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;
55 uint32_t palette[256];
60 int crow_size; /* compressed row size (include filter type) */
61 int row_size; /* decompressed row size */
62 int pass_row_size; /* decompress row size of the current pass */
67 /* Mask to determine which y pixels can be written in a pass */
68 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
69 0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55,
72 /* Mask to determine which pixels to overwrite while displaying */
73 static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
74 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
77 /* NOTE: we try to construct a good looking image at each pass. width
78 is the original image width. We also do pixel format conversion at
80 static void png_put_interlaced_row(uint8_t *dst, int width,
81 int bits_per_pixel, int pass,
82 int color_type, const uint8_t *src)
84 int x, mask, dsp_mask, j, src_x, b, bpp;
88 mask = ff_png_pass_mask[pass];
89 dsp_mask = png_pass_dsp_mask[pass];
90 switch(bits_per_pixel) {
92 /* we must initialize the line to zero before writing to it */
94 memset(dst, 0, (width + 7) >> 3);
96 for(x = 0; x < width; x++) {
98 if ((dsp_mask << j) & 0x80) {
99 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
100 dst[x >> 3] |= b << (7 - j);
102 if ((mask << j) & 0x80)
107 bpp = bits_per_pixel >> 3;
110 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
111 for(x = 0; x < width; x++) {
113 if ((dsp_mask << j) & 0x80) {
114 *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
117 if ((mask << j) & 0x80)
121 for(x = 0; x < width; x++) {
123 if ((dsp_mask << j) & 0x80) {
127 if ((mask << j) & 0x80)
135 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
138 for(i = 0; i < w; i++) {
139 int a, b, c, p, pa, pb, pc;
152 if (pa <= pb && pa <= pc)
162 #define UNROLL1(bpp, op) {\
164 if(bpp >= 2) g = dst[1];\
165 if(bpp >= 3) b = dst[2];\
166 if(bpp >= 4) a = dst[3];\
167 for(; i < size; i+=bpp) {\
168 dst[i+0] = r = op(r, src[i+0], last[i+0]);\
169 if(bpp == 1) continue;\
170 dst[i+1] = g = op(g, src[i+1], last[i+1]);\
171 if(bpp == 2) continue;\
172 dst[i+2] = b = op(b, src[i+2], last[i+2]);\
173 if(bpp == 3) continue;\
174 dst[i+3] = a = op(a, src[i+3], last[i+3]);\
178 #define UNROLL_FILTER(op)\
179 if(bpp == 1) UNROLL1(1, op)\
180 else if(bpp == 2) UNROLL1(2, op)\
181 else if(bpp == 3) UNROLL1(3, op)\
182 else if(bpp == 4) UNROLL1(4, op)\
184 /* NOTE: 'dst' can be equal to 'last' */
185 static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
186 uint8_t *src, uint8_t *last, int size, int bpp)
188 int i, p, r, g, b, a;
190 switch(filter_type) {
191 case PNG_FILTER_VALUE_NONE:
192 memcpy(dst, src, size);
194 case PNG_FILTER_VALUE_SUB:
195 for(i = 0; i < bpp; i++) {
200 for(; i < size; i+=bpp) {
201 int s = *(int*)(src+i);
202 p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080);
206 #define OP_SUB(x,s,l) x+s
207 UNROLL_FILTER(OP_SUB);
210 case PNG_FILTER_VALUE_UP:
211 dsp->add_bytes_l2(dst, src, last, size);
213 case PNG_FILTER_VALUE_AVG:
214 for(i = 0; i < bpp; i++) {
218 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
219 UNROLL_FILTER(OP_AVG);
221 case PNG_FILTER_VALUE_PAETH:
222 for(i = 0; i < bpp; i++) {
226 if(bpp > 1 && size > 4) {
227 // would write off the end of the array if we let it process the last pixel with bpp=3
228 int w = bpp==4 ? size : size-3;
229 dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp);
232 ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp);
237 static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco)
240 unsigned int r, g, b, a;
242 for(j = 0;j < width; j++) {
251 *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
257 static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco)
260 convert_to_rgb32_loco(dst, src, width, 1);
262 convert_to_rgb32_loco(dst, src, width, 0);
265 static void deloco_rgb24(uint8_t *dst, int size)
268 for(i=0; i<size; i+=3) {
275 /* process exactly one decompressed row */
276 static void png_handle_row(PNGDecContext *s)
278 uint8_t *ptr, *last_row;
281 if (!s->interlace_type) {
282 ptr = s->image_buf + s->image_linesize * s->y;
283 /* need to swap bytes correctly for RGB_ALPHA */
284 if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
285 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
286 s->last_row, s->row_size, s->bpp);
287 convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO);
288 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
290 /* in normal case, we avoid one copy */
292 last_row = s->last_row;
294 last_row = ptr - s->image_linesize;
296 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
297 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 &&
301 s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0)
302 deloco_rgb24(ptr - s->image_linesize, s->row_size);
304 if (s->y == s->height) {
305 s->state |= PNG_ALLIMAGE;
306 if (s->filter_type == PNG_FILTER_TYPE_LOCO &&
307 s->color_type == PNG_COLOR_TYPE_RGB)
308 deloco_rgb24(ptr, s->row_size);
313 ptr = s->image_buf + s->image_linesize * s->y;
314 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
315 /* if we already read one row, it is time to stop to
316 wait for the next one */
319 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
320 s->last_row, s->pass_row_size, s->bpp);
321 FFSWAP(uint8_t*, s->last_row, s->tmp_row);
324 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
325 /* NOTE: RGB32 is handled directly in png_put_interlaced_row */
326 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
327 s->color_type, s->last_row);
330 if (s->y == s->height) {
332 if (s->pass == NB_PASSES - 1) {
333 s->state |= PNG_ALLIMAGE;
338 s->pass_row_size = ff_png_pass_row_size(s->pass,
341 s->crow_size = s->pass_row_size + 1;
342 if (s->pass_row_size != 0)
344 /* skip pass if empty row */
353 static int png_decode_idat(PNGDecContext *s, int length)
356 s->zstream.avail_in = length;
357 s->zstream.next_in = s->bytestream;
358 s->bytestream += length;
360 if(s->bytestream > s->bytestream_end)
363 /* decode one line if possible */
364 while (s->zstream.avail_in > 0) {
365 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
366 if (ret != Z_OK && ret != Z_STREAM_END) {
369 if (s->zstream.avail_out == 0) {
370 if (!(s->state & PNG_ALLIMAGE)) {
373 s->zstream.avail_out = s->crow_size;
374 s->zstream.next_out = s->crow_buf;
380 static int decode_frame(AVCodecContext *avctx,
381 void *data, int *data_size,
382 const uint8_t *buf, int buf_size)
384 PNGDecContext * const s = avctx->priv_data;
385 AVFrame *picture = data;
386 AVFrame * const p= (AVFrame*)&s->picture;
387 uint32_t tag, length;
392 s->bytestream_end= buf + buf_size;
394 /* check signature */
395 if (memcmp(s->bytestream, ff_pngsig, 8) != 0 &&
396 memcmp(s->bytestream, ff_mngsig, 8) != 0)
401 // memset(s, 0, sizeof(PNGDecContext));
403 s->zstream.zalloc = ff_png_zalloc;
404 s->zstream.zfree = ff_png_zfree;
405 s->zstream.opaque = NULL;
406 ret = inflateInit(&s->zstream);
411 if (s->bytestream >= s->bytestream_end)
413 length = bytestream_get_be32(&s->bytestream);
414 if (length > 0x7fffffff)
416 tag32 = bytestream_get_be32(&s->bytestream);
417 tag = bswap_32(tag32);
419 av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
422 ((tag >> 16) & 0xff),
423 ((tag >> 24) & 0xff), length);
426 case MKTAG('I', 'H', 'D', 'R'):
429 s->width = bytestream_get_be32(&s->bytestream);
430 s->height = bytestream_get_be32(&s->bytestream);
431 if(avcodec_check_dimensions(avctx, s->width, s->height)){
432 s->width= s->height= 0;
435 s->bit_depth = *s->bytestream++;
436 s->color_type = *s->bytestream++;
437 s->compression_type = *s->bytestream++;
438 s->filter_type = *s->bytestream++;
439 s->interlace_type = *s->bytestream++;
440 crc = bytestream_get_be32(&s->bytestream);
441 s->state |= PNG_IHDR;
443 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",
444 s->width, s->height, s->bit_depth, s->color_type,
445 s->compression_type, s->filter_type, s->interlace_type);
448 case MKTAG('I', 'D', 'A', 'T'):
449 if (!(s->state & PNG_IHDR))
451 if (!(s->state & PNG_IDAT)) {
452 /* init image info */
453 avctx->width = s->width;
454 avctx->height = s->height;
456 s->channels = ff_png_get_nb_channels(s->color_type);
457 s->bits_per_pixel = s->bit_depth * s->channels;
458 s->bpp = (s->bits_per_pixel + 7) >> 3;
459 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
461 if (s->bit_depth == 8 &&
462 s->color_type == PNG_COLOR_TYPE_RGB) {
463 avctx->pix_fmt = PIX_FMT_RGB24;
464 } else if (s->bit_depth == 8 &&
465 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
466 avctx->pix_fmt = PIX_FMT_RGB32;
467 } else if (s->bit_depth == 8 &&
468 s->color_type == PNG_COLOR_TYPE_GRAY) {
469 avctx->pix_fmt = PIX_FMT_GRAY8;
470 } else if (s->bit_depth == 16 &&
471 s->color_type == PNG_COLOR_TYPE_GRAY) {
472 avctx->pix_fmt = PIX_FMT_GRAY16BE;
473 } else if (s->bit_depth == 1 &&
474 s->color_type == PNG_COLOR_TYPE_GRAY) {
475 avctx->pix_fmt = PIX_FMT_MONOBLACK;
476 } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
477 avctx->pix_fmt = PIX_FMT_PAL8;
482 avctx->release_buffer(avctx, p);
485 if(avctx->get_buffer(avctx, p) < 0){
486 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
489 p->pict_type= FF_I_TYPE;
491 p->interlaced_frame = !!s->interlace_type;
493 /* compute the compressed row size */
494 if (!s->interlace_type) {
495 s->crow_size = s->row_size + 1;
498 s->pass_row_size = ff_png_pass_row_size(s->pass,
501 s->crow_size = s->pass_row_size + 1;
504 av_log(avctx, AV_LOG_DEBUG, "row_size=%d crow_size =%d\n",
505 s->row_size, s->crow_size);
507 s->image_buf = p->data[0];
508 s->image_linesize = p->linesize[0];
509 /* copy the palette if needed */
510 if (s->color_type == PNG_COLOR_TYPE_PALETTE)
511 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
512 /* empty row is used if differencing to the first row */
513 s->last_row = av_mallocz(s->row_size);
516 if (s->interlace_type ||
517 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
518 s->tmp_row = av_malloc(s->row_size);
523 s->crow_buf = av_malloc(s->row_size + 1);
526 s->zstream.avail_out = s->crow_size;
527 s->zstream.next_out = s->crow_buf;
529 s->state |= PNG_IDAT;
530 if (png_decode_idat(s, length) < 0)
533 crc = bytestream_get_be32(&s->bytestream);
535 case MKTAG('P', 'L', 'T', 'E'):
539 if ((length % 3) != 0 || length > 256 * 3)
541 /* read the palette */
544 r = *s->bytestream++;
545 g = *s->bytestream++;
546 b = *s->bytestream++;
547 s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
550 s->palette[i] = (0xff << 24);
552 s->state |= PNG_PLTE;
553 crc = bytestream_get_be32(&s->bytestream);
556 case MKTAG('t', 'R', 'N', 'S'):
560 /* read the transparency. XXX: Only palette mode supported */
561 if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
563 !(s->state & PNG_PLTE))
565 for(i=0;i<length;i++) {
566 v = *s->bytestream++;
567 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
569 crc = bytestream_get_be32(&s->bytestream);
572 case MKTAG('I', 'E', 'N', 'D'):
573 if (!(s->state & PNG_ALLIMAGE))
575 crc = bytestream_get_be32(&s->bytestream);
580 s->bytestream += length + 4;
585 *picture= *(AVFrame*)&s->picture;
586 *data_size = sizeof(AVPicture);
588 ret = s->bytestream - s->bytestream_start;
590 inflateEnd(&s->zstream);
591 av_freep(&s->crow_buf);
592 av_freep(&s->last_row);
593 av_freep(&s->tmp_row);
600 static av_cold int png_dec_init(AVCodecContext *avctx){
601 PNGDecContext *s = avctx->priv_data;
603 avcodec_get_frame_defaults((AVFrame*)&s->picture);
604 avctx->coded_frame= (AVFrame*)&s->picture;
605 dsputil_init(&s->dsp, avctx);
610 AVCodec png_decoder = {
614 sizeof(PNGDecContext),
619 0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,