1 /* read with libwebp
2 *
3 * 6/8/13
4 * - from png2vips.c
5 * 24/2/14
6 * - oops, buffer path was broken, thanks Lovell
7 * 28/2/16
8 * - add @shrink
9 * 7/11/16
10 * - support XMP/ICC/EXIF metadata
11 * 18/10/17
12 * - sniff file type from magic number
13 * 2/11/18
14 * - rework for demux API
15 * - add animated read
16 * 19/4/19
17 * - could memleak on some read errors
18 * 24/4/19
19 * - fix bg handling in animations
20 * 30/4/19
21 * - deprecate shrink, use scale instead, and make it a double ... this
22 * lets us do faster and more accurate thumbnailing
23 * 27/6/19
24 * - disable alpha output if all frame fill the canvas and are solid
25 * 6/7/19 [deftomat]
26 * - support array of delays
27 * 14/10/19
28 * - revise for source IO
29 * 27/10/21
30 * - disable shrink-on-load if we need subpixel accuracy in animations
31 */
32
33 /*
34
35 This file is part of VIPS.
36
37 VIPS is free software; you can redistribute it and/or modify
38 it under the terms of the GNU Lesser General Public License as published by
39 the Free Software Foundation; either version 2 of the License, or
40 (at your option) any later version.
41
42 This program is distributed in the hope that it will be useful,
43 but WITHOUT ANY WARRANTY; without even the implied warranty of
44 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
45 GNU Lesser General Public License for more details.
46
47 You should have received a copy of the GNU Lesser General Public License
48 along with this program; if not, write to the Free Software
49 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
50 02110-1301 USA
51
52 */
53
54 /*
55
56 These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
57
58 */
59
60 /*
61 #define DEBUG_VERBOSE
62 #define DEBUG
63 */
64
65 #ifdef HAVE_CONFIG_H
66 #include <config.h>
67 #endif /*HAVE_CONFIG_H*/
68 #include <vips/intl.h>
69
70 #ifdef HAVE_LIBWEBP
71
72 #include <stdlib.h>
73 #include <string.h>
74
75 #include <webp/decode.h>
76 #include <webp/demux.h>
77
78 #include <vips/vips.h>
79 #include <vips/internal.h>
80
81 #include "pforeign.h"
82
83 /* What we track during a read.
84 */
85 typedef struct {
86 VipsImage *out;
87 VipsSource *source;
88
89 /* The data we load, as a webp object.
90 */
91 WebPData data;
92
93 /* Load this page (frame number).
94 */
95 int page;
96
97 /* Load this many pages.
98 */
99 int n;
100
101 /* Scale-on-load factor. Use this to set frame_width.
102 */
103 double scale;
104
105 /* Size of each frame in input image coordinates.
106 */
107 int canvas_width;
108 int canvas_height;
109
110 /* Size of each frame, in scaled output image coordinates,
111 */
112 int frame_width;
113 int frame_height;
114
115 /* Size of final output image.
116 */
117 int width;
118 int height;
119
120 /* TRUE if we will save the final image as RGBA.
121 */
122 int alpha;
123
124 /* Number of frames in file.
125 */
126 int frame_count;
127
128 /* Delays between frames (in miliseconds).
129 */
130 int *delays;
131
132 /* Parse with this.
133 */
134 WebPDemuxer *demux;
135
136 /* Decoder config.
137 */
138 WebPDecoderConfig config;
139
140 /* The current accumulated frame as a VipsImage. These are the pixels
141 * we send to the output. It's a frame_width * frame_height memory
142 * image.
143 */
144 VipsImage *frame;
145
146 /* The frame number currently in @frame. Numbered from 1, so 0 means
147 * before the first frame.
148 */
149 int frame_no;
150
151 /* Iterate through the frames with this. iter.frame_num is the number
152 * of the currently loaded frame.
153 */
154 WebPIterator iter;
155
156 /* How to junk the current frame when we move on.
157 */
158 WebPMuxAnimDispose dispose_method;
159 VipsRect dispose_rect;
160 } Read;
161
162 const char *
vips__error_webp(VP8StatusCode code)163 vips__error_webp( VP8StatusCode code )
164 {
165 switch( code ) {
166 case VP8_STATUS_OK:
167 return( "VP8_STATUS_OK" );
168
169 case VP8_STATUS_OUT_OF_MEMORY:
170 return( "VP8_STATUS_OUT_OF_MEMORY" );
171
172 case VP8_STATUS_INVALID_PARAM:
173 return( "VP8_STATUS_INVALID_PARAM" );
174
175 case VP8_STATUS_BITSTREAM_ERROR:
176 return( "VP8_STATUS_BITSTREAM_ERROR" );
177
178 case VP8_STATUS_UNSUPPORTED_FEATURE:
179 return( "VP8_STATUS_UNSUPPORTED_FEATURE" );
180
181 case VP8_STATUS_SUSPENDED:
182 return( "VP8_STATUS_SUSPENDED" );
183
184 case VP8_STATUS_USER_ABORT:
185 return( "VP8_STATUS_USER_ABORT" );
186
187 case VP8_STATUS_NOT_ENOUGH_DATA:
188 return( "VP8_STATUS_NOT_ENOUGH_DATA" );
189
190 default:
191 return( "<unkown>" );
192 }
193 }
194
195 static void
vips_image_paint_area(VipsImage * image,const VipsRect * r,const VipsPel * ink)196 vips_image_paint_area( VipsImage *image, const VipsRect *r, const VipsPel *ink )
197 {
198 VipsRect valid = { 0, 0, image->Xsize, image->Ysize };
199 VipsRect ovl;
200
201 vips_rect_intersectrect( r, &valid, &ovl );
202 if( !vips_rect_isempty( &ovl ) ) {
203 int ps = VIPS_IMAGE_SIZEOF_PEL( image );
204 int ls = VIPS_IMAGE_SIZEOF_LINE( image );
205 int ws = ovl.width * ps;
206
207 VipsPel *to, *q;
208 int x, y, z;
209
210 /* We plot the first line pointwise, then memcpy() it for the
211 * subsequent lines. We need to work for RGB and RGBA, so we
212 * can't just write uint32s.
213 */
214 to = VIPS_IMAGE_ADDR( image, ovl.left, ovl.top );
215
216 q = to;
217 for( x = 0; x < ovl.width; x++ ) {
218 /* Faster than memcpy() for about ps < 20.
219 */
220 for( z = 0; z < ps; z++ )
221 q[z] = ink[z];
222
223 q += ps;
224 }
225
226 q = to + ls;
227 for( y = 1; y < ovl.height; y++ ) {
228 memcpy( q, to, ws );
229 q += ls;
230 }
231 }
232 }
233
234 /* Blend two guint8.
235 */
236 #define BLEND( X, aX, Y, aY, scale ) \
237 (((X * aX + Y * aY) * scale + (1 << 12)) >> 24)
238
239 /* Extract R, G, B, A, assuming little-endian.
240 */
241 #define getR( V ) (V & 0xff)
242 #define getG( V ) ((V >> 8) & 0xff)
243 #define getB( V ) ((V >> 16) & 0xff)
244 #define getA( V ) ((V >> 24) & 0xff)
245
246 /* Rebuild RGBA, assuming little-endian.
247 */
248 #define setRGBA( R, G, B, A ) \
249 (R | (G << 8) | (B << 16) | ((guint32) A << 24))
250
251 /* OVER blend of two unpremultiplied RGBA guint32
252 *
253 * We assume little-endian (x86), add a byteswap before this if necessary.
254 */
255 static guint32
blend_pixel(guint32 A,guint32 B)256 blend_pixel( guint32 A, guint32 B )
257 {
258 guint8 aA = getA( A );
259
260 if( aA == 0 )
261 return( B );
262
263 guint8 aB = getA( B );
264
265 guint8 fac = (aB * (255 - aA) + 127) >> 8;
266 guint8 aR = aA + fac;
267 int scale = aR == 0 ? 0 : (1 << 24) / aR;
268
269 guint8 rR = BLEND( getR( A ), aA, getR( B ), fac, scale );
270 guint8 gR = BLEND( getG( A ), aA, getG( B ), fac, scale );
271 guint8 bR = BLEND( getB( A ), aA, getB( B ), fac, scale );
272
273 return( setRGBA( rR, gR, bR, aR ) );
274 }
275
276 /* Blend sub into frame at left, top.
277 */
278 static void
vips_image_paint_image(VipsImage * frame,VipsImage * sub,int left,int top,gboolean blend)279 vips_image_paint_image( VipsImage *frame,
280 VipsImage *sub, int left, int top, gboolean blend )
281 {
282 VipsRect frame_rect = { 0, 0, frame->Xsize, frame->Ysize };
283 VipsRect sub_rect = { left, top, sub->Xsize, sub->Ysize };
284 int ps = VIPS_IMAGE_SIZEOF_PEL( frame );
285
286 VipsRect ovl;
287
288 g_assert( VIPS_IMAGE_SIZEOF_PEL( sub ) == ps );
289
290 vips_rect_intersectrect( &frame_rect, &sub_rect, &ovl );
291 if( !vips_rect_isempty( &ovl ) ) {
292 VipsPel *p, *q;
293 int x, y;
294
295 p = VIPS_IMAGE_ADDR( sub, ovl.left - left, ovl.top - top );
296 q = VIPS_IMAGE_ADDR( frame, ovl.left, ovl.top );
297
298 for( y = 0; y < ovl.height; y++ ) {
299 if( blend ) {
300 guint32 *A = (guint32 *) p;
301 guint32 *B = (guint32 *) q;
302
303 for( x = 0; x < ovl.width; x++ )
304 B[x] = blend_pixel( A[x], B[x] );
305 }
306 else
307 memcpy( (char *) q, (char *) p,
308 ovl.width * ps );
309
310 p += VIPS_IMAGE_SIZEOF_LINE( sub );
311 q += VIPS_IMAGE_SIZEOF_LINE( frame );
312 }
313 }
314 }
315
316 int
vips__iswebp_source(VipsSource * source)317 vips__iswebp_source( VipsSource *source )
318 {
319 const unsigned char *p;
320
321 /* WebP is "RIFF xxxx WEBP" at the start, so we need 12 bytes.
322 */
323 if( (p = vips_source_sniff( source, 12 )) &&
324 vips_isprefix( "RIFF", (char *) p ) &&
325 vips_isprefix( "WEBP", (char *) p + 8 ) )
326 return( 1 );
327
328 return( 0 );
329 }
330
331 static int
read_free(Read * read)332 read_free( Read *read )
333 {
334 WebPDemuxReleaseIterator( &read->iter );
335 VIPS_UNREF( read->frame );
336 VIPS_FREEF( WebPDemuxDelete, read->demux );
337 WebPFreeDecBuffer( &read->config.output );
338
339 VIPS_UNREF( read->source );
340 VIPS_FREE( read->delays );
341 VIPS_FREE( read );
342
343 return( 0 );
344 }
345
346 static void
read_close_cb(VipsImage * image,Read * read)347 read_close_cb( VipsImage *image, Read *read )
348 {
349 read_free( read );
350 }
351
352 static Read *
read_new(VipsImage * out,VipsSource * source,int page,int n,double scale)353 read_new( VipsImage *out, VipsSource *source, int page, int n, double scale )
354 {
355 Read *read;
356
357 if( !(read = VIPS_NEW( NULL, Read )) )
358 return( NULL );
359
360 read->out = out;
361 read->source = source;
362 g_object_ref( source );
363 read->page = page;
364 read->n = n;
365 read->scale = scale;
366 read->delays = NULL;
367 read->demux = NULL;
368 read->frame = NULL;
369 read->dispose_method = WEBP_MUX_DISPOSE_NONE;
370 read->frame_no = 0;
371
372 /* Everything has to stay open until read has finished, unfortunately,
373 * since webp relies on us mapping the whole file.
374 */
375 g_signal_connect( out, "close",
376 G_CALLBACK( read_close_cb ), read );
377
378 WebPInitDecoderConfig( &read->config );
379 read->config.options.use_threads = 1;
380 read->config.output.is_external_memory = 1;
381
382 if( !(read->data.bytes =
383 vips_source_map( source, &read->data.size )) )
384 return( NULL );
385
386 return( read );
387 }
388
389 /* Map vips metadata names to webp names.
390 */
391 const VipsWebPNames vips__webp_names[] = {
392 { VIPS_META_ICC_NAME, "ICCP", ICCP_FLAG },
393 { VIPS_META_EXIF_NAME, "EXIF", EXIF_FLAG },
394 { VIPS_META_XMP_NAME, "XMP ", XMP_FLAG }
395 };
396 const int vips__n_webp_names = VIPS_NUMBER( vips__webp_names );
397
398 static int
read_header(Read * read,VipsImage * out)399 read_header( Read *read, VipsImage *out )
400 {
401 int flags;
402 int i;
403
404 if( !(read->demux = WebPDemux( &read->data )) ) {
405 vips_error( "webp", "%s", _( "unable to parse image" ) );
406 return( -1 );
407 }
408
409 flags = WebPDemuxGetI( read->demux, WEBP_FF_FORMAT_FLAGS );
410
411 read->alpha = flags & ALPHA_FLAG;
412
413 /* We do everything as RGBA and then, if we can, drop the alpha on
414 * save.
415 */
416 read->config.output.colorspace = MODE_RGBA;
417
418 read->canvas_width =
419 WebPDemuxGetI( read->demux, WEBP_FF_CANVAS_WIDTH );
420 read->canvas_height =
421 WebPDemuxGetI( read->demux, WEBP_FF_CANVAS_HEIGHT );
422
423 if( flags & ANIMATION_FLAG ) {
424 int loop_count;
425 WebPIterator iter;
426
427 loop_count = WebPDemuxGetI( read->demux, WEBP_FF_LOOP_COUNT );
428 read->frame_count = WebPDemuxGetI( read->demux,
429 WEBP_FF_FRAME_COUNT );
430
431 #ifdef DEBUG
432 printf( "webp2vips: animation\n" );
433 printf( "webp2vips: loop_count = %d\n", loop_count );
434 printf( "webp2vips: frame_count = %d\n", read->frame_count );
435 #endif /*DEBUG*/
436
437 vips_image_set_int( out, "loop", loop_count );
438
439 /* DEPRECATED "gif-loop"
440 *
441 * Not the correct behavior as loop=1 became gif-loop=0
442 * but we want to keep the old behavior untouched!
443 */
444 vips_image_set_int( out, "gif-loop",
445 loop_count == 0 ? 0 : loop_count - 1 );
446
447 if( WebPDemuxGetFrame( read->demux, 1, &iter ) ) {
448 int i;
449
450 read->delays = (int *)
451 g_malloc0( read->frame_count * sizeof( int ) );
452 for( i = 0; i < read->frame_count; i++ )
453 read->delays[i] = 40;
454
455 do {
456 g_assert( iter.frame_num >= 1 &&
457 iter.frame_num <= read->frame_count );
458
459 read->delays[iter.frame_num - 1] =
460 iter.duration;
461
462 /* We need the alpha in an animation if:
463 * - any frame has transparent pixels
464 * - any frame doesn't fill the whole canvas.
465 */
466 if( iter.has_alpha ||
467 iter.width != read->canvas_width ||
468 iter.height != read->canvas_height )
469 read->alpha = TRUE;
470
471 /* We must disable shrink-on-load if any frame
472 * does not fill the whole canvas. We won't be
473 * able to shrink-on-load it to the exact
474 * position in a downsized canvas.
475 */
476 if( iter.width != read->canvas_width ||
477 iter.height != read->canvas_height )
478 read->scale = 1.0;
479 } while( WebPDemuxNextFrame( &iter ) );
480
481 vips_image_set_array_int( out,
482 "delay", read->delays, read->frame_count );
483
484 /* webp uses ms for delays, gif uses centiseconds.
485 */
486 vips_image_set_int( out, "gif-delay",
487 VIPS_RINT( read->delays[0] / 10.0 ) );
488 }
489
490 WebPDemuxReleaseIterator( &iter );
491
492 if( read->n == -1 )
493 read->n = read->frame_count - read->page;
494
495 if( read->page < 0 ||
496 read->n <= 0 ||
497 read->page + read->n > read->frame_count ) {
498 vips_error( "webp",
499 "%s", _( "bad page number" ) );
500 return( -1 );
501 }
502
503 /* Note that n-pages is the number of pages in the original,
504 * not the number of pages in the image we are writing.
505 */
506 vips_image_set_int( out, VIPS_META_N_PAGES, read->frame_count );
507 }
508
509 /* We round-to-nearest cf. pdfload etc.
510 */
511 read->frame_width = VIPS_RINT( read->canvas_width * read->scale );
512 read->frame_height = VIPS_RINT( read->canvas_height * read->scale );
513
514 #ifdef DEBUG
515 printf( "webp2vips: canvas_width = %d\n", read->canvas_width );
516 printf( "webp2vips: canvas_height = %d\n", read->canvas_height );
517 printf( "webp2vips: frame_width = %d\n", read->frame_width );
518 printf( "webp2vips: frame_height = %d\n", read->frame_height );
519 #endif /*DEBUG*/
520
521 if( flags & ANIMATION_FLAG ) {
522 /* Only set page-height if we have more than one page, or
523 * this could accidentally turn into an animated image later.
524 */
525 if( read->n > 1 )
526 vips_image_set_int( out,
527 VIPS_META_PAGE_HEIGHT, read->frame_height );
528
529 read->width = read->frame_width;
530 read->height = read->n * read->frame_height;
531 }
532 else {
533 read->width = read->frame_width;
534 read->height = read->frame_height;
535 read->frame_count = 1;
536 }
537
538 /* height can be huge if this is an animated webp image.
539 */
540 if( read->width <= 0 ||
541 read->height <= 0 ||
542 read->width > 0x3FFF ||
543 read->height >= VIPS_MAX_COORD ||
544 read->frame_width <= 0 ||
545 read->frame_height <= 0 ||
546 read->frame_width > 0x3FFF ||
547 read->frame_height > 0x3FFF ) {
548 vips_error( "webp", "%s", _( "bad image dimensions" ) );
549 return( -1 );
550 }
551
552 for( i = 0; i < vips__n_webp_names; i++ ) {
553 const char *vips = vips__webp_names[i].vips;
554 const char *webp = vips__webp_names[i].webp;
555
556 if( flags & vips__webp_names[i].flags ) {
557 WebPChunkIterator iter;
558
559 WebPDemuxGetChunk( read->demux, webp, 1, &iter );
560 vips_image_set_blob_copy( out,
561 vips, iter.chunk.bytes, iter.chunk.size );
562 WebPDemuxReleaseChunkIterator( &iter );
563 }
564 }
565
566 /* The canvas is always RGBA, we drop alpha to RGB on output if we
567 * can.
568 */
569 read->frame = vips_image_new_memory();
570 vips_image_init_fields( read->frame,
571 read->frame_width, read->frame_height, 4,
572 VIPS_FORMAT_UCHAR, VIPS_CODING_NONE,
573 VIPS_INTERPRETATION_sRGB,
574 1.0, 1.0 );
575 if( vips_image_pipelinev( read->frame,
576 VIPS_DEMAND_STYLE_THINSTRIP, NULL ) ||
577 vips_image_write_prepare( read->frame ) )
578 return( -1 );
579
580 vips_image_init_fields( out,
581 read->width, read->height,
582 read->alpha ? 4 : 3,
583 VIPS_FORMAT_UCHAR, VIPS_CODING_NONE,
584 VIPS_INTERPRETATION_sRGB,
585 1.0, 1.0 );
586 if( vips_image_pipelinev( out, VIPS_DEMAND_STYLE_THINSTRIP, NULL ) )
587 return( -1 );
588 VIPS_SETSTR( out->filename,
589 vips_connection_filename( VIPS_CONNECTION( read->source ) ) );
590
591 if( !WebPDemuxGetFrame( read->demux, 1, &read->iter ) ) {
592 vips_error( "webp",
593 "%s", _( "unable to loop through frames" ) );
594 return( -1 );
595 }
596
597 return( 0 );
598 }
599
600 /* Read a single frame -- a width * height block of pixels. This will get
601 * blended into the accumulator at some offset.
602 */
603 static VipsImage *
read_frame(Read * read,int width,int height,const guint8 * data,size_t length)604 read_frame( Read *read,
605 int width, int height, const guint8 *data, size_t length )
606 {
607 VipsImage *frame;
608
609 #ifdef DEBUG
610 printf( "read_frame:\n" );
611 #endif /*DEBUG*/
612
613 frame = vips_image_new_memory();
614 vips_image_init_fields( frame,
615 width, height, 4,
616 VIPS_FORMAT_UCHAR, VIPS_CODING_NONE,
617 VIPS_INTERPRETATION_sRGB,
618 1.0, 1.0 );
619 if( vips_image_pipelinev( frame, VIPS_DEMAND_STYLE_THINSTRIP, NULL ) ||
620 vips_image_write_prepare( frame ) ) {
621 g_object_unref( frame );
622 return( NULL );
623 }
624
625 read->config.output.u.RGBA.rgba = VIPS_IMAGE_ADDR( frame, 0, 0 );
626 read->config.output.u.RGBA.stride = VIPS_IMAGE_SIZEOF_LINE( frame );
627 read->config.output.u.RGBA.size = VIPS_IMAGE_SIZEOF_IMAGE( frame );
628 if( read->scale != 1.0 ) {
629 read->config.options.use_scaling = 1;
630 read->config.options.scaled_width = width;
631 read->config.options.scaled_height = height;
632 }
633
634 if( WebPDecode( data, length, &read->config ) != VP8_STATUS_OK ) {
635 g_object_unref( frame );
636 vips_error( "webp2vips", "%s", _( "unable to read pixels" ) );
637 return( NULL );
638 }
639
640 return( frame );
641 }
642
643 static int
read_next_frame(Read * read)644 read_next_frame( Read *read )
645 {
646 VipsImage *frame;
647 VipsRect area;
648
649 #ifdef DEBUG
650 printf( "read_next_frame:\n" );
651 #endif /*DEBUG*/
652
653 /* Area of this frame, in output image coordinates. We must rint(),
654 * since we need the same rules as the overall image scale, or we'll
655 * sometimes have missing pixels on edges.
656 */
657 area.left = VIPS_RINT( read->iter.x_offset * read->scale );
658 area.top = VIPS_RINT( read->iter.y_offset * read->scale );
659 area.width = VIPS_RINT( read->iter.width * read->scale );
660 area.height = VIPS_RINT( read->iter.height * read->scale );
661
662 /* Dispose from the previous frame.
663 */
664 if( read->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ) {
665 /* We must clear the pixels occupied by the previous webp
666 * frame (not the whole of the read frame) to 0 (transparent).
667 *
668 * We do not clear to WEBP_FF_BACKGROUND_COLOR. That's only
669 * used to composite down to RGB. Perhaps we
670 * should attach background as metadata.
671 */
672 guint32 zero = 0;
673
674 vips_image_paint_area( read->frame,
675 &read->dispose_rect, (VipsPel *) &zero );
676 }
677
678 /* Note this frame's dispose for next time.
679 */
680 read->dispose_method = read->iter.dispose_method;
681 read->dispose_rect = area;
682
683 #ifdef DEBUG
684 printf( "webp2vips: frame_num = %d\n", read->iter.frame_num );
685 printf( " left = %d\n", area.left );
686 printf( " top = %d\n", area.top );
687 printf( " width = %d\n", area.width );
688 printf( " height = %d\n", area.height );
689 printf( " duration = %d\n", read->iter.duration );
690 printf( " dispose = " );
691 if( read->iter.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND )
692 printf( "clear to background\n" );
693 else
694 printf( "none\n" );
695 printf( " has_alpha = %d\n", read->iter.has_alpha );
696 printf( " blend_method = " );
697 if( read->iter.blend_method == WEBP_MUX_BLEND )
698 printf( "blend with previous\n" );
699 else
700 printf( "don't blend\n" );
701 #endif /*DEBUG*/
702
703 if( !(frame = read_frame( read,
704 area.width, area.height,
705 read->iter.fragment.bytes, read->iter.fragment.size )) )
706 return( -1 );
707
708 /* Now blend or copy the new pixels into our accumulator.
709 */
710 vips_image_paint_image( read->frame, frame,
711 area.left, area.top,
712 read->iter.frame_num > 1 &&
713 read->iter.blend_method == WEBP_MUX_BLEND );
714
715 g_object_unref( frame );
716
717 /* If there's another frame, move on.
718 */
719 if( read->iter.frame_num < read->frame_count ) {
720 if( !WebPDemuxNextFrame( &read->iter ) ) {
721 vips_error( "webp2vips",
722 "%s", _( "not enough frames" ) );
723 return( -1 );
724 }
725 }
726
727 return( 0 );
728 }
729
730 static int
read_webp_generate(VipsRegion * or,void * seq,void * a,void * b,gboolean * stop)731 read_webp_generate( VipsRegion *or,
732 void *seq, void *a, void *b, gboolean *stop )
733 {
734 VipsRect *r = &or->valid;
735 Read *read = (Read *) a;
736
737 /* iter.frame_num numbers from 1.
738 */
739 int frame = 1 + r->top / read->frame_height + read->page;
740 int line = r->top % read->frame_height;
741
742 #ifdef DEBUG_VERBOSE
743 printf( "read_webp_generate: line %d\n", r->top );
744 #endif /*DEBUG_VERBOSE*/
745
746 g_assert( r->height == 1 );
747
748 while( read->frame_no < frame ) {
749 if( read_next_frame( read ) )
750 return( -1 );
751
752 read->frame_no += 1;
753 }
754
755 if( or->im->Bands == 4 )
756 memcpy( VIPS_REGION_ADDR( or, 0, r->top ),
757 VIPS_IMAGE_ADDR( read->frame, 0, line ),
758 VIPS_IMAGE_SIZEOF_LINE( read->frame ) );
759 else {
760 int x;
761 VipsPel *p;
762 VipsPel *q;
763
764 /* We know that alpha is solid, so we can just drop the 4th
765 * band.
766 */
767 p = VIPS_IMAGE_ADDR( read->frame, 0, line );
768 q = VIPS_REGION_ADDR( or, 0, r->top );
769 for( x = 0; x < r->width; x++ ) {
770 q[0] = p[0];
771 q[1] = p[1];
772 q[2] = p[2];
773
774 q += 3;
775 p += 4;
776 }
777 }
778
779 return( 0 );
780 }
781
782 static int
read_image(Read * read,VipsImage * out)783 read_image( Read *read, VipsImage *out )
784 {
785 VipsImage **t = (VipsImage **)
786 vips_object_local_array( VIPS_OBJECT( out ), 3 );
787
788 t[0] = vips_image_new();
789 if( read_header( read, t[0] ) )
790 return( -1 );
791
792 if( vips_image_generate( t[0],
793 NULL, read_webp_generate, NULL, read, NULL ) ||
794 vips_sequential( t[0], &t[1], NULL ) ||
795 vips_image_write( t[1], out ) )
796 return( -1 );
797
798 return( 0 );
799 }
800
801 int
vips__webp_read_header_source(VipsSource * source,VipsImage * out,int page,int n,double scale)802 vips__webp_read_header_source( VipsSource *source, VipsImage *out,
803 int page, int n, double scale )
804 {
805 Read *read;
806
807 if( !(read = read_new( out, source, page, n, scale )) ||
808 read_header( read, out ) )
809 return( -1 );
810
811 return( 0 );
812 }
813
814 int
vips__webp_read_source(VipsSource * source,VipsImage * out,int page,int n,double scale)815 vips__webp_read_source( VipsSource *source, VipsImage *out,
816 int page, int n, double scale )
817 {
818 Read *read;
819
820 if( !(read = read_new( out, source, page, n, scale )) ||
821 read_image( read, out ) )
822 return( -1 );
823
824 return( 0 );
825 }
826
827 #endif /*HAVE_LIBWEBP*/
828