[FFmpeg-devel] [PATCH] lavfi: add smartblur filter

Jérémy Tran tran.jeremy.av at gmail.com
Wed Aug 22 22:23:34 CEST 2012


This is a port of the MPlayer smartblur filter
This is still work in progress, the checksum of the port and
the original filter aren't the same.
---
 doc/filters.texi           |  26 ++++
 libavfilter/Makefile       |   1 +
 libavfilter/allfilters.c   |   1 +
 libavfilter/vf_smartblur.c | 320 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 348 insertions(+)
 create mode 100644 libavfilter/vf_smartblur.c

diff --git a/doc/filters.texi b/doc/filters.texi
index 6e7646f..d888670 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3353,6 +3353,32 @@ not specified it will use the default value of 16.
 Adding this in the beginning of filter chains should make filtering
 faster due to better use of the memory cache.
 
+ at section smartblur
+
+Blur the input video without impacting the outlines.
+
+The filter accepts the following parameters:
+ at var{luma_radius}:@var{luma_strength}:@var{luma_threshold}[:@var{chroma_radius}:@var{chroma_strength}:@var{chroma_threshold}]
+
+Parameters prefixed by @var{luma} indicates that it works on the luminance of the
+pixels whereas parameters prefixed by @var{chroma} refer to the chrominance of
+the pixels.
+
+If the chroma parameters are not set, the luma parameters are used for
+either the luminance and the chrominance of the pixels.
+
+ at var{xxx_radius} must be a float number in the range [0.1,5.0] that specifies
+the blur filter strength (slower if larger).
+
+ at var{xxx_strength} must be a float number in the range [-1.0,1.0] that
+configures the blurring. A value included in [0.0,1.0] will blur the image
+whereas a value included in [-1.0,0.0] will sharpen the image.
+
+ at var{xxx_threshold} must be an integer in the range [-30,30] that is used as a
+coefficient to determine whether a pixel should be blurred or not. A value of
+0 will filter all the image, a value included in [0-30] will filter flat areas
+and a value included in [-30,0] will filter edges.
+
 @section split
 
 Split input video into several identical outputs.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index e91141e..35477e1 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -125,6 +125,7 @@ OBJS-$(CONFIG_SETSAR_FILTER)                 += vf_aspect.o
 OBJS-$(CONFIG_SETTB_FILTER)                  += f_settb.o
 OBJS-$(CONFIG_SHOWINFO_FILTER)               += vf_showinfo.o
 OBJS-$(CONFIG_SLICIFY_FILTER)                += vf_slicify.o
+OBJS-$(CONFIG_SMARTBLUR_FILTER)              += vf_smartblur.o
 OBJS-$(CONFIG_SPLIT_FILTER)                  += split.o
 OBJS-$(CONFIG_SUPER2XSAI_FILTER)             += vf_super2xsai.o
 OBJS-$(CONFIG_SWAPUV_FILTER)                 += vf_swapuv.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 0bc5a4a..cd9bef8 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -116,6 +116,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (SETTB,       settb,       vf);
     REGISTER_FILTER (SHOWINFO,    showinfo,    vf);
     REGISTER_FILTER (SLICIFY,     slicify,     vf);
+    REGISTER_FILTER (SMARTBLUR,   smartblur,   vf);
     REGISTER_FILTER (SPLIT,       split,       vf);
     REGISTER_FILTER (SUPER2XSAI,  super2xsai,  vf);
     REGISTER_FILTER (SWAPUV,      swapuv,      vf);
diff --git a/libavfilter/vf_smartblur.c b/libavfilter/vf_smartblur.c
new file mode 100644
index 0000000..3699ec6
--- /dev/null
+++ b/libavfilter/vf_smartblur.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright (c) 2002 Michael Niedermayer <michaelni at gmx.at>
+ * Copyright (c) 2012 Jeremy Tran
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/**
+ * @file
+ * Apply a smartblur filter to the input video
+ * Ported from MPlayer libmpcodecs/vf_smartblur.c.
+ */
+
+#include "libavutil/pixdesc.h"
+
+#include "libswscale/swscale.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+
+#define RAD_MIN 0.1
+#define RAD_MAX 5.0
+
+#define STRGTH_MIN -1.0
+#define STRGTH_MAX 1.0
+
+#define THRES_MIN -30
+#define THRES_MAX 30
+
+typedef struct {
+    float              radius;
+    float              strength;
+    int                threshold;
+    float              quality;
+    struct SwsContext *filter_context;
+} FilterParam;
+
+typedef struct {
+    FilterParam luma;
+    FilterParam chroma;
+    int         hsub;
+    int         vsub;
+} SmartblurContext;
+
+static inline int validate_input(AVFilterContext *ctx,
+                                 float lradius,    float cradius,
+                                 float lstrength,  float cstrength,
+                                 int   lthreshold, int   cthreshold)
+{
+    int ret = 0;
+
+    if (lradius < RAD_MIN || lradius > RAD_MAX) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid value for luma radius %0.1f: "
+               "must be included between range %0.1f and %0.1f\n",
+               lradius, RAD_MIN, RAD_MAX);
+        ret = AVERROR(EINVAL);
+    }
+    if (cradius < RAD_MIN || cradius > RAD_MAX) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid value for chroma radius %0.1f: "
+               "must be included between range %0.1f and %0.1f\n",
+               cradius, RAD_MIN, RAD_MAX);
+        ret = AVERROR(EINVAL);
+    }
+    if (lstrength < STRGTH_MIN || lstrength > STRGTH_MAX) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid value for luma strength %0.1f: "
+               "must be included between range %0.1f and %0.1f\n",
+               lstrength, STRGTH_MIN, STRGTH_MAX);
+        ret = AVERROR(EINVAL);
+    }
+    if (cstrength < STRGTH_MIN || cstrength > STRGTH_MAX) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid value for chroma strength %0.1f: "
+               "must be included between range %0.1f and %0.1f\n",
+               cstrength, STRGTH_MIN, STRGTH_MAX);
+        ret = AVERROR(EINVAL);
+    }
+    if (lthreshold < THRES_MIN || lthreshold > THRES_MAX) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid value for luma threshold %d: "
+               "must be included between range %d and %d\n",
+               lthreshold, THRES_MIN, THRES_MAX);
+        ret = AVERROR(EINVAL);
+    }
+    if (cthreshold < THRES_MIN || cthreshold > THRES_MAX) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid value for luma threshold %d: "
+               "must be included between range %d and %d\n",
+               cthreshold, THRES_MIN, THRES_MAX);
+        ret = AVERROR(EINVAL);
+    }
+
+    return ret;
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+    SmartblurContext *sblur = ctx->priv;
+    int n = 0;
+    float lradius, lstrength, cradius, cstrength;
+    int lthreshold, cthreshold;
+
+    if (args)
+        n = sscanf(args, "%f:%f:%d:%f:%f:%d",
+                   &lradius,
+                   &lstrength,
+                   &lthreshold,
+                   &cradius,
+                   &cstrength,
+                   &cthreshold);
+
+    if (n != 3 || n != 6) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Incorrect number of parameters: "
+               "must be luma_radius:luma_strength:luma_threshold"
+               "[:chroma_radius:chroma_strength:chroma_threshold]\n");
+        return AVERROR(EINVAL);
+    }
+
+    sblur->luma.radius      = lradius;
+    sblur->luma.strength    = lstrength;
+    sblur->luma.threshold   = lthreshold;
+
+    if (n == 3) {
+        sblur->chroma.radius    = sblur->luma.radius;
+        sblur->chroma.strength  = sblur->luma.strength;
+        sblur->chroma.threshold = sblur->luma.threshold;
+    } else {
+        sblur->chroma.radius    = cradius;
+        sblur->chroma.strength  = cstrength;
+        sblur->chroma.threshold = cthreshold;
+    }
+
+    sblur->luma.quality = sblur->chroma.quality = 3.0;
+
+    return validate_input(ctx,
+                          sblur->luma.radius,    sblur->chroma.radius,
+                          sblur->luma.strength,  sblur->chroma.strength,
+                          sblur->luma.threshold, sblur->chroma.threshold);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    SmartblurContext *sblur = ctx->priv;
+
+    sws_freeContext(sblur->luma.filter_context);
+    sws_freeContext(sblur->chroma.filter_context);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum PixelFormat pix_fmts[] = {
+        PIX_FMT_YUV444P,      PIX_FMT_YUV422P,
+        PIX_FMT_YUV420P,      PIX_FMT_YUV411P,
+        PIX_FMT_YUV410P,      PIX_FMT_YUV440P,
+        PIX_FMT_YUVA420P,
+        PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+
+    return 0;
+}
+
+static int allocStuff(FilterParam *f, int width, int height)
+{
+    SwsVector *vec;
+    SwsFilter sws_filter;
+
+    vec = sws_getGaussianVec(f->radius, f->quality);
+    sws_scaleVec(vec, f->strength);
+    vec->coeff[vec->length / 2] += 1.0 - f->strength;
+    sws_filter.lumH = sws_filter.lumV = vec;
+    sws_filter.chrH = sws_filter.chrV = NULL;
+    f->filter_context = sws_getContext(width, height, PIX_FMT_GRAY8,
+                                       width, height, PIX_FMT_GRAY8,
+                                       SWS_BICUBIC, &sws_filter, NULL, NULL);
+
+    sws_freeVec(vec);
+
+    return 0;
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+    SmartblurContext *sblur = inlink->dst->priv;
+    const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[inlink->format];
+
+    sblur->hsub = desc->log2_chroma_w;
+    sblur->vsub = desc->log2_chroma_h;
+
+    allocStuff(&sblur->luma, inlink->w, inlink->h);
+    allocStuff(&sblur->chroma, inlink->w >> sblur->hsub, inlink->h >> sblur->vsub);
+
+    return 0;
+}
+
+static void blur(uint8_t *dst, int dst_linesize,
+                 uint8_t *src, int src_linesize,
+                 int w, int h, int threshold,
+                 struct SwsContext *filter_context)
+{
+    int x, y;
+    int orig, filtered;
+    int diff;
+    const uint8_t* const src_array[1] = {src};
+    uint8_t *dst_array[1]             = {dst};
+    int src_linesize_array[1] = {src_linesize};
+    int dst_linesize_array[1] = {dst_linesize};
+
+    sws_scale(filter_context, src_array, src_linesize_array, 0, h, dst_array, dst_linesize_array);
+
+    if (threshold > 0) {
+        for (y = 0; y < h; ++y)
+            for (x = 0; x < w; ++x) {
+                orig     = src[x + y * src_linesize];
+                filtered = dst[x + y * dst_linesize];
+                diff     = orig - filtered;
+
+                if (diff > 0)
+                    if (diff > 2 * threshold)
+                        dst[x + y * dst_linesize] = orig;
+                    else /* add 'diff' and substract 'threshold' from 'filtered' */
+                        dst[x + y * dst_linesize] = orig - threshold;
+                else
+                    if (-diff > 2 * threshold)
+                        dst[x + y * dst_linesize] = orig;
+                    else /* add 'diff' and 'threshold' to 'filtered' */
+                        dst[x + y * dst_linesize] = orig + threshold;
+            }
+    } else if (threshold < 0) {
+        for (y = 0; y < h; ++y)
+            for (x = 0; x < w; ++x) {
+                orig = src[x + y * src_linesize];
+                filtered = dst[x + y * dst_linesize];
+                diff = orig - filtered;
+
+                if (diff > 0)
+                    if (diff <= -threshold)
+                        dst[x + y * dst_linesize] = orig;
+                    else if (diff <= -2 * threshold) /* substract 'diff' and 'threshold' from 'orig' */
+                        dst[x + y * dst_linesize] = filtered - threshold;
+                else
+                    if (diff >= threshold)
+                        dst[x + y * dst_linesize] = orig;
+                    else if (diff >= 2 * threshold) /* add 'threshold' and substract 'diff' from 'orig' */
+                        dst[x + y * dst_linesize] = filtered + threshold;
+            }
+    }
+}
+
+static int end_frame(AVFilterLink *inlink)
+{
+    SmartblurContext  *sblur  = inlink->dst->priv;
+    AVFilterBufferRef *inpic  = inlink->cur_buf;
+    AVFilterBufferRef *outpic = inlink->dst->outputs[0]->out_buf;
+    int cw = inlink->w >> sblur->hsub;
+    int ch = inlink->h >> sblur->vsub;
+
+    blur(outpic->data[0], outpic->linesize[0],
+         inpic->data[0],  inpic->linesize[0],
+         inlink->w, inlink->h, sblur->luma.threshold,
+         sblur->luma.filter_context);
+    blur(outpic->data[1], outpic->linesize[1],
+         inpic->data[1],  inpic->linesize[1],
+         cw, ch, sblur->chroma.threshold,
+         sblur->chroma.filter_context);
+    blur(outpic->data[2], outpic->linesize[2],
+         inpic->data[2],  inpic->linesize[2],
+         cw, ch, sblur->chroma.threshold,
+         sblur->chroma.filter_context);
+
+    return ff_end_frame(inlink->dst->outputs[0]);
+}
+
+AVFilter avfilter_vf_smartblur = {
+    .name        = "smartblur",
+    .description = NULL_IF_CONFIG_SMALL("Smart blur"),
+
+    .priv_size = sizeof(SmartblurContext),
+
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+
+    .inputs = (const AVFilterPad[]) {
+        {
+            .name         = "default",
+            .type         = AVMEDIA_TYPE_VIDEO,
+            .end_frame    = end_frame,
+            .config_props = config_props,
+            .min_perms    = AV_PERM_READ,
+        },
+        { .name = NULL }
+    },
+    .outputs = (const AVFilterPad[]) {
+        {
+            .name         = "default",
+            .type         = AVMEDIA_TYPE_VIDEO,
+        },
+        { .name = NULL }
+    }
+};
-- 
1.7.11.3



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