c2ac4901d7f9e4a9850c3e5fc35c829317244432
[libav.git] / libavcodec / pngenc.c
1 /*
2 * PNG image format
3 * Copyright (c) 2003 Fabrice Bellard
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21 #include "avcodec.h"
22 #include "bytestream.h"
23 #include "dsputil.h"
24 #include "png.h"
25
26 /* TODO:
27 * - add 2, 4 and 16 bit depth support
28 */
29
30 #include <zlib.h>
31
32 //#define DEBUG
33
34 #define IOBUF_SIZE 4096
35
36 typedef struct PNGEncContext {
37 DSPContext dsp;
38
39 uint8_t *bytestream;
40 uint8_t *bytestream_start;
41 uint8_t *bytestream_end;
42 AVFrame picture;
43
44 int filter_type;
45
46 z_stream zstream;
47 uint8_t buf[IOBUF_SIZE];
48 } PNGEncContext;
49
50 static void png_get_interlaced_row(uint8_t *dst, int row_size,
51 int bits_per_pixel, int pass,
52 const uint8_t *src, int width)
53 {
54 int x, mask, dst_x, j, b, bpp;
55 uint8_t *d;
56 const uint8_t *s;
57
58 mask = ff_png_pass_mask[pass];
59 switch(bits_per_pixel) {
60 case 1:
61 memset(dst, 0, row_size);
62 dst_x = 0;
63 for(x = 0; x < width; x++) {
64 j = (x & 7);
65 if ((mask << j) & 0x80) {
66 b = (src[x >> 3] >> (7 - j)) & 1;
67 dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
68 dst_x++;
69 }
70 }
71 break;
72 default:
73 bpp = bits_per_pixel >> 3;
74 d = dst;
75 s = src;
76 for(x = 0; x < width; x++) {
77 j = x & 7;
78 if ((mask << j) & 0x80) {
79 memcpy(d, s, bpp);
80 d += bpp;
81 }
82 s += bpp;
83 }
84 break;
85 }
86 }
87
88 static void sub_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
89 {
90 int i;
91 for(i = 0; i < w; i++) {
92 int a, b, c, p, pa, pb, pc;
93
94 a = src[i - bpp];
95 b = top[i];
96 c = top[i - bpp];
97
98 p = b - c;
99 pc = a - c;
100
101 pa = abs(p);
102 pb = abs(pc);
103 pc = abs(p + pc);
104
105 if (pa <= pb && pa <= pc)
106 p = a;
107 else if (pb <= pc)
108 p = b;
109 else
110 p = c;
111 dst[i] = src[i] - p;
112 }
113 }
114
115 static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
116 uint8_t *src, uint8_t *top, int size, int bpp)
117 {
118 int i;
119
120 switch(filter_type) {
121 case PNG_FILTER_VALUE_NONE:
122 memcpy(dst, src, size);
123 break;
124 case PNG_FILTER_VALUE_SUB:
125 dsp->diff_bytes(dst, src, src-bpp, size);
126 memcpy(dst, src, bpp);
127 break;
128 case PNG_FILTER_VALUE_UP:
129 dsp->diff_bytes(dst, src, top, size);
130 break;
131 case PNG_FILTER_VALUE_AVG:
132 for(i = 0; i < bpp; i++)
133 dst[i] = src[i] - (top[i] >> 1);
134 for(; i < size; i++)
135 dst[i] = src[i] - ((src[i-bpp] + top[i]) >> 1);
136 break;
137 case PNG_FILTER_VALUE_PAETH:
138 for(i = 0; i < bpp; i++)
139 dst[i] = src[i] - top[i];
140 sub_png_paeth_prediction(dst+i, src+i, top+i, size-i, bpp);
141 break;
142 }
143 }
144
145 static uint8_t *png_choose_filter(PNGEncContext *s, uint8_t *dst,
146 uint8_t *src, uint8_t *top, int size, int bpp)
147 {
148 int pred = s->filter_type;
149 assert(bpp || !pred);
150 if(!top && pred)
151 pred = PNG_FILTER_VALUE_SUB;
152 if(pred == PNG_FILTER_VALUE_MIXED) {
153 int i;
154 int cost, bcost = INT_MAX;
155 uint8_t *buf1 = dst, *buf2 = dst + size + 16;
156 for(pred=0; pred<5; pred++) {
157 png_filter_row(&s->dsp, buf1+1, pred, src, top, size, bpp);
158 buf1[0] = pred;
159 cost = 0;
160 for(i=0; i<=size; i++)
161 cost += abs((int8_t)buf1[i]);
162 if(cost < bcost) {
163 bcost = cost;
164 FFSWAP(uint8_t*, buf1, buf2);
165 }
166 }
167 return buf2;
168 } else {
169 png_filter_row(&s->dsp, dst+1, pred, src, top, size, bpp);
170 dst[0] = pred;
171 return dst;
172 }
173 }
174
175 static void convert_from_rgb32(uint8_t *dst, const uint8_t *src, int width)
176 {
177 uint8_t *d;
178 int j;
179 unsigned int v;
180
181 d = dst;
182 for(j = 0; j < width; j++) {
183 v = ((const uint32_t *)src)[j];
184 d[0] = v >> 16;
185 d[1] = v >> 8;
186 d[2] = v;
187 d[3] = v >> 24;
188 d += 4;
189 }
190 }
191
192 static void png_write_chunk(uint8_t **f, uint32_t tag,
193 const uint8_t *buf, int length)
194 {
195 uint32_t crc;
196 uint8_t tagbuf[4];
197
198 bytestream_put_be32(f, length);
199 crc = crc32(0, Z_NULL, 0);
200 AV_WL32(tagbuf, tag);
201 crc = crc32(crc, tagbuf, 4);
202 bytestream_put_be32(f, av_bswap32(tag));
203 if (length > 0) {
204 crc = crc32(crc, buf, length);
205 memcpy(*f, buf, length);
206 *f += length;
207 }
208 bytestream_put_be32(f, crc);
209 }
210
211 /* XXX: do filtering */
212 static int png_write_row(PNGEncContext *s, const uint8_t *data, int size)
213 {
214 int ret;
215
216 s->zstream.avail_in = size;
217 s->zstream.next_in = (uint8_t *)data;
218 while (s->zstream.avail_in > 0) {
219 ret = deflate(&s->zstream, Z_NO_FLUSH);
220 if (ret != Z_OK)
221 return -1;
222 if (s->zstream.avail_out == 0) {
223 if(s->bytestream_end - s->bytestream > IOBUF_SIZE + 100)
224 png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
225 s->zstream.avail_out = IOBUF_SIZE;
226 s->zstream.next_out = s->buf;
227 }
228 }
229 return 0;
230 }
231
232 static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
233 PNGEncContext *s = avctx->priv_data;
234 AVFrame *pict = data;
235 AVFrame * const p= &s->picture;
236 int bit_depth, color_type, y, len, row_size, ret, is_progressive;
237 int bits_per_pixel, pass_row_size;
238 int compression_level;
239 uint8_t *ptr, *top;
240 uint8_t *crow_base = NULL, *crow_buf, *crow;
241 uint8_t *progressive_buf = NULL;
242 uint8_t *rgba_buf = NULL;
243 uint8_t *top_buf = NULL;
244
245 *p = *pict;
246 p->pict_type= AV_PICTURE_TYPE_I;
247 p->key_frame= 1;
248
249 s->bytestream_start=
250 s->bytestream= buf;
251 s->bytestream_end= buf+buf_size;
252
253 is_progressive = !!(avctx->flags & CODEC_FLAG_INTERLACED_DCT);
254 switch(avctx->pix_fmt) {
255 case PIX_FMT_RGB32:
256 bit_depth = 8;
257 color_type = PNG_COLOR_TYPE_RGB_ALPHA;
258 break;
259 case PIX_FMT_RGB24:
260 bit_depth = 8;
261 color_type = PNG_COLOR_TYPE_RGB;
262 break;
263 case PIX_FMT_GRAY8:
264 bit_depth = 8;
265 color_type = PNG_COLOR_TYPE_GRAY;
266 break;
267 case PIX_FMT_MONOBLACK:
268 bit_depth = 1;
269 color_type = PNG_COLOR_TYPE_GRAY;
270 break;
271 case PIX_FMT_PAL8:
272 bit_depth = 8;
273 color_type = PNG_COLOR_TYPE_PALETTE;
274 break;
275 default:
276 return -1;
277 }
278 bits_per_pixel = ff_png_get_nb_channels(color_type) * bit_depth;
279 row_size = (avctx->width * bits_per_pixel + 7) >> 3;
280
281 s->zstream.zalloc = ff_png_zalloc;
282 s->zstream.zfree = ff_png_zfree;
283 s->zstream.opaque = NULL;
284 compression_level = avctx->compression_level == FF_COMPRESSION_DEFAULT ?
285 Z_DEFAULT_COMPRESSION :
286 av_clip(avctx->compression_level, 0, 9);
287 ret = deflateInit2(&s->zstream, compression_level,
288 Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
289 if (ret != Z_OK)
290 return -1;
291 crow_base = av_malloc((row_size + 32) << (s->filter_type == PNG_FILTER_VALUE_MIXED));
292 if (!crow_base)
293 goto fail;
294 crow_buf = crow_base + 15; // pixel data should be aligned, but there's a control byte before it
295 if (is_progressive) {
296 progressive_buf = av_malloc(row_size + 1);
297 if (!progressive_buf)
298 goto fail;
299 }
300 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
301 rgba_buf = av_malloc(row_size + 1);
302 if (!rgba_buf)
303 goto fail;
304 }
305 if (is_progressive || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
306 top_buf = av_malloc(row_size + 1);
307 if (!top_buf)
308 goto fail;
309 }
310
311 /* write png header */
312 memcpy(s->bytestream, ff_pngsig, 8);
313 s->bytestream += 8;
314
315 AV_WB32(s->buf, avctx->width);
316 AV_WB32(s->buf + 4, avctx->height);
317 s->buf[8] = bit_depth;
318 s->buf[9] = color_type;
319 s->buf[10] = 0; /* compression type */
320 s->buf[11] = 0; /* filter type */
321 s->buf[12] = is_progressive; /* interlace type */
322
323 png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
324
325 /* put the palette if needed */
326 if (color_type == PNG_COLOR_TYPE_PALETTE) {
327 int has_alpha, alpha, i;
328 unsigned int v;
329 uint32_t *palette;
330 uint8_t *alpha_ptr;
331
332 palette = (uint32_t *)p->data[1];
333 ptr = s->buf;
334 alpha_ptr = s->buf + 256 * 3;
335 has_alpha = 0;
336 for(i = 0; i < 256; i++) {
337 v = palette[i];
338 alpha = v >> 24;
339 if (alpha && alpha != 0xff)
340 has_alpha = 1;
341 *alpha_ptr++ = alpha;
342 bytestream_put_be24(&ptr, v);
343 }
344 png_write_chunk(&s->bytestream, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
345 if (has_alpha) {
346 png_write_chunk(&s->bytestream, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
347 }
348 }
349
350 /* now put each row */
351 s->zstream.avail_out = IOBUF_SIZE;
352 s->zstream.next_out = s->buf;
353 if (is_progressive) {
354 int pass;
355
356 for(pass = 0; pass < NB_PASSES; pass++) {
357 /* NOTE: a pass is completely omited if no pixels would be
358 output */
359 pass_row_size = ff_png_pass_row_size(pass, bits_per_pixel, avctx->width);
360 if (pass_row_size > 0) {
361 top = NULL;
362 for(y = 0; y < avctx->height; y++) {
363 if ((ff_png_pass_ymask[pass] << (y & 7)) & 0x80) {
364 ptr = p->data[0] + y * p->linesize[0];
365 FFSWAP(uint8_t*, progressive_buf, top_buf);
366 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
367 convert_from_rgb32(rgba_buf, ptr, avctx->width);
368 ptr = rgba_buf;
369 }
370 png_get_interlaced_row(progressive_buf, pass_row_size,
371 bits_per_pixel, pass,
372 ptr, avctx->width);
373 crow = png_choose_filter(s, crow_buf, progressive_buf, top, pass_row_size, bits_per_pixel>>3);
374 png_write_row(s, crow, pass_row_size + 1);
375 top = progressive_buf;
376 }
377 }
378 }
379 }
380 } else {
381 top = NULL;
382 for(y = 0; y < avctx->height; y++) {
383 ptr = p->data[0] + y * p->linesize[0];
384 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
385 FFSWAP(uint8_t*, rgba_buf, top_buf);
386 convert_from_rgb32(rgba_buf, ptr, avctx->width);
387 ptr = rgba_buf;
388 }
389 crow = png_choose_filter(s, crow_buf, ptr, top, row_size, bits_per_pixel>>3);
390 png_write_row(s, crow, row_size + 1);
391 top = ptr;
392 }
393 }
394 /* compress last bytes */
395 for(;;) {
396 ret = deflate(&s->zstream, Z_FINISH);
397 if (ret == Z_OK || ret == Z_STREAM_END) {
398 len = IOBUF_SIZE - s->zstream.avail_out;
399 if (len > 0 && s->bytestream_end - s->bytestream > len + 100) {
400 png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
401 }
402 s->zstream.avail_out = IOBUF_SIZE;
403 s->zstream.next_out = s->buf;
404 if (ret == Z_STREAM_END)
405 break;
406 } else {
407 goto fail;
408 }
409 }
410 png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
411
412 ret = s->bytestream - s->bytestream_start;
413 the_end:
414 av_free(crow_base);
415 av_free(progressive_buf);
416 av_free(rgba_buf);
417 av_free(top_buf);
418 deflateEnd(&s->zstream);
419 return ret;
420 fail:
421 ret = -1;
422 goto the_end;
423 }
424
425 static av_cold int png_enc_init(AVCodecContext *avctx){
426 PNGEncContext *s = avctx->priv_data;
427
428 avcodec_get_frame_defaults(&s->picture);
429 avctx->coded_frame= &s->picture;
430 dsputil_init(&s->dsp, avctx);
431
432 s->filter_type = av_clip(avctx->prediction_method, PNG_FILTER_VALUE_NONE, PNG_FILTER_VALUE_MIXED);
433 if(avctx->pix_fmt == PIX_FMT_MONOBLACK)
434 s->filter_type = PNG_FILTER_VALUE_NONE;
435
436 return 0;
437 }
438
439 AVCodec ff_png_encoder = {
440 "png",
441 AVMEDIA_TYPE_VIDEO,
442 CODEC_ID_PNG,
443 sizeof(PNGEncContext),
444 png_enc_init,
445 encode_frame,
446 NULL, //encode_end,
447 .pix_fmts= (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB32, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_MONOBLACK, PIX_FMT_NONE},
448 .long_name= NULL_IF_CONFIG_SMALL("PNG image"),
449 };