2 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
3 * Copyright (c) 2011 Stefano Sabatini
5 * This file is part of FFmpeg.
7 * FFmpeg 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.
12 * FFmpeg 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.
17 * You should have received a copy of the GNU General Public License along
18 * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 * Apply a boxblur filter to the input video.
25 * Ported from MPlayer libmpcodecs/vf_boxblur.c.
28 #include "libavutil/avstring.h"
29 #include "libavutil/common.h"
30 #include "libavutil/eval.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/pixdesc.h"
38 static const char *const var_names[] = {
58 typedef struct FilterParam {
64 typedef struct BoxBlurContext {
66 FilterParam luma_param;
67 FilterParam chroma_param;
68 FilterParam alpha_param;
73 uint8_t *temp[2]; ///< temporary buffer used in blur_power()
81 static av_cold int init(AVFilterContext *ctx)
83 BoxBlurContext *s = ctx->priv;
85 if (!s->luma_param.radius_expr) {
86 av_log(ctx, AV_LOG_ERROR, "Luma radius expression is not set.\n");
87 return AVERROR(EINVAL);
90 /* fill missing params */
91 if (!s->chroma_param.radius_expr) {
92 s->chroma_param.radius_expr = av_strdup(s->luma_param.radius_expr);
93 if (!s->chroma_param.radius_expr)
94 return AVERROR(ENOMEM);
96 if (s->chroma_param.power < 0)
97 s->chroma_param.power = s->luma_param.power;
99 if (!s->alpha_param.radius_expr) {
100 s->alpha_param.radius_expr = av_strdup(s->luma_param.radius_expr);
101 if (!s->alpha_param.radius_expr)
102 return AVERROR(ENOMEM);
104 if (s->alpha_param.power < 0)
105 s->alpha_param.power = s->luma_param.power;
110 static av_cold void uninit(AVFilterContext *ctx)
112 BoxBlurContext *s = ctx->priv;
114 av_freep(&s->temp[0]);
115 av_freep(&s->temp[1]);
118 static int query_formats(AVFilterContext *ctx)
120 static const enum AVPixelFormat pix_fmts[] = {
121 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P,
122 AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUVA420P,
123 AV_PIX_FMT_YUV440P, AV_PIX_FMT_GRAY8,
124 AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
129 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
133 static int config_input(AVFilterLink *inlink)
135 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
136 AVFilterContext *ctx = inlink->dst;
137 BoxBlurContext *s = ctx->priv;
138 int w = inlink->w, h = inlink->h;
140 double var_values[VARS_NB], res;
144 if (!(s->temp[0] = av_malloc(FFMAX(w, h))) ||
145 !(s->temp[1] = av_malloc(FFMAX(w, h))))
146 return AVERROR(ENOMEM);
148 s->hsub = desc->log2_chroma_w;
149 s->vsub = desc->log2_chroma_h;
151 var_values[VAR_W] = inlink->w;
152 var_values[VAR_H] = inlink->h;
153 var_values[VAR_CW] = cw = w>>s->hsub;
154 var_values[VAR_CH] = ch = h>>s->vsub;
155 var_values[VAR_HSUB] = 1<<s->hsub;
156 var_values[VAR_VSUB] = 1<<s->vsub;
158 #define EVAL_RADIUS_EXPR(comp) \
159 expr = s->comp##_param.radius_expr; \
160 ret = av_expr_parse_and_eval(&res, expr, var_names, var_values, \
161 NULL, NULL, NULL, NULL, NULL, 0, ctx); \
162 s->comp##_param.radius = res; \
164 av_log(NULL, AV_LOG_ERROR, \
165 "Error when evaluating " #comp " radius expression '%s'\n", expr); \
168 EVAL_RADIUS_EXPR(luma);
169 EVAL_RADIUS_EXPR(chroma);
170 EVAL_RADIUS_EXPR(alpha);
172 av_log(ctx, AV_LOG_VERBOSE,
173 "luma_radius:%d luma_power:%d "
174 "chroma_radius:%d chroma_power:%d "
175 "alpha_radius:%d alpha_power:%d "
176 "w:%d chroma_w:%d h:%d chroma_h:%d\n",
177 s->luma_param .radius, s->luma_param .power,
178 s->chroma_param.radius, s->chroma_param.power,
179 s->alpha_param .radius, s->alpha_param .power,
182 #define CHECK_RADIUS_VAL(w_, h_, comp) \
183 if (s->comp##_param.radius < 0 || \
184 2*s->comp##_param.radius > FFMIN(w_, h_)) { \
185 av_log(ctx, AV_LOG_ERROR, \
186 "Invalid " #comp " radius value %d, must be >= 0 and <= %d\n", \
187 s->comp##_param.radius, FFMIN(w_, h_)/2); \
188 return AVERROR(EINVAL); \
190 CHECK_RADIUS_VAL(w, h, luma);
191 CHECK_RADIUS_VAL(cw, ch, chroma);
192 CHECK_RADIUS_VAL(w, h, alpha);
194 s->radius[Y] = s->luma_param.radius;
195 s->radius[U] = s->radius[V] = s->chroma_param.radius;
196 s->radius[A] = s->alpha_param.radius;
198 s->power[Y] = s->luma_param.power;
199 s->power[U] = s->power[V] = s->chroma_param.power;
200 s->power[A] = s->alpha_param.power;
205 static inline void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
208 /* Naive boxblur would sum source pixels from x-radius .. x+radius
209 * for destination pixel x. That would be O(radius*width).
210 * If you now look at what source pixels represent 2 consecutive
211 * output pixels, then you see they are almost identical and only
212 * differ by 2 pixels, like:
218 * so when you know one output pixel you can find the next by just adding
219 * and subtracting 1 input pixel.
220 * The following code adopts this faster variant.
222 const int length = radius*2 + 1;
223 const int inv = ((1<<16) + length/2)/length;
226 for (x = 0; x < radius; x++)
227 sum += src[x*src_step]<<1;
228 sum += src[radius*src_step];
230 for (x = 0; x <= radius; x++) {
231 sum += src[(radius+x)*src_step] - src[(radius-x)*src_step];
232 dst[x*dst_step] = (sum*inv + (1<<15))>>16;
235 for (; x < len-radius; x++) {
236 sum += src[(radius+x)*src_step] - src[(x-radius-1)*src_step];
237 dst[x*dst_step] = (sum*inv + (1<<15))>>16;
240 for (; x < len; x++) {
241 sum += src[(2*len-radius-x-1)*src_step] - src[(x-radius-1)*src_step];
242 dst[x*dst_step] = (sum*inv + (1<<15))>>16;
246 static inline void blur_power(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
247 int len, int radius, int power, uint8_t *temp[2])
249 uint8_t *a = temp[0], *b = temp[1];
251 if (radius && power) {
252 blur(a, 1, src, src_step, len, radius);
253 for (; power > 2; power--) {
255 blur(b, 1, a, 1, len, radius);
259 blur(dst, dst_step, a, 1, len, radius);
262 for (i = 0; i < len; i++)
263 dst[i*dst_step] = a[i];
267 for (i = 0; i < len; i++)
268 dst[i*dst_step] = src[i*src_step];
272 static void hblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
273 int w, int h, int radius, int power, uint8_t *temp[2])
277 if (radius == 0 && dst == src)
280 for (y = 0; y < h; y++)
281 blur_power(dst + y*dst_linesize, 1, src + y*src_linesize, 1,
282 w, radius, power, temp);
285 static void vblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
286 int w, int h, int radius, int power, uint8_t *temp[2])
290 if (radius == 0 && dst == src)
293 for (x = 0; x < w; x++)
294 blur_power(dst + x, dst_linesize, src + x, src_linesize,
295 h, radius, power, temp);
298 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
300 AVFilterContext *ctx = inlink->dst;
301 BoxBlurContext *s = ctx->priv;
302 AVFilterLink *outlink = inlink->dst->outputs[0];
305 int cw = FF_CEIL_RSHIFT(inlink->w, s->hsub), ch = FF_CEIL_RSHIFT(in->height, s->vsub);
306 int w[4] = { inlink->w, cw, cw, inlink->w };
307 int h[4] = { in->height, ch, ch, in->height };
309 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
312 return AVERROR(ENOMEM);
314 av_frame_copy_props(out, in);
316 for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
317 hblur(out->data[plane], out->linesize[plane],
318 in ->data[plane], in ->linesize[plane],
319 w[plane], h[plane], s->radius[plane], s->power[plane],
322 for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
323 vblur(out->data[plane], out->linesize[plane],
324 out->data[plane], out->linesize[plane],
325 w[plane], h[plane], s->radius[plane], s->power[plane],
330 return ff_filter_frame(outlink, out);
333 #define OFFSET(x) offsetof(BoxBlurContext, x)
334 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
336 static const AVOption boxblur_options[] = {
337 { "luma_radius", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
338 { "lr", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
339 { "luma_power", "How many times should the boxblur be applied to luma", OFFSET(luma_param.power), AV_OPT_TYPE_INT, {.i64=2}, 0, INT_MAX, .flags = FLAGS },
340 { "lp", "How many times should the boxblur be applied to luma", OFFSET(luma_param.power), AV_OPT_TYPE_INT, {.i64=2}, 0, INT_MAX, .flags = FLAGS },
342 { "chroma_radius", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
343 { "cr", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
344 { "chroma_power", "How many times should the boxblur be applied to chroma", OFFSET(chroma_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
345 { "cp", "How many times should the boxblur be applied to chroma", OFFSET(chroma_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
347 { "alpha_radius", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
348 { "ar", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
349 { "alpha_power", "How many times should the boxblur be applied to alpha", OFFSET(alpha_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
350 { "ap", "How many times should the boxblur be applied to alpha", OFFSET(alpha_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
355 AVFILTER_DEFINE_CLASS(boxblur);
357 static const AVFilterPad avfilter_vf_boxblur_inputs[] = {
360 .type = AVMEDIA_TYPE_VIDEO,
361 .config_props = config_input,
362 .filter_frame = filter_frame,
367 static const AVFilterPad avfilter_vf_boxblur_outputs[] = {
370 .type = AVMEDIA_TYPE_VIDEO,
375 AVFilter ff_vf_boxblur = {
377 .description = NULL_IF_CONFIG_SMALL("Blur the input."),
378 .priv_size = sizeof(BoxBlurContext),
379 .priv_class = &boxblur_class,
382 .query_formats = query_formats,
383 .inputs = avfilter_vf_boxblur_inputs,
384 .outputs = avfilter_vf_boxblur_outputs,
385 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,