FFmpeg
vf_boxblur.c
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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/common.h"
29 #include "libavutil/mem.h"
30 #include "libavutil/opt.h"
31 #include "avfilter.h"
32 #include "filters.h"
33 #include "formats.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 
58 static int query_formats(const AVFilterContext *ctx,
59  AVFilterFormatsConfig **cfg_in,
60  AVFilterFormatsConfig **cfg_out)
61 {
63  int fmt, ret;
64 
65  for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
68  (desc->flags & AV_PIX_FMT_FLAG_PLANAR || desc->nb_components == 1) &&
69  (!(desc->flags & AV_PIX_FMT_FLAG_BE) == !HAVE_BIGENDIAN || desc->comp[0].depth == 8) &&
70  (ret = ff_add_format(&formats, fmt)) < 0)
71  return ret;
72  }
73 
74  return ff_set_common_formats2(ctx, cfg_in, cfg_out, formats);
75 }
76 
78 {
80  AVFilterContext *ctx = inlink->dst;
81  BoxBlurContext *s = ctx->priv;
82  int w = inlink->w, h = inlink->h;
83  int ret;
84 
85  if (!(s->temp[0] = av_malloc(2*FFMAX(w, h))) ||
86  !(s->temp[1] = av_malloc(2*FFMAX(w, h))))
87  return AVERROR(ENOMEM);
88 
89  s->hsub = desc->log2_chroma_w;
90  s->vsub = desc->log2_chroma_h;
91 
93  &s->luma_param,
94  &s->chroma_param,
95  &s->alpha_param);
96 
97  if (ret != 0) {
98  av_log(ctx, AV_LOG_ERROR, "Failed to evaluate "
99  "filter params: %d.\n", ret);
100  return ret;
101  }
102 
103  s->radius[Y] = s->luma_param.radius;
104  s->radius[U] = s->radius[V] = s->chroma_param.radius;
105  s->radius[A] = s->alpha_param.radius;
106 
107  s->power[Y] = s->luma_param.power;
108  s->power[U] = s->power[V] = s->chroma_param.power;
109  s->power[A] = s->alpha_param.power;
110 
111  return 0;
112 }
113 
114 /* Naive boxblur would sum source pixels from x-radius .. x+radius
115  * for destination pixel x. That would be O(radius*width).
116  * If you now look at what source pixels represent 2 consecutive
117  * output pixels, then you see they are almost identical and only
118  * differ by 2 pixels, like:
119  * src0 111111111
120  * dst0 1
121  * src1 111111111
122  * dst1 1
123  * src0-src1 1 -1
124  * so when you know one output pixel you can find the next by just adding
125  * and subtracting 1 input pixel.
126  * The following code adopts this faster variant.
127  */
128 #define BLUR(type, depth) \
129 static inline void blur ## depth(type *dst, int dst_step, const type *src, \
130  int src_step, int len, int radius) \
131 { \
132  const int length = radius*2 + 1; \
133  const int inv = ((1<<16) + length/2)/length; \
134  int x, sum = src[radius*src_step]; \
135  \
136  for (x = 0; x < radius; x++) \
137  sum += src[x*src_step]<<1; \
138  \
139  sum = sum*inv + (1<<15); \
140  \
141  for (x = 0; x <= radius; x++) { \
142  sum += (src[(radius+x)*src_step] - src[(radius-x)*src_step])*inv; \
143  dst[x*dst_step] = sum>>16; \
144  } \
145  \
146  for (; x < len-radius; x++) { \
147  sum += (src[(radius+x)*src_step] - src[(x-radius-1)*src_step])*inv; \
148  dst[x*dst_step] = sum >>16; \
149  } \
150  \
151  for (; x < len; x++) { \
152  sum += (src[(2*len-radius-x-1)*src_step] - src[(x-radius-1)*src_step])*inv; \
153  dst[x*dst_step] = sum>>16; \
154  } \
155 }
156 
157 BLUR(uint8_t, 8)
158 BLUR(uint16_t, 16)
159 
160 #undef BLUR
161 
162 static inline void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
163  int len, int radius, int pixsize)
164 {
165  if (pixsize == 1) blur8 (dst, dst_step , src, src_step , len, radius);
166  else blur16((uint16_t*)dst, dst_step>>1, (const uint16_t*)src, src_step>>1, len, radius);
167 }
168 
169 static inline void blur_power(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
170  int len, int radius, int power, uint8_t *temp[2], int pixsize)
171 {
172  uint8_t *a = temp[0], *b = temp[1];
173 
174  if (radius && power) {
175  blur(a, pixsize, src, src_step, len, radius, pixsize);
176  for (; power > 2; power--) {
177  uint8_t *c;
178  blur(b, pixsize, a, pixsize, len, radius, pixsize);
179  c = a; a = b; b = c;
180  }
181  if (power > 1) {
182  blur(dst, dst_step, a, pixsize, len, radius, pixsize);
183  } else {
184  int i;
185  if (pixsize == 1) {
186  for (i = 0; i < len; i++)
187  dst[i*dst_step] = a[i];
188  } else
189  for (i = 0; i < len; i++)
190  *(uint16_t*)(dst + i*dst_step) = ((uint16_t*)a)[i];
191  }
192  } else {
193  int i;
194  if (pixsize == 1) {
195  for (i = 0; i < len; i++)
196  dst[i*dst_step] = src[i*src_step];
197  } else
198  for (i = 0; i < len; i++)
199  *(uint16_t*)(dst + i*dst_step) = *(uint16_t*)(src + i*src_step);
200  }
201 }
202 
203 static void hblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
204  int w, int h, int radius, int power, uint8_t *temp[2], int pixsize)
205 {
206  int y;
207 
208  if (radius == 0 && dst == src)
209  return;
210 
211  for (y = 0; y < h; y++)
212  blur_power(dst + y*dst_linesize, pixsize, src + y*src_linesize, pixsize,
213  w, radius, power, temp, pixsize);
214 }
215 
216 static void vblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
217  int w, int h, int radius, int power, uint8_t *temp[2], int pixsize)
218 {
219  int x;
220 
221  if (radius == 0 && dst == src)
222  return;
223 
224  for (x = 0; x < w; x++)
225  blur_power(dst + x*pixsize, dst_linesize, src + x*pixsize, src_linesize,
226  h, radius, power, temp, pixsize);
227 }
228 
230 {
231  AVFilterContext *ctx = inlink->dst;
232  BoxBlurContext *s = ctx->priv;
233  AVFilterLink *outlink = inlink->dst->outputs[0];
234  AVFrame *out;
235  int plane;
236  int cw = AV_CEIL_RSHIFT(inlink->w, s->hsub), ch = AV_CEIL_RSHIFT(in->height, s->vsub);
237  int w[4] = { inlink->w, cw, cw, inlink->w };
238  int h[4] = { in->height, ch, ch, in->height };
240  const int depth = desc->comp[0].depth;
241  const int pixsize = (depth+7)/8;
242 
243  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
244  if (!out) {
245  av_frame_free(&in);
246  return AVERROR(ENOMEM);
247  }
249 
250  for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
251  hblur(out->data[plane], out->linesize[plane],
252  in ->data[plane], in ->linesize[plane],
253  w[plane], h[plane], s->radius[plane], s->power[plane],
254  s->temp, pixsize);
255 
256  for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
257  vblur(out->data[plane], out->linesize[plane],
258  out->data[plane], out->linesize[plane],
259  w[plane], h[plane], s->radius[plane], s->power[plane],
260  s->temp, pixsize);
261 
262  av_frame_free(&in);
263 
264  return ff_filter_frame(outlink, out);
265 }
266 
267 #define OFFSET(x) offsetof(BoxBlurContext, x)
268 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
269 
270 static const AVOption boxblur_options[] = {
271  { "luma_radius", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
272  { "lr", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
273  { "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 },
274  { "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 },
275 
276  { "chroma_radius", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
277  { "cr", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
278  { "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 },
279  { "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 },
280 
281  { "alpha_radius", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
282  { "ar", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
283  { "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 },
284  { "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 },
285 
286  { NULL }
287 };
288 
289 AVFILTER_DEFINE_CLASS(boxblur);
290 
292  {
293  .name = "default",
294  .type = AVMEDIA_TYPE_VIDEO,
295  .config_props = config_input,
296  .filter_frame = filter_frame,
297  },
298 };
299 
301  .name = "boxblur",
302  .description = NULL_IF_CONFIG_SMALL("Blur the input."),
303  .priv_size = sizeof(BoxBlurContext),
304  .priv_class = &boxblur_class,
305  .uninit = uninit,
310 };
BoxBlurContext::vsub
int vsub
Definition: vf_boxblur.c:44
formats
formats
Definition: signature.h:47
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:116
A
#define A(x)
Definition: vpx_arith.h:28
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:55
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1062
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:3025
ff_set_common_formats2
int ff_set_common_formats2(const AVFilterContext *ctx, AVFilterFormatsConfig **cfg_in, AVFilterFormatsConfig **cfg_out, AVFilterFormats *formats)
Definition: formats.c:1007
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:162
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:169
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: filters.h:262
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:429
b
#define b
Definition: input.c:41
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:205
video.h
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:410
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
AVFilterFormats
A list of supported formats for one end of a filter link.
Definition: formats.h:64
formats.h
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: filters.h:38
query_formats
static int query_formats(const AVFilterContext *ctx, AVFilterFormatsConfig **cfg_in, AVFilterFormatsConfig **cfg_out)
Definition: vf_boxblur.c:58
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:47
ff_vf_boxblur
const AVFilter ff_vf_boxblur
Definition: vf_boxblur.c:300
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:209
av_cold
#define av_cold
Definition: attributes.h:90
ff_video_default_filterpad
const AVFilterPad ff_video_default_filterpad[1]
An AVFilterPad array whose only entry has name "default" and is of type AVMEDIA_TYPE_VIDEO.
Definition: video.c:37
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:60
BoxBlurContext::power
int power[4]
Definition: vf_boxblur.c:46
filters.h
ctx
AVFormatContext * ctx
Definition: movenc.c:49
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: filters.h:263
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_boxblur.c:77
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:203
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
boxblur_options
static const AVOption boxblur_options[]
Definition: vf_boxblur.c:270
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:713
V
#define V
Definition: avdct.c:31
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:504
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_boxblur.c:229
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
AVFilterFormatsConfig
Lists of formats / etc.
Definition: avfilter.h:111
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:162
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:94
dst
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst
Definition: dsp.h:83
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:267
Y
#define Y
Definition: boxblur.h:37
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:182
avfilter_vf_boxblur_inputs
static const AVFilterPad avfilter_vf_boxblur_inputs[]
Definition: vf_boxblur.c:291
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
common.h
FILTER_QUERY_FUNC2
#define FILTER_QUERY_FUNC2(func)
Definition: filters.h:239
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: filters.h:44
AVFilter
Filter definition.
Definition: avfilter.h:201
ret
ret
Definition: filter_design.txt:187
BoxBlurContext::hsub
int hsub
Definition: vf_boxblur.c:44
U
#define U(x)
Definition: vpx_arith.h:37
AVFrame::height
int height
Definition: frame.h:461
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
Underlying C type is int.
Definition: opt.h:259
avfilter.h
temp
else temp
Definition: vf_mcdeint.c:263
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:457
desc
const char * desc
Definition: libsvtav1.c:79
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
BLUR
#define BLUR(type, depth)
Definition: vf_boxblur.c:128
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
FLAGS
#define FLAGS
Definition: vf_boxblur.c:268
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:434
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
h
h
Definition: vp9dsp_template.c:2070
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:216
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Underlying C type is a uint8_t* that is either NULL or points to a C string allocated with the av_mal...
Definition: opt.h:276
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)
src
#define src
Definition: vp8dsp.c:248
BoxBlurContext::radius
int radius[4]
Definition: vf_boxblur.c:45