summaryrefslogtreecommitdiffstats
path: root/libass/ass_bitmap.c
blob: ad00df2af7e4e0c7df35036473d1f5d8e51738a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
/*
 * Copyright (C) 2006 Evgeniy Stepanov <eugeni.stepanov@gmail.com>
 * Copyright (C) 2011 Grigori Goronzy <greg@chown.ath.cx>
 *
 * This file is part of libass.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <ft2build.h>
#include FT_GLYPH_H
#include FT_OUTLINE_H

#include "ass_utils.h"
#include "ass_bitmap.h"
#include "ass_render.h"

static const unsigned base = 256;

int generate_tables(ASS_SynthPriv *priv, double radius)
{
    double A = log(1.0 / base) / (radius * radius * 2);
    int mx, i;
    double volume_diff, volume_factor = 0;
    unsigned volume;

    if (priv->radius == radius)
        return 0;
    else
        priv->radius = radius;

    priv->g_r = ceil(radius);
    priv->g_w = 2 * priv->g_r + 1;

    if (priv->g_r) {
        priv->g0 = realloc(priv->g0, priv->g_w * sizeof(double));
        priv->g = realloc(priv->g, priv->g_w * sizeof(unsigned));
        priv->gt2 = realloc(priv->gt2, 256 * priv->g_w * sizeof(unsigned));
        if (priv->g == NULL || priv->gt2 == NULL) {
            return -1;
        }
    }

    if (priv->g_r) {
        // exact gaussian curve
        for (i = 0; i < priv->g_w; ++i) {
            priv->g0[i] = exp(A * (i - priv->g_r) * (i - priv->g_r));
        }

        // integer gaussian curve with volume = 65536
        for (volume_diff = 10000000; volume_diff > 0.0000001;
             volume_diff *= 0.5) {
            volume_factor += volume_diff;
            volume = 0;
            for (i = 0; i < priv->g_w; ++i) {
                priv->g[i] = (unsigned) (priv->g0[i] * volume_factor + .5);
                volume += priv->g[i];
            }
            if (volume > 65536)
                volume_factor -= volume_diff;
        }
        volume = 0;
        for (i = 0; i < priv->g_w; ++i) {
            priv->g[i] = (unsigned) (priv->g0[i] * volume_factor + .5);
            volume += priv->g[i];
        }

        // gauss table:
        for (mx = 0; mx < priv->g_w; mx++) {
            for (i = 0; i < 256; i++) {
                priv->gt2[mx + i * priv->g_w] = i * priv->g[mx];
            }
        }
    }

    return 0;
}

void resize_tmp(ASS_SynthPriv *priv, int w, int h)
{
    if (priv->tmp_w >= w && priv->tmp_h >= h)
        return;
    if (priv->tmp_w == 0)
        priv->tmp_w = 64;
    if (priv->tmp_h == 0)
        priv->tmp_h = 64;
    while (priv->tmp_w < w)
        priv->tmp_w *= 2;
    while (priv->tmp_h < h)
        priv->tmp_h *= 2;
    free(priv->tmp);
    priv->tmp = malloc((priv->tmp_w + 1) * priv->tmp_h * sizeof(unsigned));
}

ASS_SynthPriv *ass_synth_init(double radius)
{
    ASS_SynthPriv *priv = calloc(1, sizeof(ASS_SynthPriv));
    generate_tables(priv, radius);
    return priv;
}

void ass_synth_done(ASS_SynthPriv *priv)
{
    free(priv->tmp);
    free(priv->g0);
    free(priv->g);
    free(priv->gt2);
    free(priv);
}

Bitmap *alloc_bitmap(int w, int h)
{
    Bitmap *bm;

    uintptr_t alignment_offset = (w > 31) ? 31 : ((w > 15) ? 15 : 0);
    unsigned s = (w + alignment_offset) & ~alignment_offset;
    bm = malloc(sizeof(Bitmap));
    bm->buffer_ptr = malloc(s * h + alignment_offset + 32);
    bm->buffer = (unsigned char*)
        (((uintptr_t)bm->buffer_ptr + alignment_offset) & ~alignment_offset);
    memset(bm->buffer, 0, s * h + 32);
    bm->w = w;
    bm->h = h;
    bm->stride = s;
    bm->left = bm->top = 0;
    return bm;
}

void ass_free_bitmap(Bitmap *bm)
{
    if (bm)
        free(bm->buffer_ptr);
    free(bm);
}

Bitmap *copy_bitmap(const Bitmap *src)
{
    Bitmap *dst = alloc_bitmap(src->w, src->h);
    dst->left = src->left;
    dst->top = src->top;
    memcpy(dst->buffer, src->buffer, src->stride * src->h);
    return dst;
}

Bitmap *outline_to_bitmap(ASS_Library *library, FT_Library ftlib,
                          FT_Outline *outline, int bord)
{
    Bitmap *bm;
    int w, h;
    int error;
    FT_BBox bbox;
    FT_Bitmap bitmap;

    FT_Outline_Get_CBox(outline, &bbox);
    // move glyph to origin (0, 0)
    bbox.xMin &= ~63;
    bbox.yMin &= ~63;
    FT_Outline_Translate(outline, -bbox.xMin, -bbox.yMin);
    // bitmap size
    bbox.xMax = (bbox.xMax + 63) & ~63;
    bbox.yMax = (bbox.yMax + 63) & ~63;
    w = (bbox.xMax - bbox.xMin) >> 6;
    h = (bbox.yMax - bbox.yMin) >> 6;
    // pen offset
    bbox.xMin >>= 6;
    bbox.yMax >>= 6;

    if (w * h > 8000000) {
        ass_msg(library, MSGL_WARN, "Glyph bounding box too large: %dx%dpx",
                w, h);
        return NULL;
    }

    // allocate and set up bitmap
    bm = alloc_bitmap(w + 2 * bord, h + 2 * bord);
    bm->left = bbox.xMin - bord;
    bm->top = -bbox.yMax - bord;
    bitmap.width = w;
    bitmap.rows = h;
    bitmap.pitch = bm->stride;
    bitmap.buffer = bm->buffer + bord + bm->stride * bord;
    bitmap.num_grays = 256;
    bitmap.pixel_mode = FT_PIXEL_MODE_GRAY;

    // render into target bitmap
    if ((error = FT_Outline_Get_Bitmap(ftlib, outline, &bitmap))) {
        ass_msg(library, MSGL_WARN, "Failed to rasterize glyph: %d\n", error);
        ass_free_bitmap(bm);
        return NULL;
    }

    return bm;
}

/**
 * \brief fix outline bitmap
 *
 * The glyph bitmap is subtracted from outline bitmap. This way looks much
 * better in some cases.
 */
void fix_outline(Bitmap *bm_g, Bitmap *bm_o)
{
    int x, y;
    const int l = bm_o->left > bm_g->left ? bm_o->left : bm_g->left;
    const int t = bm_o->top > bm_g->top ? bm_o->top : bm_g->top;
    const int r =
        bm_o->left + bm_o->stride <
        bm_g->left + bm_g->stride ? bm_o->left + bm_o->stride : bm_g->left + bm_g->stride;
    const int b =
        bm_o->top + bm_o->h <
        bm_g->top + bm_g->h ? bm_o->top + bm_o->h : bm_g->top + bm_g->h;

    unsigned char *g =
        bm_g->buffer + (t - bm_g->top) * bm_g->stride + (l - bm_g->left);
    unsigned char *o =
        bm_o->buffer + (t - bm_o->top) * bm_o->stride + (l - bm_o->left);

    for (y = 0; y < b - t; ++y) {
        for (x = 0; x < r - l; ++x) {
            unsigned char c_g, c_o;
            c_g = g[x];
            c_o = o[x];
            o[x] = (c_o > c_g) ? c_o - (c_g / 2) : 0;
        }
        g += bm_g->stride;
        o += bm_o->stride;
    }
}

/**
 * \brief Shift a bitmap by the fraction of a pixel in x and y direction
 * expressed in 26.6 fixed point
 */
void shift_bitmap(Bitmap *bm, int shift_x, int shift_y)
{
    int x, y, b;
    int w = bm->w;
    int h = bm->h;
    int s = bm->stride;
    unsigned char *buf = bm->buffer;

    // Shift in x direction
    if (shift_x > 0) {
        for (y = 0; y < h; y++) {
            for (x = w - 1; x > 0; x--) {
                b = (buf[x + y * s - 1] * shift_x) >> 6;
                buf[x + y * s - 1] -= b;
                buf[x + y * s] += b;
            }
        }
    } else if (shift_x < 0) {
        shift_x = -shift_x;
        for (y = 0; y < h; y++) {
            for (x = 0; x < w - 1; x++) {
                b = (buf[x + y * s + 1] * shift_x) >> 6;
                buf[x + y * s + 1] -= b;
                buf[x + y * s] += b;
            }
        }
    }

    // Shift in y direction
    if (shift_y > 0) {
        for (x = 0; x < w; x++) {
            for (y = h - 1; y > 0; y--) {
                b = (buf[x + (y - 1) * s] * shift_y) >> 6;
                buf[x + (y - 1) * s] -= b;
                buf[x + y * s] += b;
            }
        }
    } else if (shift_y < 0) {
        shift_y = -shift_y;
        for (x = 0; x < w; x++) {
            for (y = 0; y < h - 1; y++) {
                b = (buf[x + (y + 1) * s] * shift_y) >> 6;
                buf[x + (y + 1) * s] -= b;
                buf[x + y * s] += b;
            }
        }
    }
}

/*
 * Gaussian blur.  An fast pure C implementation from MPlayer.
 */
void ass_gauss_blur(unsigned char *buffer, unsigned *tmp2,
                    int width, int height, int stride,
                    unsigned *m2, int r, int mwidth)
{

    int x, y;

    unsigned char *s = buffer;
    unsigned *t = tmp2 + 1;
    for (y = 0; y < height; y++) {
        memset(t - 1, 0, (width + 1) * sizeof(unsigned));
        t[-1] = 32768;

        for (x = 0; x < r; x++) {
            const int src = s[x];
            if (src) {
                register unsigned *dstp = t + x - r;
                int mx;
                unsigned *m3 = m2 + src * mwidth;
                for (mx = r - x; mx < mwidth; mx++) {
                    dstp[mx] += m3[mx];
                }
            }
        }

        for (; x < width - r; x++) {
            const int src = s[x];
            if (src) {
                register unsigned *dstp = t + x - r;
                int mx;
                unsigned *m3 = m2 + src * mwidth;
                for (mx = 0; mx < mwidth; mx++) {
                    dstp[mx] += m3[mx];
                }
            }
        }

        for (; x < width; x++) {
            const int src = s[x];
            if (src) {
                register unsigned *dstp = t + x - r;
                int mx;
                const int x2 = r + width - x;
                unsigned *m3 = m2 + src * mwidth;
                for (mx = 0; mx < x2; mx++) {
                    dstp[mx] += m3[mx];
                }
            }
        }

        s += stride;
        t += width + 1;
    }

    t = tmp2;
    for (x = 0; x < width; x++) {
        for (y = 0; y < r; y++) {
            unsigned *srcp = t + y * (width + 1) + 1;
            int src = *srcp;
            if (src) {
                register unsigned *dstp = srcp - 1 - y * (width + 1);
                const int src2 = (src + 32768) >> 16;
                unsigned *m3 = m2 + src2 * mwidth;

                int mx;
                *srcp = 32768;
                for (mx = r - y; mx < mwidth; mx++) {
                    *dstp += m3[mx];
                    dstp += width + 1;
                }
            }
        }
        for (; y < height - r; y++) {
            unsigned *srcp = t + y * (width + 1) + 1;
            int src = *srcp;
            if (src) {
                register unsigned *dstp = srcp - 1 - r * (width + 1);
                const int src2 = (src + 32768) >> 16;
                unsigned *m3 = m2 + src2 * mwidth;

                int mx;
                *srcp = 32768;
                for (mx = 0; mx < mwidth; mx++) {
                    *dstp += m3[mx];
                    dstp += width + 1;
                }
            }
        }
        for (; y < height; y++) {
            unsigned *srcp = t + y * (width + 1) + 1;
            int src = *srcp;
            if (src) {
                const int y2 = r + height - y;
                register unsigned *dstp = srcp - 1 - r * (width + 1);
                const int src2 = (src + 32768) >> 16;
                unsigned *m3 = m2 + src2 * mwidth;

                int mx;
                *srcp = 32768;
                for (mx = 0; mx < y2; mx++) {
                    *dstp += m3[mx];
                    dstp += width + 1;
                }
            }
        }
        t++;
    }

    t = tmp2;
    s = buffer;
    for (y = 0; y < height; y++) {
        for (x = 0; x < width; x++) {
            s[x] = t[x] >> 16;
        }
        s += stride;
        t += width + 1;
    }
}

/**
 * \brief Blur with [[1,2,1]. [2,4,2], [1,2,1]] kernel
 * This blur is the same as the one employed by vsfilter.
 * Pure C implementation.
 */
void be_blur_c(uint8_t *buf, intptr_t w,
               intptr_t h, intptr_t stride,
               uint16_t *tmp)
{
    unsigned short *col_pix_buf = tmp;
    unsigned short *col_sum_buf = tmp + w * sizeof(unsigned short);
    unsigned x, y, old_pix, old_sum, new_sum, temp1, temp2;
    unsigned char *src, *dst;
    memset(col_pix_buf, 0, w * sizeof(unsigned short));
    memset(col_sum_buf, 0, w * sizeof(unsigned short));
    {
        y = 0;
        src=buf+y*stride;

        x = 2;
        old_pix = src[x-1];
        old_sum = old_pix + src[x-2];
        for ( ; x < w; x++) {
            temp1 = src[x];
            temp2 = old_pix + temp1;
            old_pix = temp1;
            temp1 = old_sum + temp2;
            old_sum = temp2;
            col_pix_buf[x] = temp1;
        }
    }
    new_sum = 2 * buf[y * stride + w - 1];
    buf[y * stride + w - 1] = (old_sum + new_sum) >> 2;
    {
        x = 2;
        old_pix = src[x-1];
        old_sum = old_pix + src[x-2];
        for ( ; x < w; x++) {
            temp1 = src[x];
            temp2 = old_pix + temp1;
            old_pix = temp1;
            temp1 = old_sum + temp2;
            old_sum = temp2;

            temp2 = col_pix_buf[x] + temp1;
            col_pix_buf[x] = temp1;
            col_sum_buf[x] = temp2;
        }
    }

    for (y = 2; y < h; y++) {
        src=buf+y*stride;
        dst=buf+(y-1)*stride;

        x = 2;
        old_pix = src[x-1];
        old_sum = old_pix + src[x-2];
        for ( ; x < w; x++) {
            temp1 = src[x];
            temp2 = old_pix + temp1;
            old_pix = temp1;
            temp1 = old_sum + temp2;
            old_sum = temp2;

            temp2 = col_pix_buf[x] + temp1;
            col_pix_buf[x] = temp1;
            dst[x-1] = (col_sum_buf[x] + temp2) >> 4;
            col_sum_buf[x] = temp2;
        }
    }
}

int outline_to_bitmap3(ASS_Library *library, ASS_SynthPriv *priv_blur,
                       FT_Library ftlib, FT_Outline *outline, FT_Outline *border,
                       Bitmap **bm_g, Bitmap **bm_o, Bitmap **bm_s,
                       int be, double blur_radius, FT_Vector shadow_offset,
                       int border_style, int border_visible)
{
    blur_radius *= 2;
    int bbord = be > 0 ? sqrt(2 * be) : 0;
    int gbord = blur_radius > 0.0 ? blur_radius + 1 : 0;
    int bord = FFMAX(bbord, gbord);
    if (bord == 0 && (shadow_offset.x || shadow_offset.y))
        bord = 1;

    assert(bm_g && bm_o && bm_s);

    *bm_g = *bm_o = *bm_s = 0;

    if (outline)
        *bm_g = outline_to_bitmap(library, ftlib, outline, bord);
    if (!*bm_g)
        return 1;

    if (border) {
        *bm_o = outline_to_bitmap(library, ftlib, border, bord);
        if (!*bm_o) {
            return 1;
        }
    }

    return 0;
}

/**
 * \brief Add two bitmaps together at a given position
 * Uses additive blending, clipped to [0,255]. Pure C implementation.
 */
void add_bitmaps_c(uint8_t *dst, intptr_t dst_stride,
                   uint8_t *src, intptr_t src_stride,
                   intptr_t height, intptr_t width)
{
    unsigned out;
    uint8_t* end = dst + dst_stride * height;
    while (dst < end) {
        for (unsigned j = 0; j < width; ++j) {
            out = dst[j] + src[j];
            dst[j] = FFMIN(out, 255);
        }
        dst += dst_stride;
        src += src_stride;
    }
}

void sub_bitmaps_c(uint8_t *dst, intptr_t dst_stride,
                   uint8_t *src, intptr_t src_stride,
                   intptr_t height, intptr_t width)
{
    unsigned out;
    uint8_t* end = dst + dst_stride * height;
    while (dst < end) {
        for (unsigned j = 0; j < width; ++j) {
            out = dst[j] - src[j];
            dst[j] = FFMAX(out, 0);
        }
        dst += dst_stride;
        src += src_stride;
    }
}

void restride_bitmap_c(uint8_t *dst, intptr_t dst_stride,
                       uint8_t *src, intptr_t src_stride,
                       intptr_t width, intptr_t height)
{
    uint8_t* end = dst + dst_stride * height;
    while (dst < end) {
        memcpy(dst, src, width);
        dst += dst_stride;
        src += src_stride;
    }
}

void mul_bitmaps_c(uint8_t *dst, intptr_t dst_stride,
                   uint8_t *src1, intptr_t src1_stride,
                   uint8_t *src2, intptr_t src2_stride,
                   intptr_t w, intptr_t h)
{
    uint8_t* end = src1 + src1_stride * h;
    while (src1 < end) {
        for (unsigned x = 0; x < w; ++x) {
            dst[x] = (src1[x] * src2[x] + 255) >> 8;
        }
        dst  += dst_stride;
        src1 += src1_stride;
        src2 += src2_stride;
    }
}