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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /**
20  * @file
21  * misc image utilities
22  */
23 
24 #include "avassert.h"
25 #include "common.h"
26 #include "imgutils.h"
27 #include "imgutils_internal.h"
28 #include "internal.h"
29 #include "intreadwrite.h"
30 #include "log.h"
31 #include "mathematics.h"
32 #include "pixdesc.h"
33 #include "rational.h"
34 
av_image_fill_max_pixsteps(int max_pixsteps[4],int max_pixstep_comps[4],const AVPixFmtDescriptor * pixdesc)35 void av_image_fill_max_pixsteps(int max_pixsteps[4], int max_pixstep_comps[4],
36                                 const AVPixFmtDescriptor *pixdesc)
37 {
38     int i;
39     memset(max_pixsteps, 0, 4*sizeof(max_pixsteps[0]));
40     if (max_pixstep_comps)
41         memset(max_pixstep_comps, 0, 4*sizeof(max_pixstep_comps[0]));
42 
43     for (i = 0; i < 4; i++) {
44         const AVComponentDescriptor *comp = &(pixdesc->comp[i]);
45         if (comp->step > max_pixsteps[comp->plane]) {
46             max_pixsteps[comp->plane] = comp->step;
47             if (max_pixstep_comps)
48                 max_pixstep_comps[comp->plane] = i;
49         }
50     }
51 }
52 
53 static inline
image_get_linesize(int width,int plane,int max_step,int max_step_comp,const AVPixFmtDescriptor * desc)54 int image_get_linesize(int width, int plane,
55                        int max_step, int max_step_comp,
56                        const AVPixFmtDescriptor *desc)
57 {
58     int s, shifted_w, linesize;
59 
60     if (!desc)
61         return AVERROR(EINVAL);
62 
63     if (width < 0)
64         return AVERROR(EINVAL);
65     s = (max_step_comp == 1 || max_step_comp == 2) ? desc->log2_chroma_w : 0;
66     shifted_w = ((width + (1 << s) - 1)) >> s;
67     if (shifted_w && max_step > INT_MAX / shifted_w)
68         return AVERROR(EINVAL);
69     linesize = max_step * shifted_w;
70 
71     if (desc->flags & AV_PIX_FMT_FLAG_BITSTREAM)
72         linesize = (linesize + 7) >> 3;
73     return linesize;
74 }
75 
av_image_get_linesize(enum AVPixelFormat pix_fmt,int width,int plane)76 int av_image_get_linesize(enum AVPixelFormat pix_fmt, int width, int plane)
77 {
78     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
79     int max_step     [4];       /* max pixel step for each plane */
80     int max_step_comp[4];       /* the component for each plane which has the max pixel step */
81 
82     if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
83         return AVERROR(EINVAL);
84 
85     av_image_fill_max_pixsteps(max_step, max_step_comp, desc);
86     return image_get_linesize(width, plane, max_step[plane], max_step_comp[plane], desc);
87 }
88 
av_image_fill_linesizes(int linesizes[4],enum AVPixelFormat pix_fmt,int width)89 int av_image_fill_linesizes(int linesizes[4], enum AVPixelFormat pix_fmt, int width)
90 {
91     int i, ret;
92     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
93     int max_step     [4];       /* max pixel step for each plane */
94     int max_step_comp[4];       /* the component for each plane which has the max pixel step */
95 
96     memset(linesizes, 0, 4*sizeof(linesizes[0]));
97 
98     if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
99         return AVERROR(EINVAL);
100 
101     av_image_fill_max_pixsteps(max_step, max_step_comp, desc);
102     for (i = 0; i < 4; i++) {
103         if ((ret = image_get_linesize(width, i, max_step[i], max_step_comp[i], desc)) < 0)
104             return ret;
105         linesizes[i] = ret;
106     }
107 
108     return 0;
109 }
110 
av_image_fill_plane_sizes(size_t sizes[4],enum AVPixelFormat pix_fmt,int height,const ptrdiff_t linesizes[4])111 int av_image_fill_plane_sizes(size_t sizes[4], enum AVPixelFormat pix_fmt,
112                               int height, const ptrdiff_t linesizes[4])
113 {
114     int i, has_plane[4] = { 0 };
115 
116     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
117     memset(sizes    , 0, sizeof(sizes[0])*4);
118 
119     if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
120         return AVERROR(EINVAL);
121 
122     if (linesizes[0] > SIZE_MAX / height)
123         return AVERROR(EINVAL);
124     sizes[0] = linesizes[0] * (size_t)height;
125 
126     if (desc->flags & AV_PIX_FMT_FLAG_PAL ||
127         desc->flags & FF_PSEUDOPAL) {
128         sizes[1] = 256 * 4; /* palette is stored here as 256 32 bits words */
129         return 0;
130     }
131 
132     for (i = 0; i < 4; i++)
133         has_plane[desc->comp[i].plane] = 1;
134 
135     for (i = 1; i < 4 && has_plane[i]; i++) {
136         int h, s = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
137         h = (height + (1 << s) - 1) >> s;
138         if (linesizes[i] > SIZE_MAX / h)
139             return AVERROR(EINVAL);
140         sizes[i] = (size_t)h * linesizes[i];
141     }
142 
143     return 0;
144 }
145 
av_image_fill_pointers(uint8_t * data[4],enum AVPixelFormat pix_fmt,int height,uint8_t * ptr,const int linesizes[4])146 int av_image_fill_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt, int height,
147                            uint8_t *ptr, const int linesizes[4])
148 {
149     int i, ret;
150     ptrdiff_t linesizes1[4];
151     size_t sizes[4];
152 
153     memset(data     , 0, sizeof(data[0])*4);
154 
155     for (i = 0; i < 4; i++)
156         linesizes1[i] = linesizes[i];
157 
158     ret = av_image_fill_plane_sizes(sizes, pix_fmt, height, linesizes1);
159     if (ret < 0)
160         return ret;
161 
162     ret = 0;
163     for (i = 0; i < 4; i++) {
164         if (sizes[i] > INT_MAX - ret)
165             return AVERROR(EINVAL);
166         ret += sizes[i];
167     }
168 
169     data[0] = ptr;
170     for (i = 1; i < 4 && sizes[i]; i++)
171         data[i] = data[i - 1] + sizes[i - 1];
172 
173     return ret;
174 }
175 
avpriv_set_systematic_pal2(uint32_t pal[256],enum AVPixelFormat pix_fmt)176 int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt)
177 {
178     int i;
179 
180     for (i = 0; i < 256; i++) {
181         int r, g, b;
182 
183         switch (pix_fmt) {
184         case AV_PIX_FMT_RGB8:
185             r = (i>>5    )*36;
186             g = ((i>>2)&7)*36;
187             b = (i&3     )*85;
188             break;
189         case AV_PIX_FMT_BGR8:
190             b = (i>>6    )*85;
191             g = ((i>>3)&7)*36;
192             r = (i&7     )*36;
193             break;
194         case AV_PIX_FMT_RGB4_BYTE:
195             r = (i>>3    )*255;
196             g = ((i>>1)&3)*85;
197             b = (i&1     )*255;
198             break;
199         case AV_PIX_FMT_BGR4_BYTE:
200             b = (i>>3    )*255;
201             g = ((i>>1)&3)*85;
202             r = (i&1     )*255;
203             break;
204         case AV_PIX_FMT_GRAY8:
205             r = b = g = i;
206             break;
207         default:
208             return AVERROR(EINVAL);
209         }
210         pal[i] = b + (g << 8) + (r << 16) + (0xFFU << 24);
211     }
212 
213     return 0;
214 }
215 
av_image_alloc(uint8_t * pointers[4],int linesizes[4],int w,int h,enum AVPixelFormat pix_fmt,int align)216 int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
217                    int w, int h, enum AVPixelFormat pix_fmt, int align)
218 {
219     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
220     int i, ret;
221     ptrdiff_t linesizes1[4];
222     size_t total_size, sizes[4];
223     uint8_t *buf;
224 
225     if (!desc)
226         return AVERROR(EINVAL);
227 
228     if ((ret = av_image_check_size(w, h, 0, NULL)) < 0)
229         return ret;
230     if ((ret = av_image_fill_linesizes(linesizes, pix_fmt, align>7 ? FFALIGN(w, 8) : w)) < 0)
231         return ret;
232 
233     for (i = 0; i < 4; i++) {
234         linesizes[i] = FFALIGN(linesizes[i], align);
235         linesizes1[i] = linesizes[i];
236     }
237 
238     if ((ret = av_image_fill_plane_sizes(sizes, pix_fmt, h, linesizes1)) < 0)
239         return ret;
240     total_size = align;
241     for (i = 0; i < 4; i++) {
242         if (total_size > SIZE_MAX - sizes[i])
243             return AVERROR(EINVAL);
244         total_size += sizes[i];
245     }
246     buf = av_malloc(total_size);
247     if (!buf)
248         return AVERROR(ENOMEM);
249     if ((ret = av_image_fill_pointers(pointers, pix_fmt, h, buf, linesizes)) < 0) {
250         av_free(buf);
251         return ret;
252     }
253     if (desc->flags & AV_PIX_FMT_FLAG_PAL || (desc->flags & FF_PSEUDOPAL && pointers[1])) {
254         avpriv_set_systematic_pal2((uint32_t*)pointers[1], pix_fmt);
255         if (align < 4) {
256             av_log(NULL, AV_LOG_ERROR, "Formats with a palette require a minimum alignment of 4\n");
257             av_free(buf);
258             return AVERROR(EINVAL);
259         }
260     }
261 
262     if ((desc->flags & AV_PIX_FMT_FLAG_PAL ||
263          desc->flags & FF_PSEUDOPAL) && pointers[1] &&
264         pointers[1] - pointers[0] > linesizes[0] * h) {
265         /* zero-initialize the padding before the palette */
266         memset(pointers[0] + linesizes[0] * h, 0,
267                pointers[1] - pointers[0] - linesizes[0] * h);
268     }
269 
270     return ret;
271 }
272 
273 typedef struct ImgUtils {
274     const AVClass *class;
275     int   log_offset;
276     void *log_ctx;
277 } ImgUtils;
278 
279 static const AVClass imgutils_class = {
280     .class_name                = "IMGUTILS",
281     .item_name                 = av_default_item_name,
282     .option                    = NULL,
283     .version                   = LIBAVUTIL_VERSION_INT,
284     .log_level_offset_offset   = offsetof(ImgUtils, log_offset),
285     .parent_log_context_offset = offsetof(ImgUtils, log_ctx),
286 };
287 
av_image_check_size2(unsigned int w,unsigned int h,int64_t max_pixels,enum AVPixelFormat pix_fmt,int log_offset,void * log_ctx)288 int av_image_check_size2(unsigned int w, unsigned int h, int64_t max_pixels, enum AVPixelFormat pix_fmt, int log_offset, void *log_ctx)
289 {
290     ImgUtils imgutils = {
291         .class      = &imgutils_class,
292         .log_offset = log_offset,
293         .log_ctx    = log_ctx,
294     };
295     int64_t stride = av_image_get_linesize(pix_fmt, w, 0);
296     if (stride <= 0)
297         stride = 8LL*w;
298     stride += 128*8;
299 
300     if ((int)w<=0 || (int)h<=0 || stride >= INT_MAX || stride*(uint64_t)(h+128) >= INT_MAX) {
301         av_log(&imgutils, AV_LOG_ERROR, "Picture size %ux%u is invalid\n", w, h);
302         return AVERROR(EINVAL);
303     }
304 
305     if (max_pixels < INT64_MAX) {
306         if (w*(int64_t)h > max_pixels) {
307             av_log(&imgutils, AV_LOG_ERROR,
308                     "Picture size %ux%u exceeds specified max pixel count %"PRId64", see the documentation if you wish to increase it\n",
309                     w, h, max_pixels);
310             return AVERROR(EINVAL);
311         }
312     }
313 
314     return 0;
315 }
316 
av_image_check_size(unsigned int w,unsigned int h,int log_offset,void * log_ctx)317 int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
318 {
319     return av_image_check_size2(w, h, INT64_MAX, AV_PIX_FMT_NONE, log_offset, log_ctx);
320 }
321 
av_image_check_sar(unsigned int w,unsigned int h,AVRational sar)322 int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar)
323 {
324     int64_t scaled_dim;
325 
326     if (sar.den <= 0 || sar.num < 0)
327         return AVERROR(EINVAL);
328 
329     if (!sar.num || sar.num == sar.den)
330         return 0;
331 
332     if (sar.num < sar.den)
333         scaled_dim = av_rescale_rnd(w, sar.num, sar.den, AV_ROUND_ZERO);
334     else
335         scaled_dim = av_rescale_rnd(h, sar.den, sar.num, AV_ROUND_ZERO);
336 
337     if (scaled_dim > 0)
338         return 0;
339 
340     return AVERROR(EINVAL);
341 }
342 
image_copy_plane(uint8_t * dst,ptrdiff_t dst_linesize,const uint8_t * src,ptrdiff_t src_linesize,ptrdiff_t bytewidth,int height)343 static void image_copy_plane(uint8_t       *dst, ptrdiff_t dst_linesize,
344                              const uint8_t *src, ptrdiff_t src_linesize,
345                              ptrdiff_t bytewidth, int height)
346 {
347     if (!dst || !src)
348         return;
349     av_assert0(FFABS(src_linesize) >= bytewidth);
350     av_assert0(FFABS(dst_linesize) >= bytewidth);
351     for (;height > 0; height--) {
352         memcpy(dst, src, bytewidth);
353         dst += dst_linesize;
354         src += src_linesize;
355     }
356 }
357 
image_copy_plane_uc_from(uint8_t * dst,ptrdiff_t dst_linesize,const uint8_t * src,ptrdiff_t src_linesize,ptrdiff_t bytewidth,int height)358 static void image_copy_plane_uc_from(uint8_t       *dst, ptrdiff_t dst_linesize,
359                                      const uint8_t *src, ptrdiff_t src_linesize,
360                                      ptrdiff_t bytewidth, int height)
361 {
362     int ret = -1;
363 
364 #if ARCH_X86
365     ret = ff_image_copy_plane_uc_from_x86(dst, dst_linesize, src, src_linesize,
366                                           bytewidth, height);
367 #endif
368 
369     if (ret < 0)
370         image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
371 }
372 
av_image_copy_plane(uint8_t * dst,int dst_linesize,const uint8_t * src,int src_linesize,int bytewidth,int height)373 void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
374                          const uint8_t *src, int src_linesize,
375                          int bytewidth, int height)
376 {
377     image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
378 }
379 
image_copy(uint8_t * dst_data[4],const ptrdiff_t dst_linesizes[4],const uint8_t * src_data[4],const ptrdiff_t src_linesizes[4],enum AVPixelFormat pix_fmt,int width,int height,void (* copy_plane)(uint8_t *,ptrdiff_t,const uint8_t *,ptrdiff_t,ptrdiff_t,int))380 static void image_copy(uint8_t *dst_data[4], const ptrdiff_t dst_linesizes[4],
381                        const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
382                        enum AVPixelFormat pix_fmt, int width, int height,
383                        void (*copy_plane)(uint8_t *, ptrdiff_t, const uint8_t *,
384                                           ptrdiff_t, ptrdiff_t, int))
385 {
386     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
387 
388     if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
389         return;
390 
391     if (desc->flags & AV_PIX_FMT_FLAG_PAL ||
392         desc->flags & FF_PSEUDOPAL) {
393         copy_plane(dst_data[0], dst_linesizes[0],
394                    src_data[0], src_linesizes[0],
395                    width, height);
396         /* copy the palette */
397         if ((desc->flags & AV_PIX_FMT_FLAG_PAL) || (dst_data[1] && src_data[1]))
398             memcpy(dst_data[1], src_data[1], 4*256);
399     } else {
400         int i, planes_nb = 0;
401 
402         for (i = 0; i < desc->nb_components; i++)
403             planes_nb = FFMAX(planes_nb, desc->comp[i].plane + 1);
404 
405         for (i = 0; i < planes_nb; i++) {
406             int h = height;
407             ptrdiff_t bwidth = av_image_get_linesize(pix_fmt, width, i);
408             if (bwidth < 0) {
409                 av_log(NULL, AV_LOG_ERROR, "av_image_get_linesize failed\n");
410                 return;
411             }
412             if (i == 1 || i == 2) {
413                 h = AV_CEIL_RSHIFT(height, desc->log2_chroma_h);
414             }
415             copy_plane(dst_data[i], dst_linesizes[i],
416                        src_data[i], src_linesizes[i],
417                        bwidth, h);
418         }
419     }
420 }
421 
av_image_copy(uint8_t * dst_data[4],int dst_linesizes[4],const uint8_t * src_data[4],const int src_linesizes[4],enum AVPixelFormat pix_fmt,int width,int height)422 void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
423                    const uint8_t *src_data[4], const int src_linesizes[4],
424                    enum AVPixelFormat pix_fmt, int width, int height)
425 {
426     ptrdiff_t dst_linesizes1[4], src_linesizes1[4];
427     int i;
428 
429     for (i = 0; i < 4; i++) {
430         dst_linesizes1[i] = dst_linesizes[i];
431         src_linesizes1[i] = src_linesizes[i];
432     }
433 
434     image_copy(dst_data, dst_linesizes1, src_data, src_linesizes1, pix_fmt,
435                width, height, image_copy_plane);
436 }
437 
av_image_copy_uc_from(uint8_t * dst_data[4],const ptrdiff_t dst_linesizes[4],const uint8_t * src_data[4],const ptrdiff_t src_linesizes[4],enum AVPixelFormat pix_fmt,int width,int height)438 void av_image_copy_uc_from(uint8_t *dst_data[4], const ptrdiff_t dst_linesizes[4],
439                            const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
440                            enum AVPixelFormat pix_fmt, int width, int height)
441 {
442     image_copy(dst_data, dst_linesizes, src_data, src_linesizes, pix_fmt,
443                width, height, image_copy_plane_uc_from);
444 }
445 
av_image_fill_arrays(uint8_t * dst_data[4],int dst_linesize[4],const uint8_t * src,enum AVPixelFormat pix_fmt,int width,int height,int align)446 int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
447                          const uint8_t *src, enum AVPixelFormat pix_fmt,
448                          int width, int height, int align)
449 {
450     int ret, i;
451 
452     ret = av_image_check_size(width, height, 0, NULL);
453     if (ret < 0)
454         return ret;
455 
456     ret = av_image_fill_linesizes(dst_linesize, pix_fmt, width);
457     if (ret < 0)
458         return ret;
459 
460     for (i = 0; i < 4; i++)
461         dst_linesize[i] = FFALIGN(dst_linesize[i], align);
462 
463     return av_image_fill_pointers(dst_data, pix_fmt, height, (uint8_t *)src, dst_linesize);
464 }
465 
av_image_get_buffer_size(enum AVPixelFormat pix_fmt,int width,int height,int align)466 int av_image_get_buffer_size(enum AVPixelFormat pix_fmt,
467                              int width, int height, int align)
468 {
469     int ret, i;
470     int linesize[4];
471     ptrdiff_t aligned_linesize[4];
472     size_t sizes[4];
473     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
474     if (!desc)
475         return AVERROR(EINVAL);
476 
477     ret = av_image_check_size(width, height, 0, NULL);
478     if (ret < 0)
479         return ret;
480 
481     // do not include palette for these pseudo-paletted formats
482     if (desc->flags & FF_PSEUDOPAL)
483         return FFALIGN(width, align) * height;
484 
485     ret = av_image_fill_linesizes(linesize, pix_fmt, width);
486     if (ret < 0)
487         return ret;
488 
489     for (i = 0; i < 4; i++)
490         aligned_linesize[i] = FFALIGN(linesize[i], align);
491 
492     ret = av_image_fill_plane_sizes(sizes, pix_fmt, height, aligned_linesize);
493     if (ret < 0)
494         return ret;
495 
496     ret = 0;
497     for (i = 0; i < 4; i++) {
498         if (sizes[i] > INT_MAX - ret)
499             return AVERROR(EINVAL);
500         ret += sizes[i];
501     }
502     return ret;
503 }
504 
av_image_copy_to_buffer(uint8_t * dst,int dst_size,const uint8_t * const src_data[4],const int src_linesize[4],enum AVPixelFormat pix_fmt,int width,int height,int align)505 int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
506                             const uint8_t * const src_data[4],
507                             const int src_linesize[4],
508                             enum AVPixelFormat pix_fmt,
509                             int width, int height, int align)
510 {
511     int i, j, nb_planes = 0, linesize[4];
512     int size = av_image_get_buffer_size(pix_fmt, width, height, align);
513     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
514     int ret;
515 
516     if (size > dst_size || size < 0 || !desc)
517         return AVERROR(EINVAL);
518 
519     for (i = 0; i < desc->nb_components; i++)
520         nb_planes = FFMAX(desc->comp[i].plane, nb_planes);
521 
522     nb_planes++;
523 
524     ret = av_image_fill_linesizes(linesize, pix_fmt, width);
525     av_assert0(ret >= 0); // was checked previously
526 
527     for (i = 0; i < nb_planes; i++) {
528         int h, shift = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
529         const uint8_t *src = src_data[i];
530         h = (height + (1 << shift) - 1) >> shift;
531 
532         for (j = 0; j < h; j++) {
533             memcpy(dst, src, linesize[i]);
534             dst += FFALIGN(linesize[i], align);
535             src += src_linesize[i];
536         }
537     }
538 
539     if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
540         uint32_t *d32 = (uint32_t *)dst;
541 
542         for (i = 0; i<256; i++)
543             AV_WL32(d32 + i, AV_RN32(src_data[1] + 4*i));
544     }
545 
546     return size;
547 }
548 
549 // Fill dst[0..dst_size] with the bytes in clear[0..clear_size]. The clear
550 // bytes are repeated until dst_size is reached. If dst_size is unaligned (i.e.
551 // dst_size%clear_size!=0), the remaining data will be filled with the beginning
552 // of the clear data only.
memset_bytes(uint8_t * dst,size_t dst_size,uint8_t * clear,size_t clear_size)553 static void memset_bytes(uint8_t *dst, size_t dst_size, uint8_t *clear,
554                          size_t clear_size)
555 {
556     int same = 1;
557     int i;
558 
559     if (!clear_size)
560         return;
561 
562     // Reduce to memset() if possible.
563     for (i = 0; i < clear_size; i++) {
564         if (clear[i] != clear[0]) {
565             same = 0;
566             break;
567         }
568     }
569     if (same)
570         clear_size = 1;
571 
572     if (clear_size == 1) {
573         memset(dst, clear[0], dst_size);
574     } else {
575         if (clear_size > dst_size)
576             clear_size = dst_size;
577         memcpy(dst, clear, clear_size);
578         av_memcpy_backptr(dst + clear_size, clear_size, dst_size - clear_size);
579     }
580 }
581 
582 // Maximum size in bytes of a plane element (usually a pixel, or multiple pixels
583 // if it's a subsampled packed format).
584 #define MAX_BLOCK_SIZE 32
585 
av_image_fill_black(uint8_t * dst_data[4],const ptrdiff_t dst_linesize[4],enum AVPixelFormat pix_fmt,enum AVColorRange range,int width,int height)586 int av_image_fill_black(uint8_t *dst_data[4], const ptrdiff_t dst_linesize[4],
587                         enum AVPixelFormat pix_fmt, enum AVColorRange range,
588                         int width, int height)
589 {
590     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
591     int nb_planes = av_pix_fmt_count_planes(pix_fmt);
592     // A pixel or a group of pixels on each plane, with a value that represents black.
593     // Consider e.g. AV_PIX_FMT_UYVY422 for non-trivial cases.
594     uint8_t clear_block[4][MAX_BLOCK_SIZE] = {{0}}; // clear padding with 0
595     int clear_block_size[4] = {0};
596     ptrdiff_t plane_line_bytes[4] = {0};
597     int rgb, limited;
598     int plane, c;
599 
600     if (!desc || nb_planes < 1 || nb_planes > 4 || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
601         return AVERROR(EINVAL);
602 
603     rgb = !!(desc->flags & AV_PIX_FMT_FLAG_RGB);
604     limited = !rgb && range != AVCOL_RANGE_JPEG;
605 
606     if (desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) {
607         ptrdiff_t bytewidth = av_image_get_linesize(pix_fmt, width, 0);
608         uint8_t *data;
609         int mono = pix_fmt == AV_PIX_FMT_MONOWHITE || pix_fmt == AV_PIX_FMT_MONOBLACK;
610         int fill = pix_fmt == AV_PIX_FMT_MONOWHITE ? 0xFF : 0;
611         if (nb_planes != 1 || !(rgb || mono) || bytewidth < 1)
612             return AVERROR(EINVAL);
613 
614         if (!dst_data)
615             return 0;
616 
617         data = dst_data[0];
618 
619         // (Bitstream + alpha will be handled incorrectly - it'll remain transparent.)
620         for (;height > 0; height--) {
621             memset(data, fill, bytewidth);
622             data += dst_linesize[0];
623         }
624         return 0;
625     }
626 
627     for (c = 0; c < desc->nb_components; c++) {
628         const AVComponentDescriptor comp = desc->comp[c];
629 
630         // We try to operate on entire non-subsampled pixel groups (for
631         // AV_PIX_FMT_UYVY422 this would mean two consecutive pixels).
632         clear_block_size[comp.plane] = FFMAX(clear_block_size[comp.plane], comp.step);
633 
634         if (clear_block_size[comp.plane] > MAX_BLOCK_SIZE)
635             return AVERROR(EINVAL);
636     }
637 
638     // Create a byte array for clearing 1 pixel (sometimes several pixels).
639     for (c = 0; c < desc->nb_components; c++) {
640         const AVComponentDescriptor comp = desc->comp[c];
641         // (Multiple pixels happen e.g. with AV_PIX_FMT_UYVY422.)
642         int w = clear_block_size[comp.plane] / comp.step;
643         uint8_t *c_data[4];
644         const int c_linesize[4] = {0};
645         uint16_t src_array[MAX_BLOCK_SIZE];
646         uint16_t src = 0;
647         int x;
648 
649         if (comp.depth > 16)
650             return AVERROR(EINVAL);
651         if (!rgb && comp.depth < 8)
652             return AVERROR(EINVAL);
653         if (w < 1)
654             return AVERROR(EINVAL);
655 
656         if (c == 0 && limited) {
657             src = 16 << (comp.depth - 8);
658         } else if ((c == 1 || c == 2) && !rgb) {
659             src = 128 << (comp.depth - 8);
660         } else if (c == 3) {
661             // (Assume even limited YUV uses full range alpha.)
662             src = (1 << comp.depth) - 1;
663         }
664 
665         for (x = 0; x < w; x++)
666             src_array[x] = src;
667 
668         for (x = 0; x < 4; x++)
669             c_data[x] = &clear_block[x][0];
670 
671         av_write_image_line(src_array, c_data, c_linesize, desc, 0, 0, c, w);
672     }
673 
674     for (plane = 0; plane < nb_planes; plane++) {
675         plane_line_bytes[plane] = av_image_get_linesize(pix_fmt, width, plane);
676         if (plane_line_bytes[plane] < 0)
677             return AVERROR(EINVAL);
678     }
679 
680     if (!dst_data)
681         return 0;
682 
683     for (plane = 0; plane < nb_planes; plane++) {
684         size_t bytewidth = plane_line_bytes[plane];
685         uint8_t *data = dst_data[plane];
686         int chroma_div = plane == 1 || plane == 2 ? desc->log2_chroma_h : 0;
687         int plane_h = ((height + ( 1 << chroma_div) - 1)) >> chroma_div;
688 
689         for (; plane_h > 0; plane_h--) {
690             memset_bytes(data, bytewidth, &clear_block[plane][0], clear_block_size[plane]);
691             data += dst_linesize[plane];
692         }
693     }
694 
695     return 0;
696 }
697