[FFmpeg-devel] [PATCH] lavfi: add kerndeint filter

Stefano Sabatini stefasab at gmail.com
Sat Oct 20 01:51:24 CEST 2012


On date Thursday 2012-10-18 09:50:53 +0200, Jérémy Tran encoded:
> This is a port of the vf_kerndeint filter (libmpcodecs/vf_kerndeint) by
> Donal A. Graft (original avisynth plugin author).
> 

> The filter works fine using YUV colorspace.
> When using RGB, it is not binary equal with mp=kerndeint (the output video
> looks fine so this may be a little mistake I did somewhere).

Uhm bit-exactness is important for a port. I compared the code with
the original code, and couldn't spot significant differences. Does the
difference depends on some specific options (this should help to
circumscribe the investigation)?

> I also removed many non-32bits colorspaces since the alogrithm does not
> seem to be made to work on shorter pixels, is this okay ?

For the moment discard all formats not supported by the ported filter.

> The only non-32-bits colorspace left is YUYV422 which is what mp=kerndeint
> uses, but I don't seem to get the same results (my first thought was
> because it does not have 32bpp).

> The FATE test will come after this.
> ---
>  configure                  |   1 +
>  doc/filters.texi           |  45 ++++++
>  libavfilter/Makefile       |   1 +
>  libavfilter/allfilters.c   |   1 +
>  libavfilter/vf_kerndeint.c | 377 +++++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 425 insertions(+)
>  create mode 100644 libavfilter/vf_kerndeint.c
> 
> diff --git a/configure b/configure
> index 5aa891b..31abba2 100755
> --- a/configure
> +++ b/configure
> @@ -1917,6 +1917,7 @@ frei0r_filter_extralibs='$ldl'
>  frei0r_src_filter_deps="frei0r dlopen"
>  frei0r_src_filter_extralibs='$ldl'
>  hqdn3d_filter_deps="gpl"
> +kerndeint_filter_deps="gpl"
>  movie_filter_deps="avcodec avformat"
>  mp_filter_deps="gpl avcodec swscale postproc inline_asm"
>  mptestsrc_filter_deps="gpl"
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 725c7b5..94df075 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -2431,6 +2431,51 @@ If a parameter is omitted, it is kept at its current value.
>  Interlaceing detect filter. This filter tries to detect if the input is
>  interlaced or progressive. Top or bottom field first.
>  
> + at section kerndeint
> +
> +Donald Graft's adaptive kernel deinterlacer. Work on interlaced parts of a video
> +to produce progressive frames.
> +

> +This @var{kerndeint} filter accepts the following optional parameters:
> +[@var{threshold}[:@var{map}[:@var{order}[:@var{sharp}[:@var{twoway}]]]]]

Need to be updated.

> +
> + at var{threshold} must be an integer in the range [0,255] and defaults to 10.
> +Affect the filter's tolerance when determining if a pixel line must be
> +processed. A value of 0 will result in applying the process on every pixels.
> +

> + at var{map} must be 0 (ignore pixels exceeding the threshold) or 1 (paint pixels
> +exceeding the threshold white) and defaults to 0.

What is the "threshold white"?

> +
> + at var{order} must be 0 (leave fields alone) or 1 (swap fields) and defaults to 0.

Maybe this description could be improved, for example I can't
understand what is "leave fields alone".

> +
> + at var{sharp} must be 0 (disable additional sharpening) or 1 (enable additional
> +sharpening) and defaults to 0.
> +
> + at var{twoway} must be 0 (disable twoway sharpening) or 1 (enable twoway
> +sharpening) and defaults to 0.
> +
> +Some examples follow:
> + at itemize
> + at item
> +Those two commands are equivalent
> + at example
> +kerndeint
> +kerndeint=10:0:0:0:0
> + at end example
> +
> + at item
> +Enable additional sharpening
> + at example
> +kerndeint=10:0:0:1:0
> + at end example
> +
> + at item
> +Paint processed pixels in white
> + at example
> +kerndeint=10:1:0:0:0
> + at end example
> + at end itemize

Maybe give priority to the named option syntax, should be easier to
read.

> +
>  @section lut, lutrgb, lutyuv
>  
>  Compute a look-up table for binding each pixel component input value
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 3618f10..35d85e4 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -109,6 +109,7 @@ 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 348f369..72db7d7 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -101,6 +101,7 @@ 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/vf_kerndeint.c b/libavfilter/vf_kerndeint.c
> new file mode 100644
> index 0000000..e533842
> --- /dev/null
> +++ b/libavfilter/vf_kerndeint.c
> @@ -0,0 +1,377 @@
> +/*
> + * 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/opt.h"
> +#include "libavutil/pixdesc.h"
> +
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "internal.h"
> +
> +#define PLANAR_Y 0
> +#define PLANAR_U 1
> +#define PLANAR_V 2
> +
> +#define RGB  0
> +#define YUYV 1
> +#define YUV  2
> +
> +typedef struct {
> +    const AVClass *class;

> +    int           frame;
> +    int           map;
> +    int           order;

doxy may help

> +    int           thresh;
> +    int           sharp;
> +    int           twoway;
> +    int           do_deinterlace;
> +    int           hsub;
> +    int           vsub;
> +    int           format;        ///< Pixel format: RGB, YUYV or YUV

Nit: "pixel format" is a bit ambiguous/misleading, "colorspace" or
"format_class" may fit better

> +    uint8_t       *temp_data[4]; ///< Temporary video plane data buffer

> +    int           bpp;

bytes or bits per pixel? (that's why doxy helps)

> +} 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,
> +      { 10 }, 0, 255, FLAGS },
> +    { "map", "set the map", OFFSET(map), AV_OPT_TYPE_INT,
> +      { 0 }, 0, 1, FLAGS },
> +    { "order", "set the order", OFFSET(order), AV_OPT_TYPE_INT,
> +      { 0 }, 0, 1, FLAGS },
> +    { "sharp", "set the sharpening mode", OFFSET(sharp), AV_OPT_TYPE_INT,
> +      { 0 }, 0, 1, FLAGS },
> +    { "twoway", "activate twoway", OFFSET(twoway), AV_OPT_TYPE_INT,
> +      { 0 }, 0, 1, FLAGS },
> +    { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(kerndeint);
> +
> +static av_cold int init(AVFilterContext *ctx, const char *args)
> +{
> +    KerndeintContext *kerndeint = ctx->priv;
> +    int i;
> +    const char const * shorthand[] = { "thresh", "map", "order", "sharp", "twoway", NULL };
> +
> +    kerndeint->class = &kerndeint_class;
> +    kerndeint->do_deinterlace = 1;

> +    for (i = 0; i < 4; ++i)
> +        kerndeint->temp_data[i] = NULL;

Nit: slightly simpler: memset(kerndeint->tmp_data, 0, ...);

also maybe the priv structure is already 0-inited.

> +    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;
> +    int i;
> +
> +    for (i = 0; i < 4; ++i)
> +        av_free(kerndeint->temp_data[i]);

Nit: av_opt_free(kerndeint) for safeness (in case an allocable field
is added)

> +}
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> +    static const enum PixelFormat pix_fmts[] = {
> +        PIX_FMT_YUV420P,
> +        PIX_FMT_YUYV422,
> +        PIX_FMT_ARGB,
> +        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];
> +    int i;
> +
> +    kerndeint->hsub = desc->log2_chroma_w;
> +    kerndeint->vsub = desc->log2_chroma_h;
> +    kerndeint->bpp = av_get_bits_per_pixel(desc) / 8;
> +
> +    for (i = 0; i < 4; ++i)
> +        kerndeint->temp_data[i] = av_mallocz(inlink->h * inlink->w * kerndeint->bpp);
> +

> +    switch (inlink->format) {
> +        case PIX_FMT_YUV420P:
> +            kerndeint->format = YUV;
> +            break;
> +        case PIX_FMT_YUYV422:
> +            kerndeint->format = YUYV;
> +            break;
> +        case PIX_FMT_ARGB:
> +            kerndeint->format = RGB;
> +            break;
> +    }

since the mapping is a bijection you could avoid it

> +
> +    return 0;
> +}
> +

> +#define AVWN32(buf, value) *(uint32_t *)(buf) = value

Nit: since this is only used two times, I'd prefer to avoid it, and
remove one level of obfuscation.

> +
> +static int end_frame(AVFilterLink *inlink)
> +{
> +    KerndeintContext *kerndeint = inlink->dst->priv;
> +    AVFilterBufferRef *inpic  = inlink->cur_buf;
> +    AVFilterBufferRef *outpic = inlink->dst->outputs[0]->out_buf;
> +    int cw = inlink->w >> kerndeint->hsub;
> +    int ch = inlink->h >> kerndeint->vsub;
> +

> +    const unsigned char *prvp;   ///< Previous field's pixel line number n
> +    const unsigned char *prvpp;  ///< Previous field's pixel line number (n - 1)
> +    const unsigned char *prvpn;  ///< Previous field's pixel line number (n + 1)
> +    const unsigned char *prvppp; ///< Previous field's pixel line number (n - 2)
> +    const unsigned char *prvpnn; ///< Previous field's pixel line number (n + 2)
> +    const unsigned char *prvp4p; ///< Previous field's pixel line number (n - 4)
> +    const unsigned char *prvp4n; ///< Previous field's pixel line number (n + 4)
> +

> +    const unsigned char *srcp;   ///< Current field's pixel line number n
> +    const unsigned char *srcpp;  ///< Current field's pixel line number (n - 1)
> +    const unsigned char *srcpn;  ///< Current field's pixel line number (n + 1)
> +    const unsigned char *srcppp; ///< Current field's pixel line number (n - 2)
> +    const unsigned char *srcpnn; ///< Current field's pixel line number (n + 2)
> +    const unsigned char *srcp3p; ///< Current field's pixel line number (n - 3)
> +    const unsigned char *srcp3n; ///< Current field's pixel line number (n + 3)
> +    const unsigned char *srcp4p; ///< Current field's pixel line number (n - 4)
> +    const unsigned char *srcp4n; ///< Current field's pixel line number (n + 4)

following this scheme maybe cur* may be better (but unrelated to the
patch, and better to leave it to a separate patch in case)

BTW thanks for commenting the vars, it really helps.

> +
> +    unsigned char *dstp, *dstp_saved;

nit: uint8_t is more FFmpeg-ish.

> +    const unsigned char *srcp_saved;

same here

> +
> +    int src_linesize;
> +    int psrc_linesize;
> +    int dst_linesize;
> +    int x, y, plane, g;
> +    int n = kerndeint->frame++;
> +    int val, hi, lo, w, h;
> +    double valf;
> +    const int threshold = kerndeint->thresh;
> +    const int order     = kerndeint->order;
> +    const int map       = kerndeint->map;
> +    const int sharp     = kerndeint->sharp;
> +    const int twoway    = kerndeint->twoway;
> +

> +    if (kerndeint->do_deinterlace) {

Given the complexity of the algo, I'd prefer to avoid another reindent
level.
You can do:

if (!kerndeint->do_deinterlace)
   copy;
   goto end;
}

or
if (!kerndeint->do_deinterlace) {
   copy
   return ff_end_frame
}


> +        for (plane = 0; inpic->data[plane] && plane < 4; plane++) {
> +            h = plane == PLANAR_Y ? inlink->h : ch;
> +            w = plane == PLANAR_Y ? inlink->w * kerndeint->bpp : cw;
> +
> +            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, w);
> +                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, w);
> +            memcpy(dstp_saved + (2 + order)     * dst_linesize, srcp_saved + (3 - order)     * src_linesize, w);
> +            memcpy(dstp_saved + (h - 2 + order) * dst_linesize, srcp_saved + (h - 1 - order) * src_linesize, w);
> +            memcpy(dstp_saved + (h - 4 + order) * dst_linesize, srcp_saved + (h - 3 - order) * src_linesize, w);
> +
> +            /* For the other field choose adaptively between using the previous field
> +               or the interpolant from the current field. */
> +            prvp   = kerndeint->temp_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 < w; x++) {
> +                    if ((threshold == 0) || (n == 0) ||
> +                        (abs((int)prvp[x]  - (int)srcp[x])  > threshold) ||
> +                        (abs((int)prvpp[x] - (int)srcpp[x]) > threshold) ||
> +                        (abs((int)prvpn[x] - (int)srcpn[x]) > threshold)) {
> +                        if (map == 1) {

> +                            g = x & ~3;

Nit: keep the variable declared within this scope (like in the
original code)

> +
> +                            if (kerndeint->format == RGB) {
> +                                AVWN32(dstp + g, 0xffffffff);
> +                                x = g + 3;
> +                            } else if (kerndeint->format == YUYV) {

> +                                AVWN32(dstp + g, 0xeb80eb80);

Nit: add comment like: y <- 235, u <- 128, y <- 235, v <- 128

> +                                x = g + 3;
> +                            } else {
> +                                dstp[x] = plane == PLANAR_Y ? 235 : 128;
> +                            }
> +                        } else {

> +                            if (kerndeint->format == RGB) {
> +                                hi = 255;
> +                                lo = 0;
> +                            } else if (kerndeint->format == YUYV) {
> +                                hi = (x & 1) ? 240 : 235;
> +                                lo = 16;
> +                            } else {
> +                                hi = (plane == PLANAR_Y) ? 235 : 240;
> +                                lo = 16;
> +                            }

This could be computed once and for all during the
initialization/configuration stage.

> +
> +                            if (sharp == 1) {
> +                                if (twoway == 1) {
> +                                    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])

Nit: single line? (like in ported code?)

> +                                           - 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]);
> +                                }
> +

> +                                valf = av_clip(valf, lo, hi);
> +                                dstp[x] = (int) valf;

you can merge these two

> +                            } else {
> +                                if (twoway == 1) {

> +                                    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;

I guess some ASCII table my help understand what this is about (seem
like a convolution or such).

> +                                }
> +

> +                                val = av_clip(val, lo, hi);
> +                                dstp[x] = val;

ditto

> +                            }
> +                        }
> +                    } 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->temp_data[plane];
> +            av_image_copy_plane(dstp, psrc_linesize, srcp, src_linesize, w, h);
> +        }
> +    } else {

> +        for (plane = 0; inpic->data[plane] && plane < 4; plane++) {
> +            h = plane == PLANAR_Y ? inlink->h : ch;
> +            w = plane == PLANAR_Y ? inlink->w * kerndeint->bpp : cw;
> +            av_image_copy_plane(outpic->data[plane], outpic->linesize[plane],
> +                                inpic->data[plane],  inpic->linesize[plane],
> +                                w, h);

av_image_copy?

Also I suspect that the memcpy could be avoided, by implementing a
start_frame (check for example transpose passthrough mode).

> +        }
> +    }
> +
> +    return ff_end_frame(inlink->dst->outputs[0]);
> +}
> +
> +AVFilter avfilter_vf_kerndeint = {
> +    .name        = "kerndeint",

> +    .description = NULL_IF_CONFIG_SMALL("Kernel deinterlacer"),

"Apply kernel deinterlacer." (tell what the filter *does*)

[...]
-- 
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