lavfi: use const for AVFilterPad declarations in all filters.
[libav.git] / libavfilter / vf_boxblur.c
1 /*
2 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
3 * Copyright (c) 2011 Stefano Sabatini
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with Libav; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22 /**
23 * @file
24 * Apply a boxblur filter to the input video.
25 * Ported from MPlayer libmpcodecs/vf_boxblur.c.
26 */
27
28 #include "libavutil/avstring.h"
29 #include "libavutil/eval.h"
30 #include "libavutil/pixdesc.h"
31 #include "avfilter.h"
32 #include "formats.h"
33 #include "internal.h"
34 #include "video.h"
35
36 static const char *const var_names[] = {
37 "w",
38 "h",
39 "cw",
40 "ch",
41 "hsub",
42 "vsub",
43 NULL
44 };
45
46 enum var_name {
47 VAR_W,
48 VAR_H,
49 VAR_CW,
50 VAR_CH,
51 VAR_HSUB,
52 VAR_VSUB,
53 VARS_NB
54 };
55
56 typedef struct {
57 int radius;
58 int power;
59 } FilterParam;
60
61 typedef struct {
62 FilterParam luma_param;
63 FilterParam chroma_param;
64 FilterParam alpha_param;
65 char luma_radius_expr [256];
66 char chroma_radius_expr[256];
67 char alpha_radius_expr [256];
68
69 int hsub, vsub;
70 int radius[4];
71 int power[4];
72 uint8_t *temp[2]; ///< temporary buffer used in blur_power()
73 } BoxBlurContext;
74
75 #define Y 0
76 #define U 1
77 #define V 2
78 #define A 3
79
80 static av_cold int init(AVFilterContext *ctx, const char *args)
81 {
82 BoxBlurContext *boxblur = ctx->priv;
83 int e;
84
85 if (!args) {
86 av_log(ctx, AV_LOG_ERROR,
87 "Filter expects 2 or 4 or 6 arguments, none provided\n");
88 return AVERROR(EINVAL);
89 }
90
91 e = sscanf(args, "%255[^:]:%d:%255[^:]:%d:%255[^:]:%d",
92 boxblur->luma_radius_expr, &boxblur->luma_param .power,
93 boxblur->chroma_radius_expr, &boxblur->chroma_param.power,
94 boxblur->alpha_radius_expr, &boxblur->alpha_param .power);
95
96 if (e != 2 && e != 4 && e != 6) {
97 av_log(ctx, AV_LOG_ERROR,
98 "Filter expects 2 or 4 or 6 params, provided %d\n", e);
99 return AVERROR(EINVAL);
100 }
101
102 if (e < 4) {
103 boxblur->chroma_param.power = boxblur->luma_param.power;
104 av_strlcpy(boxblur->chroma_radius_expr, boxblur->luma_radius_expr,
105 sizeof(boxblur->chroma_radius_expr));
106 }
107 if (e < 6) {
108 boxblur->alpha_param.power = boxblur->luma_param.power;
109 av_strlcpy(boxblur->alpha_radius_expr, boxblur->luma_radius_expr,
110 sizeof(boxblur->alpha_radius_expr));
111 }
112
113 return 0;
114 }
115
116 static av_cold void uninit(AVFilterContext *ctx)
117 {
118 BoxBlurContext *boxblur = ctx->priv;
119
120 av_freep(&boxblur->temp[0]);
121 av_freep(&boxblur->temp[1]);
122 }
123
124 static int query_formats(AVFilterContext *ctx)
125 {
126 enum PixelFormat pix_fmts[] = {
127 PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV420P,
128 PIX_FMT_YUV411P, PIX_FMT_YUV410P, PIX_FMT_YUVA420P,
129 PIX_FMT_YUV440P, PIX_FMT_GRAY8,
130 PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
131 PIX_FMT_YUVJ440P,
132 PIX_FMT_NONE
133 };
134
135 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
136 return 0;
137 }
138
139 static int config_input(AVFilterLink *inlink)
140 {
141 const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[inlink->format];
142 AVFilterContext *ctx = inlink->dst;
143 BoxBlurContext *boxblur = ctx->priv;
144 int w = inlink->w, h = inlink->h;
145 int cw, ch;
146 double var_values[VARS_NB], res;
147 char *expr;
148 int ret;
149
150 av_freep(&boxblur->temp[0]);
151 av_freep(&boxblur->temp[1]);
152 if (!(boxblur->temp[0] = av_malloc(FFMAX(w, h))))
153 return AVERROR(ENOMEM);
154 if (!(boxblur->temp[1] = av_malloc(FFMAX(w, h)))) {
155 av_freep(&boxblur->temp[0]);
156 return AVERROR(ENOMEM);
157 }
158
159 boxblur->hsub = desc->log2_chroma_w;
160 boxblur->vsub = desc->log2_chroma_h;
161
162 var_values[VAR_W] = inlink->w;
163 var_values[VAR_H] = inlink->h;
164 var_values[VAR_CW] = cw = w>>boxblur->hsub;
165 var_values[VAR_CH] = ch = h>>boxblur->vsub;
166 var_values[VAR_HSUB] = 1<<boxblur->hsub;
167 var_values[VAR_VSUB] = 1<<boxblur->vsub;
168
169 #define EVAL_RADIUS_EXPR(comp) \
170 expr = boxblur->comp##_radius_expr; \
171 ret = av_expr_parse_and_eval(&res, expr, var_names, var_values, \
172 NULL, NULL, NULL, NULL, NULL, 0, ctx); \
173 boxblur->comp##_param.radius = res; \
174 if (ret < 0) { \
175 av_log(NULL, AV_LOG_ERROR, \
176 "Error when evaluating " #comp " radius expression '%s'\n", expr); \
177 return ret; \
178 }
179 EVAL_RADIUS_EXPR(luma);
180 EVAL_RADIUS_EXPR(chroma);
181 EVAL_RADIUS_EXPR(alpha);
182
183 av_log(ctx, AV_LOG_DEBUG,
184 "luma_radius:%d luma_power:%d "
185 "chroma_radius:%d chroma_power:%d "
186 "alpha_radius:%d alpha_power:%d "
187 "w:%d chroma_w:%d h:%d chroma_h:%d\n",
188 boxblur->luma_param .radius, boxblur->luma_param .power,
189 boxblur->chroma_param.radius, boxblur->chroma_param.power,
190 boxblur->alpha_param .radius, boxblur->alpha_param .power,
191 w, cw, h, ch);
192
193 #define CHECK_RADIUS_VAL(w_, h_, comp) \
194 if (boxblur->comp##_param.radius < 0 || \
195 2*boxblur->comp##_param.radius > FFMIN(w_, h_)) { \
196 av_log(ctx, AV_LOG_ERROR, \
197 "Invalid " #comp " radius value %d, must be >= 0 and <= %d\n", \
198 boxblur->comp##_param.radius, FFMIN(w_, h_)/2); \
199 return AVERROR(EINVAL); \
200 }
201 CHECK_RADIUS_VAL(w, h, luma);
202 CHECK_RADIUS_VAL(cw, ch, chroma);
203 CHECK_RADIUS_VAL(w, h, alpha);
204
205 boxblur->radius[Y] = boxblur->luma_param.radius;
206 boxblur->radius[U] = boxblur->radius[V] = boxblur->chroma_param.radius;
207 boxblur->radius[A] = boxblur->alpha_param.radius;
208
209 boxblur->power[Y] = boxblur->luma_param.power;
210 boxblur->power[U] = boxblur->power[V] = boxblur->chroma_param.power;
211 boxblur->power[A] = boxblur->alpha_param.power;
212
213 return 0;
214 }
215
216 static inline void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
217 int len, int radius)
218 {
219 /* Naive boxblur would sum source pixels from x-radius .. x+radius
220 * for destination pixel x. That would be O(radius*width).
221 * If you now look at what source pixels represent 2 consecutive
222 * output pixels, then you see they are almost identical and only
223 * differ by 2 pixels, like:
224 * src0 111111111
225 * dst0 1
226 * src1 111111111
227 * dst1 1
228 * src0-src1 1 -1
229 * so when you know one output pixel you can find the next by just adding
230 * and subtracting 1 input pixel.
231 * The following code adopts this faster variant.
232 */
233 const int length = radius*2 + 1;
234 const int inv = ((1<<16) + length/2)/length;
235 int x, sum = 0;
236
237 for (x = 0; x < radius; x++)
238 sum += src[x*src_step]<<1;
239 sum += src[radius*src_step];
240
241 for (x = 0; x <= radius; x++) {
242 sum += src[(radius+x)*src_step] - src[(radius-x)*src_step];
243 dst[x*dst_step] = (sum*inv + (1<<15))>>16;
244 }
245
246 for (; x < len-radius; x++) {
247 sum += src[(radius+x)*src_step] - src[(x-radius-1)*src_step];
248 dst[x*dst_step] = (sum*inv + (1<<15))>>16;
249 }
250
251 for (; x < len; x++) {
252 sum += src[(2*len-radius-x-1)*src_step] - src[(x-radius-1)*src_step];
253 dst[x*dst_step] = (sum*inv + (1<<15))>>16;
254 }
255 }
256
257 static inline void blur_power(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
258 int len, int radius, int power, uint8_t *temp[2])
259 {
260 uint8_t *a = temp[0], *b = temp[1];
261
262 if (radius && power) {
263 blur(a, 1, src, src_step, len, radius);
264 for (; power > 2; power--) {
265 uint8_t *c;
266 blur(b, 1, a, 1, len, radius);
267 c = a; a = b; b = c;
268 }
269 if (power > 1) {
270 blur(dst, dst_step, a, 1, len, radius);
271 } else {
272 int i;
273 for (i = 0; i < len; i++)
274 dst[i*dst_step] = a[i];
275 }
276 } else {
277 int i;
278 for (i = 0; i < len; i++)
279 dst[i*dst_step] = src[i*src_step];
280 }
281 }
282
283 static void hblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
284 int w, int h, int radius, int power, uint8_t *temp[2])
285 {
286 int y;
287
288 if (radius == 0 && dst == src)
289 return;
290
291 for (y = 0; y < h; y++)
292 blur_power(dst + y*dst_linesize, 1, src + y*src_linesize, 1,
293 w, radius, power, temp);
294 }
295
296 static void vblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
297 int w, int h, int radius, int power, uint8_t *temp[2])
298 {
299 int x;
300
301 if (radius == 0 && dst == src)
302 return;
303
304 for (x = 0; x < w; x++)
305 blur_power(dst + x, dst_linesize, src + x, src_linesize,
306 h, radius, power, temp);
307 }
308
309 static void draw_slice(AVFilterLink *inlink, int y0, int h0, int slice_dir)
310 {
311 AVFilterContext *ctx = inlink->dst;
312 BoxBlurContext *boxblur = ctx->priv;
313 AVFilterLink *outlink = inlink->dst->outputs[0];
314 AVFilterBufferRef *inpicref = inlink ->cur_buf;
315 AVFilterBufferRef *outpicref = outlink->out_buf;
316 int plane;
317 int cw = inlink->w >> boxblur->hsub, ch = h0 >> boxblur->vsub;
318 int w[4] = { inlink->w, cw, cw, inlink->w };
319 int h[4] = { h0, ch, ch, h0 };
320
321 for (plane = 0; inpicref->data[plane] && plane < 4; plane++)
322 hblur(outpicref->data[plane], outpicref->linesize[plane],
323 inpicref ->data[plane], inpicref ->linesize[plane],
324 w[plane], h[plane], boxblur->radius[plane], boxblur->power[plane],
325 boxblur->temp);
326
327 for (plane = 0; inpicref->data[plane] && plane < 4; plane++)
328 vblur(outpicref->data[plane], outpicref->linesize[plane],
329 outpicref->data[plane], outpicref->linesize[plane],
330 w[plane], h[plane], boxblur->radius[plane], boxblur->power[plane],
331 boxblur->temp);
332
333 ff_draw_slice(outlink, y0, h0, slice_dir);
334 }
335
336 AVFilter avfilter_vf_boxblur = {
337 .name = "boxblur",
338 .description = NULL_IF_CONFIG_SMALL("Blur the input."),
339 .priv_size = sizeof(BoxBlurContext),
340 .init = init,
341 .uninit = uninit,
342 .query_formats = query_formats,
343
344 .inputs = (const AVFilterPad[]) {{ .name = "default",
345 .type = AVMEDIA_TYPE_VIDEO,
346 .config_props = config_input,
347 .draw_slice = draw_slice,
348 .min_perms = AV_PERM_READ },
349 { .name = NULL}},
350 .outputs = (const AVFilterPad[]) {{ .name = "default",
351 .type = AVMEDIA_TYPE_VIDEO, },
352 { .name = NULL}},
353 };