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
23 #include "bytestream.h"
27 #include "libavutil/avassert.h"
28 #include "libavutil/opt.h"
32 #define IOBUF_SIZE 4096
34 typedef struct PNGEncContext {
39 uint8_t *bytestream_start;
40 uint8_t *bytestream_end;
45 uint8_t buf[IOBUF_SIZE];
46 int dpi; ///< Physical pixel density, in dots per inch, if set
47 int dpm; ///< Physical pixel density, in dots per meter, if set
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)
54 int x, mask, dst_x, j, b, bpp;
57 static const int masks[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
60 switch(bits_per_pixel) {
62 memset(dst, 0, row_size);
64 for(x = 0; x < width; x++) {
66 if ((mask << j) & 0x80) {
67 b = (src[x >> 3] >> (7 - j)) & 1;
68 dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
74 bpp = bits_per_pixel >> 3;
77 for(x = 0; x < width; x++) {
79 if ((mask << j) & 0x80) {
89 static void sub_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
92 for(i = 0; i < w; i++) {
93 int a, b, c, p, pa, pb, pc;
106 if (pa <= pb && pa <= pc)
116 static void sub_left_prediction(DSPContext *dsp, uint8_t *dst, const uint8_t *src, int bpp, int size)
118 const uint8_t *src1 = src + bpp;
119 const uint8_t *src2 = src;
122 memcpy(dst, src, bpp);
125 unaligned_w = FFMIN(32 - bpp, size);
126 for (x = 0; x < unaligned_w; x++)
127 *dst++ = *src1++ - *src2++;
129 dsp->diff_bytes(dst, src1, src2, size);
132 static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type,
133 uint8_t *src, uint8_t *top, int size, int bpp)
137 switch(filter_type) {
138 case PNG_FILTER_VALUE_NONE:
139 memcpy(dst, src, size);
141 case PNG_FILTER_VALUE_SUB:
142 sub_left_prediction(dsp, dst, src, bpp, size);
144 case PNG_FILTER_VALUE_UP:
145 dsp->diff_bytes(dst, src, top, size);
147 case PNG_FILTER_VALUE_AVG:
148 for(i = 0; i < bpp; i++)
149 dst[i] = src[i] - (top[i] >> 1);
151 dst[i] = src[i] - ((src[i-bpp] + top[i]) >> 1);
153 case PNG_FILTER_VALUE_PAETH:
154 for(i = 0; i < bpp; i++)
155 dst[i] = src[i] - top[i];
156 sub_png_paeth_prediction(dst+i, src+i, top+i, size-i, bpp);
161 static uint8_t *png_choose_filter(PNGEncContext *s, uint8_t *dst,
162 uint8_t *src, uint8_t *top, int size, int bpp)
164 int pred = s->filter_type;
165 av_assert0(bpp || !pred);
167 pred = PNG_FILTER_VALUE_SUB;
168 if(pred == PNG_FILTER_VALUE_MIXED) {
170 int cost, bcost = INT_MAX;
171 uint8_t *buf1 = dst, *buf2 = dst + size + 16;
172 for(pred=0; pred<5; pred++) {
173 png_filter_row(&s->dsp, buf1+1, pred, src, top, size, bpp);
176 for(i=0; i<=size; i++)
177 cost += abs((int8_t)buf1[i]);
180 FFSWAP(uint8_t*, buf1, buf2);
185 png_filter_row(&s->dsp, dst+1, pred, src, top, size, bpp);
191 static void png_write_chunk(uint8_t **f, uint32_t tag,
192 const uint8_t *buf, int length)
197 bytestream_put_be32(f, length);
198 crc = crc32(0, Z_NULL, 0);
199 AV_WL32(tagbuf, tag);
200 crc = crc32(crc, tagbuf, 4);
201 bytestream_put_be32(f, av_bswap32(tag));
203 crc = crc32(crc, buf, length);
204 memcpy(*f, buf, length);
207 bytestream_put_be32(f, crc);
210 /* XXX: do filtering */
211 static int png_write_row(PNGEncContext *s, const uint8_t *data, int size)
215 s->zstream.avail_in = size;
216 s->zstream.next_in = (uint8_t *)data;
217 while (s->zstream.avail_in > 0) {
218 ret = deflate(&s->zstream, Z_NO_FLUSH);
221 if (s->zstream.avail_out == 0) {
222 if(s->bytestream_end - s->bytestream > IOBUF_SIZE + 100)
223 png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
224 s->zstream.avail_out = IOBUF_SIZE;
225 s->zstream.next_out = s->buf;
231 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
232 const AVFrame *pict, int *got_packet)
234 PNGEncContext *s = avctx->priv_data;
235 const AVFrame * const p = pict;
236 int bit_depth, color_type, y, len, row_size, ret, is_progressive;
237 int bits_per_pixel, pass_row_size, enc_row_size;
238 int64_t max_packet_size;
239 int compression_level;
241 uint8_t *crow_base = NULL, *crow_buf, *crow;
242 uint8_t *progressive_buf = NULL;
243 uint8_t *top_buf = NULL;
245 is_progressive = !!(avctx->flags & CODEC_FLAG_INTERLACED_DCT);
246 switch(avctx->pix_fmt) {
247 case AV_PIX_FMT_RGBA64BE:
249 color_type = PNG_COLOR_TYPE_RGB_ALPHA;
251 case AV_PIX_FMT_RGB48BE:
253 color_type = PNG_COLOR_TYPE_RGB;
255 case AV_PIX_FMT_RGBA:
257 color_type = PNG_COLOR_TYPE_RGB_ALPHA;
259 case AV_PIX_FMT_RGB24:
261 color_type = PNG_COLOR_TYPE_RGB;
263 case AV_PIX_FMT_GRAY16BE:
265 color_type = PNG_COLOR_TYPE_GRAY;
267 case AV_PIX_FMT_GRAY8:
269 color_type = PNG_COLOR_TYPE_GRAY;
271 case AV_PIX_FMT_GRAY8A:
273 color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
275 case AV_PIX_FMT_MONOBLACK:
277 color_type = PNG_COLOR_TYPE_GRAY;
279 case AV_PIX_FMT_PAL8:
281 color_type = PNG_COLOR_TYPE_PALETTE;
286 bits_per_pixel = ff_png_get_nb_channels(color_type) * bit_depth;
287 row_size = (avctx->width * bits_per_pixel + 7) >> 3;
289 s->zstream.zalloc = ff_png_zalloc;
290 s->zstream.zfree = ff_png_zfree;
291 s->zstream.opaque = NULL;
292 compression_level = avctx->compression_level == FF_COMPRESSION_DEFAULT ?
293 Z_DEFAULT_COMPRESSION :
294 av_clip(avctx->compression_level, 0, 9);
295 ret = deflateInit2(&s->zstream, compression_level,
296 Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
300 enc_row_size = deflateBound(&s->zstream, row_size);
301 max_packet_size = avctx->height * (int64_t)(enc_row_size +
302 ((enc_row_size + IOBUF_SIZE - 1) / IOBUF_SIZE) * 12)
303 + FF_MIN_BUFFER_SIZE;
304 if (max_packet_size > INT_MAX)
305 return AVERROR(ENOMEM);
306 if ((ret = ff_alloc_packet2(avctx, pkt, max_packet_size)) < 0)
309 s->bytestream_start =
310 s->bytestream = pkt->data;
311 s->bytestream_end = pkt->data + pkt->size;
313 crow_base = av_malloc((row_size + 32) << (s->filter_type == PNG_FILTER_VALUE_MIXED));
316 crow_buf = crow_base + 15; // pixel data should be aligned, but there's a control byte before it
317 if (is_progressive) {
318 progressive_buf = av_malloc(row_size + 1);
319 if (!progressive_buf)
322 if (is_progressive) {
323 top_buf = av_malloc(row_size + 1);
328 /* write png header */
329 AV_WB64(s->bytestream, PNGSIG);
332 AV_WB32(s->buf, avctx->width);
333 AV_WB32(s->buf + 4, avctx->height);
334 s->buf[8] = bit_depth;
335 s->buf[9] = color_type;
336 s->buf[10] = 0; /* compression type */
337 s->buf[11] = 0; /* filter type */
338 s->buf[12] = is_progressive; /* interlace type */
340 png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
343 AV_WB32(s->buf, s->dpm);
344 AV_WB32(s->buf + 4, s->dpm);
345 s->buf[8] = 1; /* unit specifier is meter */
347 AV_WB32(s->buf, avctx->sample_aspect_ratio.num);
348 AV_WB32(s->buf + 4, avctx->sample_aspect_ratio.den);
349 s->buf[8] = 0; /* unit specifier is unknown */
351 png_write_chunk(&s->bytestream, MKTAG('p', 'H', 'Y', 's'), s->buf, 9);
353 /* put the palette if needed */
354 if (color_type == PNG_COLOR_TYPE_PALETTE) {
355 int has_alpha, alpha, i;
360 palette = (uint32_t *)p->data[1];
362 alpha_ptr = s->buf + 256 * 3;
364 for(i = 0; i < 256; i++) {
369 *alpha_ptr++ = alpha;
370 bytestream_put_be24(&ptr, v);
372 png_write_chunk(&s->bytestream, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
374 png_write_chunk(&s->bytestream, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
378 /* now put each row */
379 s->zstream.avail_out = IOBUF_SIZE;
380 s->zstream.next_out = s->buf;
381 if (is_progressive) {
384 for(pass = 0; pass < NB_PASSES; pass++) {
385 /* NOTE: a pass is completely omitted if no pixels would be
387 pass_row_size = ff_png_pass_row_size(pass, bits_per_pixel, avctx->width);
388 if (pass_row_size > 0) {
390 for(y = 0; y < avctx->height; y++) {
391 if ((ff_png_pass_ymask[pass] << (y & 7)) & 0x80) {
392 ptr = p->data[0] + y * p->linesize[0];
393 FFSWAP(uint8_t*, progressive_buf, top_buf);
394 png_get_interlaced_row(progressive_buf, pass_row_size,
395 bits_per_pixel, pass,
397 crow = png_choose_filter(s, crow_buf, progressive_buf, top, pass_row_size, bits_per_pixel>>3);
398 png_write_row(s, crow, pass_row_size + 1);
399 top = progressive_buf;
406 for(y = 0; y < avctx->height; y++) {
407 ptr = p->data[0] + y * p->linesize[0];
408 crow = png_choose_filter(s, crow_buf, ptr, top, row_size, bits_per_pixel>>3);
409 png_write_row(s, crow, row_size + 1);
413 /* compress last bytes */
415 ret = deflate(&s->zstream, Z_FINISH);
416 if (ret == Z_OK || ret == Z_STREAM_END) {
417 len = IOBUF_SIZE - s->zstream.avail_out;
418 if (len > 0 && s->bytestream_end - s->bytestream > len + 100) {
419 png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
421 s->zstream.avail_out = IOBUF_SIZE;
422 s->zstream.next_out = s->buf;
423 if (ret == Z_STREAM_END)
429 png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
431 pkt->size = s->bytestream - s->bytestream_start;
432 pkt->flags |= AV_PKT_FLAG_KEY;
438 av_free(progressive_buf);
440 deflateEnd(&s->zstream);
447 static av_cold int png_enc_init(AVCodecContext *avctx){
448 PNGEncContext *s = avctx->priv_data;
450 switch(avctx->pix_fmt) {
451 case AV_PIX_FMT_RGBA:
452 avctx->bits_per_coded_sample = 32;
454 case AV_PIX_FMT_RGB24:
455 avctx->bits_per_coded_sample = 24;
457 case AV_PIX_FMT_GRAY8:
458 avctx->bits_per_coded_sample = 0x28;
460 case AV_PIX_FMT_MONOBLACK:
461 avctx->bits_per_coded_sample = 1;
463 case AV_PIX_FMT_PAL8:
464 avctx->bits_per_coded_sample = 8;
467 avctx->coded_frame = av_frame_alloc();
468 if (!avctx->coded_frame)
469 return AVERROR(ENOMEM);
471 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
472 avctx->coded_frame->key_frame = 1;
474 ff_dsputil_init(&s->dsp, avctx);
476 s->filter_type = av_clip(avctx->prediction_method, PNG_FILTER_VALUE_NONE, PNG_FILTER_VALUE_MIXED);
477 if(avctx->pix_fmt == AV_PIX_FMT_MONOBLACK)
478 s->filter_type = PNG_FILTER_VALUE_NONE;
480 if (s->dpi && s->dpm) {
481 av_log(avctx, AV_LOG_ERROR, "Only one of 'dpi' or 'dpm' options should be set\n");
482 return AVERROR(EINVAL);
484 s->dpm = s->dpi * 10000 / 254;
490 static av_cold int png_enc_close(AVCodecContext *avctx)
492 av_frame_free(&avctx->coded_frame);
496 #define OFFSET(x) offsetof(PNGEncContext, x)
497 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
498 static const AVOption options[] = {
499 {"dpi", "Set image resolution (in dots per inch)", OFFSET(dpi), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE},
500 {"dpm", "Set image resolution (in dots per meter)", OFFSET(dpm), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE},
504 static const AVClass pngenc_class = {
505 .class_name = "PNG encoder",
506 .item_name = av_default_item_name,
508 .version = LIBAVUTIL_VERSION_INT,
511 AVCodec ff_png_encoder = {
513 .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
514 .type = AVMEDIA_TYPE_VIDEO,
515 .id = AV_CODEC_ID_PNG,
516 .priv_data_size = sizeof(PNGEncContext),
517 .init = png_enc_init,
518 .close = png_enc_close,
519 .encode2 = encode_frame,
520 .capabilities = CODEC_CAP_FRAME_THREADS | CODEC_CAP_INTRA_ONLY,
521 .pix_fmts = (const enum AVPixelFormat[]){
522 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA,
523 AV_PIX_FMT_RGB48BE, AV_PIX_FMT_RGBA64BE,
525 AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY8A,
527 AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE
529 .priv_class = &pngenc_class,