[FFmpeg-devel] [Patch][GSoC] Motion Estimation filter

Paul B Mahol onemda at gmail.com
Wed Apr 6 15:10:57 CEST 2016


> From 68560d7d4764587ad72f1901edc45450391f1378 Mon Sep 17 00:00:00 2001
> From: dsmudhar <ds.mudhar at gmail.com>
> Date: Mon, 4 Apr 2016 01:06:07 +0530
> Subject: [PATCH] motion estimation filter
>
> ---
>  libavfilter/Makefile       |   1 +
>  libavfilter/allfilters.c   |   1 +
>  libavfilter/vf_mestimate.c | 236 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 238 insertions(+)
>  create mode 100644 libavfilter/vf_mestimate.c
>
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index b6e1999..a89db52 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -198,6 +198,7 @@ OBJS-$(CONFIG_LUTYUV_FILTER)                 += vf_lut.o
>  OBJS-$(CONFIG_MASKEDMERGE_FILTER)            += vf_maskedmerge.o framesync.o
>  OBJS-$(CONFIG_MCDEINT_FILTER)                += vf_mcdeint.o
>  OBJS-$(CONFIG_MERGEPLANES_FILTER)            += vf_mergeplanes.o framesync.o
> +OBJS-$(CONFIG_MESTIMATE_FILTER)              += vf_mestimate.o
>  OBJS-$(CONFIG_METADATA_FILTER)               += f_metadata.o
>  OBJS-$(CONFIG_MPDECIMATE_FILTER)             += vf_mpdecimate.o
>  OBJS-$(CONFIG_NEGATE_FILTER)                 += vf_lut.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 5c18fd1..f4c60ad 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -219,6 +219,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER(MASKEDMERGE,    maskedmerge,    vf);
>      REGISTER_FILTER(MCDEINT,        mcdeint,        vf);
>      REGISTER_FILTER(MERGEPLANES,    mergeplanes,    vf);
> +    REGISTER_FILTER(MESTIMATE,      mestimate,      vf);
>      REGISTER_FILTER(METADATA,       metadata,       vf);
>      REGISTER_FILTER(MPDECIMATE,     mpdecimate,     vf);
>      REGISTER_FILTER(NEGATE,         negate,         vf);
> diff --git a/libavfilter/vf_mestimate.c b/libavfilter/vf_mestimate.c
> new file mode 100644
> index 0000000..02b5430
> --- /dev/null
> +++ b/libavfilter/vf_mestimate.c
> @@ -0,0 +1,236 @@
> +/**
> + *
> + * Developed by Davinder Singh (DSM_ / @dsmudhar) during GSoC 2016
> + * As qualification task: Basic but working motion estimation filter
> + *
> + * Used vf_w3fdif.c as base, needed two frames for bi-directional prediction.
> + *
> + * The filter uses block matching exhaustive search algorithm
> + *
> + * 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/common.h"
> +#include "libavutil/imgutils.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/pixdesc.h"
> +#include "libavutil/motion_vector.h"
> +#include "avfilter.h"
> +#include "formats.h"
> +#include "internal.h"
> +#include "video.h"
> +
> +typedef struct MEContext {
> +    const AVClass *class;
> +    AVMotionVector *mvs; ///< motion vectors
> +    AVFrame *prev, *cur, *next;  ///< previous, current, next frames
> +    int block_size; ///< block size
> +    int reg_size; ///< search region
> +    int32_t mv_count; ///< no of motion vectors per frame
> +
> +} MEContext;
> +
> +#define OFFSET(x) offsetof(MEContext, x)
> +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
> +#define CONST(name, help, val, unit) { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, 0, 0, FLAGS, unit }
> +
> +static const AVOption mestimate_options[] = {
> +    { "block", "specify the block size", OFFSET(block_size), AV_OPT_TYPE_INT, {.i64=8}, 4, 32, FLAGS, "block" },
> +    { "search",  "specify search region", OFFSET(reg_size), AV_OPT_TYPE_INT, {.i64=7}, 4, 32, FLAGS, "search" },
> +    { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(mestimate);
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> +    static const enum AVPixelFormat pix_fmts[] = {
> +        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_YUVJ444P, AV_PIX_FMT_YUVJ440P,
> +        AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
> +        AV_PIX_FMT_YUVJ411P,
> +        AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
> +        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
> +        AV_PIX_FMT_GRAY8,
> +        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 int config_input(AVFilterLink *inlink)
> +{
> +    MEContext *s = inlink->dst->priv;
> +    int nb_blocks_y = inlink->h / s->block_size;
> +    int nb_blocks_x = inlink->w / s->block_size;
> +
> +    s->mvs = av_malloc_array(nb_blocks_x * nb_blocks_y, 2 * sizeof(AVMotionVector));
> +    if (!s->mvs)
> +        return AVERROR(ENOMEM);
> +
> +    return 0;
> +}
> +
> +static int64_t get_mse(MEContext *s, int width, int x_cur, int y_cur, int x_sb, int y_sb, int source)
> +{
> +    // source == -1 means forward prediction => frame k - 1 as reference
> +    uint8_t *buf_src = source == -1 ? s->prev->data[0] : s->next->data[0];
> +    uint8_t *buf_cur = s->cur->data[0];
> +    int64_t mse = 0;
> +    int i, j;
> +
> +    for (i = 0; i < s->block_size; i++)
> +        for (j = 0; j < s->block_size; j++) {
> +            int64_t sb = ((int64_t) y_sb + i) * width + x_sb + j;
> +            int64_t cur = ((int64_t) y_cur + i) * width + x_cur + j;
> +            int diff = (int) buf_src[sb] - (int) buf_cur[cur];
> +            mse += pow(diff, 2);

No need to use pow, just multiply directly.

> +        }
> +
> +    return mse / pow(s->block_size, 2);

No need to use pow, just multiply directly.

> +}
> +
> +static void add_mv_data(AVMotionVector *mv, int block_size,
> +                  int dst_x, int dst_y, int src_x, int src_y,
> +                  int source)
> +{
> +    mv->w = block_size;
> +    mv->h = block_size;
> +    mv->dst_x = dst_x;
> +    mv->dst_y = dst_y;
> +    mv->src_x = src_x;
> +    mv->src_y = src_y;
> +    mv->source = source;
> +    mv->flags = 0;
> +}
> +
> +static void get_motion_vector(AVFilterLink *inlink, int x_cur, int y_cur, int source)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    MEContext *s = ctx->priv;
> +
> +    int i, j, x_sb, y_sb, dx = 0, dy = 0;
> +    int sign_i = 1, sign_j = 1;
> +    int y_sb_max = av_clip(y_cur + s->reg_size, 0, inlink->h - 1);
> +    int x_sb_max = av_clip(x_cur + s->reg_size, 0, inlink->w - 1);
> +    int64_t mse, mse_min = -1;
> +
> +    for (i = 0; i < s->reg_size; i = sign_i ? -(i + 1) : -i, sign_i = !sign_i) {
> +        y_sb = y_cur + i;
> +
> +        if (y_sb < 0 || y_sb > y_sb_max)
> +            continue;
> +
> +        for (j = 0; j < s->reg_size; j = sign_j ? -(j + 1) : -j, sign_j = !sign_j) {
> +            x_sb = x_cur + j;
> +
> +            if (x_sb < 0 || x_sb > x_sb_max)
> +                continue;
> +
> +            if (mse_min == -1 || (mse = get_mse(s, inlink->w, x_cur, y_cur, x_sb, y_sb, source)) < mse_min) {

Above condition doesn't makes sense. Using signed is not optimal in
this case, you can kill one extra operation here.

> +                mse_min = mse;
> +                dx = x_sb - x_cur;
> +                dy = y_sb - y_cur;
> +            }
> +        }
> +    }
> +
> +    if (dx != 0 || dy != 0)
> +        add_mv_data(s->mvs + s->mv_count++, s->block_size, x_cur + dx, y_cur + dy, x_cur, y_cur, source);
> +}
> +

[...]


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