avfilter: add deblock filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -2,6 +2,10 @@ Entries are sorted chronologically from oldest to youngest within each release,
 releases are sorted from youngest to oldest.
 
 version <next>:
+- deblock filter
+
+
+version 4.0:
 - Bitstream filters for editing metadata in H.264, HEVC and MPEG-2 streams
 - Dropped support for OpenJPEG versions 2.0 and below. Using OpenJPEG now
   requires 2.1 (or later) and pkg-config.

doc/filters.texi

@@ -7078,6 +7078,65 @@ e.g. banding detection threshold is triggered for all color components.
 The default is disabled.
 @end table
 
+@section deblock
+
+Remove blocking artifacts from input video.
+
+The filter accepts the following options:
+
+@table @option
+@item filter
+Set filter type, can be @var{weak} or @var{strong}. Default is @var{strong}.
+This controls what kind of deblocking is applied.
+
+@item block
+Set size of block, allowed range is from 4 to 512. Default is @var{8}.
+
+@item alpha
+@item beta
+@item gamma
+@item delta
+Set blocking detection thresholds. Allowed range is 0 to 1.
+Defaults are: @var{0.098} for @var{alpha} and @var{0.05} for the rest.
+Using higher threshold gives more deblocking strength.
+Setting @var{alpha} controls threshold detection at exact edge of block.
+Remaining options controls threshold detection near the edge. Each one for
+below/above or left/right. Setting any of those to @var{0} disables
+deblocking.
+
+@item planes
+Set planes to filter. Default is to filter all available planes.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Deblock using weak filter and block size of 4 pixels.
+@example
+deblock=filter=weak:block=4
+@end example
+
+@item
+Deblock using strong filter, block size of 4 pixels and custom thresholds for
+deblocking more edges.
+@example
+deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05
+@end example
+
+@item
+Similar as above, but filter only first plane.
+@example
+deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=1
+@end example
+
+@item
+Similar as above, but filter only second and third plane.
+@example
+deblock=filter=strong:block=4:alpha=0.12:beta=0.07:gamma=0.06:delta=0.05:planes=6
+@end example
+@end itemize
+
 @anchor{decimate}
 @section decimate
 

libavfilter/Makefile

@@ -173,6 +173,7 @@ OBJS-$(CONFIG_CURVES_FILTER)                 += vf_curves.o
 OBJS-$(CONFIG_DATASCOPE_FILTER)              += vf_datascope.o
 OBJS-$(CONFIG_DCTDNOIZ_FILTER)               += vf_dctdnoiz.o
 OBJS-$(CONFIG_DEBAND_FILTER)                 += vf_deband.o
+OBJS-$(CONFIG_DEBLOCK_FILTER)                += vf_deblock.o
 OBJS-$(CONFIG_DECIMATE_FILTER)               += vf_decimate.o
 OBJS-$(CONFIG_DECONVOLVE_FILTER)             += vf_convolve.o framesync.o
 OBJS-$(CONFIG_DEFLATE_FILTER)                += vf_neighbor.o

libavfilter/allfilters.c

@@ -165,6 +165,7 @@ extern AVFilter ff_vf_curves;
 extern AVFilter ff_vf_datascope;
 extern AVFilter ff_vf_dctdnoiz;
 extern AVFilter ff_vf_deband;
+extern AVFilter ff_vf_deblock;
 extern AVFilter ff_vf_decimate;
 extern AVFilter ff_vf_deconvolve;
 extern AVFilter ff_vf_deflate;

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   7
-#define LIBAVFILTER_VERSION_MINOR  18
+#define LIBAVFILTER_VERSION_MINOR  19
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vf_deblock.c

@@ -0,0 +1,413 @@
+/*
+ * Copyright (c) 2018 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
+ */
+
+/*
+ * Based on paper: A Simple and Efficient Deblocking Algorithm for Low Bit-Rate Video Coding.
+ */
+
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+enum FilterType { WEAK, STRONG, NB_FILTER };
+
+typedef struct DeblockContext {
+    const AVClass *class;
+    const AVPixFmtDescriptor *desc;
+    int filter;
+    int block;
+    int planes;
+    float alpha;
+    float beta;
+    float gamma;
+    float delta;
+
+    int ath;
+    int bth;
+    int gth;
+    int dth;
+    int max;
+    int depth;
+    int bpc;
+    int nb_planes;
+    int planewidth[4];
+    int planeheight[4];
+
+    void (*deblockh)(uint8_t *dst, ptrdiff_t dst_linesize, int block,
+                     int ath, int bth, int gth, int dth, int max);
+    void (*deblockv)(uint8_t *dst, ptrdiff_t dst_linesize, int block,
+                     int ath, int bth, int gth, int dth, int max);
+} DeblockContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pixel_fmts[] = {
+        AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
+        AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
+        AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
+        AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+        AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
+        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_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12,
+        AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
+        AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
+        AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
+        AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
+        AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
+        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_GBRAP, AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
+        AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY16,
+        AV_PIX_FMT_NONE
+    };
+    AVFilterFormats *formats = ff_make_format_list(pixel_fmts);
+    if (!formats)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, formats);
+}
+
+#define WEAK_HFILTER(name, type, ldiv)                                              \
+static void deblockh##name##_weak(uint8_t *dstp, ptrdiff_t dst_linesize, int block, \
+                                  int ath, int bth, int gth, int dth, int max)      \
+{                                                                                   \
+    type *dst;                                                                      \
+    int x;                                                                          \
+                                                                                    \
+    dst = (type *)dstp;                                                             \
+    dst_linesize /= ldiv;                                                           \
+                                                                                    \
+    for (x = 0; x < block; x++) {                                                   \
+        int delta = dst[x] - dst[x - dst_linesize];                                 \
+        int A, B, C, D, a, b, c, d;                                                 \
+                                                                                    \
+        if (FFABS(delta) >= ath ||                                                  \
+            FFABS(dst[x - 1 * dst_linesize] - dst[x - 2 * dst_linesize]) >= bth ||  \
+            FFABS(dst[x + 0 * dst_linesize] - dst[x + 1 * dst_linesize]) >= gth)    \
+            continue;                                                               \
+                                                                                    \
+        A = dst[x - 2 * dst_linesize];                                              \
+        B = dst[x - 1 * dst_linesize];                                              \
+        C = dst[x + 0 * dst_linesize];                                              \
+        D = dst[x + 1 * dst_linesize];                                              \
+                                                                                    \
+        a = A + delta / 8;                                                          \
+        b = B + delta / 2;                                                          \
+        c = C - delta / 2;                                                          \
+        d = D - delta / 8;                                                          \
+                                                                                    \
+        dst[x - 2 * dst_linesize] = av_clip(a, 0, max);                             \
+        dst[x - 1 * dst_linesize] = av_clip(b, 0, max);                             \
+        dst[x + 0 * dst_linesize] = av_clip(c, 0, max);                             \
+        dst[x + 1 * dst_linesize] = av_clip(d, 0, max);                             \
+    }                                                                               \
+}
+
+WEAK_HFILTER(8, uint8_t, 1)
+WEAK_HFILTER(16, uint16_t, 2)
+
+#define WEAK_VFILTER(name, type, ldiv)                                              \
+static void deblockv##name##_weak(uint8_t *dstp, ptrdiff_t dst_linesize, int block, \
+                                  int ath, int bth, int gth, int dth, int max)      \
+{                                                                                   \
+    type *dst;                                                                      \
+    int y;                                                                          \
+                                                                                    \
+    dst = (type *)dstp;                                                             \
+    dst_linesize /= ldiv;                                                           \
+                                                                                    \
+    for (y = 0; y < block; y++) {                                                   \
+        int delta = dst[0] - dst[-1];                                               \
+        int A, B, C, D, a, b, c, d;                                                 \
+                                                                                    \
+        if (FFABS(delta) >= ath ||                                                  \
+            FFABS(dst[-1] - dst[-2]) >= bth ||                                      \
+            FFABS(dst[0] - dst[1]) >= gth)                                          \
+            continue;                                                               \
+                                                                                    \
+        A = dst[-2];                                                                \
+        B = dst[-1];                                                                \
+        C = dst[+0];                                                                \
+        D = dst[+1];                                                                \
+                                                                                    \
+        a = A + delta / 8;                                                          \
+        b = B + delta / 2;                                                          \
+        c = C - delta / 2;                                                          \
+        d = D - delta / 8;                                                          \
+                                                                                    \
+        dst[-2] = av_clip(a, 0, max);                                               \
+        dst[-1] = av_clip(b, 0, max);                                               \
+        dst[+0] = av_clip(c, 0, max);                                               \
+        dst[+1] = av_clip(d, 0, max);                                               \
+                                                                                    \
+        dst += dst_linesize;                                                        \
+    }                                                                               \
+}
+
+WEAK_VFILTER(8, uint8_t, 1)
+WEAK_VFILTER(16, uint16_t, 2)
+
+#define STRONG_HFILTER(name, type, ldiv)                                           \
+static void deblockh##name##_strong(uint8_t *dstp, ptrdiff_t dst_linesize, int block,\
+                                    int ath, int bth, int gth, int dth, int max)   \
+{                                                                                  \
+    type *dst;                                                                     \
+    int x;                                                                         \
+                                                                                   \
+    dst = (type *)dstp;                                                            \
+    dst_linesize /= ldiv;                                                          \
+                                                                                   \
+    for (x = 0; x < block; x++) {                                                  \
+        int A, B, C, D, E, F, a, b, c, d, e, f;                                    \
+        int delta = dst[x] - dst[x - dst_linesize];                                \
+                                                                                   \
+        if (FFABS(delta) >= ath ||                                                 \
+            FFABS(dst[x - 1 * dst_linesize] - dst[x - 2 * dst_linesize]) >= bth || \
+            FFABS(dst[x + 1 * dst_linesize] - dst[x + 2 * dst_linesize]) >= gth || \
+            FFABS(dst[x + 0 * dst_linesize] - dst[x + 1 * dst_linesize]) >= dth)   \
+            continue;                                                              \
+                                                                                   \
+        A = dst[x - 3 * dst_linesize];                                             \
+        B = dst[x - 2 * dst_linesize];                                             \
+        C = dst[x - 1 * dst_linesize];                                             \
+        D = dst[x + 0 * dst_linesize];                                             \
+        E = dst[x + 1 * dst_linesize];                                             \
+        F = dst[x + 2 * dst_linesize];                                             \
+                                                                                   \
+        a = A + delta / 8;                                                         \
+        b = B + delta / 4;                                                         \
+        c = C + delta / 2;                                                         \
+        d = D - delta / 2;                                                         \
+        e = E - delta / 4;                                                         \
+        f = F - delta / 8;                                                         \
+                                                                                   \
+        dst[x - 3 * dst_linesize] = av_clip(a, 0, max);                            \
+        dst[x - 2 * dst_linesize] = av_clip(b, 0, max);                            \
+        dst[x - 1 * dst_linesize] = av_clip(c, 0, max);                            \
+        dst[x + 0 * dst_linesize] = av_clip(d, 0, max);                            \
+        dst[x + 1 * dst_linesize] = av_clip(e, 0, max);                            \
+        dst[x + 2 * dst_linesize] = av_clip(f, 0, max);                            \
+    }                                                                              \
+}
+
+STRONG_HFILTER(8, uint8_t, 1)
+STRONG_HFILTER(16, uint16_t, 2)
+
+#define STRONG_VFILTER(name, type, ldiv)                                           \
+static void deblockv##name##_strong(uint8_t *dstp, ptrdiff_t dst_linesize, int block,\
+                                    int ath, int bth, int gth, int dth, int max)   \
+{                                                                                  \
+    type *dst;                                                                     \
+    int y;                                                                         \
+                                                                                   \
+    dst = (type *)dstp;                                                            \
+    dst_linesize /= ldiv;                                                          \
+                                                                                   \
+    for (y = 0; y < block; y++) {                                                  \
+        int A, B, C, D, E, F, a, b, c, d, e, f;                                    \
+        int delta = dst[0] - dst[-1];                                              \
+                                                                                   \
+        if (FFABS(delta) >= ath ||                                                 \
+            FFABS(dst[-1] - dst[-2]) >= bth ||                                     \
+            FFABS(dst[+1] - dst[+2]) >= gth ||                                     \
+            FFABS(dst[+0] - dst[+1]) >= dth)                                       \
+            continue;                                                              \
+                                                                                   \
+        A = dst[-3];                                                               \
+        B = dst[-2];                                                               \
+        C = dst[-1];                                                               \
+        D = dst[+0];                                                               \
+        E = dst[+1];                                                               \
+        F = dst[+2];                                                               \
+                                                                                   \
+        a = A + delta / 8;                                                         \
+        b = B + delta / 4;                                                         \
+        c = C + delta / 2;                                                         \
+        d = D - delta / 2;                                                         \
+        e = E - delta / 4;                                                         \
+        f = F - delta / 8;                                                         \
+                                                                                   \
+        dst[-3] = av_clip(a, 0, max);                                              \
+        dst[-2] = av_clip(b, 0, max);                                              \
+        dst[-1] = av_clip(c, 0, max);                                              \
+        dst[+0] = av_clip(d, 0, max);                                              \
+        dst[+1] = av_clip(e, 0, max);                                              \
+        dst[+2] = av_clip(f, 0, max);                                              \
+                                                                                   \
+        dst += dst_linesize;                                                       \
+    }                                                                              \
+}
+
+STRONG_VFILTER(8, uint8_t, 1)
+STRONG_VFILTER(16, uint16_t, 2)
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    DeblockContext *s = ctx->priv;
+    AVFilterLink *inlink = ctx->inputs[0];
+
+    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->bpc = (s->depth + 7) / 8;
+    s->max = (1 << s->depth) - 1;
+    s->ath = s->alpha * s->max;
+    s->bth = s->beta  * s->max;
+    s->gth = s->gamma * s->max;
+    s->dth = s->delta * s->max;
+
+    if (s->depth <= 8 && s->filter == WEAK) {
+        s->deblockh = deblockh8_weak;
+        s->deblockv = deblockv8_weak;
+    } else if (s->depth >= 8 && s->filter == WEAK) {
+        s->deblockh = deblockh16_weak;
+        s->deblockv = deblockv16_weak;
+    }
+    if (s->depth <= 8 && s->filter == STRONG) {
+        s->deblockh = deblockh8_strong;
+        s->deblockv = deblockv8_strong;
+    } else if (s->depth >= 8 && s->filter == STRONG) {
+        s->deblockh = deblockh16_strong;
+        s->deblockv = deblockv16_strong;
+    }
+
+    s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, s->desc->log2_chroma_w);
+    s->planewidth[0] = s->planewidth[3] = inlink->w;
+
+    s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
+    s->planeheight[0] = s->planeheight[3] = inlink->h;
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    DeblockContext *s = ctx->priv;
+    const int block = s->block;
+    AVFrame *out;
+    int plane, x, y;
+
+    if (av_frame_is_writable(in)) {
+        out = in;
+    } else {
+        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+        if (!out) {
+            av_frame_free(&in);
+            return AVERROR(ENOMEM);
+        }
+        av_frame_copy_props(out, in);
+    }
+
+    for (plane = 0; plane < s->nb_planes; plane++) {
+        const int width = s->planewidth[plane];
+        const int height = s->planeheight[plane];
+        const uint8_t *src = (const uint8_t *)in->data[plane];
+        uint8_t *dst = (uint8_t *)out->data[plane];
+
+        if (in != out)
+            av_image_copy_plane(dst, out->linesize[plane],
+                                src, in->linesize[plane],
+                                width * s->bpc, height);
+
+        if (!((1 << plane) & s->planes))
+            continue;
+
+        for (x = block; x < width; x += block)
+            s->deblockv(dst + x * s->bpc, out->linesize[plane],
+                        FFMIN(block, height), s->ath, s->bth, s->gth, s->dth, s->max);
+
+        for (y = block; y < height; y += block) {
+            dst += out->linesize[plane] * block;
+
+            s->deblockh(dst, out->linesize[plane],
+                        FFMIN(block, width),
+                        s->ath, s->bth, s->gth, s->dth, s->max);
+
+            for (x = block; x < width; x += block) {
+                s->deblockh(dst + x * s->bpc, out->linesize[plane],
+                            FFMIN(block, width - x),
+                            s->ath, s->bth, s->gth, s->dth, s->max);
+                s->deblockv(dst + x * s->bpc, out->linesize[plane],
+                            FFMIN(block, height - y),
+                            s->ath, s->bth, s->gth, s->dth, s->max);
+            }
+        }
+    }
+
+    if (in != out)
+        av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+#define OFFSET(x) offsetof(DeblockContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption deblock_options[] = {
+    { "filter",    "set type of filter",          OFFSET(filter),    AV_OPT_TYPE_INT,   {.i64=STRONG},0, 1,  FLAGS, "filter" },
+    { "weak",      0,                             0,                 AV_OPT_TYPE_CONST, {.i64=WEAK},  0, 0,  FLAGS, "filter" },
+    { "strong",    0,                             0,                 AV_OPT_TYPE_CONST, {.i64=STRONG},0, 0,  FLAGS, "filter" },
+    { "block",     "set size of block",           OFFSET(block),     AV_OPT_TYPE_INT,   {.i64=8},    4, 512, FLAGS },
+    { "alpha",     "set 1st detection threshold", OFFSET(alpha),     AV_OPT_TYPE_FLOAT, {.dbl=.098}, 0,  1,  FLAGS },
+    { "beta",      "set 2nd detection threshold", OFFSET(beta),      AV_OPT_TYPE_FLOAT, {.dbl=.05},  0,  1,  FLAGS },
+    { "gamma",     "set 3rd detection threshold", OFFSET(gamma),     AV_OPT_TYPE_FLOAT, {.dbl=.05},  0,  1,  FLAGS },
+    { "delta",     "set 4th detection threshold", OFFSET(delta),     AV_OPT_TYPE_FLOAT, {.dbl=.05},  0,  1,  FLAGS },
+    { "planes",    "set planes to filter",        OFFSET(planes),    AV_OPT_TYPE_INT,   {.i64=15},   0, 15,  FLAGS },
+    { NULL },
+};
+
+static const AVFilterPad inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .filter_frame   = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+    },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(deblock);
+
+AVFilter ff_vf_deblock = {
+    .name          = "deblock",
+    .description   = NULL_IF_CONFIG_SMALL("Deblock video."),
+    .priv_size     = sizeof(DeblockContext),
+    .priv_class    = &deblock_class,
+    .query_formats = query_formats,
+    .inputs        = inputs,
+    .outputs       = outputs,
+};