lavfi: add kerndeint filter

This is a port of the kerndeint filter (libmpcodecs/vf_kerndeint) by
Donal A. Graft (original avisynth plugin author), and is based on the
work by Jérémy Tran <tran.jeremy.av@gmail.com> done for SOCIS 2012.

4 files changed, 322 insertions, 2 deletions

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index d84bf5d17a..a7aa8ccc97 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -114,6 +114,7 @@ OBJS-$(CONFIG_HFLIP_FILTER)                  += vf_hflip.o
 OBJS-$(CONFIG_HQDN3D_FILTER)                 += vf_hqdn3d.o
 OBJS-$(CONFIG_HUE_FILTER)                    += vf_hue.o
 OBJS-$(CONFIG_IDET_FILTER)                   += vf_idet.o
+OBJS-$(CONFIG_KERNDEINT_FILTER)              += vf_kerndeint.o
 OBJS-$(CONFIG_LUT_FILTER)                    += vf_lut.o
 OBJS-$(CONFIG_LUTRGB_FILTER)                 += vf_lut.o
 OBJS-$(CONFIG_LUTYUV_FILTER)                 += vf_lut.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 4458917822..fdb7f3746e 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -108,6 +108,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(HQDN3D,         hqdn3d,         vf);
     REGISTER_FILTER(HUE,            hue,            vf);
     REGISTER_FILTER(IDET,           idet,           vf);
+    REGISTER_FILTER(KERNDEINT,      kerndeint,      vf);
     REGISTER_FILTER(LUT,            lut,            vf);
     REGISTER_FILTER(LUTRGB,         lutrgb,         vf);
     REGISTER_FILTER(LUTYUV,         lutyuv,         vf);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 39117b5a6d..e935d3f8a4 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,8 +29,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  30
-#define LIBAVFILTER_VERSION_MICRO 104
+#define LIBAVFILTER_VERSION_MINOR  31
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_kerndeint.c b/libavfilter/vf_kerndeint.c
new file mode 100644
index 0000000000..3569bfaa64
--- /dev/null
+++ b/libavfilter/vf_kerndeint.c
@@ -0,0 +1,318 @@
+/*
+ * Copyright (c) 2012 Jeremy Tran
+ * Copyright (c) 2004 Tobias Diedrich
+ * Copyright (c) 2003 Donald A. Graft
+ *
+ * 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
+ * Kernel Deinterlacer
+ * Ported from MPlayer libmpcodecs/vf_kerndeint.c.
+ */
+
+#include "libavutil/imgutils.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+
+typedef struct {
+    const AVClass *class;
+    int           frame; ///< frame count, starting from 0
+    int           thresh, map, order, sharp, twoway;
+    int           vsub;
+    uint8_t       *tmp_data [4];  ///< temporary plane data buffer
+    int           tmp_bwidth[4];  ///< temporary plane byte width
+    int           pixel_step;
+} KerndeintContext;
+
+#define OFFSET(x) offsetof(KerndeintContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption kerndeint_options[] = {
+    { "thresh", "set the threshold", OFFSET(thresh), AV_OPT_TYPE_INT, {.i64=10}, 0, 255, FLAGS },
+    { "map",    "set the map", OFFSET(map), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
+    { "order",  "set the order", OFFSET(order), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
+    { "sharp",  "enable sharpening", OFFSET(sharp), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
+    { "twoway", "enable twoway", OFFSET(twoway), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(kerndeint);
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+    KerndeintContext *kerndeint = ctx->priv;
+    const char const * shorthand[] = { "thresh", "map", "order", "sharp", "twoway", NULL };
+
+    kerndeint->class = &kerndeint_class;
+    av_opt_set_defaults(kerndeint);
+
+    return av_opt_set_from_string(kerndeint, args, shorthand, "=", ":");
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    KerndeintContext *kerndeint = ctx->priv;
+
+    av_free(kerndeint->tmp_data[0]);
+    av_opt_free(kerndeint);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum PixelFormat pix_fmts[] = {
+        AV_PIX_FMT_YUV420P,
+        AV_PIX_FMT_YUYV422,
+        AV_PIX_FMT_ARGB,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+
+    return 0;
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+    KerndeintContext *kerndeint = inlink->dst->priv;
+    const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[inlink->format];
+
+    kerndeint->vsub = desc->log2_chroma_h;
+    kerndeint->pixel_step = av_get_bits_per_pixel(desc) >> 3;
+
+    return av_image_alloc(kerndeint->tmp_data, kerndeint->tmp_bwidth,
+                          inlink->w, inlink->h, inlink->format, 1);
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *inpic)
+{
+    KerndeintContext *kerndeint = inlink->dst->priv;
+    AVFilterLink *outlink = inlink->dst->outputs[0];
+    AVFilterBufferRef *outpic;
+    const uint8_t *prvp;   ///< Previous field's pixel line number n
+    const uint8_t *prvpp;  ///< Previous field's pixel line number (n - 1)
+    const uint8_t *prvpn;  ///< Previous field's pixel line number (n + 1)
+    const uint8_t *prvppp; ///< Previous field's pixel line number (n - 2)
+    const uint8_t *prvpnn; ///< Previous field's pixel line number (n + 2)
+    const uint8_t *prvp4p; ///< Previous field's pixel line number (n - 4)
+    const uint8_t *prvp4n; ///< Previous field's pixel line number (n + 4)
+
+    const uint8_t *srcp;   ///< Current field's pixel line number n
+    const uint8_t *srcpp;  ///< Current field's pixel line number (n - 1)
+    const uint8_t *srcpn;  ///< Current field's pixel line number (n + 1)
+    const uint8_t *srcppp; ///< Current field's pixel line number (n - 2)
+    const uint8_t *srcpnn; ///< Current field's pixel line number (n + 2)
+    const uint8_t *srcp3p; ///< Current field's pixel line number (n - 3)
+    const uint8_t *srcp3n; ///< Current field's pixel line number (n + 3)
+    const uint8_t *srcp4p; ///< Current field's pixel line number (n - 4)
+    const uint8_t *srcp4n; ///< Current field's pixel line number (n + 4)
+
+    uint8_t *dstp, *dstp_saved;
+    const uint8_t *srcp_saved;
+
+    int src_linesize, psrc_linesize, dst_linesize, bwidth;
+    int x, y, plane, val, hi, lo, g, h, n = kerndeint->frame++;
+    double valf;
+
+    const int thresh = kerndeint->thresh;
+    const int order  = kerndeint->order;
+    const int map    = kerndeint->map;
+    const int sharp  = kerndeint->sharp;
+    const int twoway = kerndeint->twoway;
+
+    outpic = ff_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_ALIGN, outlink->w, outlink->h);
+    if (!outpic) {
+        avfilter_unref_bufferp(&inpic);
+        return AVERROR(ENOMEM);
+    }
+    avfilter_copy_buffer_ref_props(outpic, inpic);
+    outpic->video->interlaced = 0;
+
+    for (plane = 0; inpic->data[plane] && plane < 4; plane++) {
+        h = plane == 0 ? inlink->h : inlink->h >> kerndeint->vsub;
+        bwidth = kerndeint->tmp_bwidth[plane];
+
+        srcp = srcp_saved = inpic->data[plane];
+        src_linesize      = inpic->linesize[plane];
+        psrc_linesize     = outpic->linesize[plane];
+        dstp = dstp_saved = outpic->data[plane];
+        dst_linesize      = outpic->linesize[plane];
+        srcp              = srcp_saved + (1 - order) * src_linesize;
+        dstp              = dstp_saved + (1 - order) * dst_linesize;
+
+        for (y = 0; y < h; y += 2) {
+            memcpy(dstp, srcp, bwidth);
+            srcp += 2 * src_linesize;
+            dstp += 2 * dst_linesize;
+        }
+
+        // Copy through the lines that will be missed below.
+        memcpy(dstp_saved + order            * dst_linesize, srcp_saved + (1 -     order) * src_linesize, bwidth);
+        memcpy(dstp_saved + (2 + order    )  * dst_linesize, srcp_saved + (3 -     order) * src_linesize, bwidth);
+        memcpy(dstp_saved + (h - 2 + order)  * dst_linesize, srcp_saved + (h - 1 - order) * src_linesize, bwidth);
+        memcpy(dstp_saved + (h - 4 + order)  * dst_linesize, srcp_saved + (h - 3 - order) * src_linesize, bwidth);
+
+        /* For the other field choose adaptively between using the previous field
+           or the interpolant from the current field. */
+        prvp   = kerndeint->tmp_data[plane] + 5 * psrc_linesize - (1 - order) * psrc_linesize;
+        prvpp  = prvp - psrc_linesize;
+        prvppp = prvp - 2 * psrc_linesize;
+        prvp4p = prvp - 4 * psrc_linesize;
+        prvpn  = prvp + psrc_linesize;
+        prvpnn = prvp + 2 * psrc_linesize;
+        prvp4n = prvp + 4 * psrc_linesize;
+
+        srcp   = srcp_saved + 5 * src_linesize - (1 - order) * src_linesize;
+        srcpp  = srcp - src_linesize;
+        srcppp = srcp - 2 * src_linesize;
+        srcp3p = srcp - 3 * src_linesize;
+        srcp4p = srcp - 4 * src_linesize;
+
+        srcpn  = srcp + src_linesize;
+        srcpnn = srcp + 2 * src_linesize;
+        srcp3n = srcp + 3 * src_linesize;
+        srcp4n = srcp + 4 * src_linesize;
+
+        dstp   = dstp_saved + 5 * dst_linesize - (1 - order) * dst_linesize;
+
+        for (y = 5 - (1 - order); y <= h - 5 - (1 - order); y += 2) {
+            for (x = 0; x < bwidth; x++) {
+                if (thresh == 0 || n == 0 ||
+                    (abs((int)prvp[x]  - (int)srcp[x])  > thresh) ||
+                    (abs((int)prvpp[x] - (int)srcpp[x]) > thresh) ||
+                    (abs((int)prvpn[x] - (int)srcpn[x]) > thresh)) {
+                    if (map) {
+                        g = x & ~3;
+
+                        if (inlink->format == AV_PIX_FMT_RGBA) {
+                            AV_WB32(dstp + g, 0xffffffff);
+                            x = g + 3;
+                        } else if (inlink->format == AV_PIX_FMT_YUYV422) {
+                            // y <- 235, u <- 128, y <- 235, v <- 128
+                            AV_WB32(dstp + g, 0xeb80eb80);
+                            x = g + 3;
+                        } else {
+                            dstp[x] = plane == 0 ? 235 : 128;
+                        }
+                    } else {
+                        if (inlink->format == AV_PIX_FMT_RGBA) {
+                            hi = 255;
+                            lo = 0;
+                        } else if (inlink->format == AV_PIX_FMT_YUYV422) {
+                            hi = x & 1 ? 240 : 235;
+                            lo = 16;
+                        } else {
+                            hi = plane == 0 ? 235 : 240;
+                            lo = 16;
+                        }
+
+                        if (sharp) {
+                            if (twoway) {
+                                valf = + 0.526 * ((int)srcpp[x] + (int)srcpn[x])
+                                    + 0.170 * ((int)srcp[x] + (int)prvp[x])
+                                    - 0.116 * ((int)srcppp[x] + (int)srcpnn[x] + (int)prvppp[x] + (int)prvpnn[x])
+                                    - 0.026 * ((int)srcp3p[x] + (int)srcp3n[x])
+                                    + 0.031 * ((int)srcp4p[x] + (int)srcp4n[x] + (int)prvp4p[x] + (int)prvp4n[x]);
+                            } else {
+                                valf = + 0.526 * ((int)srcpp[x] + (int)srcpn[x])
+                                    + 0.170 * ((int)prvp[x])
+                                    - 0.116 * ((int)prvppp[x] + (int)prvpnn[x])
+                                    - 0.026 * ((int)srcp3p[x] + (int)srcp3n[x])
+                                    + 0.031 * ((int)prvp4p[x] + (int)prvp4p[x]);
+                            }
+                            dstp[x] = av_clip(valf, lo, hi);
+                        } else {
+                            if (twoway) {
+                                val = (8 * ((int)srcpp[x] + (int)srcpn[x]) + 2 * ((int)srcp[x] + (int)prvp[x])
+                                       - (int)(srcppp[x]) - (int)(srcpnn[x])
+                                       - (int)(prvppp[x]) - (int)(prvpnn[x])) >> 4;
+                            } else {
+                                val = (8 * ((int)srcpp[x] + (int)srcpn[x]) + 2 * ((int)prvp[x])
+                                       - (int)(prvppp[x]) - (int)(prvpnn[x])) >> 4;
+                            }
+                            dstp[x] = av_clip(val, lo, hi);
+                        }
+                    }
+                } else {
+                    dstp[x] = srcp[x];
+                }
+            }
+            prvp   += 2 * psrc_linesize;
+            prvpp  += 2 * psrc_linesize;
+            prvppp += 2 * psrc_linesize;
+            prvpn  += 2 * psrc_linesize;
+            prvpnn += 2 * psrc_linesize;
+            prvp4p += 2 * psrc_linesize;
+            prvp4n += 2 * psrc_linesize;
+            srcp   += 2 * src_linesize;
+            srcpp  += 2 * src_linesize;
+            srcppp += 2 * src_linesize;
+            srcp3p += 2 * src_linesize;
+            srcp4p += 2 * src_linesize;
+            srcpn  += 2 * src_linesize;
+            srcpnn += 2 * src_linesize;
+            srcp3n += 2 * src_linesize;
+            srcp4n += 2 * src_linesize;
+            dstp   += 2 * dst_linesize;
+        }
+
+        srcp = inpic->data[plane];
+        dstp = kerndeint->tmp_data[plane];
+        av_image_copy_plane(dstp, psrc_linesize, srcp, src_linesize, bwidth, h);
+    }
+
+    avfilter_unref_buffer(inpic);
+    return ff_filter_frame(outlink, outpic);
+}
+
+static const AVFilterPad kerndeint_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+        .config_props = config_props,
+        .min_perms    = AV_PERM_READ,
+    },
+    { NULL }
+};
+
+static const AVFilterPad kerndeint_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_vf_kerndeint = {
+    .name          = "kerndeint",
+    .description   = NULL_IF_CONFIG_SMALL("Apply kernel deinterlacing to the input."),
+    .priv_size     = sizeof(KerndeintContext),
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+
+    .inputs        = kerndeint_inputs,
+    .outputs       = kerndeint_outputs,
+
+    .priv_class = &kerndeint_class,
+};