zstream.next_out - buf;
421 if (ret == Z_STREAM_END)
424 inflateEnd(&zstream);
425 bp->str[bp->len] = 0;
429 inflateEnd(&zstream);
430 av_bprint_finalize(bp, NULL);
434 static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
439 for (i = 0; i < size_in; i++)
440 extra += in[i] >= 0x80;
441 if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
443 q = out = av_malloc(size_in + extra + 1);
446 for (i = 0; i < size_in; i++) {
448 *(q++) = 0xC0 | (in[i] >> 6);
449 *(q++) = 0x80 | (in[i] & 0x3F);
458 static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed,
462 const uint8_t *data = s->gb.buffer;
463 const uint8_t *data_end = data + length;
464 const uint8_t *keyword = data;
465 const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
466 uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
471 return AVERROR_INVALIDDATA;
472 data = keyword_end + 1;
475 if (data == data_end)
476 return AVERROR_INVALIDDATA;
479 return AVERROR_INVALIDDATA;
480 if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
483 av_bprint_finalize(&bp, (char **)&text);
485 return AVERROR(ENOMEM);
487 text = (uint8_t *)data;
488 text_len = data_end - text;
491 kw_utf8 = iso88591_to_utf8(keyword, keyword_end - keyword);
492 txt_utf8 = iso88591_to_utf8(text, text_len);
495 if (!(kw_utf8 && txt_utf8)) {
498 return AVERROR(ENOMEM);
501 av_dict_set(dict, kw_utf8, txt_utf8,
502 AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
506 static int decode_frame(AVCodecContext *avctx,
507 void *data, int *data_size,
510 const uint8_t *buf = avpkt->data;
511 int buf_size = avpkt->size;
512 PNGDecContext * const s = avctx->priv_data;
513 AVFrame *picture = data;
515 AVDictionary *metadata = NULL;
516 uint8_t *crow_buf_base = NULL;
517 uint32_t tag, length;
521 FFSWAP(AVFrame *, s->current_picture, s->last_picture);
522 avctx->coded_frame= s->current_picture;
523 p = s->current_picture;
525 bytestream2_init(&s->gb, buf, buf_size);
527 /* check signature */
528 sig = bytestream2_get_be64(&s->gb);
531 av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
537 // memset(s, 0, sizeof(PNGDecContext));
539 s->zstream.zalloc = ff_png_zalloc;
540 s->zstream.zfree = ff_png_zfree;
541 s->zstream.opaque = NULL;
542 ret = inflateInit(&s->zstream);
544 av_log(avctx, AV_LOG_ERROR, "inflateInit returned %d\n", ret);
548 if (bytestream2_get_bytes_left(&s->gb) <= 0) {
549 av_log(avctx, AV_LOG_ERROR, "No bytes left\n");
553 length = bytestream2_get_be32(&s->gb);
554 if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) {
555 av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
558 tag = bytestream2_get_le32(&s->gb);
559 if (avctx->debug & FF_DEBUG_STARTCODE)
560 av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
563 ((tag >> 16) & 0xff),
564 ((tag >> 24) & 0xff), length);
566 case MKTAG('I', 'H', 'D', 'R'):
569 s->width = bytestream2_get_be32(&s->gb);
570 s->height = bytestream2_get_be32(&s->gb);
571 if(av_image_check_size(s->width, s->height, 0, avctx)){
572 s->width= s->height= 0;
573 av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
576 s->bit_depth = bytestream2_get_byte(&s->gb);
577 s->color_type = bytestream2_get_byte(&s->gb);
578 s->compression_type = bytestream2_get_byte(&s->gb);
579 s->filter_type = bytestream2_get_byte(&s->gb);
580 s->interlace_type = bytestream2_get_byte(&s->gb);
581 bytestream2_skip(&s->gb, 4); /* crc */
582 s->state |= PNG_IHDR;
583 if (avctx->debug & FF_DEBUG_PICT_INFO)
584 av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
585 s->width, s->height, s->bit_depth, s->color_type,
586 s->compression_type, s->filter_type, s->interlace_type);
588 case MKTAG('p', 'H', 'Y', 's'):
589 if (s->state & PNG_IDAT) {
590 av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
593 avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
594 avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
595 if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
596 avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
597 bytestream2_skip(&s->gb, 1); /* unit specifier */
598 bytestream2_skip(&s->gb, 4); /* crc */
600 case MKTAG('I', 'D', 'A', 'T'):
601 if (!(s->state & PNG_IHDR)) {
602 av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
605 if (!(s->state & PNG_IDAT)) {
606 /* init image info */
607 avctx->width = s->width;
608 avctx->height = s->height;
610 s->channels = ff_png_get_nb_channels(s->color_type);
611 s->bits_per_pixel = s->bit_depth * s->channels;
612 s->bpp = (s->bits_per_pixel + 7) >> 3;
613 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
615 if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
616 s->color_type == PNG_COLOR_TYPE_RGB) {
617 avctx->pix_fmt = AV_PIX_FMT_RGB24;
618 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
619 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
620 avctx->pix_fmt = AV_PIX_FMT_RGBA;
621 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
622 s->color_type == PNG_COLOR_TYPE_GRAY) {
623 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
624 } else if (s->bit_depth == 16 &&
625 s->color_type == PNG_COLOR_TYPE_GRAY) {
626 avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
627 } else if (s->bit_depth == 16 &&
628 s->color_type == PNG_COLOR_TYPE_RGB) {
629 avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
630 } else if (s->bit_depth == 16 &&
631 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
632 avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
633 } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
634 s->color_type == PNG_COLOR_TYPE_PALETTE) {
635 avctx->pix_fmt = AV_PIX_FMT_PAL8;
636 } else if (s->bit_depth == 1) {
637 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
638 } else if (s->bit_depth == 8 &&
639 s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
640 avctx->pix_fmt = AV_PIX_FMT_Y400A;
642 av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
643 "and color type %d\n",
644 s->bit_depth, s->color_type);
648 avctx->release_buffer(avctx, p);
651 if(avctx->get_buffer(avctx, p) < 0){
652 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
655 p->pict_type= AV_PICTURE_TYPE_I;
657 p->interlaced_frame = !!s->interlace_type;
659 /* compute the compressed row size */
660 if (!s->interlace_type) {
661 s->crow_size = s->row_size + 1;
664 s->pass_row_size = ff_png_pass_row_size(s->pass,
667 s->crow_size = s->pass_row_size + 1;
669 av_dlog(avctx, "row_size=%d crow_size =%d\n",
670 s->row_size, s->crow_size);
671 s->image_buf = p->data[0];
672 s->image_linesize = p->linesize[0];
673 /* copy the palette if needed */
674 if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
675 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
676 /* empty row is used if differencing to the first row */
677 s->last_row = av_mallocz(s->row_size);
680 if (s->interlace_type ||
681 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
682 s->tmp_row = av_malloc(s->row_size);
687 crow_buf_base = av_malloc(s->row_size + 16);
691 /* we want crow_buf+1 to be 16-byte aligned */
692 s->crow_buf = crow_buf_base + 15;
693 s->zstream.avail_out = s->crow_size;
694 s->zstream.next_out = s->crow_buf;
696 s->state |= PNG_IDAT;
697 if (png_decode_idat(s, length) < 0)
699 bytestream2_skip(&s->gb, 4); /* crc */
701 case MKTAG('P', 'L', 'T', 'E'):
705 if ((length % 3) != 0 || length > 256 * 3)
707 /* read the palette */
710 r = bytestream2_get_byte(&s->gb);
711 g = bytestream2_get_byte(&s->gb);
712 b = bytestream2_get_byte(&s->gb);
713 s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
716 s->palette[i] = (0xFFU << 24);
718 s->state |= PNG_PLTE;
719 bytestream2_skip(&s->gb, 4); /* crc */
722 case MKTAG('t', 'R', 'N', 'S'):
726 /* read the transparency. XXX: Only palette mode supported */
727 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
729 !(s->state & PNG_PLTE))
731 for(i=0;i<length;i++) {
732 v = bytestream2_get_byte(&s->gb);
733 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
735 bytestream2_skip(&s->gb, 4); /* crc */
738 case MKTAG('t', 'E', 'X', 't'):
739 if (decode_text_chunk(s, length, 0, &metadata) < 0)
740 av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
741 bytestream2_skip(&s->gb, length + 4);
743 case MKTAG('z', 'T', 'X', 't'):
744 if (decode_text_chunk(s, length, 1, &metadata) < 0)
745 av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
746 bytestream2_skip(&s->gb, length + 4);
748 case MKTAG('I', 'E', 'N', 'D'):
749 if (!(s->state & PNG_ALLIMAGE))
750 av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
751 if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
754 bytestream2_skip(&s->gb, 4); /* crc */
759 bytestream2_skip(&s->gb, length + 4);
765 if(s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE){
767 uint8_t *pd = s->current_picture->data[0];
768 for(j=0; j < s->height; j++) {
769 for(i=s->width/8-1; i>=0; i--) {
771 pd[8*i+6]= (pd[i]>>1)&1;
772 pd[8*i+5]= (pd[i]>>2)&1;
773 pd[8*i+4]= (pd[i]>>3)&1;
774 pd[8*i+3]= (pd[i]>>4)&1;
775 pd[8*i+2]= (pd[i]>>5)&1;
776 pd[8*i+1]= (pd[i]>>6)&1;
779 pd += s->image_linesize;
782 if(s->bits_per_pixel == 2){
784 uint8_t *pd = s->current_picture->data[0];
785 for(j=0; j < s->height; j++) {
786 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
787 for(i=s->width/4-1; i>=0; i--) {
789 pd[4*i+2]= (pd[i]>>2)&3;
790 pd[4*i+1]= (pd[i]>>4)&3;
794 for(i=s->width/4-1; i>=0; i--) {
795 pd[4*i+3]= ( pd[i] &3)*0x55;
796 pd[4*i+2]= ((pd[i]>>2)&3)*0x55;
797 pd[4*i+1]= ((pd[i]>>4)&3)*0x55;
798 pd[4*i+0]= ( pd[i]>>6 )*0x55;
801 pd += s->image_linesize;
804 if(s->bits_per_pixel == 4){
806 uint8_t *pd = s->current_picture->data[0];
807 for(j=0; j < s->height; j++) {
808 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
809 for(i=s->width/2-1; i>=0; i--) {
814 for(i=s->width/2-1; i>=0; i--) {
815 pd[2*i+1]= (pd[i]&15)*0x11;
816 pd[2*i+0]= (pd[i]>>4)*0x11;
819 pd += s->image_linesize;
823 /* handle p-frames only if a predecessor frame is available */
824 if(s->last_picture->data[0] != NULL) {
825 if( !(avpkt->flags & AV_PKT_FLAG_KEY)
826 && s->last_picture->width == s->current_picture->width
827 && s->last_picture->height== s->current_picture->height
828 && s->last_picture->format== s->current_picture->format
831 uint8_t *pd = s->current_picture->data[0];
832 uint8_t *pd_last = s->last_picture->data[0];
834 for(j=0; j < s->height; j++) {
835 for(i=0; i < s->width * s->bpp; i++) {
838 pd += s->image_linesize;
839 pd_last += s->image_linesize;
844 s->current_picture->metadata = metadata;
846 *picture= *s->current_picture;
847 *data_size = sizeof(AVFrame);
849 ret = bytestream2_tell(&s->gb);
851 inflateEnd(&s->zstream);
852 av_free(crow_buf_base);
854 av_freep(&s->last_row);
855 av_freep(&s->tmp_row);
858 av_dict_free(&metadata);
863 static av_cold int png_dec_init(AVCodecContext *avctx)
865 PNGDecContext *s = avctx->priv_data;
867 s->current_picture = &s->picture1;
868 s->last_picture = &s->picture2;
869 avcodec_get_frame_defaults(&s->picture1);
870 avcodec_get_frame_defaults(&s->picture2);
872 ff_pngdsp_init(&s->dsp);
879 static av_cold int png_dec_end(AVCodecContext *avctx)
881 PNGDecContext *s = avctx->priv_data;
883 if (s->picture1.data[0])
884 avctx->release_buffer(avctx, &s->picture1);
885 if (s->picture2.data[0])
886 avctx->release_buffer(avctx, &s->picture2);
891 AVCodec ff_png_decoder = {
893 .type = AVMEDIA_TYPE_VIDEO,
894 .id = AV_CODEC_ID_PNG,
895 .priv_data_size = sizeof(PNGDecContext),
896 .init = png_dec_init,
897 .close = png_dec_end,
898 .decode = decode_frame,
899 .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
900 .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),