[FFmpeg-devel] [PATCH] lavfi: add geq filter.

Clément Bœsch ubitux at gmail.com
Wed Oct 31 20:40:15 CET 2012


TODO: bump minor
---
Another portage from MPlayer filters. It seems to work, but I still have some
issues with ffplay when the filter is complex/heavy. Try for instance this one
(stolen from a random guy on #mplayer):

    ffplay -f lavfi -i 'testsrc,geq=p(lt(X\,W/2)*X*(1+sin(N*PI/100))+not(lt(X\,W/2))*(W-X)*(1+sin(N*PI/100))\,lt(Y\,H/2)*Y*(1+sin(N*PI/100))+not(lt(Y\,H/2))*(H-Y)*(1+sin(N*PI/100)))'

mplayer seems to deal relatively well with slow filters contrary to ffplay, but
I have no idea how to avoid the current frame drop (playing with the options
didn't help).

Except that, the filter seems to work fine.

BTW, I took the complex example from the git log (9e5e086b), but feel free
to propose more fancy/useful equations for the documentation.

About FATE, given the amount of floating operations, I'm not really confident
about adding such test.

Last thing: I'll drop mp=geq soon after this gets applied.
---
 Changelog                |   1 +
 LICENSE                  |   1 +
 configure                |   1 +
 doc/filters.texi         |  53 ++++++++++++
 libavfilter/Makefile     |   1 +
 libavfilter/allfilters.c |   1 +
 libavfilter/vf_geq.c     | 213 +++++++++++++++++++++++++++++++++++++++++++++++
 7 files changed, 271 insertions(+)
 create mode 100644 libavfilter/vf_geq.c

diff --git a/Changelog b/Changelog
index 8f6c90b..ccc2fdc 100644
--- a/Changelog
+++ b/Changelog
@@ -19,6 +19,7 @@ version <next>:
 - ffescape tool
 - metadata (info chunk) support in CAF muxer
 - field filter ported from libmpcodecs
+- geq filter ported from libmpcodecs
 
 
 version 1.0:
diff --git a/LICENSE b/LICENSE
index f38fc16..a1204f4 100644
--- a/LICENSE
+++ b/LICENSE
@@ -30,6 +30,7 @@ Specifically, the GPL parts of FFmpeg are
     - vf_cropdetect.c
     - vf_decimate.c
     - vf_delogo.c
+    - vf_geq.c
     - vf_hqdn3d.c
     - vf_hue.c
     - vf_mp.c
diff --git a/configure b/configure
index dc1aa79..2c16f82 100755
--- a/configure
+++ b/configure
@@ -1939,6 +1939,7 @@ frei0r_filter_deps="frei0r dlopen"
 frei0r_filter_extralibs='$ldl'
 frei0r_src_filter_deps="frei0r dlopen"
 frei0r_src_filter_extralibs='$ldl'
+geq_filter_deps="gpl"
 hqdn3d_filter_deps="gpl"
 hue_filter_deps="gpl"
 movie_filter_deps="avcodec avformat"
diff --git a/doc/filters.texi b/doc/filters.texi
index 786b2db..1cba190 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2310,6 +2310,59 @@ frei0r=perspective:0.2/0.2:0.8/0.2
 For more information see:
 @url{http://frei0r.dyne.org}
 
+ at section geq
+
+The filter takes one, two or three equations as parameter, separated by ':'.
+The first equation is mandatory and applies to the luma plane. The two
+following are respectively for chroma blue and chroma red planes. If one
+equation is not specified, it is using the same as the previous one.
+
+The expressions can use the following variables:
+
+ at table @option
+ at item X, Y
+The coordinates of the current sample
+
+ at item W, H
+The width and height of the image
+
+ at item SW, SH
+Width and height scale depending on the currently filtered plane, e.g. 1,1 and
+0.5,0.5 for YUV 4:2:0.
+
+ at item p(x, y)
+Return the value of the pixel at location (@var{x};@var{y}) of the current
+plane.
+
+ at item lum(x, y)
+Return the value of the pixel at location (@var{x};@var{y}) of the luminance
+plane.
+
+ at item cb(x, y)
+Return the value of the pixel at location (@var{x};@var{y}) of the
+blue-difference chroma plane.
+
+ at item cr(x, y)
+Return the value of the pixel at location (@var{x};@var{y}) of the
+red-difference chroma plane.
+ at end table
+
+Some examples follow:
+
+ at itemize
+ at item
+Flip the image horizontally:
+ at example
+geq=p(W-X\,Y)
+ at end example
+
+ at item
+Fancy enigmatic moving light:
+ at example
+color=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
+ at end example
+ at end itemize
+
 @section gradfun
 
 Fix the banding artifacts that are sometimes introduced into nearly flat
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 0ab0633..dfd5200 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -105,6 +105,7 @@ OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
 OBJS-$(CONFIG_FRAMESTEP_FILTER)              += vf_framestep.o
 OBJS-$(CONFIG_FPS_FILTER)                    += vf_fps.o
 OBJS-$(CONFIG_FREI0R_FILTER)                 += vf_frei0r.o
+OBJS-$(CONFIG_GEQ_FILTER)                    += vf_geq.o
 OBJS-$(CONFIG_GRADFUN_FILTER)                += vf_gradfun.o
 OBJS-$(CONFIG_HFLIP_FILTER)                  += vf_hflip.o
 OBJS-$(CONFIG_HQDN3D_FILTER)                 += vf_hqdn3d.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index fef40e9..88e8d68 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -97,6 +97,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (FPS,         fps,         vf);
     REGISTER_FILTER (FRAMESTEP,   framestep,   vf);
     REGISTER_FILTER (FREI0R,      frei0r,      vf);
+    REGISTER_FILTER (GEQ,         geq,         vf);
     REGISTER_FILTER (GRADFUN,     gradfun,     vf);
     REGISTER_FILTER (HFLIP,       hflip,       vf);
     REGISTER_FILTER (HQDN3D,      hqdn3d,      vf);
diff --git a/libavfilter/vf_geq.c b/libavfilter/vf_geq.c
new file mode 100644
index 0000000..2080dfa
--- /dev/null
+++ b/libavfilter/vf_geq.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2006 Michael Niedermayer <michaelni at gmx.at>
+ * Copyright (C) 2012 Clément Bœsch <ubitux at gmail.com>
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer 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.
+ *
+ * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/**
+ * @file
+ * Generic equation change filter
+ * Originally written by Michael Niedermayer for the MPlayer project, and
+ * ported by Clément Bœsch for FFmpeg.
+ */
+
+#include "libavcodec/avcodec.h"
+#include "libavutil/eval.h"
+#include "libavutil/avstring.h"
+#include "libavutil/pixdesc.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct {
+    AVExpr *e[3];               ///< expressions for each plane
+    int framenum;               ///< frame counter
+    AVFilterBufferRef *picref;  ///< current input buffer
+    int hsub, vsub;
+} GEQContext;
+
+static inline double getpix(void *priv, double x, double y, int plane)
+{
+    int xi, yi;
+    GEQContext *geq = priv;
+    AVFilterBufferRef *picref = geq->picref;
+    const uint8_t *src = picref->data[plane];
+    const int linesize = picref->linesize[plane];
+    const int w = picref->video->w >> (plane ? geq->hsub : 0);
+    const int h = picref->video->h >> (plane ? geq->vsub : 0);
+
+    xi = x = FFMIN(FFMAX(x, 0), w - 1);
+    yi = y = FFMIN(FFMAX(y, 0), h - 1);
+
+    x -= xi;
+    y -= yi;
+
+    return (1-y)*((1-x)*src[xi +  yi    * linesize] + x*src[xi + 1 +  yi    * linesize])
+          +   y *((1-x)*src[xi + (yi+1) * linesize] + x*src[xi + 1 + (yi+1) * linesize]);
+}
+
+//TODO: cubic interpolate
+//TODO: keep the last few frames
+static double lum(void *priv, double x, double y) { return getpix(priv, x, y, 0); }
+static double  cb(void *priv, double x, double y) { return getpix(priv, x, y, 1); }
+static double  cr(void *priv, double x, double y) { return getpix(priv, x, y, 2); }
+
+static const char *const var_names[] = {   "X",   "Y",   "W",   "H",   "N",   "SW",   "SH",        NULL };
+enum                                   { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_N, VAR_SW, VAR_SH, VAR_VARS_NB };
+
+static av_cold int geq_init(AVFilterContext *ctx, const char *args)
+{
+    GEQContext *geq = ctx->priv;
+    char *args1 = av_strdup(args);
+    char *bufptr = NULL;
+    char *arg = args1;
+    const char *expr[3] = {0};
+    int plane, ret = 0;
+
+    if (!args1) {
+        ret = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    for (plane = 0; plane < 3; plane++, arg = NULL) {
+        static double (*p[])(void *, double, double) = { lum, cb, cr };
+        static const char *const func2_names[]    = { "lum", "cb", "cr", "p", NULL };
+        double (*func2[])(void *, double, double) = { lum, cb, cr, p[plane], NULL };
+
+        expr[plane] = av_strtok(arg, ":", &bufptr);
+        if (!expr[plane]) {
+            if (plane == 0) {
+                av_log(ctx, AV_LOG_ERROR, "At least one expression must be specified\n");
+                ret = AVERROR(EINVAL);
+                goto end;
+            }
+            expr[plane] = expr[plane - 1];
+        }
+        ret = av_expr_parse(&geq->e[plane], expr[plane], var_names, NULL, NULL,
+                            func2_names, func2, 0, ctx);
+        if (ret < 0)
+            goto end;
+    }
+
+end:
+    av_free(args1);
+    return ret;
+}
+
+static int geq_query_formats(AVFilterContext *ctx)
+{
+    static const enum PixelFormat pix_fmts[] = {
+        AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV420P,
+        AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV410P,  AV_PIX_FMT_YUV440P,
+        AV_PIX_FMT_YUVA420P,
+        AV_PIX_FMT_NONE
+    };
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+    return 0;
+}
+
+static int geq_config_props(AVFilterLink *inlink)
+{
+    GEQContext *geq = inlink->dst->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+    geq->hsub = desc->log2_chroma_w;
+    geq->vsub = desc->log2_chroma_h;
+    return 0;
+}
+
+static int geq_end_frame(AVFilterLink *inlink)
+{
+    int ret, plane;
+    GEQContext *geq = inlink->dst->priv;
+    AVFilterLink *outlink = inlink->dst->outputs[0];
+    AVFilterBufferRef *outpicref = outlink->out_buf;
+    double values[VAR_VARS_NB] = {
+        [VAR_N] = geq->framenum++,
+    };
+
+    geq->picref = inlink->cur_buf;
+
+    for (plane = 0; plane < 3; plane++) {
+        int x, y;
+        uint8_t *dst = outpicref->data[plane];
+        const int linesize = outpicref->linesize[plane];
+        const int w = inlink->w >> (plane ? geq->hsub : 0);
+        const int h = inlink->h >> (plane ? geq->vsub : 0);
+
+        values[VAR_W]  = w;
+        values[VAR_H]  = h;
+        values[VAR_SW] = w / (double)inlink->w;
+        values[VAR_SH] = h / (double)inlink->h;
+
+        for (y = 0; y < h; y++) {
+            values[VAR_Y] = y;
+            for (x = 0; x < w; x++) {
+                values[VAR_X] = x;
+                dst[x] = av_expr_eval(geq->e[plane], values, geq);
+            }
+            dst += linesize;
+        }
+    }
+
+    if ((ret = ff_draw_slice(outlink, 0, outlink->h, 1)) < 0 ||
+        (ret = ff_end_frame(outlink)) < 0)
+        return ret;
+    return 0;
+}
+
+static av_cold void geq_uninit(AVFilterContext *ctx)
+{
+    int i;
+    GEQContext *geq = ctx->priv;
+
+    for (i = 0; i < FF_ARRAY_ELEMS(geq->e); i++)
+        av_expr_free(geq->e[i]);
+}
+
+static int null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { return 0; }
+
+static const AVFilterPad avfilter_vf_geq_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .draw_slice   = null_draw_slice,
+        .config_props = geq_config_props,
+        .end_frame    = geq_end_frame,
+        .min_perms    = AV_PERM_READ,
+    },
+    { NULL }
+};
+
+static const AVFilterPad avfilter_vf_geq_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_vf_geq = {
+    .name          = "geq",
+    .description   = NULL_IF_CONFIG_SMALL("Generic equation change filter"),
+    .priv_size     = sizeof(GEQContext),
+    .init          = geq_init,
+    .uninit        = geq_uninit,
+    .query_formats = geq_query_formats,
+    .inputs        = avfilter_vf_geq_inputs,
+    .outputs       = avfilter_vf_geq_outputs,
+};
-- 
1.8.0



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