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
22 #include "bytestream.h"
27 * - add 2, 4 and 16 bit depth support
34 typedef struct PNGDecContext {
37 const uint8_t *bytestream;
38 const uint8_t *bytestream_start;
39 const uint8_t *bytestream_end;
40 AVFrame picture1, picture2;
41 AVFrame *current_picture, *last_picture;
56 uint32_t palette[256];
61 int crow_size; /* compressed row size (include filter type) */
62 int row_size; /* decompressed row size */
63 int pass_row_size; /* decompress row size of the current pass */
68 /* Mask to determine which y pixels can be written in a pass */
69 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
70 0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55,
73 /* Mask to determine which pixels to overwrite while displaying */
74 static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
75 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
78 /* NOTE: we try to construct a good looking image at each pass. width
79 is the original image width. We also do pixel format conversion at
81 static void png_put_interlaced_row(uint8_t *dst, int width,
82 int bits_per_pixel, int pass,
83 int color_type, const uint8_t *src)
85 int x, mask, dsp_mask, j, src_x, b, bpp;
89 mask = ff_png_pass_mask[pass];
90 dsp_mask = png_pass_dsp_mask[pass];
91 switch(bits_per_pixel) {
93 /* we must initialize the line to zero before writing to it */
95 memset(dst, 0, (width + 7) >> 3);
97 for(x = 0; x < width; x++) {
99 if ((dsp_mask << j) & 0x80) {
100 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
101 dst[x >> 3] |= b << (7 - j);
103 if ((mask << j) & 0x80)
108 bpp = bits_per_pixel >> 3;
111 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
112 for(x = 0; x < width; x++) {
114 if ((dsp_mask << j) & 0x80) {
115 *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
118 if ((mask << j) & 0x80)
122 for(x = 0; x < width; x++) {
124 if ((dsp_mask << j) & 0x80) {
128 if ((mask << j) & 0x80)
136 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
139 for(i = 0; i < w; i++) {
140 int a, b, c, p, pa, pb, pc;
153 if (pa <= pb && pa <= pc)
163 #define UNROLL1(bpp, op) {\
165 if(bpp >= 2) g = dst[1];\
166 if(bpp >= 3) b = dst[2];\
167 if(bpp >= 4) a = dst[3];\
168 for(; i < size; i+=bpp) {\
169 dst[i+0] = r = op(r, src[i+0], last[i+0]);\
170 if(bpp == 1) continue;\
171 dst[i+1] = g = op(g, src[i+1], last[i+1]);\
172 if(bpp == 2) continue;\
173 dst[i+2] = b = op(b, src[i+2], last[i+2]);\
174 if(bpp == 3) continue;\
175 dst[i+3] = a = op(a, src[i+3], last[i+3]);\
179 #define UNROLL_FILTER(op)\
180 if(bpp == 1) UNROLL1(1, op)\
181 else if(bpp == 2) UNROLL1(2, op)\
182 else if(bpp == 3) UNROLL1(3, op)\
183 else if(bpp == 4) UNROLL1(4, op)\
185 /* NOTE: 'dst' can be equal to 'last' */
186 static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
187 uint8_t *src, uint8_t *last, int size, int bpp)
189 int i, p, r, g, b, a;
191 switch(filter_type) {
192 case PNG_FILTER_VALUE_NONE:
193 memcpy(dst, src, size);
195 case PNG_FILTER_VALUE_SUB:
196 for(i = 0; i < bpp; i++) {
201 for(; i < size; i+=bpp) {
202 int s = *(int*)(src+i);
203 p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080);
207 #define OP_SUB(x,s,l) x+s
208 UNROLL_FILTER(OP_SUB);
211 case PNG_FILTER_VALUE_UP:
212 dsp->add_bytes_l2(dst, src, last, size);
214 case PNG_FILTER_VALUE_AVG:
215 for(i = 0; i < bpp; i++) {
219 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
220 UNROLL_FILTER(OP_AVG);
222 case PNG_FILTER_VALUE_PAETH:
223 for(i = 0; i < bpp; i++) {
227 if(bpp > 1 && size > 4) {
228 // would write off the end of the array if we let it process the last pixel with bpp=3
229 int w = bpp==4 ? size : size-3;
230 dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp);
233 ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp);
238 static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco)
241 unsigned int r, g, b, a;
243 for(j = 0;j < width; j++) {
252 *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
258 static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco)
261 convert_to_rgb32_loco(dst, src, width, 1);
263 convert_to_rgb32_loco(dst, src, width, 0);
266 static void deloco_rgb24(uint8_t *dst, int size)
269 for(i=0; i<size; i+=3) {
276 /* process exactly one decompressed row */
277 static void png_handle_row(PNGDecContext *s)
279 uint8_t *ptr, *last_row;
282 if (!s->interlace_type) {
283 ptr = s->image_buf + s->image_linesize * s->y;
284 /* need to swap bytes correctly for RGB_ALPHA */
285 if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
286 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
287 s->last_row, s->row_size, s->bpp);
288 convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO);
289 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
291 /* in normal case, we avoid one copy */
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);
300 /* loco lags by 1 row so that it doesn't interfere with top prediction */
301 if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
302 s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0)
303 deloco_rgb24(ptr - s->image_linesize, s->row_size);
305 if (s->y == s->height) {
306 s->state |= PNG_ALLIMAGE;
307 if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
308 s->color_type == PNG_COLOR_TYPE_RGB)
309 deloco_rgb24(ptr, s->row_size);
314 ptr = s->image_buf + s->image_linesize * s->y;
315 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
316 /* if we already read one row, it is time to stop to
317 wait for the next one */
320 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
321 s->last_row, s->pass_row_size, s->bpp);
322 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
325 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
326 /* NOTE: RGB32 is handled directly in png_put_interlaced_row */
327 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
328 s->color_type, s->last_row);
331 if (s->y == s->height) {
333 if (s->pass == NB_PASSES - 1) {
334 s->state |= PNG_ALLIMAGE;
339 s->pass_row_size = ff_png_pass_row_size(s->pass,
342 s->crow_size = s->pass_row_size + 1;
343 if (s->pass_row_size != 0)
345 /* skip pass if empty row */
354 static int png_decode_idat(PNGDecContext *s, int length)
357 s->zstream.avail_in = length;
358 s->zstream.next_in = s->bytestream;
359 s->bytestream += length;
361 if(s->bytestream > s->bytestream_end)
364 /* decode one line if possible */
365 while (s->zstream.avail_in > 0) {
366 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
367 if (ret != Z_OK && ret != Z_STREAM_END) {
370 if (s->zstream.avail_out == 0) {
371 if (!(s->state & PNG_ALLIMAGE)) {
374 s->zstream.avail_out = s->crow_size;
375 s->zstream.next_out = s->crow_buf;
381 static int decode_frame(AVCodecContext *avctx,
382 void *data, int *data_size,
385 const uint8_t *buf = avpkt->data;
386 int buf_size = avpkt->size;
387 PNGDecContext * const s = avctx->priv_data;
388 AVFrame *picture = data;
390 uint32_t tag, length;
393 FFSWAP(AVFrame *, s->current_picture, s->last_picture);
394 avctx->coded_frame= s->current_picture;
395 p = s->current_picture;
399 s->bytestream_end= buf + buf_size;
401 /* check signature */
402 if (memcmp(s->bytestream, ff_pngsig, 8) != 0 &&
403 memcmp(s->bytestream, ff_mngsig, 8) != 0)
408 // memset(s, 0, sizeof(PNGDecContext));
410 s->zstream.zalloc = ff_png_zalloc;
411 s->zstream.zfree = ff_png_zfree;
412 s->zstream.opaque = NULL;
413 ret = inflateInit(&s->zstream);
418 if (s->bytestream >= s->bytestream_end)
420 length = bytestream_get_be32(&s->bytestream);
421 if (length > 0x7fffffff)
423 tag32 = bytestream_get_be32(&s->bytestream);
424 tag = bswap_32(tag32);
426 av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
429 ((tag >> 16) & 0xff),
430 ((tag >> 24) & 0xff), length);
433 case MKTAG('I', 'H', 'D', 'R'):
436 s->width = bytestream_get_be32(&s->bytestream);
437 s->height = bytestream_get_be32(&s->bytestream);
438 if(avcodec_check_dimensions(avctx, s->width, s->height)){
439 s->width= s->height= 0;
442 s->bit_depth = *s->bytestream++;
443 s->color_type = *s->bytestream++;
444 s->compression_type = *s->bytestream++;
445 s->filter_type = *s->bytestream++;
446 s->interlace_type = *s->bytestream++;
447 crc = bytestream_get_be32(&s->bytestream);
448 s->state |= PNG_IHDR;
450 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",
451 s->width, s->height, s->bit_depth, s->color_type,
452 s->compression_type, s->filter_type, s->interlace_type);
455 case MKTAG('I', 'D', 'A', 'T'):
456 if (!(s->state & PNG_IHDR))
458 if (!(s->state & PNG_IDAT)) {
459 /* init image info */
460 avctx->width = s->width;
461 avctx->height = s->height;
463 s->channels = ff_png_get_nb_channels(s->color_type);
464 s->bits_per_pixel = s->bit_depth * s->channels;
465 s->bpp = (s->bits_per_pixel + 7) >> 3;
466 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
468 if (s->bit_depth == 8 &&
469 s->color_type == PNG_COLOR_TYPE_RGB) {
470 avctx->pix_fmt = PIX_FMT_RGB24;
471 } else if (s->bit_depth == 8 &&
472 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
473 avctx->pix_fmt = PIX_FMT_RGB32;
474 } else if (s->bit_depth == 8 &&
475 s->color_type == PNG_COLOR_TYPE_GRAY) {
476 avctx->pix_fmt = PIX_FMT_GRAY8;
477 } else if (s->bit_depth == 16 &&
478 s->color_type == PNG_COLOR_TYPE_GRAY) {
479 avctx->pix_fmt = PIX_FMT_GRAY16BE;
480 } else if (s->bit_depth == 1 &&
481 s->color_type == PNG_COLOR_TYPE_GRAY) {
482 avctx->pix_fmt = PIX_FMT_MONOBLACK;
483 } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
484 avctx->pix_fmt = PIX_FMT_PAL8;
489 avctx->release_buffer(avctx, p);
492 if(avctx->get_buffer(avctx, p) < 0){
493 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
496 p->pict_type= FF_I_TYPE;
498 p->interlaced_frame = !!s->interlace_type;
500 /* compute the compressed row size */
501 if (!s->interlace_type) {
502 s->crow_size = s->row_size + 1;
505 s->pass_row_size = ff_png_pass_row_size(s->pass,
508 s->crow_size = s->pass_row_size + 1;
511 av_log(avctx, AV_LOG_DEBUG, "row_size=%d crow_size =%d\n",
512 s->row_size, s->crow_size);
514 s->image_buf = p->data[0];
515 s->image_linesize = p->linesize[0];
516 /* copy the palette if needed */
517 if (s->color_type == PNG_COLOR_TYPE_PALETTE)
518 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
519 /* empty row is used if differencing to the first row */
520 s->last_row = av_mallocz(s->row_size);
523 if (s->interlace_type ||
524 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
525 s->tmp_row = av_malloc(s->row_size);
530 s->crow_buf = av_malloc(s->row_size + 1);
533 s->zstream.avail_out = s->crow_size;
534 s->zstream.next_out = s->crow_buf;
536 s->state |= PNG_IDAT;
537 if (png_decode_idat(s, length) < 0)
540 crc = bytestream_get_be32(&s->bytestream);
542 case MKTAG('P', 'L', 'T', 'E'):
546 if ((length % 3) != 0 || length > 256 * 3)
548 /* read the palette */
551 r = *s->bytestream++;
552 g = *s->bytestream++;
553 b = *s->bytestream++;
554 s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
557 s->palette[i] = (0xff << 24);
559 s->state |= PNG_PLTE;
560 crc = bytestream_get_be32(&s->bytestream);
563 case MKTAG('t', 'R', 'N', 'S'):
567 /* read the transparency. XXX: Only palette mode supported */
568 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
570 !(s->state & PNG_PLTE))
572 for(i=0;i<length;i++) {
573 v = *s->bytestream++;
574 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
576 crc = bytestream_get_be32(&s->bytestream);
579 case MKTAG('I', 'E', 'N', 'D'):
580 if (!(s->state & PNG_ALLIMAGE))
582 crc = bytestream_get_be32(&s->bytestream);
587 s->bytestream += length + 4;
592 /* handle p-frames only if a predecessor frame is available */
593 if(s->last_picture->data[0] != NULL) {
594 if(!(avpkt->flags & PKT_FLAG_KEY)) {
596 uint8_t *pd = s->current_picture->data[0];
597 uint8_t *pd_last = s->last_picture->data[0];
599 for(j=0; j < s->height; j++) {
600 for(i=0; i < s->width * s->bpp; i++) {
603 pd += s->image_linesize;
604 pd_last += s->image_linesize;
609 *picture= *s->current_picture;
610 *data_size = sizeof(AVFrame);
612 ret = s->bytestream - s->bytestream_start;
614 inflateEnd(&s->zstream);
615 av_freep(&s->crow_buf);
616 av_freep(&s->last_row);
617 av_freep(&s->tmp_row);
624 static av_cold int png_dec_init(AVCodecContext *avctx){
625 PNGDecContext *s = avctx->priv_data;
627 s->current_picture = &s->picture1;
628 s->last_picture = &s->picture2;
629 avcodec_get_frame_defaults(&s->picture1);
630 avcodec_get_frame_defaults(&s->picture2);
631 dsputil_init(&s->dsp, avctx);
636 AVCodec png_decoder = {
640 sizeof(PNGDecContext),
645 0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
647 .long_name = NULL_IF_CONFIG_SMALL("PNG image"),