1 /*
2 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
3 * Copyright (c) 2011 Stefano Sabatini
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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.
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/common.h"
30 #include "libavutil/opt.h"
31 #include "avfilter.h"
32 #include "formats.h"
33 #include "internal.h"
34 #include "video.h"
35 #include "boxblur.h"
36
37
38 typedef struct BoxBlurContext {
39 const AVClass *class;
40 FilterParam luma_param;
41 FilterParam chroma_param;
42 FilterParam alpha_param;
43
44 int hsub, vsub;
45 int radius[4];
46 int power[4];
47 uint8_t *temp[2]; ///< temporary buffer used in blur_power()
48 } BoxBlurContext;
49
uninit(AVFilterContext * ctx)50 static av_cold void uninit(AVFilterContext *ctx)
51 {
52 BoxBlurContext *s = ctx->priv;
53
54 av_freep(&s->temp[0]);
55 av_freep(&s->temp[1]);
56 }
57
query_formats(AVFilterContext * ctx)58 static int query_formats(AVFilterContext *ctx)
59 {
60 AVFilterFormats *formats = NULL;
61 int fmt, ret;
62
63 for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
64 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
65 if (!(desc->flags & (AV_PIX_FMT_FLAG_HWACCEL | AV_PIX_FMT_FLAG_BITSTREAM | AV_PIX_FMT_FLAG_PAL)) &&
66 (desc->flags & AV_PIX_FMT_FLAG_PLANAR || desc->nb_components == 1) &&
67 (!(desc->flags & AV_PIX_FMT_FLAG_BE) == !HAVE_BIGENDIAN || desc->comp[0].depth == 8) &&
68 (ret = ff_add_format(&formats, fmt)) < 0)
69 return ret;
70 }
71
72 return ff_set_common_formats(ctx, formats);
73 }
74
config_input(AVFilterLink * inlink)75 static int config_input(AVFilterLink *inlink)
76 {
77 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
78 AVFilterContext *ctx = inlink->dst;
79 BoxBlurContext *s = ctx->priv;
80 int w = inlink->w, h = inlink->h;
81 int ret;
82
83 if (!(s->temp[0] = av_malloc(2*FFMAX(w, h))) ||
84 !(s->temp[1] = av_malloc(2*FFMAX(w, h))))
85 return AVERROR(ENOMEM);
86
87 s->hsub = desc->log2_chroma_w;
88 s->vsub = desc->log2_chroma_h;
89
90 ret = ff_boxblur_eval_filter_params(inlink,
91 &s->luma_param,
92 &s->chroma_param,
93 &s->alpha_param);
94
95 if (ret != 0) {
96 av_log(ctx, AV_LOG_ERROR, "Failed to evaluate "
97 "filter params: %d.\n", ret);
98 return ret;
99 }
100
101 s->radius[Y] = s->luma_param.radius;
102 s->radius[U] = s->radius[V] = s->chroma_param.radius;
103 s->radius[A] = s->alpha_param.radius;
104
105 s->power[Y] = s->luma_param.power;
106 s->power[U] = s->power[V] = s->chroma_param.power;
107 s->power[A] = s->alpha_param.power;
108
109 return 0;
110 }
111
112 /* Naive boxblur would sum source pixels from x-radius .. x+radius
113 * for destination pixel x. That would be O(radius*width).
114 * If you now look at what source pixels represent 2 consecutive
115 * output pixels, then you see they are almost identical and only
116 * differ by 2 pixels, like:
117 * src0 111111111
118 * dst0 1
119 * src1 111111111
120 * dst1 1
121 * src0-src1 1 -1
122 * so when you know one output pixel you can find the next by just adding
123 * and subtracting 1 input pixel.
124 * The following code adopts this faster variant.
125 */
126 #define BLUR(type, depth) \
127 static inline void blur ## depth(type *dst, int dst_step, const type *src, \
128 int src_step, int len, int radius) \
129 { \
130 const int length = radius*2 + 1; \
131 const int inv = ((1<<16) + length/2)/length; \
132 int x, sum = src[radius*src_step]; \
133 \
134 for (x = 0; x < radius; x++) \
135 sum += src[x*src_step]<<1; \
136 \
137 sum = sum*inv + (1<<15); \
138 \
139 for (x = 0; x <= radius; x++) { \
140 sum += (src[(radius+x)*src_step] - src[(radius-x)*src_step])*inv; \
141 dst[x*dst_step] = sum>>16; \
142 } \
143 \
144 for (; x < len-radius; x++) { \
145 sum += (src[(radius+x)*src_step] - src[(x-radius-1)*src_step])*inv; \
146 dst[x*dst_step] = sum >>16; \
147 } \
148 \
149 for (; x < len; x++) { \
150 sum += (src[(2*len-radius-x-1)*src_step] - src[(x-radius-1)*src_step])*inv; \
151 dst[x*dst_step] = sum>>16; \
152 } \
153 }
154
155 BLUR(uint8_t, 8)
156 BLUR(uint16_t, 16)
157
158 #undef BLUR
159
blur(uint8_t * dst,int dst_step,const uint8_t * src,int src_step,int len,int radius,int pixsize)160 static inline void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
161 int len, int radius, int pixsize)
162 {
163 if (pixsize == 1) blur8 (dst, dst_step , src, src_step , len, radius);
164 else blur16((uint16_t*)dst, dst_step>>1, (const uint16_t*)src, src_step>>1, len, radius);
165 }
166
blur_power(uint8_t * dst,int dst_step,const uint8_t * src,int src_step,int len,int radius,int power,uint8_t * temp[2],int pixsize)167 static inline void blur_power(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
168 int len, int radius, int power, uint8_t *temp[2], int pixsize)
169 {
170 uint8_t *a = temp[0], *b = temp[1];
171
172 if (radius && power) {
173 blur(a, pixsize, src, src_step, len, radius, pixsize);
174 for (; power > 2; power--) {
175 uint8_t *c;
176 blur(b, pixsize, a, pixsize, len, radius, pixsize);
177 c = a; a = b; b = c;
178 }
179 if (power > 1) {
180 blur(dst, dst_step, a, pixsize, len, radius, pixsize);
181 } else {
182 int i;
183 if (pixsize == 1) {
184 for (i = 0; i < len; i++)
185 dst[i*dst_step] = a[i];
186 } else
187 for (i = 0; i < len; i++)
188 *(uint16_t*)(dst + i*dst_step) = ((uint16_t*)a)[i];
189 }
190 } else {
191 int i;
192 if (pixsize == 1) {
193 for (i = 0; i < len; i++)
194 dst[i*dst_step] = src[i*src_step];
195 } else
196 for (i = 0; i < len; i++)
197 *(uint16_t*)(dst + i*dst_step) = *(uint16_t*)(src + i*src_step);
198 }
199 }
200
hblur(uint8_t * dst,int dst_linesize,const uint8_t * src,int src_linesize,int w,int h,int radius,int power,uint8_t * temp[2],int pixsize)201 static void hblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
202 int w, int h, int radius, int power, uint8_t *temp[2], int pixsize)
203 {
204 int y;
205
206 if (radius == 0 && dst == src)
207 return;
208
209 for (y = 0; y < h; y++)
210 blur_power(dst + y*dst_linesize, pixsize, src + y*src_linesize, pixsize,
211 w, radius, power, temp, pixsize);
212 }
213
vblur(uint8_t * dst,int dst_linesize,const uint8_t * src,int src_linesize,int w,int h,int radius,int power,uint8_t * temp[2],int pixsize)214 static void vblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
215 int w, int h, int radius, int power, uint8_t *temp[2], int pixsize)
216 {
217 int x;
218
219 if (radius == 0 && dst == src)
220 return;
221
222 for (x = 0; x < w; x++)
223 blur_power(dst + x*pixsize, dst_linesize, src + x*pixsize, src_linesize,
224 h, radius, power, temp, pixsize);
225 }
226
filter_frame(AVFilterLink * inlink,AVFrame * in)227 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
228 {
229 AVFilterContext *ctx = inlink->dst;
230 BoxBlurContext *s = ctx->priv;
231 AVFilterLink *outlink = inlink->dst->outputs[0];
232 AVFrame *out;
233 int plane;
234 int cw = AV_CEIL_RSHIFT(inlink->w, s->hsub), ch = AV_CEIL_RSHIFT(in->height, s->vsub);
235 int w[4] = { inlink->w, cw, cw, inlink->w };
236 int h[4] = { in->height, ch, ch, in->height };
237 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
238 const int depth = desc->comp[0].depth;
239 const int pixsize = (depth+7)/8;
240
241 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
242 if (!out) {
243 av_frame_free(&in);
244 return AVERROR(ENOMEM);
245 }
246 av_frame_copy_props(out, in);
247
248 for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
249 hblur(out->data[plane], out->linesize[plane],
250 in ->data[plane], in ->linesize[plane],
251 w[plane], h[plane], s->radius[plane], s->power[plane],
252 s->temp, pixsize);
253
254 for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
255 vblur(out->data[plane], out->linesize[plane],
256 out->data[plane], out->linesize[plane],
257 w[plane], h[plane], s->radius[plane], s->power[plane],
258 s->temp, pixsize);
259
260 av_frame_free(&in);
261
262 return ff_filter_frame(outlink, out);
263 }
264
265 #define OFFSET(x) offsetof(BoxBlurContext, x)
266 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
267
268 static const AVOption boxblur_options[] = {
269 { "luma_radius", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
270 { "lr", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
271 { "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 },
272 { "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 },
273
274 { "chroma_radius", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
275 { "cr", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
276 { "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 },
277 { "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 },
278
279 { "alpha_radius", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
280 { "ar", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
281 { "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 },
282 { "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 },
283
284 { NULL }
285 };
286
287 AVFILTER_DEFINE_CLASS(boxblur);
288
289 static const AVFilterPad avfilter_vf_boxblur_inputs[] = {
290 {
291 .name = "default",
292 .type = AVMEDIA_TYPE_VIDEO,
293 .config_props = config_input,
294 .filter_frame = filter_frame,
295 },
296 { NULL }
297 };
298
299 static const AVFilterPad avfilter_vf_boxblur_outputs[] = {
300 {
301 .name = "default",
302 .type = AVMEDIA_TYPE_VIDEO,
303 },
304 { NULL }
305 };
306
307 AVFilter ff_vf_boxblur = {
308 .name = "boxblur",
309 .description = NULL_IF_CONFIG_SMALL("Blur the input."),
310 .priv_size = sizeof(BoxBlurContext),
311 .priv_class = &boxblur_class,
312 .uninit = uninit,
313 .query_formats = query_formats,
314 .inputs = avfilter_vf_boxblur_inputs,
315 .outputs = avfilter_vf_boxblur_outputs,
316 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
317 };
318