avfilter: add xmedian filter

Changelog

@@ -28,6 +28,7 @@ version <next>:
 - asoftclip filter
 - Support decoding of HEVC 4:4:4 content in vdpau
 - colorhold filter
+- xmedian filter
 
 
 version 4.1:

doc/filters.texi

@@ -18418,6 +18418,20 @@ Set the scaling dimension: @code{2} for @code{2xBR}, @code{3} for
 Default is @code{3}.
 @end table
 
+@section xmedian
+Pick median pixels from several input videos.
+
+The filter accept the following options:
+
+@table @option
+@item nb_inputs
+Set number of inputs. This must be odd number.
+Default is 3. Allowed range is from 3 to 255.
+
+@item planes
+Set which planes to filter. Default value is @code{15}, by which all planes are processed.
+@end table
+
 @section xstack
 Stack video inputs into custom layout.
 

libavfilter/Makefile

@@ -421,6 +421,7 @@ OBJS-$(CONFIG_W3FDIF_FILTER)                 += vf_w3fdif.o
 OBJS-$(CONFIG_WAVEFORM_FILTER)               += vf_waveform.o
 OBJS-$(CONFIG_WEAVE_FILTER)                  += vf_weave.o
 OBJS-$(CONFIG_XBR_FILTER)                    += vf_xbr.o
+OBJS-$(CONFIG_XMEDIAN_FILTER)                += vf_xmedian.o framesync.o
 OBJS-$(CONFIG_XSTACK_FILTER)                 += vf_stack.o framesync.o
 OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o yadif_common.o
 OBJS-$(CONFIG_YADIF_CUDA_FILTER)             += vf_yadif_cuda.o vf_yadif_cuda.ptx.o \

libavfilter/allfilters.c

@@ -400,6 +400,7 @@ extern AVFilter ff_vf_w3fdif;
 extern AVFilter ff_vf_waveform;
 extern AVFilter ff_vf_weave;
 extern AVFilter ff_vf_xbr;
+extern AVFilter ff_vf_xmedian;
 extern AVFilter ff_vf_xstack;
 extern AVFilter ff_vf_yadif;
 extern AVFilter ff_vf_yadif_cuda;

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   7
-#define LIBAVFILTER_VERSION_MINOR  51
+#define LIBAVFILTER_VERSION_MINOR  52
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vf_xmedian.c

@@ -0,0 +1,347 @@
+/*
+ * Copyright (c) 2019 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/qsort.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "framesync.h"
+#include "video.h"
+
+typedef struct XMedianContext {
+    const AVClass *class;
+    const AVPixFmtDescriptor *desc;
+    int nb_inputs;
+    int planes;
+
+    int radius;
+    int depth;
+    int max;
+    int nb_planes;
+    int linesize[4];
+    int width[4];
+    int height[4];
+
+    AVFrame **frames;
+    FFFrameSync fs;
+
+    int (*median_frames)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
+} XMedianContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pixel_fmts[] = {
+        AV_PIX_FMT_GRAY8,
+        AV_PIX_FMT_GRAY9,
+        AV_PIX_FMT_GRAY10,
+        AV_PIX_FMT_GRAY12,
+        AV_PIX_FMT_GRAY14,
+        AV_PIX_FMT_GRAY16,
+        AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
+        AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
+        AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
+        AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
+        AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
+        AV_PIX_FMT_YUVJ411P,
+        AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
+        AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
+        AV_PIX_FMT_YUV440P10,
+        AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12,
+        AV_PIX_FMT_YUV440P12,
+        AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14,
+        AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
+        AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
+        AV_PIX_FMT_NONE
+    };
+    AVFilterFormats *formats = ff_make_format_list(pixel_fmts);
+    if (!formats)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, formats);
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    XMedianContext *s = ctx->priv;
+    int ret;
+
+    if (!(s->nb_inputs & 1))
+        av_log(s, AV_LOG_WARNING, "nb_intputs: %d is not odd number.\n", s->nb_inputs);
+
+    s->nb_inputs = s->nb_inputs | 1;
+    s->radius = s->nb_inputs / 2;
+    s->frames = av_calloc(s->nb_inputs, sizeof(*s->frames));
+    if (!s->frames)
+        return AVERROR(ENOMEM);
+
+    for (int i = 0; i < s->nb_inputs; i++) {
+        AVFilterPad pad = { 0 };
+
+        pad.type = AVMEDIA_TYPE_VIDEO;
+        pad.name = av_asprintf("input%d", i);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+
+        if ((ret = ff_insert_inpad(ctx, i, &pad)) < 0) {
+            av_freep(&pad.name);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+typedef struct ThreadData {
+    AVFrame **in, *out;
+} ThreadData;
+
+static int comparei(const void *p1, const void *p2)
+{
+    int left  = *(const int *)p1;
+    int right = *(const int *)p2;
+    return FFDIFFSIGN(left, right);
+}
+
+static int median_frames16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+    XMedianContext *s = ctx->priv;
+    ThreadData *td = arg;
+    AVFrame **in = td->in;
+    AVFrame *out = td->out;
+    const int nb_inputs = s->nb_inputs;
+    const int radius = s->radius;
+    int values[256];
+
+    for (int p = 0; p < s->nb_planes; p++) {
+        const int slice_start = (s->height[p] * jobnr) / nb_jobs;
+        const int slice_end = (s->height[p] * (jobnr+1)) / nb_jobs;
+        uint16_t *dst = (uint16_t *)(out->data[p] + slice_start * out->linesize[p]);
+
+        if (!((1 << p) & s->planes)) {
+            av_image_copy_plane((uint8_t *)dst, out->linesize[p],
+                                in[0]->data[p] + slice_start * in[radius]->linesize[p],
+                                in[0]->linesize[p],
+                                s->linesize[p], slice_end - slice_start);
+            continue;
+        }
+
+        for (int y = slice_start; y < slice_end; y++) {
+            for (int x = 0; x < s->width[p]; x++) {
+                for (int i = 0; i < nb_inputs; i++) {
+                    const uint16_t *src = (const uint16_t *)(in[i]->data[p] + y * in[i]->linesize[p]);
+                    values[i] = src[x];
+                }
+
+                AV_QSORT(values, nb_inputs, int, comparei);
+                dst[x] = values[radius];
+            }
+
+            dst += out->linesize[p] / 2;
+        }
+    }
+
+    return 0;
+}
+
+static int median_frames8(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+    XMedianContext *s = ctx->priv;
+    ThreadData *td = arg;
+    AVFrame **in = td->in;
+    AVFrame *out = td->out;
+    const int nb_inputs = s->nb_inputs;
+    const int radius = s->radius;
+    int values[256];
+
+    for (int p = 0; p < s->nb_planes; p++) {
+        const int slice_start = (s->height[p] * jobnr) / nb_jobs;
+        const int slice_end = (s->height[p] * (jobnr+1)) / nb_jobs;
+        uint8_t *dst = out->data[p] + slice_start * out->linesize[p];
+
+        if (!((1 << p) & s->planes)) {
+            av_image_copy_plane(dst, out->linesize[p],
+                                in[0]->data[p] + slice_start * in[0]->linesize[p],
+                                in[0]->linesize[p],
+                                s->linesize[p], slice_end - slice_start);
+            continue;
+        }
+
+        for (int y = slice_start; y < slice_end; y++) {
+            for (int x = 0; x < s->width[p]; x++) {
+                for (int i = 0; i < nb_inputs; i++)
+                    values[i] = in[i]->data[p][y * in[i]->linesize[p] + x];
+
+                AV_QSORT(values, nb_inputs, int, comparei);
+                dst[x] = values[radius];
+            }
+
+            dst += out->linesize[p];
+        }
+    }
+
+    return 0;
+}
+
+static int process_frame(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    AVFilterLink *outlink = ctx->outputs[0];
+    XMedianContext *s = fs->opaque;
+    AVFrame **in = s->frames;
+    AVFrame *out;
+    ThreadData td;
+    int i, ret;
+
+    for (i = 0; i < s->nb_inputs; i++) {
+        if ((ret = ff_framesync_get_frame(&s->fs, i, &in[i], 0)) < 0)
+            return ret;
+    }
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out)
+        return AVERROR(ENOMEM);
+    out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);
+
+    td.in = in;
+    td.out = out;
+    ctx->internal->execute(ctx, s->median_frames, &td, NULL, FFMIN(s->height[1], ff_filter_get_nb_threads(ctx)));
+
+    return ff_filter_frame(outlink, out);
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    XMedianContext *s = ctx->priv;
+    AVRational frame_rate = ctx->inputs[0]->frame_rate;
+    AVFilterLink *inlink = ctx->inputs[0];
+    int height = ctx->inputs[0]->h;
+    int width = ctx->inputs[0]->w;
+    FFFrameSyncIn *in;
+    int i, ret;
+
+    for (int i = 1; i < s->nb_inputs; i++) {
+        if (ctx->inputs[i]->h != height || ctx->inputs[i]->w != width) {
+            av_log(ctx, AV_LOG_ERROR, "Input %d size (%dx%d) does not match input %d size (%dx%d).\n", i, ctx->inputs[i]->w, ctx->inputs[i]->h, 0, width, height);
+            return AVERROR(EINVAL);
+        }
+    }
+
+    s->desc = av_pix_fmt_desc_get(outlink->format);
+    if (!s->desc)
+        return AVERROR_BUG;
+    s->nb_planes = av_pix_fmt_count_planes(outlink->format);
+    s->depth = s->desc->comp[0].depth;
+    s->max = (1 << s->depth) - 1;
+
+    if (s->depth <= 8)
+        s->median_frames = median_frames8;
+    else
+        s->median_frames = median_frames16;
+
+    if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
+        return ret;
+
+    s->width[1] = s->width[2] = AV_CEIL_RSHIFT(inlink->w, s->desc->log2_chroma_w);
+    s->width[0] = s->width[3] = inlink->w;
+    s->height[1] = s->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
+    s->height[0] = s->height[3] = inlink->h;
+
+    outlink->w          = width;
+    outlink->h          = height;
+    outlink->frame_rate = frame_rate;
+
+    if ((ret = ff_framesync_init(&s->fs, ctx, s->nb_inputs)) < 0)
+        return ret;
+
+    in = s->fs.in;
+    s->fs.opaque = s;
+    s->fs.on_event = process_frame;
+
+    for (i = 0; i < s->nb_inputs; i++) {
+        AVFilterLink *inlink = ctx->inputs[i];
+
+        in[i].time_base = inlink->time_base;
+        in[i].sync   = 1;
+        in[i].before = EXT_STOP;
+        in[i].after  = EXT_STOP;
+    }
+
+    ret = ff_framesync_configure(&s->fs);
+    outlink->time_base = s->fs.time_base;
+
+    return ret;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    XMedianContext *s = ctx->priv;
+
+    ff_framesync_uninit(&s->fs);
+    av_freep(&s->frames);
+
+    for (int i = 0; i < ctx->nb_inputs; i++)
+        av_freep(&ctx->input_pads[i].name);
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    XMedianContext *s = ctx->priv;
+    return ff_framesync_activate(&s->fs);
+}
+
+#define OFFSET(x) offsetof(XMedianContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption xmedian_options[] = {
+    { "nb_inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=3},  3, 255, .flags = FLAGS },
+    { "planes",    "set planes to filter", OFFSET(planes),    AV_OPT_TYPE_INT, {.i64=15}, 0,  15, .flags = FLAGS },
+    { NULL },
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+    },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(xmedian);
+
+AVFilter ff_vf_xmedian = {
+    .name          = "xmedian",
+    .description   = NULL_IF_CONFIG_SMALL("Pick median pixels from several video inputs."),
+    .priv_size     = sizeof(XMedianContext),
+    .priv_class    = &xmedian_class,
+    .query_formats = query_formats,
+    .outputs       = outputs,
+    .init          = init,
+    .uninit        = uninit,
+    .activate      = activate,
+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_SLICE_THREADS,
+};