FFmpeg
vf_boxblur.c
Go to the documentation of this file.
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;
43 
44  int hsub, vsub;
45  int radius[4];
46  int power[4];
47  uint8_t *temp[2]; ///< temporary buffer used in blur_power()
49 
51 {
52  BoxBlurContext *s = ctx->priv;
53 
54  av_freep(&s->temp[0]);
55  av_freep(&s->temp[1]);
56 }
57 
59 {
61  int fmt, ret;
62 
63  for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
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 
73 }
74 
76 {
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 
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 
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 
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 
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 
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 
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 };
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  }
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 
290  {
291  .name = "default",
292  .type = AVMEDIA_TYPE_VIDEO,
293  .config_props = config_input,
294  .filter_frame = filter_frame,
295  },
296 };
297 
299  {
300  .name = "default",
301  .type = AVMEDIA_TYPE_VIDEO,
302  },
303 };
304 
306  .name = "boxblur",
307  .description = NULL_IF_CONFIG_SMALL("Blur the input."),
308  .priv_size = sizeof(BoxBlurContext),
309  .priv_class = &boxblur_class,
310  .uninit = uninit,
315 };
BoxBlurContext::vsub
int vsub
Definition: vf_boxblur.c:44
formats
formats
Definition: signature.h:48
ff_get_video_buffer
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
Definition: video.c:98
BoxBlurContext
Definition: vf_boxblur.c:38
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
BoxBlurContext::chroma_param
FilterParam chroma_param
Definition: vf_boxblur.c:41
out
FILE * out
Definition: movenc.c:54
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1018
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2564
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: vf_boxblur.c:58
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
blur_power
static void 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)
Definition: vf_boxblur.c:167
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:247
b
#define b
Definition: input.c:40
FILTER_QUERY_FUNC
#define FILTER_QUERY_FUNC(func)
Definition: internal.h:168
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_boxblur.c:50
BoxBlurContext::luma_param
FilterParam luma_param
Definition: vf_boxblur.c:40
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
video.h
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:317
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVFilterFormats
A list of supported formats for one end of a filter link.
Definition: formats.h:64
formats.h
A
#define A(x)
Definition: vp56_arith.h:28
U
#define U(x)
Definition: vp56_arith.h:37
AV_PIX_FMT_FLAG_HWACCEL
#define AV_PIX_FMT_FLAG_HWACCEL
Pixel format is an HW accelerated format.
Definition: pixdesc.h:128
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
ff_boxblur_eval_filter_params
int ff_boxblur_eval_filter_params(AVFilterLink *inlink, FilterParam *luma_param, FilterParam *chroma_param, FilterParam *alpha_param)
Definition: boxblur.c:46
ff_vf_boxblur
const AVFilter ff_vf_boxblur
Definition: vf_boxblur.c:305
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
ff_set_common_formats
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:699
s
#define s(width, name)
Definition: cbs_vp9.c:257
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:51
BoxBlurContext::power
int power[4]
Definition: vf_boxblur.c:46
ctx
AVFormatContext * ctx
Definition: movenc.c:48
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:191
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_boxblur.c:75
hblur
static void 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)
Definition: vf_boxblur.c:201
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
boxblur_options
static const AVOption boxblur_options[]
Definition: vf_boxblur.c:268
NULL
#define NULL
Definition: coverity.c:32
av_frame_copy_props
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:537
V
#define V
Definition: avdct.c:30
src
#define src
Definition: vp8dsp.c:255
ff_add_format
int ff_add_format(AVFilterFormats **avff, int64_t fmt)
Add fmt to the list of media formats contained in *avff.
Definition: formats.c:420
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_boxblur.c:227
BoxBlurContext::alpha_param
FilterParam alpha_param
Definition: vf_boxblur.c:42
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
blur
static void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step, int len, int radius, int pixsize)
Definition: vf_boxblur.c:160
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
BoxBlurContext::temp
uint8_t * temp[2]
temporary buffer used in blur_power()
Definition: vf_boxblur.c:47
AV_PIX_FMT_FLAG_BITSTREAM
#define AV_PIX_FMT_FLAG_BITSTREAM
All values of a component are bit-wise packed end to end.
Definition: pixdesc.h:124
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
FilterParam
Definition: boxblur.h:31
OFFSET
#define OFFSET(x)
Definition: vf_boxblur.c:265
Y
#define Y
Definition: boxblur.h:37
internal.h
AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
Definition: avfilter.h:130
avfilter_vf_boxblur_inputs
static const AVFilterPad avfilter_vf_boxblur_inputs[]
Definition: vf_boxblur.c:289
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
common.h
AV_PIX_FMT_FLAG_BE
#define AV_PIX_FMT_FLAG_BE
Pixel format is big-endian.
Definition: pixdesc.h:116
boxblur.h
len
int len
Definition: vorbis_enc_data.h:426
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
AVFilter
Filter definition.
Definition: avfilter.h:149
ret
ret
Definition: filter_design.txt:187
BoxBlurContext::hsub
int hsub
Definition: vf_boxblur.c:44
AVFrame::height
int height
Definition: frame.h:361
power
static float power(float r, float g, float b, float max)
Definition: preserve_color.h:45
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
avfilter.h
temp
else temp
Definition: vf_mcdeint.c:248
AV_PIX_FMT_FLAG_PLANAR
#define AV_PIX_FMT_FLAG_PLANAR
At least one pixel component is not in the first data plane.
Definition: pixdesc.h:132
AVFilterContext
An instance of a filter.
Definition: avfilter.h:386
desc
const char * desc
Definition: libsvtav1.c:79
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
BLUR
#define BLUR(type, depth)
Definition: vf_boxblur.c:126
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:192
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
FLAGS
#define FLAGS
Definition: vf_boxblur.c:266
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:334
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
h
h
Definition: vp9dsp_template.c:2038
vblur
static void 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)
Definition: vf_boxblur.c:214
avstring.h
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:228
avfilter_vf_boxblur_outputs
static const AVFilterPad avfilter_vf_boxblur_outputs[]
Definition: vf_boxblur.c:298
AV_PIX_FMT_FLAG_PAL
#define AV_PIX_FMT_FLAG_PAL
Pixel format has a palette in data[1], values are indexes in this palette.
Definition: pixdesc.h:120
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(boxblur)
BoxBlurContext::radius
int radius[4]
Definition: vf_boxblur.c:45