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,
164 for (i = 0; i < w; i++) {
165 int a, b, c, p, pa, pb, pc;
178 if (pa <= pb && pa <= pc)
188 #define UNROLL1(bpp, op) { \
196 for (; i <= size - bpp; i += bpp) { \
197 dst[i + 0] = r = op(r, src[i + 0], last[i + 0]); \
200 dst[i + 1] = g = op(g, src[i + 1], last[i + 1]); \
203 dst[i + 2] = b = op(b, src[i + 2], last[i + 2]); \
206 dst[i + 3] = a = op(a, src[i + 3], last[i + 3]); \
210 #define UNROLL_FILTER(op)\
211 if (bpp == 1) UNROLL1(1, op)\
212 else if (bpp == 2) UNROLL1(2, op)\
213 else if (bpp == 3) UNROLL1(3, op)\
214 else if (bpp == 4) UNROLL1(4, op)\
215 for (; i < size; i++) {\
216 dst[i] = op(dst[i - bpp], src[i], last[i]);\
219 /* NOTE: 'dst' can be equal to 'last' */
220 static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
221 uint8_t *src, uint8_t *last, int size, int bpp)
223 int i, p, r, g, b, a;
225 switch (filter_type) {
226 case PNG_FILTER_VALUE_NONE:
227 memcpy(dst, src, size);
229 case PNG_FILTER_VALUE_SUB:
230 for (i = 0; i < bpp; i++)
234 for (; i < size; i += bpp) {
235 unsigned s = *(int *)(src + i);
236 p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
237 *(int *)(dst + i) = p;
240 #define OP_SUB(x, s, l) x + s
241 UNROLL_FILTER(OP_SUB);
244 case PNG_FILTER_VALUE_UP:
245 dsp->add_bytes_l2(dst, src, last, size);
247 case PNG_FILTER_VALUE_AVG:
248 for (i = 0; i < bpp; i++) {
252 #define OP_AVG(x, s, l) (((x + l) >> 1) + s) & 0xff
253 UNROLL_FILTER(OP_AVG);
255 case PNG_FILTER_VALUE_PAETH:
256 for (i = 0; i < bpp; i++) {
260 if (bpp > 2 && size > 4) {
261 /* would write off the end of the array if we let it process
262 * the last pixel with bpp=3 */
263 int w = bpp == 4 ? size : size - 3;
264 dsp->add_paeth_prediction(dst + i, src + i, last + i, w - i, bpp);
267 ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
272 /* This used to be called "deloco" in FFmpeg
273 * and is actually an inverse reversible colorspace transformation */
274 #define YUV2RGB(NAME, TYPE) \
275 static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
278 for (i = 0; i < size; i += 3 + alpha) { \
279 int g = dst [i + 1]; \
285 YUV2RGB(rgb8, uint8_t)
286 YUV2RGB(rgb16, uint16_t)
288 /* process exactly one decompressed row */
289 static void png_handle_row(PNGDecContext *s)
291 uint8_t *ptr, *last_row;
294 if (!s->interlace_type) {
295 ptr = s->image_buf + s->image_linesize * s->y;
297 last_row = s->last_row;
299 last_row = ptr - s->image_linesize;
301 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
302 last_row, s->row_size, s->bpp);
303 /* loco lags by 1 row so that it doesn't interfere with top prediction */
304 if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
305 if (s->bit_depth == 16) {
306 deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2,
307 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
309 deloco_rgb8(ptr - s->image_linesize, s->row_size,
310 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
314 if (s->y == s->height) {
315 s->state |= PNG_ALLIMAGE;
316 if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
317 if (s->bit_depth == 16) {
318 deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
319 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
321 deloco_rgb8(ptr, s->row_size,
322 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
329 ptr = s->image_buf + s->image_linesize * s->y;
330 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
331 /* if we already read one row, it is time to stop to
332 * wait for the next one */
335 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
336 s->last_row, s->pass_row_size, s->bpp);
337 FFSWAP(uint8_t *, s->last_row, s->tmp_row);
338 FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size);
341 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
342 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
343 s->color_type, s->last_row);
346 if (s->y == s->height) {
347 memset(s->last_row, 0, s->row_size);
349 if (s->pass == NB_PASSES - 1) {
350 s->state |= PNG_ALLIMAGE;
355 s->pass_row_size = ff_png_pass_row_size(s->pass,
358 s->crow_size = s->pass_row_size + 1;
359 if (s->pass_row_size != 0)
361 /* skip pass if empty row */
370 static int png_decode_idat(PNGDecContext *s, int length)
373 s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
374 s->zstream.next_in = (unsigned char *)s->gb.buffer;
375 bytestream2_skip(&s->gb, length);
377 /* decode one line if possible */
378 while (s->zstream.avail_in > 0) {
379 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
380 if (ret != Z_OK && ret != Z_STREAM_END) {
381 av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
382 return AVERROR_EXTERNAL;
384 if (s->zstream.avail_out == 0) {
385 if (!(s->state & PNG_ALLIMAGE)) {
388 s->zstream.avail_out = s->crow_size;
389 s->zstream.next_out = s->crow_buf;
391 if (ret == Z_STREAM_END && s->zstream.avail_in > 0) {
392 av_log(NULL, AV_LOG_WARNING,
393 "%d undecompressed bytes left in buffer\n", s->zstream.avail_in);
400 static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
401 const uint8_t *data_end)
408 zstream.zalloc = ff_png_zalloc;
409 zstream.zfree = ff_png_zfree;
410 zstream.opaque = NULL;
411 if (inflateInit(&zstream) != Z_OK)
412 return AVERROR_EXTERNAL;
413 zstream.next_in = (unsigned char *)data;
414 zstream.avail_in = data_end - data;
415 av_bprint_init(bp, 0, -1);
417 while (zstream.avail_in > 0) {
418 av_bprint_get_buffer(bp, 1, &buf, &buf_size);
420 ret = AVERROR(ENOMEM);
423 zstream.next_out = buf;
424 zstream.avail_out = buf_size;
425 ret = inflate(&zstream, Z_PARTIAL_FLUSH);
426 if (ret != Z_OK && ret != Z_STREAM_END) {
427 ret = AVERROR_EXTERNAL;
430 bp->len += zstream.next_out - buf;
431 if (ret == Z_STREAM_END)
434 inflateEnd(&zstream);
435 bp->str[bp->len] = 0;
439 inflateEnd(&zstream);
440 av_bprint_finalize(bp, NULL);
444 static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
449 for (i = 0; i < size_in; i++)
450 extra += in[i] >= 0x80;
451 if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
453 q = out = av_malloc(size_in + extra + 1);
456 for (i = 0; i < size_in; i++) {
458 *(q++) = 0xC0 | (in[i] >> 6);
459 *(q++) = 0x80 | (in[i] & 0x3F);
468 static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed,
472 const uint8_t *data = s->gb.buffer;
473 const uint8_t *data_end = data + length;
474 const uint8_t *keyword = data;
475 const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
476 uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
481 return AVERROR_INVALIDDATA;
482 data = keyword_end + 1;
485 if (data == data_end)
486 return AVERROR_INVALIDDATA;
489 return AVERROR_INVALIDDATA;
490 if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
493 av_bprint_finalize(&bp, (char **)&text);
495 return AVERROR(ENOMEM);
497 text = (uint8_t *)data;
498 text_len = data_end - text;
501 kw_utf8 = iso88591_to_utf8(keyword, keyword_end - keyword);
502 txt_utf8 = iso88591_to_utf8(text, text_len);
505 if (!(kw_utf8 && txt_utf8)) {
508 return AVERROR(ENOMEM);
511 av_dict_set(dict, kw_utf8, txt_utf8,
512 AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
516 static int decode_frame(AVCodecContext *avctx,
517 void *data, int *got_frame,
520 PNGDecContext *const s = avctx->priv_data;
521 const uint8_t *buf = avpkt->data;
522 int buf_size = avpkt->size;
524 AVDictionary *metadata = NULL;
525 uint32_t tag, length;
529 ff_thread_release_buffer(avctx, &s->last_picture);
530 FFSWAP(ThreadFrame, s->picture, s->last_picture);
533 bytestream2_init(&s->gb, buf, buf_size);
535 /* check signature */
536 sig = bytestream2_get_be64(&s->gb);
539 av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
540 return AVERROR_INVALIDDATA;
546 s->zstream.zalloc = ff_png_zalloc;
547 s->zstream.zfree = ff_png_zfree;
548 s->zstream.opaque = NULL;
549 ret = inflateInit(&s->zstream);
551 av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
552 return AVERROR_EXTERNAL;
555 if (bytestream2_get_bytes_left(&s->gb) <= 0) {
556 av_log(avctx, AV_LOG_ERROR, "No bytes left\n");
557 if ( s->state & PNG_ALLIMAGE
558 && avctx->strict_std_compliance <= FF_COMPLIANCE_NORMAL)
563 length = bytestream2_get_be32(&s->gb);
564 if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) {
565 av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
568 tag = bytestream2_get_le32(&s->gb);
569 if (avctx->debug & FF_DEBUG_STARTCODE)
570 av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
573 ((tag >> 16) & 0xff),
574 ((tag >> 24) & 0xff), length);
576 case MKTAG('I', 'H', 'D', 'R'):
579 s->width = bytestream2_get_be32(&s->gb);
580 s->height = bytestream2_get_be32(&s->gb);
581 if (av_image_check_size(s->width, s->height, 0, avctx)) {
582 s->width = s->height = 0;
583 av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
586 s->bit_depth = bytestream2_get_byte(&s->gb);
587 s->color_type = bytestream2_get_byte(&s->gb);
588 s->compression_type = bytestream2_get_byte(&s->gb);
589 s->filter_type = bytestream2_get_byte(&s->gb);
590 s->interlace_type = bytestream2_get_byte(&s->gb);
591 bytestream2_skip(&s->gb, 4); /* crc */
592 s->state |= PNG_IHDR;
593 if (avctx->debug & FF_DEBUG_PICT_INFO)
594 av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d "
595 "compression_type=%d filter_type=%d interlace_type=%d\n",
596 s->width, s->height, s->bit_depth, s->color_type,
597 s->compression_type, s->filter_type, s->interlace_type);
599 case MKTAG('p', 'H', 'Y', 's'):
600 if (s->state & PNG_IDAT) {
601 av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
604 avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
605 avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
606 if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
607 avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
608 bytestream2_skip(&s->gb, 1); /* unit specifier */
609 bytestream2_skip(&s->gb, 4); /* crc */
611 case MKTAG('I', 'D', 'A', 'T'):
612 if (!(s->state & PNG_IHDR)) {
613 av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
616 if (!(s->state & PNG_IDAT)) {
617 /* init image info */
618 avctx->width = s->width;
619 avctx->height = s->height;
621 s->channels = ff_png_get_nb_channels(s->color_type);
622 s->bits_per_pixel = s->bit_depth * s->channels;
623 s->bpp = (s->bits_per_pixel + 7) >> 3;
624 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
626 if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
627 s->color_type == PNG_COLOR_TYPE_RGB) {
628 avctx->pix_fmt = AV_PIX_FMT_RGB24;
629 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
630 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
631 avctx->pix_fmt = AV_PIX_FMT_RGBA;
632 } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
633 s->color_type == PNG_COLOR_TYPE_GRAY) {
634 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
635 } else if (s->bit_depth == 16 &&
636 s->color_type == PNG_COLOR_TYPE_GRAY) {
637 avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
638 } else if (s->bit_depth == 16 &&
639 s->color_type == PNG_COLOR_TYPE_RGB) {
640 avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
641 } else if (s->bit_depth == 16 &&
642 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
643 avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
644 } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
645 s->color_type == PNG_COLOR_TYPE_PALETTE) {
646 avctx->pix_fmt = AV_PIX_FMT_PAL8;
647 } else if (s->bit_depth == 1) {
648 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
649 } else if (s->bit_depth == 8 &&
650 s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
651 avctx->pix_fmt = AV_PIX_FMT_Y400A;
653 av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
654 "and color type %d\n",
655 s->bit_depth, s->color_type);
659 if (ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF) < 0)
661 ff_thread_finish_setup(avctx);
663 p->pict_type = AV_PICTURE_TYPE_I;
665 p->interlaced_frame = !!s->interlace_type;
667 /* compute the compressed row size */
668 if (!s->interlace_type) {
669 s->crow_size = s->row_size + 1;
672 s->pass_row_size = ff_png_pass_row_size(s->pass,
675 s->crow_size = s->pass_row_size + 1;
677 av_dlog(avctx, "row_size=%d crow_size =%d\n",
678 s->row_size, s->crow_size);
679 s->image_buf = p->data[0];
680 s->image_linesize = p->linesize[0];
681 /* copy the palette if needed */
682 if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
683 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
684 /* empty row is used if differencing to the first row */
685 av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
688 if (s->interlace_type ||
689 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
690 av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size);
695 av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
699 /* we want crow_buf+1 to be 16-byte aligned */
700 s->crow_buf = s->buffer + 15;
701 s->zstream.avail_out = s->crow_size;
702 s->zstream.next_out = s->crow_buf;
704 s->state |= PNG_IDAT;
705 if (png_decode_idat(s, length) < 0)
707 bytestream2_skip(&s->gb, 4); /* crc */
709 case MKTAG('P', 'L', 'T', 'E'):
713 if ((length % 3) != 0 || length > 256 * 3)
715 /* read the palette */
717 for (i = 0; i < n; i++) {
718 r = bytestream2_get_byte(&s->gb);
719 g = bytestream2_get_byte(&s->gb);
720 b = bytestream2_get_byte(&s->gb);
721 s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
724 s->palette[i] = (0xFFU << 24);
725 s->state |= PNG_PLTE;
726 bytestream2_skip(&s->gb, 4); /* crc */
729 case MKTAG('t', 'R', 'N', 'S'):
733 /* read the transparency. XXX: Only palette mode supported */
734 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
736 !(s->state & PNG_PLTE))
738 for (i = 0; i < length; i++) {
739 v = bytestream2_get_byte(&s->gb);
740 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
742 bytestream2_skip(&s->gb, 4); /* crc */
745 case MKTAG('t', 'E', 'X', 't'):
746 if (decode_text_chunk(s, length, 0, &metadata) < 0)
747 av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
748 bytestream2_skip(&s->gb, length + 4);
750 case MKTAG('z', 'T', 'X', 't'):
751 if (decode_text_chunk(s, length, 1, &metadata) < 0)
752 av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
753 bytestream2_skip(&s->gb, length + 4);
755 case MKTAG('I', 'E', 'N', 'D'):
756 if (!(s->state & PNG_ALLIMAGE))
757 av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
758 if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
761 bytestream2_skip(&s->gb, 4); /* crc */
766 bytestream2_skip(&s->gb, length + 4);
772 if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE){
774 uint8_t *pd = p->data[0];
775 for (j = 0; j < s->height; j++) {
777 for (k = 7; k >= 1; k--)
778 if ((s->width&7) >= k)
779 pd[8*i + k - 1] = (pd[i]>>8-k) & 1;
780 for (i--; i >= 0; i--) {
781 pd[8*i + 7]= pd[i] & 1;
782 pd[8*i + 6]= (pd[i]>>1) & 1;
783 pd[8*i + 5]= (pd[i]>>2) & 1;
784 pd[8*i + 4]= (pd[i]>>3) & 1;
785 pd[8*i + 3]= (pd[i]>>4) & 1;
786 pd[8*i + 2]= (pd[i]>>5) & 1;
787 pd[8*i + 1]= (pd[i]>>6) & 1;
788 pd[8*i + 0]= pd[i]>>7;
790 pd += s->image_linesize;
793 if (s->bits_per_pixel == 2){
795 uint8_t *pd = p->data[0];
796 for (j = 0; j < s->height; j++) {
798 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
799 if ((s->width&3) >= 3) pd[4*i + 2]= (pd[i] >> 2) & 3;
800 if ((s->width&3) >= 2) pd[4*i + 1]= (pd[i] >> 4) & 3;
801 if ((s->width&3) >= 1) pd[4*i + 0]= pd[i] >> 6;
802 for (i--; i >= 0; i--) {
803 pd[4*i + 3]= pd[i] & 3;
804 pd[4*i + 2]= (pd[i]>>2) & 3;
805 pd[4*i + 1]= (pd[i]>>4) & 3;
806 pd[4*i + 0]= pd[i]>>6;
809 if ((s->width&3) >= 3) pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
810 if ((s->width&3) >= 2) pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
811 if ((s->width&3) >= 1) pd[4*i + 0]= ( pd[i]>>6 )*0x55;
812 for (i--; i >= 0; i--) {
813 pd[4*i + 3]= ( pd[i] & 3)*0x55;
814 pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
815 pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
816 pd[4*i + 0]= ( pd[i]>>6 )*0x55;
819 pd += s->image_linesize;
822 if (s->bits_per_pixel == 4){
824 uint8_t *pd = p->data[0];
825 for (j = 0; j < s->height; j++) {
827 if (s->color_type == PNG_COLOR_TYPE_PALETTE){
828 if (s->width&1) pd[2*i+0]= pd[i]>>4;
829 for (i--; i >= 0; i--) {
830 pd[2*i + 1] = pd[i] & 15;
831 pd[2*i + 0] = pd[i] >> 4;
834 if (s->width & 1) pd[2*i + 0]= (pd[i] >> 4) * 0x11;
835 for (i--; i >= 0; i--) {
836 pd[2*i + 1] = (pd[i] & 15) * 0x11;
837 pd[2*i + 0] = (pd[i] >> 4) * 0x11;
840 pd += s->image_linesize;
844 /* handle p-frames only if a predecessor frame is available */
845 if (s->last_picture.f->data[0]) {
846 if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
847 && s->last_picture.f->width == p->width
848 && s->last_picture.f->height== p->height
849 && s->last_picture.f->format== p->format
852 uint8_t *pd = p->data[0];
853 uint8_t *pd_last = s->last_picture.f->data[0];
855 ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
856 for (j = 0; j < s->height; j++) {
857 for (i = 0; i < s->width * s->bpp; i++)
859 pd += s->image_linesize;
860 pd_last += s->image_linesize;
864 ff_thread_report_progress(&s->picture, INT_MAX, 0);
866 av_frame_set_metadata(p, metadata);
869 if ((ret = av_frame_ref(data, s->picture.f)) < 0)
874 ret = bytestream2_tell(&s->gb);
876 inflateEnd(&s->zstream);
880 av_dict_free(&metadata);
881 ff_thread_report_progress(&s->picture, INT_MAX, 0);
882 ret = AVERROR_INVALIDDATA;
886 static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
888 PNGDecContext *psrc = src->priv_data;
889 PNGDecContext *pdst = dst->priv_data;
894 ff_thread_release_buffer(dst, &pdst->picture);
895 if (psrc->picture.f->data[0])
896 return ff_thread_ref_frame(&pdst->picture, &psrc->picture);
901 static av_cold int png_dec_init(AVCodecContext *avctx)
903 PNGDecContext *s = avctx->priv_data;
906 s->last_picture.f = av_frame_alloc();
907 s->picture.f = av_frame_alloc();
908 if (!s->last_picture.f || !s->picture.f)
909 return AVERROR(ENOMEM);
911 if (!avctx->internal->is_copy) {
912 avctx->internal->allocate_progress = 1;
913 ff_pngdsp_init(&s->dsp);
919 static av_cold int png_dec_end(AVCodecContext *avctx)
921 PNGDecContext *s = avctx->priv_data;
923 ff_thread_release_buffer(avctx, &s->last_picture);
924 av_frame_free(&s->last_picture.f);
925 ff_thread_release_buffer(avctx, &s->picture);
926 av_frame_free(&s->picture.f);
927 av_freep(&s->buffer);
929 av_freep(&s->last_row);
930 s->last_row_size = 0;
931 av_freep(&s->tmp_row);
937 AVCodec ff_png_decoder = {
939 .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
940 .type = AVMEDIA_TYPE_VIDEO,
941 .id = AV_CODEC_ID_PNG,
942 .priv_data_size = sizeof(PNGDecContext),
943 .init = png_dec_init,
944 .close = png_dec_end,
945 .decode = decode_frame,
946 .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
947 .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
948 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,