xref: /third_party/ffmpeg/libavutil/imgutils.c (revision cabdff1a)
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
35void 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
53static inline
54int 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
76int 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
89int 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
111int 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        sizes[1] = 256 * 4; /* palette is stored here as 256 32 bits words */
128        return 0;
129    }
130
131    for (i = 0; i < 4; i++)
132        has_plane[desc->comp[i].plane] = 1;
133
134    for (i = 1; i < 4 && has_plane[i]; i++) {
135        int h, s = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
136        h = (height + (1 << s) - 1) >> s;
137        if (linesizes[i] > SIZE_MAX / h)
138            return AVERROR(EINVAL);
139        sizes[i] = (size_t)h * linesizes[i];
140    }
141
142    return 0;
143}
144
145int av_image_fill_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt, int height,
146                           uint8_t *ptr, const int linesizes[4])
147{
148    int i, ret;
149    ptrdiff_t linesizes1[4];
150    size_t sizes[4];
151
152    memset(data     , 0, sizeof(data[0])*4);
153
154    for (i = 0; i < 4; i++)
155        linesizes1[i] = linesizes[i];
156
157    ret = av_image_fill_plane_sizes(sizes, pix_fmt, height, linesizes1);
158    if (ret < 0)
159        return ret;
160
161    ret = 0;
162    for (i = 0; i < 4; i++) {
163        if (sizes[i] > INT_MAX - ret)
164            return AVERROR(EINVAL);
165        ret += sizes[i];
166    }
167
168    if (!ptr)
169        return ret;
170
171    data[0] = ptr;
172    for (i = 1; i < 4 && sizes[i]; i++)
173        data[i] = data[i - 1] + sizes[i - 1];
174
175    return ret;
176}
177
178int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt)
179{
180    int i;
181
182    for (i = 0; i < 256; i++) {
183        int r, g, b;
184
185        switch (pix_fmt) {
186        case AV_PIX_FMT_RGB8:
187            r = (i>>5    )*36;
188            g = ((i>>2)&7)*36;
189            b = (i&3     )*85;
190            break;
191        case AV_PIX_FMT_BGR8:
192            b = (i>>6    )*85;
193            g = ((i>>3)&7)*36;
194            r = (i&7     )*36;
195            break;
196        case AV_PIX_FMT_RGB4_BYTE:
197            r = (i>>3    )*255;
198            g = ((i>>1)&3)*85;
199            b = (i&1     )*255;
200            break;
201        case AV_PIX_FMT_BGR4_BYTE:
202            b = (i>>3    )*255;
203            g = ((i>>1)&3)*85;
204            r = (i&1     )*255;
205            break;
206        case AV_PIX_FMT_GRAY8:
207            r = b = g = i;
208            break;
209        default:
210            return AVERROR(EINVAL);
211        }
212        pal[i] = b + (g << 8) + (r << 16) + (0xFFU << 24);
213    }
214
215    return 0;
216}
217
218int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
219                   int w, int h, enum AVPixelFormat pix_fmt, int align)
220{
221    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
222    int i, ret;
223    ptrdiff_t linesizes1[4];
224    size_t total_size, sizes[4];
225    uint8_t *buf;
226
227    if (!desc)
228        return AVERROR(EINVAL);
229
230    if ((ret = av_image_check_size(w, h, 0, NULL)) < 0)
231        return ret;
232    if ((ret = av_image_fill_linesizes(linesizes, pix_fmt, align>7 ? FFALIGN(w, 8) : w)) < 0)
233        return ret;
234
235    for (i = 0; i < 4; i++) {
236        linesizes[i] = FFALIGN(linesizes[i], align);
237        linesizes1[i] = linesizes[i];
238    }
239
240    if ((ret = av_image_fill_plane_sizes(sizes, pix_fmt, h, linesizes1)) < 0)
241        return ret;
242    total_size = align;
243    for (i = 0; i < 4; i++) {
244        if (total_size > SIZE_MAX - sizes[i])
245            return AVERROR(EINVAL);
246        total_size += sizes[i];
247    }
248    buf = av_malloc(total_size);
249    if (!buf)
250        return AVERROR(ENOMEM);
251    if ((ret = av_image_fill_pointers(pointers, pix_fmt, h, buf, linesizes)) < 0) {
252        av_free(buf);
253        return ret;
254    }
255    if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
256        avpriv_set_systematic_pal2((uint32_t*)pointers[1], pix_fmt);
257        if (align < 4) {
258            av_log(NULL, AV_LOG_ERROR, "Formats with a palette require a minimum alignment of 4\n");
259            av_free(buf);
260            return AVERROR(EINVAL);
261        }
262    }
263
264    if (desc->flags & AV_PIX_FMT_FLAG_PAL && pointers[1] &&
265        pointers[1] - pointers[0] > linesizes[0] * h) {
266        /* zero-initialize the padding before the palette */
267        memset(pointers[0] + linesizes[0] * h, 0,
268               pointers[1] - pointers[0] - linesizes[0] * h);
269    }
270
271    return ret;
272}
273
274typedef struct ImgUtils {
275    const AVClass *class;
276    int   log_offset;
277    void *log_ctx;
278} ImgUtils;
279
280static const AVClass imgutils_class = {
281    .class_name                = "IMGUTILS",
282    .item_name                 = av_default_item_name,
283    .option                    = NULL,
284    .version                   = LIBAVUTIL_VERSION_INT,
285    .log_level_offset_offset   = offsetof(ImgUtils, log_offset),
286    .parent_log_context_offset = offsetof(ImgUtils, log_ctx),
287};
288
289int av_image_check_size2(unsigned int w, unsigned int h, int64_t max_pixels, enum AVPixelFormat pix_fmt, int log_offset, void *log_ctx)
290{
291    ImgUtils imgutils = {
292        .class      = &imgutils_class,
293        .log_offset = log_offset,
294        .log_ctx    = log_ctx,
295    };
296    int64_t stride = av_image_get_linesize(pix_fmt, w, 0);
297    if (stride <= 0)
298        stride = 8LL*w;
299    stride += 128*8;
300
301    if ((int)w<=0 || (int)h<=0 || stride >= INT_MAX || stride*(uint64_t)(h+128) >= INT_MAX) {
302        av_log(&imgutils, AV_LOG_ERROR, "Picture size %ux%u is invalid\n", w, h);
303        return AVERROR(EINVAL);
304    }
305
306    if (max_pixels < INT64_MAX) {
307        if (w*(int64_t)h > max_pixels) {
308            av_log(&imgutils, AV_LOG_ERROR,
309                    "Picture size %ux%u exceeds specified max pixel count %"PRId64", see the documentation if you wish to increase it\n",
310                    w, h, max_pixels);
311            return AVERROR(EINVAL);
312        }
313    }
314
315    return 0;
316}
317
318int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
319{
320    return av_image_check_size2(w, h, INT64_MAX, AV_PIX_FMT_NONE, log_offset, log_ctx);
321}
322
323int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar)
324{
325    int64_t scaled_dim;
326
327    if (sar.den <= 0 || sar.num < 0)
328        return AVERROR(EINVAL);
329
330    if (!sar.num || sar.num == sar.den)
331        return 0;
332
333    if (sar.num < sar.den)
334        scaled_dim = av_rescale_rnd(w, sar.num, sar.den, AV_ROUND_ZERO);
335    else
336        scaled_dim = av_rescale_rnd(h, sar.den, sar.num, AV_ROUND_ZERO);
337
338    if (scaled_dim > 0)
339        return 0;
340
341    return AVERROR(EINVAL);
342}
343
344static void image_copy_plane(uint8_t       *dst, ptrdiff_t dst_linesize,
345                             const uint8_t *src, ptrdiff_t src_linesize,
346                             ptrdiff_t bytewidth, int height)
347{
348    if (!dst || !src)
349        return;
350    av_assert0(FFABS(src_linesize) >= bytewidth);
351    av_assert0(FFABS(dst_linesize) >= bytewidth);
352    for (;height > 0; height--) {
353        memcpy(dst, src, bytewidth);
354        dst += dst_linesize;
355        src += src_linesize;
356    }
357}
358
359void av_image_copy_plane_uc_from(uint8_t *dst, ptrdiff_t dst_linesize,
360                                 const uint8_t *src, ptrdiff_t src_linesize,
361                                 ptrdiff_t bytewidth, int height)
362{
363    int ret = -1;
364
365#if ARCH_X86
366    ret = ff_image_copy_plane_uc_from_x86(dst, dst_linesize, src, src_linesize,
367                                          bytewidth, height);
368#endif
369
370    if (ret < 0)
371        image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
372}
373
374void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
375                         const uint8_t *src, int src_linesize,
376                         int bytewidth, int height)
377{
378    image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
379}
380
381static void image_copy(uint8_t *dst_data[4], const ptrdiff_t dst_linesizes[4],
382                       const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
383                       enum AVPixelFormat pix_fmt, int width, int height,
384                       void (*copy_plane)(uint8_t *, ptrdiff_t, const uint8_t *,
385                                          ptrdiff_t, ptrdiff_t, int))
386{
387    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
388
389    if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
390        return;
391
392    if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
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
422void 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
438void 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, av_image_copy_plane_uc_from);
444}
445
446int 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
466int 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    ret = av_image_fill_linesizes(linesize, pix_fmt, width);
482    if (ret < 0)
483        return ret;
484
485    for (i = 0; i < 4; i++)
486        aligned_linesize[i] = FFALIGN(linesize[i], align);
487
488    ret = av_image_fill_plane_sizes(sizes, pix_fmt, height, aligned_linesize);
489    if (ret < 0)
490        return ret;
491
492    ret = 0;
493    for (i = 0; i < 4; i++) {
494        if (sizes[i] > INT_MAX - ret)
495            return AVERROR(EINVAL);
496        ret += sizes[i];
497    }
498    return ret;
499}
500
501int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
502                            const uint8_t * const src_data[4],
503                            const int src_linesize[4],
504                            enum AVPixelFormat pix_fmt,
505                            int width, int height, int align)
506{
507    int i, j, nb_planes = 0, linesize[4];
508    int size = av_image_get_buffer_size(pix_fmt, width, height, align);
509    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
510    int ret;
511
512    if (size > dst_size || size < 0 || !desc)
513        return AVERROR(EINVAL);
514
515    for (i = 0; i < desc->nb_components; i++)
516        nb_planes = FFMAX(desc->comp[i].plane, nb_planes);
517
518    nb_planes++;
519
520    ret = av_image_fill_linesizes(linesize, pix_fmt, width);
521    av_assert0(ret >= 0); // was checked previously
522
523    for (i = 0; i < nb_planes; i++) {
524        int h, shift = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
525        const uint8_t *src = src_data[i];
526        h = (height + (1 << shift) - 1) >> shift;
527
528        for (j = 0; j < h; j++) {
529            memcpy(dst, src, linesize[i]);
530            dst += FFALIGN(linesize[i], align);
531            src += src_linesize[i];
532        }
533    }
534
535    if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
536        uint32_t *d32 = (uint32_t *)dst;
537
538        for (i = 0; i<256; i++)
539            AV_WL32(d32 + i, AV_RN32(src_data[1] + 4*i));
540    }
541
542    return size;
543}
544
545// Fill dst[0..dst_size] with the bytes in clear[0..clear_size]. The clear
546// bytes are repeated until dst_size is reached. If dst_size is unaligned (i.e.
547// dst_size%clear_size!=0), the remaining data will be filled with the beginning
548// of the clear data only.
549static void memset_bytes(uint8_t *dst, size_t dst_size, uint8_t *clear,
550                         size_t clear_size)
551{
552    int same = 1;
553    int i;
554
555    if (!clear_size)
556        return;
557
558    // Reduce to memset() if possible.
559    for (i = 0; i < clear_size; i++) {
560        if (clear[i] != clear[0]) {
561            same = 0;
562            break;
563        }
564    }
565    if (same)
566        clear_size = 1;
567
568    if (clear_size == 1) {
569        memset(dst, clear[0], dst_size);
570    } else {
571        if (clear_size > dst_size)
572            clear_size = dst_size;
573        memcpy(dst, clear, clear_size);
574        av_memcpy_backptr(dst + clear_size, clear_size, dst_size - clear_size);
575    }
576}
577
578// Maximum size in bytes of a plane element (usually a pixel, or multiple pixels
579// if it's a subsampled packed format).
580#define MAX_BLOCK_SIZE 32
581
582int av_image_fill_black(uint8_t *dst_data[4], const ptrdiff_t dst_linesize[4],
583                        enum AVPixelFormat pix_fmt, enum AVColorRange range,
584                        int width, int height)
585{
586    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
587    int nb_planes = av_pix_fmt_count_planes(pix_fmt);
588    // A pixel or a group of pixels on each plane, with a value that represents black.
589    // Consider e.g. AV_PIX_FMT_UYVY422 for non-trivial cases.
590    uint8_t clear_block[4][MAX_BLOCK_SIZE] = {{0}}; // clear padding with 0
591    int clear_block_size[4] = {0};
592    ptrdiff_t plane_line_bytes[4] = {0};
593    int rgb, limited;
594    int plane, c;
595
596    if (!desc || nb_planes < 1 || nb_planes > 4 || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
597        return AVERROR(EINVAL);
598
599    rgb = !!(desc->flags & AV_PIX_FMT_FLAG_RGB);
600    limited = !rgb && range != AVCOL_RANGE_JPEG;
601
602    if (desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) {
603        ptrdiff_t bytewidth = av_image_get_linesize(pix_fmt, width, 0);
604        uint8_t *data;
605        int mono = pix_fmt == AV_PIX_FMT_MONOWHITE || pix_fmt == AV_PIX_FMT_MONOBLACK;
606        int fill = pix_fmt == AV_PIX_FMT_MONOWHITE ? 0xFF : 0;
607        if (nb_planes != 1 || !(rgb || mono) || bytewidth < 1)
608            return AVERROR(EINVAL);
609
610        if (!dst_data)
611            return 0;
612
613        data = dst_data[0];
614
615        // (Bitstream + alpha will be handled incorrectly - it'll remain transparent.)
616        for (;height > 0; height--) {
617            memset(data, fill, bytewidth);
618            data += dst_linesize[0];
619        }
620        return 0;
621    }
622
623    for (c = 0; c < desc->nb_components; c++) {
624        const AVComponentDescriptor comp = desc->comp[c];
625
626        // We try to operate on entire non-subsampled pixel groups (for
627        // AV_PIX_FMT_UYVY422 this would mean two consecutive pixels).
628        clear_block_size[comp.plane] = FFMAX(clear_block_size[comp.plane], comp.step);
629
630        if (clear_block_size[comp.plane] > MAX_BLOCK_SIZE)
631            return AVERROR(EINVAL);
632    }
633
634    // Create a byte array for clearing 1 pixel (sometimes several pixels).
635    for (c = 0; c < desc->nb_components; c++) {
636        const AVComponentDescriptor comp = desc->comp[c];
637        // (Multiple pixels happen e.g. with AV_PIX_FMT_UYVY422.)
638        int w = clear_block_size[comp.plane] / comp.step;
639        uint8_t *c_data[4];
640        const int c_linesize[4] = {0};
641        uint16_t src_array[MAX_BLOCK_SIZE];
642        uint16_t src = 0;
643        int x;
644
645        if (comp.depth > 16)
646            return AVERROR(EINVAL);
647        if (!rgb && comp.depth < 8)
648            return AVERROR(EINVAL);
649        if (w < 1)
650            return AVERROR(EINVAL);
651
652        if (c == 0 && limited) {
653            src = 16 << (comp.depth - 8);
654        } else if ((c == 1 || c == 2) && !rgb) {
655            src = 128 << (comp.depth - 8);
656        } else if (c == 3) {
657            // (Assume even limited YUV uses full range alpha.)
658            src = (1 << comp.depth) - 1;
659        }
660
661        for (x = 0; x < w; x++)
662            src_array[x] = src;
663
664        for (x = 0; x < 4; x++)
665            c_data[x] = &clear_block[x][0];
666
667        av_write_image_line(src_array, c_data, c_linesize, desc, 0, 0, c, w);
668    }
669
670    for (plane = 0; plane < nb_planes; plane++) {
671        plane_line_bytes[plane] = av_image_get_linesize(pix_fmt, width, plane);
672        if (plane_line_bytes[plane] < 0)
673            return AVERROR(EINVAL);
674    }
675
676    if (!dst_data)
677        return 0;
678
679    for (plane = 0; plane < nb_planes; plane++) {
680        size_t bytewidth = plane_line_bytes[plane];
681        uint8_t *data = dst_data[plane];
682        int chroma_div = plane == 1 || plane == 2 ? desc->log2_chroma_h : 0;
683        int plane_h = ((height + ( 1 << chroma_div) - 1)) >> chroma_div;
684
685        for (; plane_h > 0; plane_h--) {
686            memset_bytes(data, bytewidth, &clear_block[plane][0], clear_block_size[plane]);
687            data += dst_linesize[plane];
688        }
689    }
690
691    return 0;
692}
693