aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_rotate.c
blob: 378be44ae92980bbd35e2f424898ec80ab5ebc0f (plain) (blame)
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
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
/*
 * Copyright (c) 2013 Stefano Sabatini
 * Copyright (c) 2008 Vitor Sessak
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * rotation filter, partially based on the tests/rotozoom.c program
*/

#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"

#include "avfilter.h"
#include "drawutils.h"
#include "internal.h"
#include "video.h"

#include <float.h>

static const char * const var_names[] = {
    "in_w" , "iw",  ///< width of the input video
    "in_h" , "ih",  ///< height of the input video
    "out_w", "ow",  ///< width of the input video
    "out_h", "oh",  ///< height of the input video
    "hsub", "vsub",
    "n",            ///< number of frame
    "t",            ///< timestamp expressed in seconds
    NULL
};

enum var_name {
    VAR_IN_W , VAR_IW,
    VAR_IN_H , VAR_IH,
    VAR_OUT_W, VAR_OW,
    VAR_OUT_H, VAR_OH,
    VAR_HSUB, VAR_VSUB,
    VAR_N,
    VAR_T,
    VAR_VARS_NB
};

typedef struct RotContext {
    const AVClass *class;
    double angle;
    char *angle_expr_str;   ///< expression for the angle
    AVExpr *angle_expr;     ///< parsed expression for the angle
    char *outw_expr_str, *outh_expr_str;
    int outh, outw;
    uint8_t fillcolor[4];   ///< color expressed either in YUVA or RGBA colorspace for the padding area
    char *fillcolor_str;
    int fillcolor_enable;
    int hsub, vsub;
    int nb_planes;
    int use_bilinear;
    float sinx, cosx;
    double var_values[VAR_VARS_NB];
    FFDrawContext draw;
    FFDrawColor color;
    uint8_t *(*interpolate_bilinear)(uint8_t *dst_color,
                                    const uint8_t *src, int src_linesize, int src_linestep,
                                    int x, int y, int max_x, int max_y);
} RotContext;

typedef struct ThreadData {
    AVFrame *in, *out;
    int inw,  inh;
    int outw, outh;
    int plane;
    int xi, yi;
    int xprime, yprime;
    int c, s;
} ThreadData;

#define OFFSET(x) offsetof(RotContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define TFLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM

static const AVOption rotate_options[] = {
    { "angle",     "set angle (in radians)",       OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=TFLAGS },
    { "a",         "set angle (in radians)",       OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=TFLAGS },
    { "out_w",     "set output width expression",  OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
    { "ow",        "set output width expression",  OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
    { "out_h",     "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
    { "oh",        "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
    { "fillcolor", "set background fill color",    OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
    { "c",         "set background fill color",    OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
    { "bilinear",  "use bilinear interpolation",   OFFSET(use_bilinear),  AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, .flags=FLAGS },
    { NULL }
};

AVFILTER_DEFINE_CLASS(rotate);

static av_cold int init(AVFilterContext *ctx)
{
    RotContext *rot = ctx->priv;

    if (!strcmp(rot->fillcolor_str, "none"))
        rot->fillcolor_enable = 0;
    else if (av_parse_color(rot->fillcolor, rot->fillcolor_str, -1, ctx) >= 0)
        rot->fillcolor_enable = 1;
    else
        return AVERROR(EINVAL);
    return 0;
}

static av_cold void uninit(AVFilterContext *ctx)
{
    RotContext *rot = ctx->priv;

    av_expr_free(rot->angle_expr);
    rot->angle_expr = NULL;
}

static int query_formats(AVFilterContext *ctx)
{
    static const enum AVPixelFormat pix_fmts[] = {
        AV_PIX_FMT_GBRP,   AV_PIX_FMT_GBRAP,
        AV_PIX_FMT_ARGB,   AV_PIX_FMT_RGBA,
        AV_PIX_FMT_ABGR,   AV_PIX_FMT_BGRA,
        AV_PIX_FMT_0RGB,   AV_PIX_FMT_RGB0,
        AV_PIX_FMT_0BGR,   AV_PIX_FMT_BGR0,
        AV_PIX_FMT_RGB24,  AV_PIX_FMT_BGR24,
        AV_PIX_FMT_GRAY8,
        AV_PIX_FMT_YUV410P,
        AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUVJ444P,
        AV_PIX_FMT_YUV420P,  AV_PIX_FMT_YUVJ420P,
        AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA420P,
        AV_PIX_FMT_YUV420P10LE, AV_PIX_FMT_YUVA420P10LE,
        AV_PIX_FMT_YUV444P10LE, AV_PIX_FMT_YUVA444P10LE,
        AV_PIX_FMT_YUV420P12LE,
        AV_PIX_FMT_YUV444P12LE,
        AV_PIX_FMT_YUV444P16LE, AV_PIX_FMT_YUVA444P16LE,
        AV_PIX_FMT_YUV420P16LE, AV_PIX_FMT_YUVA420P16LE,
        AV_PIX_FMT_YUV444P9LE, AV_PIX_FMT_YUVA444P9LE,
        AV_PIX_FMT_YUV420P9LE, AV_PIX_FMT_YUVA420P9LE,
        AV_PIX_FMT_NONE
    };

    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
    if (!fmts_list)
        return AVERROR(ENOMEM);
    return ff_set_common_formats(ctx, fmts_list);
}

static double get_rotated_w(void *opaque, double angle)
{
    RotContext *rot = opaque;
    double inw = rot->var_values[VAR_IN_W];
    double inh = rot->var_values[VAR_IN_H];
    float sinx = sin(angle);
    float cosx = cos(angle);

    return FFMAX(0, inh * sinx) + FFMAX(0, -inw * cosx) +
           FFMAX(0, inw * cosx) + FFMAX(0, -inh * sinx);
}

static double get_rotated_h(void *opaque, double angle)
{
    RotContext *rot = opaque;
    double inw = rot->var_values[VAR_IN_W];
    double inh = rot->var_values[VAR_IN_H];
    float sinx = sin(angle);
    float cosx = cos(angle);

    return FFMAX(0, -inh * cosx) + FFMAX(0, -inw * sinx) +
           FFMAX(0,  inh * cosx) + FFMAX(0,  inw * sinx);
}

static double (* const func1[])(void *, double) = {
    get_rotated_w,
    get_rotated_h,
    NULL
};

static const char * const func1_names[] = {
    "rotw",
    "roth",
    NULL
};

#define FIXP (1<<16)
#define FIXP2 (1<<20)
#define INT_PI 3294199 //(M_PI * FIXP2)

/**
 * Compute the sin of a using integer values.
 * Input is scaled by FIXP2 and output values are scaled by FIXP.
 */
static int64_t int_sin(int64_t a)
{
    int64_t a2, res = 0;
    int i;
    if (a < 0) a = INT_PI-a; // 0..inf
    a %= 2 * INT_PI;         // 0..2PI

    if (a >= INT_PI*3/2) a -= 2*INT_PI;  // -PI/2 .. 3PI/2
    if (a >= INT_PI/2  ) a = INT_PI - a; // -PI/2 ..  PI/2

    /* compute sin using Taylor series approximated to the fifth term */
    a2 = (a*a)/(FIXP2);
    for (i = 2; i < 11; i += 2) {
        res += a;
        a = -a*a2 / (FIXP2*i*(i+1));
    }
    return (res + 8)>>4;
}

/**
 * Interpolate the color in src at position x and y using bilinear
 * interpolation.
 */
static uint8_t *interpolate_bilinear8(uint8_t *dst_color,
                                      const uint8_t *src, int src_linesize, int src_linestep,
                                      int x, int y, int max_x, int max_y)
{
    int int_x = av_clip(x>>16, 0, max_x);
    int int_y = av_clip(y>>16, 0, max_y);
    int frac_x = x&0xFFFF;
    int frac_y = y&0xFFFF;
    int i;
    int int_x1 = FFMIN(int_x+1, max_x);
    int int_y1 = FFMIN(int_y+1, max_y);

    for (i = 0; i < src_linestep; i++) {
        int s00 = src[src_linestep * int_x  + i + src_linesize * int_y ];
        int s01 = src[src_linestep * int_x1 + i + src_linesize * int_y ];
        int s10 = src[src_linestep * int_x  + i + src_linesize * int_y1];
        int s11 = src[src_linestep * int_x1 + i + src_linesize * int_y1];
        int s0 = (((1<<16) - frac_x)*s00 + frac_x*s01);
        int s1 = (((1<<16) - frac_x)*s10 + frac_x*s11);

        dst_color[i] = ((int64_t)((1<<16) - frac_y)*s0 + (int64_t)frac_y*s1) >> 32;
    }

    return dst_color;
}

/**
 * Interpolate the color in src at position x and y using bilinear
 * interpolation.
 */
static uint8_t *interpolate_bilinear16(uint8_t *dst_color,
                                       const uint8_t *src, int src_linesize, int src_linestep,
                                       int x, int y, int max_x, int max_y)
{
    int int_x = av_clip(x>>16, 0, max_x);
    int int_y = av_clip(y>>16, 0, max_y);
    int frac_x = x&0xFFFF;
    int frac_y = y&0xFFFF;
    int i;
    int int_x1 = FFMIN(int_x+1, max_x);
    int int_y1 = FFMIN(int_y+1, max_y);

    for (i = 0; i < src_linestep; i+=2) {
        int s00 = AV_RL16(&src[src_linestep * int_x  + i + src_linesize * int_y ]);
        int s01 = AV_RL16(&src[src_linestep * int_x1 + i + src_linesize * int_y ]);
        int s10 = AV_RL16(&src[src_linestep * int_x  + i + src_linesize * int_y1]);
        int s11 = AV_RL16(&src[src_linestep * int_x1 + i + src_linesize * int_y1]);
        int s0 = (((1<<16) - frac_x)*s00 + frac_x*s01);
        int s1 = (((1<<16) - frac_x)*s10 + frac_x*s11);

        AV_WL16(&dst_color[i], ((int64_t)((1<<16) - frac_y)*s0 + (int64_t)frac_y*s1) >> 32);
    }

    return dst_color;
}

static int config_props(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->src;
    RotContext *rot = ctx->priv;
    AVFilterLink *inlink = ctx->inputs[0];
    const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
    int ret;
    double res;
    char *expr;

    ff_draw_init(&rot->draw, inlink->format, 0);
    ff_draw_color(&rot->draw, &rot->color, rot->fillcolor);

    rot->hsub = pixdesc->log2_chroma_w;
    rot->vsub = pixdesc->log2_chroma_h;

    if (pixdesc->comp[0].depth == 8)
        rot->interpolate_bilinear = interpolate_bilinear8;
    else
        rot->interpolate_bilinear = interpolate_bilinear16;

    rot->var_values[VAR_IN_W] = rot->var_values[VAR_IW] = inlink->w;
    rot->var_values[VAR_IN_H] = rot->var_values[VAR_IH] = inlink->h;
    rot->var_values[VAR_HSUB] = 1<<rot->hsub;
    rot->var_values[VAR_VSUB] = 1<<rot->vsub;
    rot->var_values[VAR_N] = NAN;
    rot->var_values[VAR_T] = NAN;
    rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = NAN;
    rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = NAN;

    av_expr_free(rot->angle_expr);
    rot->angle_expr = NULL;
    if ((ret = av_expr_parse(&rot->angle_expr, expr = rot->angle_expr_str, var_names,
                             func1_names, func1, NULL, NULL, 0, ctx)) < 0) {
        av_log(ctx, AV_LOG_ERROR,
               "Error occurred parsing angle expression '%s'\n", rot->angle_expr_str);
        return ret;
    }

#define SET_SIZE_EXPR(name, opt_name) do {                                         \
    ret = av_expr_parse_and_eval(&res, expr = rot->name##_expr_str,                \
                                 var_names, rot->var_values,                       \
                                 func1_names, func1, NULL, NULL, rot, 0, ctx);     \
    if (ret < 0 || isnan(res) || isinf(res) || res <= 0) {                         \
        av_log(ctx, AV_LOG_ERROR,                                                  \
               "Error parsing or evaluating expression for option %s: "            \
               "invalid expression '%s' or non-positive or indefinite value %f\n", \
               opt_name, expr, res);                                               \
        return ret;                                                                \
    }                                                                              \
} while (0)

    /* evaluate width and height */
    av_expr_parse_and_eval(&res, expr = rot->outw_expr_str, var_names, rot->var_values,
                           func1_names, func1, NULL, NULL, rot, 0, ctx);
    rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
    rot->outw = res + 0.5;
    SET_SIZE_EXPR(outh, "out_h");
    rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = res;
    rot->outh = res + 0.5;

    /* evaluate the width again, as it may depend on the evaluated output height */
    SET_SIZE_EXPR(outw, "out_w");
    rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
    rot->outw = res + 0.5;

    /* compute number of planes */
    rot->nb_planes = av_pix_fmt_count_planes(inlink->format);
    outlink->w = rot->outw;
    outlink->h = rot->outh;
    return 0;
}

static av_always_inline void copy_elem(uint8_t *pout, const uint8_t *pin, int elem_size)
{
    int v;
    switch (elem_size) {
    case 1:
        *pout = *pin;
        break;
    case 2:
        *((uint16_t *)pout) = *((uint16_t *)pin);
        break;
    case 3:
        v = AV_RB24(pin);
        AV_WB24(pout, v);
        break;
    case 4:
        *((uint32_t *)pout) = *((uint32_t *)pin);
        break;
    default:
        memcpy(pout, pin, elem_size);
        break;
    }
}

static av_always_inline void simple_rotate_internal(uint8_t *dst, const uint8_t *src, int src_linesize, int angle, int elem_size, int len)
{
    int i;
    switch(angle) {
    case 0:
        memcpy(dst, src, elem_size * len);
        break;
    case 1:
        for (i = 0; i<len; i++)
            copy_elem(dst + i*elem_size, src + (len-i-1)*src_linesize, elem_size);
        break;
    case 2:
        for (i = 0; i<len; i++)
            copy_elem(dst + i*elem_size, src + (len-i-1)*elem_size, elem_size);
        break;
    case 3:
        for (i = 0; i<len; i++)
            copy_elem(dst + i*elem_size, src + i*src_linesize, elem_size);
        break;
    }
}

static av_always_inline void simple_rotate(uint8_t *dst, const uint8_t *src, int src_linesize, int angle, int elem_size, int len)
{
    switch(elem_size) {
    case 1 : simple_rotate_internal(dst, src, src_linesize, angle, 1, len); break;
    case 2 : simple_rotate_internal(dst, src, src_linesize, angle, 2, len); break;
    case 3 : simple_rotate_internal(dst, src, src_linesize, angle, 3, len); break;
    case 4 : simple_rotate_internal(dst, src, src_linesize, angle, 4, len); break;
    default: simple_rotate_internal(dst, src, src_linesize, angle, elem_size, len); break;
    }
}

#define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)*av_q2d(tb))

static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
{
    ThreadData *td = arg;
    AVFrame *in = td->in;
    AVFrame *out = td->out;
    RotContext *rot = ctx->priv;
    const int outw = td->outw, outh = td->outh;
    const int inw = td->inw, inh = td->inh;
    const int plane = td->plane;
    const int xi = td->xi, yi = td->yi;
    const int c = td->c, s = td->s;
    const int start = (outh *  job   ) / nb_jobs;
    const int end   = (outh * (job+1)) / nb_jobs;
    int xprime = td->xprime + start * s;
    int yprime = td->yprime + start * c;
    int i, j, x, y;

    for (j = start; j < end; j++) {
        x = xprime + xi + FIXP*(inw-1)/2;
        y = yprime + yi + FIXP*(inh-1)/2;

        if (fabs(rot->angle - 0) < FLT_EPSILON && outw == inw && outh == inh) {
            simple_rotate(out->data[plane] + j * out->linesize[plane],
                           in->data[plane] + j *  in->linesize[plane],
                          in->linesize[plane], 0, rot->draw.pixelstep[plane], outw);
        } else if (fabs(rot->angle - M_PI/2) < FLT_EPSILON && outw == inh && outh == inw) {
            simple_rotate(out->data[plane] + j * out->linesize[plane],
                           in->data[plane] + j * rot->draw.pixelstep[plane],
                          in->linesize[plane], 1, rot->draw.pixelstep[plane], outw);
        } else if (fabs(rot->angle - M_PI) < FLT_EPSILON && outw == inw && outh == inh) {
            simple_rotate(out->data[plane] + j * out->linesize[plane],
                           in->data[plane] + (outh-j-1) *  in->linesize[plane],
                          in->linesize[plane], 2, rot->draw.pixelstep[plane], outw);
        } else if (fabs(rot->angle - 3*M_PI/2) < FLT_EPSILON && outw == inh && outh == inw) {
            simple_rotate(out->data[plane] + j * out->linesize[plane],
                           in->data[plane] + (outh-j-1) * rot->draw.pixelstep[plane],
                          in->linesize[plane], 3, rot->draw.pixelstep[plane], outw);
        } else {

        for (i = 0; i < outw; i++) {
            int32_t v;
            int x1, y1;
            uint8_t *pin, *pout;
            x1 = x>>16;
            y1 = y>>16;

            /* the out-of-range values avoid border artifacts */
            if (x1 >= -1 && x1 <= inw && y1 >= -1 && y1 <= inh) {
                uint8_t inp_inv[4]; /* interpolated input value */
                pout = out->data[plane] + j * out->linesize[plane] + i * rot->draw.pixelstep[plane];
                if (rot->use_bilinear) {
                    pin = rot->interpolate_bilinear(inp_inv,
                                                    in->data[plane], in->linesize[plane], rot->draw.pixelstep[plane],
                                                    x, y, inw-1, inh-1);
                } else {
                    int x2 = av_clip(x1, 0, inw-1);
                    int y2 = av_clip(y1, 0, inh-1);
                    pin = in->data[plane] + y2 * in->linesize[plane] + x2 * rot->draw.pixelstep[plane];
                }
                switch (rot->draw.pixelstep[plane]) {
                case 1:
                    *pout = *pin;
                    break;
                case 2:
                    v = AV_RL16(pin);
                    AV_WL16(pout, v);
                    break;
                case 3:
                    v = AV_RB24(pin);
                    AV_WB24(pout, v);
                    break;
                case 4:
                    *((uint32_t *)pout) = *((uint32_t *)pin);
                    break;
                default:
                    memcpy(pout, pin, rot->draw.pixelstep[plane]);
                    break;
                }
            }
            x += c;
            y -= s;
        }
        }
        xprime += s;
        yprime += c;
    }

    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
    AVFilterContext *ctx = inlink->dst;
    AVFilterLink *outlink = ctx->outputs[0];
    AVFrame *out;
    RotContext *rot = ctx->priv;
    int angle_int, s, c, plane;
    double res;

    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
    if (!out) {
        av_frame_free(&in);
        return AVERROR(ENOMEM);
    }
    av_frame_copy_props(out, in);

    rot->var_values[VAR_N] = inlink->frame_count_out;
    rot->var_values[VAR_T] = TS2T(in->pts, inlink->time_base);
    rot->angle = res = av_expr_eval(rot->angle_expr, rot->var_values, rot);

    av_log(ctx, AV_LOG_DEBUG, "n:%f time:%f angle:%f/PI\n",
           rot->var_values[VAR_N], rot->var_values[VAR_T], rot->angle/M_PI);

    angle_int = res * FIXP * 16;
    s = int_sin(angle_int);
    c = int_sin(angle_int + INT_PI/2);

    /* fill background */
    if (rot->fillcolor_enable)
        ff_fill_rectangle(&rot->draw, &rot->color, out->data, out->linesize,
                          0, 0, outlink->w, outlink->h);

    for (plane = 0; plane < rot->nb_planes; plane++) {
        int hsub = plane == 1 || plane == 2 ? rot->hsub : 0;
        int vsub = plane == 1 || plane == 2 ? rot->vsub : 0;
        const int outw = AV_CEIL_RSHIFT(outlink->w, hsub);
        const int outh = AV_CEIL_RSHIFT(outlink->h, vsub);
        ThreadData td = { .in = in,   .out  = out,
                          .inw  = AV_CEIL_RSHIFT(inlink->w, hsub),
                          .inh  = AV_CEIL_RSHIFT(inlink->h, vsub),
                          .outh = outh, .outw = outw,
                          .xi = -(outw-1) * c / 2, .yi =  (outw-1) * s / 2,
                          .xprime = -(outh-1) * s / 2,
                          .yprime = -(outh-1) * c / 2,
                          .plane = plane, .c = c, .s = s };


        ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(outh, ff_filter_get_nb_threads(ctx)));
    }

    av_frame_free(&in);
    return ff_filter_frame(outlink, out);
}

static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                           char *res, int res_len, int flags)
{
    RotContext *rot = ctx->priv;
    int ret;

    if (!strcmp(cmd, "angle") || !strcmp(cmd, "a")) {
        AVExpr *old = rot->angle_expr;
        ret = av_expr_parse(&rot->angle_expr, args, var_names,
                            NULL, NULL, NULL, NULL, 0, ctx);
        if (ret < 0) {
            av_log(ctx, AV_LOG_ERROR,
                   "Error when parsing the expression '%s' for angle command\n", args);
            rot->angle_expr = old;
            return ret;
        }
        av_expr_free(old);
    } else
        ret = AVERROR(ENOSYS);

    return ret;
}

static const AVFilterPad rotate_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad rotate_outputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = config_props,
    },
    { NULL }
};

AVFilter ff_vf_rotate = {
    .name          = "rotate",
    .description   = NULL_IF_CONFIG_SMALL("Rotate the input image."),
    .priv_size     = sizeof(RotContext),
    .init          = init,
    .uninit        = uninit,
    .query_formats = query_formats,
    .process_command = process_command,
    .inputs        = rotate_inputs,
    .outputs       = rotate_outputs,
    .priv_class    = &rotate_class,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
};