[FFmpeg-devel] avfilter: add fillborders filter

diff --git a/doc/filters.texi b/doc/filters.texi
index 5d99437871..7a23d8de04 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -8607,6 +8607,37 @@  ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.m
 @end example
 @end itemize
 
+@section fillborders
+
+Fill borders of the input video.
+
+It accepts the following options:
+
+@table @option
+@item left
+Number of pixels to fill from left border.
+
+@item right
+Number of pixels to fill from right border.
+
+@item top
+Number of pixels to fill from top border.
+
+@item bottom
+Number of pixels to fill from bottom border.
+
+@item mode
+Set fill mode.
+
+It accepts the following values:
+@table @samp
+@item smear
+fill pixels using outermost pixels
+@item mirror
+fill pixels using mirroring
+@end table
+@end table
+
 @section floodfill
 
 Flood area with values of same pixel components with another values.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 9acae3ff5b..7566d19e59 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -192,6 +192,7 @@  OBJS-$(CONFIG_FIELDHINT_FILTER)              += vf_fieldhint.o
 OBJS-$(CONFIG_FIELDMATCH_FILTER)             += vf_fieldmatch.o
 OBJS-$(CONFIG_FIELDORDER_FILTER)             += vf_fieldorder.o
 OBJS-$(CONFIG_FIND_RECT_FILTER)              += vf_find_rect.o lavfutils.o
+OBJS-$(CONFIG_FILLBORDERS_FILTER)            += vf_fillborders.o
 OBJS-$(CONFIG_FLOODFILL_FILTER)              += vf_floodfill.o
 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
 OBJS-$(CONFIG_FPS_FILTER)                    += vf_fps.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index a838309569..3c61474e91 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -202,6 +202,7 @@  static void register_all(void)
     REGISTER_FILTER(FIELDMATCH,     fieldmatch,     vf);
     REGISTER_FILTER(FIELDORDER,     fieldorder,     vf);
     REGISTER_FILTER(FIND_RECT,      find_rect,      vf);
+    REGISTER_FILTER(FILLBORDERS,    fillborders,    vf);
     REGISTER_FILTER(FLOODFILL,      floodfill,      vf);
     REGISTER_FILTER(FORMAT,         format,         vf);
     REGISTER_FILTER(FPS,            fps,            vf);
diff --git a/libavfilter/vf_fillborders.c b/libavfilter/vf_fillborders.c
new file mode 100644
index 0000000000..62b5c840b0
--- /dev/null
+++ b/libavfilter/vf_fillborders.c
@@ -0,0 +1,232 @@ 
+/*
+ * Copyright (c) 2017 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/colorspace.h"
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+enum FillMode { FM_SMEAR, FM_MIRROR, NB_MODES };
+
+typedef struct Borders {
+    int left, right, top, bottom;
+} Borders;
+
+typedef struct FillBordersContext {
+    const AVClass *class;
+    int left, right, top, bottom;
+    int mode;
+
+    int nb_planes;
+    Borders borders[4];
+    int planewidth[4];
+    int planeheight[4];
+
+    void (*fillborders)(struct FillBordersContext *s, AVFrame *frame);
+} FillBordersContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat 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_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+        AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ440P,
+        AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
+        AV_PIX_FMT_NONE
+    };
+    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+    if (!fmts_list)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, fmts_list);
+}
+
+static void smear_borders(FillBordersContext *s, AVFrame *frame)
+{
+    int p, y;
+
+    for (p = 0; p < s->nb_planes; p++) {
+        uint8_t *ptr = frame->data[p];
+        int linesize = frame->linesize[p];
+
+        for (y = s->borders[p].top; y < s->planeheight[p] - s->borders[p].bottom; y++) {
+            memset(ptr + y * frame->linesize[p],
+                   *(ptr + y * frame->linesize[p] + s->borders[p].left),
+                   s->borders[p].left);
+            memset(ptr + y * frame->linesize[p] + s->planewidth[p] - s->borders[p].right,
+                   *(ptr + y * frame->linesize[p] + s->planewidth[p] - s->borders[p].right - 1),
+                   s->borders[p].right);
+        }
+
+        for (y = 0; y < s->borders[p].top; y++) {
+            memcpy(ptr + y * frame->linesize[p],
+                   ptr + s->borders[p].top * linesize, s->planewidth[p]);
+        }
+
+        for (y = s->planeheight[p] - s->borders[p].bottom; y < s->planeheight[p]; y++) {
+            memcpy(ptr + y * frame->linesize[p],
+                   ptr + (s->planeheight[p] - s->borders[p].bottom) * linesize,
+                   s->planewidth[p]);
+        }
+    }
+}
+
+static void mirror_borders(FillBordersContext *s, AVFrame *frame)
+{
+    int p, y, x;
+
+    for (p = 0; p < s->nb_planes; p++) {
+        uint8_t *ptr = frame->data[p];
+        int linesize = frame->linesize[p];
+
+        for (y = s->borders[p].top; y < s->planeheight[p] - s->borders[p].bottom; y++) {
+            for (x = 0; x < s->borders[p].left; x++) {
+                ptr[y * frame->linesize[p] + x] = ptr[y * frame->linesize[p] + s->borders[p].left * 2 - 1 - x];
+            }
+
+            for (x = 0; x < s->borders[p].right; x++) {
+                ptr[y * frame->linesize[p] + s->planewidth[p] - s->borders[p].right + x] =
+                    ptr[y * frame->linesize[p] + s->planewidth[p] - s->borders[p].right - 1 - x];
+            }
+        }
+
+        for (y = 0; y < s->borders[p].top; y++) {
+            memcpy(ptr + y * frame->linesize[p],
+                   ptr + (s->borders[p].top * 2 - 1 - y) * linesize,
+                   s->planewidth[p]);
+        }
+
+        for (y = 0; y < s->borders[p].bottom; y++) {
+            memcpy(ptr + (s->planeheight[p] - s->borders[p].bottom + y) * frame->linesize[p],
+                   ptr + (s->planeheight[p] - s->borders[p].bottom - 1 - y) * frame->linesize[p],
+                   s->planewidth[p]);
+        }
+    }
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+    FillBordersContext *s = inlink->dst->priv;
+
+    s->fillborders(s, frame);
+
+    return ff_filter_frame(inlink->dst->outputs[0], frame);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    FillBordersContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+    s->nb_planes = desc->nb_components;
+
+    s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+    s->planeheight[0] = s->planeheight[3] = inlink->h;
+    s->planewidth[1]  = s->planewidth[2]  = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
+    s->planewidth[0]  = s->planewidth[3]  = inlink->w;
+
+    s->borders[0].left   = s->borders[3].left = s->left;
+    s->borders[0].right  = s->borders[3].right = s->right;
+    s->borders[0].top    = s->borders[3].top = s->top;
+    s->borders[0].bottom = s->borders[3].bottom = s->bottom;
+
+    s->borders[1].left   = s->left >> desc->log2_chroma_w;
+    s->borders[1].right  = s->right >> desc->log2_chroma_w;
+    s->borders[1].top    = s->top >> desc->log2_chroma_h;
+    s->borders[1].bottom = s->bottom >> desc->log2_chroma_h;
+
+    s->borders[2].left   = s->left >> desc->log2_chroma_w;
+    s->borders[2].right  = s->right >> desc->log2_chroma_w;
+    s->borders[2].top    = s->top >> desc->log2_chroma_h;
+    s->borders[2].bottom = s->bottom >> desc->log2_chroma_h;
+
+    if (inlink->w < s->left + s->right ||
+        inlink->w <= s->left ||
+        inlink->w <= s->right ||
+        inlink->h < s->top + s->bottom ||
+        inlink->h <= s->top ||
+        inlink->h <= s->bottom ||
+        inlink->w < s->left * 2 ||
+        inlink->w < s->right * 2 ||
+        inlink->h < s->top * 2 ||
+        inlink->h < s->bottom * 2) {
+        av_log(ctx, AV_LOG_ERROR, "Borders are bigger than input frame size.\n");
+        return AVERROR(EINVAL);
+    }
+
+    switch (s->mode) {
+    case FM_SMEAR:  s->fillborders = smear_borders;  break;
+    case FM_MIRROR: s->fillborders = mirror_borders; break;
+    }
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(FillBordersContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption fillborders_options[] = {
+    { "left",   "set the left fill border",   OFFSET(left),   AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX,    FLAGS },
+    { "right",  "set the right fill border",  OFFSET(right),  AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX,    FLAGS },
+    { "top",    "set the top fill border",    OFFSET(top),    AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX,    FLAGS },
+    { "bottom", "set the bottom fill border", OFFSET(bottom), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX,    FLAGS },
+    { "mode",   "set the fill borders mode",  OFFSET(mode),   AV_OPT_TYPE_INT, {.i64=0}, 0, NB_MODES-1, FLAGS, "mode" },
+        { "smear",  NULL, 0, AV_OPT_TYPE_CONST, {.i64=FM_SMEAR},  0, 0, FLAGS, "mode" },
+        { "mirror", NULL, 0, AV_OPT_TYPE_CONST, {.i64=FM_MIRROR}, 0, 0, FLAGS, "mode" },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(fillborders);
+
+static const AVFilterPad fillborders_inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .config_props   = config_input,
+        .filter_frame   = filter_frame,
+        .needs_writable = 1,
+    },
+    { NULL }
+};
+
+static const AVFilterPad fillborders_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_fillborders = {
+    .name          = "fillborders",
+    .description   = NULL_IF_CONFIG_SMALL("Fill borders of the input video."),
+    .priv_size     = sizeof(FillBordersContext),
+    .priv_class    = &fillborders_class,
+    .query_formats = query_formats,
+    .inputs        = fillborders_inputs,
+    .outputs       = fillborders_outputs,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};