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 uint8_t *crow_buf_base
= NULL
;
391 uint32_t tag
, length
;
394 FFSWAP(AVFrame
*, s
->current_picture
, s
->last_picture
);
395 avctx
->coded_frame
= s
->current_picture
;
396 p
= s
->current_picture
;
400 s
->bytestream_end
= buf
+ buf_size
;
402 /* check signature */
403 if (memcmp(s
->bytestream
, ff_pngsig
, 8) != 0 &&
404 memcmp(s
->bytestream
, ff_mngsig
, 8) != 0)
409 // memset(s, 0, sizeof(PNGDecContext));
411 s
->zstream
.zalloc
= ff_png_zalloc
;
412 s
->zstream
.zfree
= ff_png_zfree
;
413 s
->zstream
.opaque
= NULL
;
414 ret
= inflateInit(&s
->zstream
);
419 if (s
->bytestream
>= s
->bytestream_end
)
421 length
= bytestream_get_be32(&s
->bytestream
);
422 if (length
> 0x7fffffff)
424 tag32
= bytestream_get_be32(&s
->bytestream
);
425 tag
= bswap_32(tag32
);
427 av_log(avctx
, AV_LOG_DEBUG
, "png: tag=%c%c%c%c length=%u\n",
430 ((tag
>> 16) & 0xff),
431 ((tag
>> 24) & 0xff), length
);
434 case MKTAG('I', 'H', 'D', 'R'):
437 s
->width
= bytestream_get_be32(&s
->bytestream
);
438 s
->height
= bytestream_get_be32(&s
->bytestream
);
439 if(avcodec_check_dimensions(avctx
, s
->width
, s
->height
)){
440 s
->width
= s
->height
= 0;
443 s
->bit_depth
= *s
->bytestream
++;
444 s
->color_type
= *s
->bytestream
++;
445 s
->compression_type
= *s
->bytestream
++;
446 s
->filter_type
= *s
->bytestream
++;
447 s
->interlace_type
= *s
->bytestream
++;
448 crc
= bytestream_get_be32(&s
->bytestream
);
449 s
->state
|= PNG_IHDR
;
451 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",
452 s
->width
, s
->height
, s
->bit_depth
, s
->color_type
,
453 s
->compression_type
, s
->filter_type
, s
->interlace_type
);
456 case MKTAG('I', 'D', 'A', 'T'):
457 if (!(s
->state
& PNG_IHDR
))
459 if (!(s
->state
& PNG_IDAT
)) {
460 /* init image info */
461 avctx
->width
= s
->width
;
462 avctx
->height
= s
->height
;
464 s
->channels
= ff_png_get_nb_channels(s
->color_type
);
465 s
->bits_per_pixel
= s
->bit_depth
* s
->channels
;
466 s
->bpp
= (s
->bits_per_pixel
+ 7) >> 3;
467 s
->row_size
= (avctx
->width
* s
->bits_per_pixel
+ 7) >> 3;
469 if (s
->bit_depth
== 8 &&
470 s
->color_type
== PNG_COLOR_TYPE_RGB
) {
471 avctx
->pix_fmt
= PIX_FMT_RGB24
;
472 } else if (s
->bit_depth
== 8 &&
473 s
->color_type
== PNG_COLOR_TYPE_RGB_ALPHA
) {
474 avctx
->pix_fmt
= PIX_FMT_RGB32
;
475 } else if (s
->bit_depth
== 8 &&
476 s
->color_type
== PNG_COLOR_TYPE_GRAY
) {
477 avctx
->pix_fmt
= PIX_FMT_GRAY8
;
478 } else if (s
->bit_depth
== 16 &&
479 s
->color_type
== PNG_COLOR_TYPE_GRAY
) {
480 avctx
->pix_fmt
= PIX_FMT_GRAY16BE
;
481 } else if (s
->bit_depth
== 1 &&
482 s
->color_type
== PNG_COLOR_TYPE_GRAY
) {
483 avctx
->pix_fmt
= PIX_FMT_MONOBLACK
;
484 } else if (s
->color_type
== PNG_COLOR_TYPE_PALETTE
) {
485 avctx
->pix_fmt
= PIX_FMT_PAL8
;
490 avctx
->release_buffer(avctx
, p
);
493 if(avctx
->get_buffer(avctx
, p
) < 0){
494 av_log(avctx
, AV_LOG_ERROR
, "get_buffer() failed\n");
497 p
->pict_type
= FF_I_TYPE
;
499 p
->interlaced_frame
= !!s
->interlace_type
;
501 /* compute the compressed row size */
502 if (!s
->interlace_type
) {
503 s
->crow_size
= s
->row_size
+ 1;
506 s
->pass_row_size
= ff_png_pass_row_size(s
->pass
,
509 s
->crow_size
= s
->pass_row_size
+ 1;
512 av_log(avctx
, AV_LOG_DEBUG
, "row_size=%d crow_size =%d\n",
513 s
->row_size
, s
->crow_size
);
515 s
->image_buf
= p
->data
[0];
516 s
->image_linesize
= p
->linesize
[0];
517 /* copy the palette if needed */
518 if (s
->color_type
== PNG_COLOR_TYPE_PALETTE
)
519 memcpy(p
->data
[1], s
->palette
, 256 * sizeof(uint32_t));
520 /* empty row is used if differencing to the first row */
521 s
->last_row
= av_mallocz(s
->row_size
);
524 if (s
->interlace_type
||
525 s
->color_type
== PNG_COLOR_TYPE_RGB_ALPHA
) {
526 s
->tmp_row
= av_malloc(s
->row_size
);
531 crow_buf_base
= av_malloc(s
->row_size
+ 16);
535 /* we want crow_buf+1 to be 16-byte aligned */
536 s
->crow_buf
= crow_buf_base
+ 15;
537 s
->zstream
.avail_out
= s
->crow_size
;
538 s
->zstream
.next_out
= s
->crow_buf
;
540 s
->state
|= PNG_IDAT
;
541 if (png_decode_idat(s
, length
) < 0)
544 crc
= bytestream_get_be32(&s
->bytestream
);
546 case MKTAG('P', 'L', 'T', 'E'):
550 if ((length
% 3) != 0 || length
> 256 * 3)
552 /* read the palette */
555 r
= *s
->bytestream
++;
556 g
= *s
->bytestream
++;
557 b
= *s
->bytestream
++;
558 s
->palette
[i
] = (0xff << 24) | (r
<< 16) | (g
<< 8) | b
;
561 s
->palette
[i
] = (0xff << 24);
563 s
->state
|= PNG_PLTE
;
564 crc
= bytestream_get_be32(&s
->bytestream
);
567 case MKTAG('t', 'R', 'N', 'S'):
571 /* read the transparency. XXX: Only palette mode supported */
572 if (s
->color_type
!= PNG_COLOR_TYPE_PALETTE
||
574 !(s
->state
& PNG_PLTE
))
576 for(i
=0;i
<length
;i
++) {
577 v
= *s
->bytestream
++;
578 s
->palette
[i
] = (s
->palette
[i
] & 0x00ffffff) | (v
<< 24);
580 crc
= bytestream_get_be32(&s
->bytestream
);
583 case MKTAG('I', 'E', 'N', 'D'):
584 if (!(s
->state
& PNG_ALLIMAGE
))
586 crc
= bytestream_get_be32(&s
->bytestream
);
591 s
->bytestream
+= length
+ 4;
596 /* handle p-frames only if a predecessor frame is available */
597 if(s
->last_picture
->data
[0] != NULL
) {
598 if(!(avpkt
->flags
& PKT_FLAG_KEY
)) {
600 uint8_t *pd
= s
->current_picture
->data
[0];
601 uint8_t *pd_last
= s
->last_picture
->data
[0];
603 for(j
=0; j
< s
->height
; j
++) {
604 for(i
=0; i
< s
->width
* s
->bpp
; i
++) {
607 pd
+= s
->image_linesize
;
608 pd_last
+= s
->image_linesize
;
613 *picture
= *s
->current_picture
;
614 *data_size
= sizeof(AVFrame
);
616 ret
= s
->bytestream
- s
->bytestream_start
;
618 inflateEnd(&s
->zstream
);
619 av_free(crow_buf_base
);
621 av_freep(&s
->last_row
);
622 av_freep(&s
->tmp_row
);
629 static av_cold
int png_dec_init(AVCodecContext
*avctx
){
630 PNGDecContext
*s
= avctx
->priv_data
;
632 s
->current_picture
= &s
->picture1
;
633 s
->last_picture
= &s
->picture2
;
634 avcodec_get_frame_defaults(&s
->picture1
);
635 avcodec_get_frame_defaults(&s
->picture2
);
636 dsputil_init(&s
->dsp
, avctx
);
641 AVCodec png_decoder
= {
645 sizeof(PNGDecContext
),
650 0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
652 .long_name
= NULL_IF_CONFIG_SMALL("PNG image"),