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1
/*
2
 * PNG image format
3
 * Copyright (c) 2003 Fabrice Bellard.
4
 *
5
 * This file is part of FFmpeg.
6
 *
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.
11
 *
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.
16
 *
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
20
 */
21
#include "avformat.h"
22

    
23
/* TODO:
24
 * - add 2, 4 and 16 bit depth support
25
 * - use filters when generating a png (better compression)
26
 */
27

    
28
#include <zlib.h>
29

    
30
//#define DEBUG
31

    
32
#define PNG_COLOR_MASK_PALETTE    1
33
#define PNG_COLOR_MASK_COLOR      2
34
#define PNG_COLOR_MASK_ALPHA      4
35

    
36
#define PNG_COLOR_TYPE_GRAY 0
37
#define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
38
#define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
39
#define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
40
#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
41

    
42
#define PNG_FILTER_VALUE_NONE  0
43
#define PNG_FILTER_VALUE_SUB   1
44
#define PNG_FILTER_VALUE_UP    2
45
#define PNG_FILTER_VALUE_AVG   3
46
#define PNG_FILTER_VALUE_PAETH 4
47

    
48
#define PNG_IHDR      0x0001
49
#define PNG_IDAT      0x0002
50
#define PNG_ALLIMAGE  0x0004
51
#define PNG_PLTE      0x0008
52

    
53
#define NB_PASSES 7
54

    
55
#define IOBUF_SIZE 4096
56

    
57
typedef struct PNGDecodeState {
58
    int state;
59
    int width, height;
60
    int bit_depth;
61
    int color_type;
62
    int compression_type;
63
    int interlace_type;
64
    int filter_type;
65
    int channels;
66
    int bits_per_pixel;
67
    int bpp;
68

    
69
    uint8_t *image_buf;
70
    int image_linesize;
71
    uint32_t palette[256];
72
    uint8_t *crow_buf;
73
    uint8_t *last_row;
74
    uint8_t *tmp_row;
75
    int pass;
76
    int crow_size; /* compressed row size (include filter type) */
77
    int row_size; /* decompressed row size */
78
    int pass_row_size; /* decompress row size of the current pass */
79
    int y;
80
    z_stream zstream;
81
} PNGDecodeState;
82

    
83
static const uint8_t pngsig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
84

    
85
/* Mask to determine which y pixels are valid in a pass */
86
static const uint8_t png_pass_ymask[NB_PASSES] = {
87
    0x80, 0x80, 0x08, 0x88, 0x22, 0xaa, 0x55,
88
};
89

    
90
/* Mask to determine which y pixels can be written in a pass */
91
static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
92
    0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55,
93
};
94

    
95
/* minimum x value */
96
static const uint8_t png_pass_xmin[NB_PASSES] = {
97
    0, 4, 0, 2, 0, 1, 0
98
};
99

    
100
/* x shift to get row width */
101
static const uint8_t png_pass_xshift[NB_PASSES] = {
102
    3, 3, 2, 2, 1, 1, 0
103
};
104

    
105
/* Mask to determine which pixels are valid in a pass */
106
static const uint8_t png_pass_mask[NB_PASSES] = {
107
    0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff
108
};
109

    
110
/* Mask to determine which pixels to overwrite while displaying */
111
static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
112
    0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
113
};
114

    
115
static int png_probe(AVProbeData *pd)
116
{
117
    if (pd->buf_size >= 8 &&
118
        memcmp(pd->buf, pngsig, 8) == 0)
119
        return AVPROBE_SCORE_MAX;
120
    else
121
        return 0;
122
}
123

    
124
static void *png_zalloc(void *opaque, unsigned int items, unsigned int size)
125
{
126
    return av_malloc(items * size);
127
}
128

    
129
static void png_zfree(void *opaque, void *ptr)
130
{
131
    av_free(ptr);
132
}
133

    
134
static int png_get_nb_channels(int color_type)
135
{
136
    int channels;
137
    channels = 1;
138
    if ((color_type & (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)) ==
139
        PNG_COLOR_MASK_COLOR)
140
        channels = 3;
141
    if (color_type & PNG_COLOR_MASK_ALPHA)
142
        channels++;
143
    return channels;
144
}
145

    
146
/* compute the row size of an interleaved pass */
147
static int png_pass_row_size(int pass, int bits_per_pixel, int width)
148
{
149
    int shift, xmin, pass_width;
150

    
151
    xmin = png_pass_xmin[pass];
152
    if (width <= xmin)
153
        return 0;
154
    shift = png_pass_xshift[pass];
155
    pass_width = (width - xmin + (1 << shift) - 1) >> shift;
156
    return (pass_width * bits_per_pixel + 7) >> 3;
157
}
158

    
159
/* NOTE: we try to construct a good looking image at each pass. width
160
   is the original image width. We also do pixel format convertion at
161
   this stage */
162
static void png_put_interlaced_row(uint8_t *dst, int width,
163
                                   int bits_per_pixel, int pass,
164
                                   int color_type, const uint8_t *src)
165
{
166
    int x, mask, dsp_mask, j, src_x, b, bpp;
167
    uint8_t *d;
168
    const uint8_t *s;
169

    
170
    mask = png_pass_mask[pass];
171
    dsp_mask = png_pass_dsp_mask[pass];
172
    switch(bits_per_pixel) {
173
    case 1:
174
        /* we must intialize the line to zero before writing to it */
175
        if (pass == 0)
176
            memset(dst, 0, (width + 7) >> 3);
177
        src_x = 0;
178
        for(x = 0; x < width; x++) {
179
            j = (x & 7);
180
            if ((dsp_mask << j) & 0x80) {
181
                b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
182
                dst[x >> 3] |= b << (7 - j);
183
            }
184
            if ((mask << j) & 0x80)
185
                src_x++;
186
        }
187
        break;
188
    default:
189
        bpp = bits_per_pixel >> 3;
190
        d = dst;
191
        s = src;
192
        if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
193
            for(x = 0; x < width; x++) {
194
                j = x & 7;
195
                if ((dsp_mask << j) & 0x80) {
196
                    *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
197
                }
198
                d += bpp;
199
                if ((mask << j) & 0x80)
200
                    s += bpp;
201
            }
202
        } else {
203
            for(x = 0; x < width; x++) {
204
                j = x & 7;
205
                if ((dsp_mask << j) & 0x80) {
206
                    memcpy(d, s, bpp);
207
                }
208
                d += bpp;
209
                if ((mask << j) & 0x80)
210
                    s += bpp;
211
            }
212
        }
213
        break;
214
    }
215
}
216

    
217
static void png_get_interlaced_row(uint8_t *dst, int row_size,
218
                                   int bits_per_pixel, int pass,
219
                                   const uint8_t *src, int width)
220
{
221
    int x, mask, dst_x, j, b, bpp;
222
    uint8_t *d;
223
    const uint8_t *s;
224

    
225
    mask = png_pass_mask[pass];
226
    switch(bits_per_pixel) {
227
    case 1:
228
        memset(dst, 0, row_size);
229
        dst_x = 0;
230
        for(x = 0; x < width; x++) {
231
            j = (x & 7);
232
            if ((mask << j) & 0x80) {
233
                b = (src[x >> 3] >> (7 - j)) & 1;
234
                dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
235
                dst_x++;
236
            }
237
        }
238
        break;
239
    default:
240
        bpp = bits_per_pixel >> 3;
241
        d = dst;
242
        s = src;
243
        for(x = 0; x < width; x++) {
244
            j = x & 7;
245
            if ((mask << j) & 0x80) {
246
                memcpy(d, s, bpp);
247
                d += bpp;
248
            }
249
            s += bpp;
250
        }
251
        break;
252
    }
253
}
254

    
255
/* XXX: optimize */
256
/* NOTE: 'dst' can be equal to 'last' */
257
static void png_filter_row(uint8_t *dst, int filter_type,
258
                           uint8_t *src, uint8_t *last, int size, int bpp)
259
{
260
    int i, p;
261

    
262
    switch(filter_type) {
263
    case PNG_FILTER_VALUE_NONE:
264
        memcpy(dst, src, size);
265
        break;
266
    case PNG_FILTER_VALUE_SUB:
267
        for(i = 0; i < bpp; i++) {
268
            dst[i] = src[i];
269
        }
270
        for(i = bpp; i < size; i++) {
271
            p = dst[i - bpp];
272
            dst[i] = p + src[i];
273
        }
274
        break;
275
    case PNG_FILTER_VALUE_UP:
276
        for(i = 0; i < size; i++) {
277
            p = last[i];
278
            dst[i] = p + src[i];
279
        }
280
        break;
281
    case PNG_FILTER_VALUE_AVG:
282
        for(i = 0; i < bpp; i++) {
283
            p = (last[i] >> 1);
284
            dst[i] = p + src[i];
285
        }
286
        for(i = bpp; i < size; i++) {
287
            p = ((dst[i - bpp] + last[i]) >> 1);
288
            dst[i] = p + src[i];
289
        }
290
        break;
291
    case PNG_FILTER_VALUE_PAETH:
292
        for(i = 0; i < bpp; i++) {
293
            p = last[i];
294
            dst[i] = p + src[i];
295
        }
296
        for(i = bpp; i < size; i++) {
297
            int a, b, c, pa, pb, pc;
298

    
299
            a = dst[i - bpp];
300
            b = last[i];
301
            c = last[i - bpp];
302

    
303
            p = b - c;
304
            pc = a - c;
305

    
306
            pa = abs(p);
307
            pb = abs(pc);
308
            pc = abs(p + pc);
309

    
310
            if (pa <= pb && pa <= pc)
311
                p = a;
312
            else if (pb <= pc)
313
                p = b;
314
            else
315
                p = c;
316
            dst[i] = p + src[i];
317
        }
318
        break;
319
    }
320
}
321

    
322
static void convert_from_rgba32(uint8_t *dst, const uint8_t *src, int width)
323
{
324
    uint8_t *d;
325
    int j;
326
    unsigned int v;
327

    
328
    d = dst;
329
    for(j = 0; j < width; j++) {
330
        v = ((const uint32_t *)src)[j];
331
        d[0] = v >> 16;
332
        d[1] = v >> 8;
333
        d[2] = v;
334
        d[3] = v >> 24;
335
        d += 4;
336
    }
337
}
338

    
339
static void convert_to_rgba32(uint8_t *dst, const uint8_t *src, int width)
340
{
341
    int j;
342
    unsigned int r, g, b, a;
343

    
344
    for(j = 0;j < width; j++) {
345
        r = src[0];
346
        g = src[1];
347
        b = src[2];
348
        a = src[3];
349
        *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
350
        dst += 4;
351
        src += 4;
352
    }
353
}
354

    
355
/* process exactly one decompressed row */
356
static void png_handle_row(PNGDecodeState *s)
357
{
358
    uint8_t *ptr, *last_row;
359
    int got_line;
360

    
361
    if (!s->interlace_type) {
362
        ptr = s->image_buf + s->image_linesize * s->y;
363
        /* need to swap bytes correctly for RGB_ALPHA */
364
        if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
365
            png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
366
                           s->last_row, s->row_size, s->bpp);
367
            memcpy(s->last_row, s->tmp_row, s->row_size);
368
            convert_to_rgba32(ptr, s->tmp_row, s->width);
369
        } else {
370
            /* in normal case, we avoid one copy */
371
            if (s->y == 0)
372
                last_row = s->last_row;
373
            else
374
                last_row = ptr - s->image_linesize;
375

    
376
            png_filter_row(ptr, s->crow_buf[0], s->crow_buf + 1,
377
                           last_row, s->row_size, s->bpp);
378
        }
379
        s->y++;
380
        if (s->y == s->height) {
381
            s->state |= PNG_ALLIMAGE;
382
        }
383
    } else {
384
        got_line = 0;
385
        for(;;) {
386
            ptr = s->image_buf + s->image_linesize * s->y;
387
            if ((png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
388
                /* if we already read one row, it is time to stop to
389
                   wait for the next one */
390
                if (got_line)
391
                    break;
392
                png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
393
                               s->last_row, s->pass_row_size, s->bpp);
394
                memcpy(s->last_row, s->tmp_row, s->pass_row_size);
395
                got_line = 1;
396
            }
397
            if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
398
                /* NOTE: rgba32 is handled directly in png_put_interlaced_row */
399
                png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
400
                                       s->color_type, s->last_row);
401
            }
402
            s->y++;
403
            if (s->y == s->height) {
404
                for(;;) {
405
                    if (s->pass == NB_PASSES - 1) {
406
                        s->state |= PNG_ALLIMAGE;
407
                        goto the_end;
408
                    } else {
409
                        s->pass++;
410
                        s->y = 0;
411
                        s->pass_row_size = png_pass_row_size(s->pass,
412
                                                             s->bits_per_pixel,
413
                                                             s->width);
414
                        s->crow_size = s->pass_row_size + 1;
415
                        if (s->pass_row_size != 0)
416
                            break;
417
                        /* skip pass if empty row */
418
                    }
419
                }
420
            }
421
        }
422
    the_end: ;
423
    }
424
}
425

    
426
static int png_decode_idat(PNGDecodeState *s, ByteIOContext *f, int length)
427
{
428
    uint8_t buf[IOBUF_SIZE];
429
    int buf_size;
430
    int ret;
431
    while (length > 0) {
432
        /* read the buffer */
433
        buf_size = IOBUF_SIZE;
434
        if (buf_size > length)
435
            buf_size = length;
436
        ret = get_buffer(f, buf, buf_size);
437
        if (ret != buf_size)
438
            return -1;
439
        s->zstream.avail_in = buf_size;
440
        s->zstream.next_in = buf;
441
        /* decode one line if possible */
442
        while (s->zstream.avail_in > 0) {
443
            ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
444
            if (ret != Z_OK && ret != Z_STREAM_END) {
445
                return -1;
446
            }
447
            if (s->zstream.avail_out == 0) {
448
                if (!(s->state & PNG_ALLIMAGE)) {
449
                    png_handle_row(s);
450
                }
451
                s->zstream.avail_out = s->crow_size;
452
                s->zstream.next_out = s->crow_buf;
453
            }
454
        }
455
        length -= buf_size;
456
    }
457
    return 0;
458
}
459

    
460
static int png_read(ByteIOContext *f,
461
                    int (*alloc_cb)(void *opaque, AVImageInfo *info), void *opaque)
462
{
463
    AVImageInfo info1, *info = &info1;
464
    PNGDecodeState s1, *s = &s1;
465
    uint32_t tag, length;
466
    int ret, crc;
467
    uint8_t buf[8];
468

    
469
    /* check signature */
470
    ret = get_buffer(f, buf, 8);
471
    if (ret != 8)
472
        return -1;
473
    if (memcmp(buf, pngsig, 8) != 0)
474
        return -1;
475
    memset(s, 0, sizeof(PNGDecodeState));
476
    /* init the zlib */
477
    s->zstream.zalloc = png_zalloc;
478
    s->zstream.zfree = png_zfree;
479
    s->zstream.opaque = NULL;
480
    ret = inflateInit(&s->zstream);
481
    if (ret != Z_OK)
482
        return -1;
483
    for(;;) {
484
        if (url_feof(f))
485
            goto fail;
486
        length = get_be32(f);
487
        if (length > 0x7fffffff)
488
            goto fail;
489
        tag = get_le32(f);
490
#ifdef DEBUG
491
        printf("png: tag=%c%c%c%c length=%u\n",
492
               (tag & 0xff),
493
               ((tag >> 8) & 0xff),
494
               ((tag >> 16) & 0xff),
495
               ((tag >> 24) & 0xff), length);
496
#endif
497
        switch(tag) {
498
        case MKTAG('I', 'H', 'D', 'R'):
499
            if (length != 13)
500
                goto fail;
501
            s->width = get_be32(f);
502
            s->height = get_be32(f);
503
            s->bit_depth = get_byte(f);
504
            s->color_type = get_byte(f);
505
            s->compression_type = get_byte(f);
506
            s->filter_type = get_byte(f);
507
            s->interlace_type = get_byte(f);
508
            crc = get_be32(f);
509
            s->state |= PNG_IHDR;
510
#ifdef DEBUG
511
            printf("width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
512
                   s->width, s->height, s->bit_depth, s->color_type,
513
                   s->compression_type, s->filter_type, s->interlace_type);
514
#endif
515
            break;
516
        case MKTAG('I', 'D', 'A', 'T'):
517
            if (!(s->state & PNG_IHDR))
518
                goto fail;
519
            if (!(s->state & PNG_IDAT)) {
520
                /* init image info */
521
                info->width = s->width;
522
                info->height = s->height;
523
                info->interleaved = (s->interlace_type != 0);
524

    
525
                s->channels = png_get_nb_channels(s->color_type);
526
                s->bits_per_pixel = s->bit_depth * s->channels;
527
                s->bpp = (s->bits_per_pixel + 7) >> 3;
528
                s->row_size = (info->width * s->bits_per_pixel + 7) >> 3;
529

    
530
                if (s->bit_depth == 8 &&
531
                    s->color_type == PNG_COLOR_TYPE_RGB) {
532
                    info->pix_fmt = PIX_FMT_RGB24;
533
                } else if (s->bit_depth == 8 &&
534
                           s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
535
                    info->pix_fmt = PIX_FMT_RGBA32;
536
                } else if (s->bit_depth == 8 &&
537
                           s->color_type == PNG_COLOR_TYPE_GRAY) {
538
                    info->pix_fmt = PIX_FMT_GRAY8;
539
                } else if (s->bit_depth == 1 &&
540
                           s->color_type == PNG_COLOR_TYPE_GRAY) {
541
                    info->pix_fmt = PIX_FMT_MONOBLACK;
542
                } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
543
                    info->pix_fmt = PIX_FMT_PAL8;
544
                } else {
545
                    goto fail;
546
                }
547
                ret = alloc_cb(opaque, info);
548
                if (ret)
549
                    goto the_end;
550

    
551
                /* compute the compressed row size */
552
                if (!s->interlace_type) {
553
                    s->crow_size = s->row_size + 1;
554
                } else {
555
                    s->pass = 0;
556
                    s->pass_row_size = png_pass_row_size(s->pass,
557
                                                         s->bits_per_pixel,
558
                                                         s->width);
559
                    s->crow_size = s->pass_row_size + 1;
560
                }
561
#ifdef DEBUG
562
                printf("row_size=%d crow_size =%d\n",
563
                       s->row_size, s->crow_size);
564
#endif
565
                s->image_buf = info->pict.data[0];
566
                s->image_linesize = info->pict.linesize[0];
567
                /* copy the palette if needed */
568
                if (s->color_type == PNG_COLOR_TYPE_PALETTE)
569
                    memcpy(info->pict.data[1], s->palette, 256 * sizeof(uint32_t));
570
                /* empty row is used if differencing to the first row */
571
                s->last_row = av_mallocz(s->row_size);
572
                if (!s->last_row)
573
                    goto fail;
574
                if (s->interlace_type ||
575
                    s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
576
                    s->tmp_row = av_malloc(s->row_size);
577
                    if (!s->tmp_row)
578
                        goto fail;
579
                }
580
                /* compressed row */
581
                s->crow_buf = av_malloc(s->row_size + 1);
582
                if (!s->crow_buf)
583
                    goto fail;
584
                s->zstream.avail_out = s->crow_size;
585
                s->zstream.next_out = s->crow_buf;
586
            }
587
            s->state |= PNG_IDAT;
588
            if (png_decode_idat(s, f, length) < 0)
589
                goto fail;
590
            /* skip crc */
591
            crc = get_be32(f);
592
            break;
593
        case MKTAG('P', 'L', 'T', 'E'):
594
            {
595
                int n, i, r, g, b;
596

    
597
                if ((length % 3) != 0 || length > 256 * 3)
598
                    goto skip_tag;
599
                /* read the palette */
600
                n = length / 3;
601
                for(i=0;i<n;i++) {
602
                    r = get_byte(f);
603
                    g = get_byte(f);
604
                    b = get_byte(f);
605
                    s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
606
                }
607
                for(;i<256;i++) {
608
                    s->palette[i] = (0xff << 24);
609
                }
610
                s->state |= PNG_PLTE;
611
                crc = get_be32(f);
612
            }
613
            break;
614
        case MKTAG('t', 'R', 'N', 'S'):
615
            {
616
                int v, i;
617

    
618
                /* read the transparency. XXX: Only palette mode supported */
619
                if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
620
                    length > 256 ||
621
                    !(s->state & PNG_PLTE))
622
                    goto skip_tag;
623
                for(i=0;i<length;i++) {
624
                    v = get_byte(f);
625
                    s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
626
                }
627
                crc = get_be32(f);
628
            }
629
            break;
630
        case MKTAG('I', 'E', 'N', 'D'):
631
            if (!(s->state & PNG_ALLIMAGE))
632
                goto fail;
633
            crc = get_be32(f);
634
            goto exit_loop;
635
        default:
636
            /* skip tag */
637
        skip_tag:
638
            url_fskip(f, length + 4);
639
            break;
640
        }
641
    }
642
 exit_loop:
643
    ret = 0;
644
 the_end:
645
    inflateEnd(&s->zstream);
646
    av_free(s->crow_buf);
647
    av_free(s->last_row);
648
    av_free(s->tmp_row);
649
    return ret;
650
 fail:
651
    ret = -1;
652
    goto the_end;
653
}
654

    
655
static void png_write_chunk(ByteIOContext *f, uint32_t tag,
656
                            const uint8_t *buf, int length)
657
{
658
    uint32_t crc;
659
    uint8_t tagbuf[4];
660

    
661
    put_be32(f, length);
662
    crc = crc32(0, Z_NULL, 0);
663
    tagbuf[0] = tag;
664
    tagbuf[1] = tag >> 8;
665
    tagbuf[2] = tag >> 16;
666
    tagbuf[3] = tag >> 24;
667
    crc = crc32(crc, tagbuf, 4);
668
    put_le32(f, tag);
669
    if (length > 0) {
670
        crc = crc32(crc, buf, length);
671
        put_buffer(f, buf, length);
672
    }
673
    put_be32(f, crc);
674
}
675

    
676
/* XXX: use avcodec generic function ? */
677
static void to_be32(uint8_t *p, uint32_t v)
678
{
679
    p[0] = v >> 24;
680
    p[1] = v >> 16;
681
    p[2] = v >> 8;
682
    p[3] = v;
683
}
684

    
685
typedef struct PNGEncodeState {
686
    ByteIOContext *f;
687
    z_stream zstream;
688
    uint8_t buf[IOBUF_SIZE];
689
} PNGEncodeState;
690

    
691

    
692
/* XXX: do filtering */
693
static int png_write_row(PNGEncodeState *s, const uint8_t *data, int size)
694
{
695
    int ret;
696

    
697
    s->zstream.avail_in = size;
698
    s->zstream.next_in = (uint8_t *)data;
699
    while (s->zstream.avail_in > 0) {
700
        ret = deflate(&s->zstream, Z_NO_FLUSH);
701
        if (ret != Z_OK)
702
            return -1;
703
        if (s->zstream.avail_out == 0) {
704
            png_write_chunk(s->f, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
705
            s->zstream.avail_out = IOBUF_SIZE;
706
            s->zstream.next_out = s->buf;
707
        }
708
    }
709
    return 0;
710
}
711

    
712
static int png_write(ByteIOContext *f, AVImageInfo *info)
713
{
714
    PNGEncodeState s1, *s = &s1;
715
    int bit_depth, color_type, y, len, row_size, ret, is_progressive;
716
    int bits_per_pixel, pass_row_size;
717
    uint8_t *ptr;
718
    uint8_t *crow_buf = NULL;
719
    uint8_t *tmp_buf = NULL;
720

    
721
    s->f = f;
722
    is_progressive = info->interleaved;
723
    switch(info->pix_fmt) {
724
    case PIX_FMT_RGBA32:
725
        bit_depth = 8;
726
        color_type = PNG_COLOR_TYPE_RGB_ALPHA;
727
        break;
728
    case PIX_FMT_RGB24:
729
        bit_depth = 8;
730
        color_type = PNG_COLOR_TYPE_RGB;
731
        break;
732
    case PIX_FMT_GRAY8:
733
        bit_depth = 8;
734
        color_type = PNG_COLOR_TYPE_GRAY;
735
        break;
736
    case PIX_FMT_MONOBLACK:
737
        bit_depth = 1;
738
        color_type = PNG_COLOR_TYPE_GRAY;
739
        break;
740
    case PIX_FMT_PAL8:
741
        bit_depth = 8;
742
        color_type = PNG_COLOR_TYPE_PALETTE;
743
        break;
744
    default:
745
        return -1;
746
    }
747
    bits_per_pixel = png_get_nb_channels(color_type) * bit_depth;
748
    row_size = (info->width * bits_per_pixel + 7) >> 3;
749

    
750
    s->zstream.zalloc = png_zalloc;
751
    s->zstream.zfree = png_zfree;
752
    s->zstream.opaque = NULL;
753
    ret = deflateInit2(&s->zstream, Z_DEFAULT_COMPRESSION,
754
                       Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
755
    if (ret != Z_OK)
756
        return -1;
757
    crow_buf = av_malloc(row_size + 1);
758
    if (!crow_buf)
759
        goto fail;
760
    if (is_progressive) {
761
        tmp_buf = av_malloc(row_size + 1);
762
        if (!tmp_buf)
763
            goto fail;
764
    }
765

    
766
    /* write png header */
767
    put_buffer(f, pngsig, 8);
768

    
769
    to_be32(s->buf, info->width);
770
    to_be32(s->buf + 4, info->height);
771
    s->buf[8] = bit_depth;
772
    s->buf[9] = color_type;
773
    s->buf[10] = 0; /* compression type */
774
    s->buf[11] = 0; /* filter type */
775
    s->buf[12] = is_progressive; /* interlace type */
776

    
777
    png_write_chunk(f, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
778

    
779
    /* put the palette if needed */
780
    if (color_type == PNG_COLOR_TYPE_PALETTE) {
781
        int has_alpha, alpha, i;
782
        unsigned int v;
783
        uint32_t *palette;
784
        uint8_t *alpha_ptr;
785

    
786
        palette = (uint32_t *)info->pict.data[1];
787
        ptr = s->buf;
788
        alpha_ptr = s->buf + 256 * 3;
789
        has_alpha = 0;
790
        for(i = 0; i < 256; i++) {
791
            v = palette[i];
792
            alpha = v >> 24;
793
            if (alpha != 0xff)
794
                has_alpha = 1;
795
            *alpha_ptr++ = alpha;
796
            ptr[0] = v >> 16;
797
            ptr[1] = v >> 8;
798
            ptr[2] = v;
799
            ptr += 3;
800
        }
801
        png_write_chunk(f, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
802
        if (has_alpha) {
803
            png_write_chunk(f, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
804
        }
805
    }
806

    
807
    /* now put each row */
808
    s->zstream.avail_out = IOBUF_SIZE;
809
    s->zstream.next_out = s->buf;
810
    if (is_progressive) {
811
        uint8_t *ptr1;
812
        int pass;
813

    
814
        for(pass = 0; pass < NB_PASSES; pass++) {
815
            /* NOTE: a pass is completely omited if no pixels would be
816
               output */
817
            pass_row_size = png_pass_row_size(pass, bits_per_pixel, info->width);
818
            if (pass_row_size > 0) {
819
                for(y = 0; y < info->height; y++) {
820
                    if ((png_pass_ymask[pass] << (y & 7)) & 0x80) {
821
                        ptr = info->pict.data[0] + y * info->pict.linesize[0];
822
                        if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
823
                            convert_from_rgba32(tmp_buf, ptr, info->width);
824
                            ptr1 = tmp_buf;
825
                        } else {
826
                            ptr1 = ptr;
827
                        }
828
                        png_get_interlaced_row(crow_buf + 1, pass_row_size,
829
                                               bits_per_pixel, pass,
830
                                               ptr1, info->width);
831
                        crow_buf[0] = PNG_FILTER_VALUE_NONE;
832
                        png_write_row(s, crow_buf, pass_row_size + 1);
833
                    }
834
                }
835
            }
836
        }
837
    } else {
838
        for(y = 0; y < info->height; y++) {
839
            ptr = info->pict.data[0] + y * info->pict.linesize[0];
840
            if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
841
                convert_from_rgba32(crow_buf + 1, ptr, info->width);
842
            else
843
                memcpy(crow_buf + 1, ptr, row_size);
844
            crow_buf[0] = PNG_FILTER_VALUE_NONE;
845
            png_write_row(s, crow_buf, row_size + 1);
846
        }
847
    }
848
    /* compress last bytes */
849
    for(;;) {
850
        ret = deflate(&s->zstream, Z_FINISH);
851
        if (ret == Z_OK || ret == Z_STREAM_END) {
852
            len = IOBUF_SIZE - s->zstream.avail_out;
853
            if (len > 0) {
854
                png_write_chunk(f, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
855
            }
856
            s->zstream.avail_out = IOBUF_SIZE;
857
            s->zstream.next_out = s->buf;
858
            if (ret == Z_STREAM_END)
859
                break;
860
        } else {
861
            goto fail;
862
        }
863
    }
864
    png_write_chunk(f, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
865

    
866
    put_flush_packet(f);
867
    ret = 0;
868
 the_end:
869
    av_free(crow_buf);
870
    av_free(tmp_buf);
871
    deflateEnd(&s->zstream);
872
    return ret;
873
 fail:
874
    ret = -1;
875
    goto the_end;
876
}
877

    
878
AVImageFormat png_image_format = {
879
    "png",
880
    "png",
881
    png_probe,
882
    png_read,
883
    (1 << PIX_FMT_RGBA32) | (1 << PIX_FMT_RGB24) | (1 << PIX_FMT_GRAY8) |
884
    (1 << PIX_FMT_MONOBLACK) | (1 << PIX_FMT_PAL8),
885
    png_write,
886
    AVIMAGE_INTERLEAVED,
887
};