[FFmpeg-devel] [PATCH] avfilter: add findandcover filter

Clément Bœsch u at pkh.me
Thu Apr 30 09:49:27 CEST 2015


On Wed, Apr 29, 2015 at 06:00:54PM +0200, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  libavfilter/Makefile          |    1 +
>  libavfilter/allfilters.c      |    1 +
>  libavfilter/vf_findandcover.c |  400 +++++++++++++++++++++++++++++++++++++++++

doc/filters.texi please...

(note: don't forget to minor bump)

>  3 files changed, 402 insertions(+)
>  create mode 100644 libavfilter/vf_findandcover.c
> 
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 48cee50..09bc465 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -126,6 +126,7 @@ OBJS-$(CONFIG_FFTFILT_FILTER)                += vf_fftfilt.o
>  OBJS-$(CONFIG_FIELD_FILTER)                  += vf_field.o
>  OBJS-$(CONFIG_FIELDMATCH_FILTER)             += vf_fieldmatch.o
>  OBJS-$(CONFIG_FIELDORDER_FILTER)             += vf_fieldorder.o
> +OBJS-$(CONFIG_FINDANDCOVER_FILTER)           += vf_findandcover.o
>  OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
>  OBJS-$(CONFIG_FRAMESTEP_FILTER)              += vf_framestep.o
>  OBJS-$(CONFIG_FPS_FILTER)                    += vf_fps.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 7961dca..c4d4d74 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -142,6 +142,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER(FIELD,          field,          vf);
>      REGISTER_FILTER(FIELDMATCH,     fieldmatch,     vf);
>      REGISTER_FILTER(FIELDORDER,     fieldorder,     vf);
> +    REGISTER_FILTER(FINDANDCOVER,   findandcover,   vf);
>      REGISTER_FILTER(FORMAT,         format,         vf);
>      REGISTER_FILTER(FPS,            fps,            vf);
>      REGISTER_FILTER(FRAMEPACK,      framepack,      vf);
> diff --git a/libavfilter/vf_findandcover.c b/libavfilter/vf_findandcover.c
> new file mode 100644
> index 0000000..5838e3b
> --- /dev/null
> +++ b/libavfilter/vf_findandcover.c
> @@ -0,0 +1,400 @@
> +/*
> + * Copyright (c) 2014-2015 Michael Niedermayer <michaelni at gmx.at>
> + *
> + * 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.
> + */
> +
> +#include "libavutil/avassert.h"
> +#include "libavutil/imgutils.h"
> +#include "libavutil/opt.h"
> +#include "internal.h"
> +
> +#include "lavfutils.h"
> +
> +enum mode {
> +    MODE_COVER,
> +    MODE_BLUR,
> +    NB_MODES
> +};
> +
> +#define MAX_MIPMAPS 5
> +
> +typedef struct FOCContext {
> +    AVClass *class;
> +    float threshold;
> +    int mipmaps;
> +    int xmin, ymin, xmax, ymax;

> +    enum mode mode;

didn't you fix a bunch of related issue recently?

> +    char *obj_filename;
> +    char *cover_filename;
> +    int last_x, last_y;
> +    AVFrame *obj_frame;
> +    AVFrame *cover_frame;
> +    AVFrame *needle_frame[MAX_MIPMAPS];
> +    AVFrame *haystack_frame[MAX_MIPMAPS];
> +} FOCContext;
> +
> +#define OFFSET(x) offsetof(FOCContext, x)
> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
> +static const AVOption foc_options[] = {
> +    { "object", "object bitmap filename", OFFSET(obj_filename), AV_OPT_TYPE_STRING, {.str = NULL}, .flags = FLAGS },
> +    { "cover",  "cover bitmap filename",  OFFSET(cover_filename),  AV_OPT_TYPE_STRING, {.str = NULL}, .flags = FLAGS },
> +    { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_FLOAT, {.dbl = 0.5}, 0, 1.0, FLAGS },
> +    { "mipmaps", "set mipmaps", OFFSET(mipmaps), AV_OPT_TYPE_INT, {.i64 = 3}, 1, MAX_MIPMAPS, FLAGS },
> +    { "xmin", "", OFFSET(xmin), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
> +    { "ymin", "", OFFSET(ymin), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
> +    { "xmax", "", OFFSET(xmax), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
> +    { "ymax", "", OFFSET(ymax), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
> +    { "mode", "set removial mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = MODE_BLUR}, 0, NB_MODES - 1, FLAGS, "mode" },
> +        { "cover", "cover area with bitmap", 0, AV_OPT_TYPE_CONST, {.i64 = MODE_COVER}, INT_MIN, INT_MAX, FLAGS, "mode" },
> +        { "blur", "blur area", 0, AV_OPT_TYPE_CONST, {.i64 = MODE_BLUR}, INT_MIN, INT_MAX, FLAGS, "mode" },
> +    { NULL }
> +};
> +
> +static const AVClass foc_class = {
> +    .class_name       = "foc",
> +    .item_name        = av_default_item_name,
> +    .option           = foc_options,
> +    .version          = LIBAVUTIL_VERSION_INT,
> +    .category         = AV_CLASS_CATEGORY_FILTER,
> +};
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> +    static const enum PixelFormat pix_fmts[] = {
> +        AV_PIX_FMT_YUV420P,
> +        AV_PIX_FMT_YUVJ420P,
> +        AV_PIX_FMT_NONE
> +    };

> +    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

missing checks

> +    return 0;
> +}
> +
> +static AVFrame *downscale(AVFrame *in)
> +{
> +    int x, y;
> +    AVFrame *frame = av_frame_alloc();
> +    uint8_t *src, *dst;
> +    if (!frame)
> +        return NULL;
> +
> +    frame->format = in->format;
> +    frame->width  = (in->width + 1) / 2;
> +    frame->height = (in->height+ 1) / 2;
> +
> +    if (av_frame_get_buffer(frame, 32) < 0) {
> +        av_frame_free(&frame);
> +        return NULL;
> +    }
> +    src = in   ->data[0];
> +    dst = frame->data[0];
> +
> +    for(y = 0; y<frame->height; y++) {
> +        for(x = 0; x<frame->width; x++) {
> +            dst[x] = (  src[2*x+0]
> +                      + src[2*x+1]
> +                      + src[2*x+0 + in->linesize[0]]
> +                      + src[2*x+1 + in->linesize[0]]
> +                      + 2) >> 2;
> +        }
> +        src += 2*in->linesize[0];
> +        dst += frame->linesize[0];
> +    }
> +    return frame;
> +}
> +

> +static float compare(AVFrame *haystack, AVFrame *obj, int offx, int offy)

i hope this compare function doesn't need write access to haystack and obj

> +{
> +    int x,y;
> +    int o_sum_v = 0;
> +    int h_sum_v = 0;
> +    int64_t oo_sum_v = 0;
> +    int64_t hh_sum_v = 0;
> +    int64_t oh_sum_v = 0;
> +    float c;
> +    int n = obj->height * obj->width;

> +    uint8_t *odat = obj     ->data[0];
> +    uint8_t *hdat = haystack->data[0] + offx + offy * haystack->linesize[0];

seems they can be const

> +    int64_t o_sigma, h_sigma;
> +
> +    for(y = 0; y<obj->height; y++) {
> +        for(x = 0; x<obj->width; x++) {
> +            int o_v = odat[x];
> +            int h_v = hdat[x];
> +            o_sum_v += o_v;
> +            h_sum_v += h_v;
> +            oo_sum_v += o_v * o_v;
> +            hh_sum_v += h_v * h_v;
> +            oh_sum_v += o_v * h_v;
> +        }
> +        odat += obj->linesize[0];
> +        hdat += haystack->linesize[0];
> +    }
> +    o_sigma = n*oo_sum_v - o_sum_v*(int64_t)o_sum_v;
> +    h_sigma = n*hh_sum_v - h_sum_v*(int64_t)h_sum_v;
> +
> +    if (o_sigma == 0 || h_sigma == 0)
> +        return 1.0;
> +

> +    c = (n*oh_sum_v - o_sum_v*(int64_t)h_sum_v) / (sqrt(o_sigma)*sqrt(h_sigma));

not using sqrt(o_sigma * h_sigma) for precision or overflow concerns?

> +
> +    return 1 - fabs(c);
> +}
> +
> +static int config_input(AVFilterLink *inlink)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    FOCContext *foc = ctx->priv;
> +
> +    if (foc->xmax <= 0)
> +        foc->xmax = inlink->w - foc->obj_frame->width;
> +    if (foc->ymax <= 0)
> +        foc->ymax = inlink->h - foc->obj_frame->height;
> +
> +    return 0;
> +}
> +
> +static float search(FOCContext *foc, int pass, int maxpass, int xmin, int xmax, int ymin, int ymax, int *best_x, int *best_y, float best_score)
> +{
> +    int x, y;
> +
> +    if (pass + 1 <= maxpass) {
> +        int sub_x, sub_y;
> +        search(foc, pass+1, maxpass, xmin>>1, (xmax+1)>>1, ymin>>1, (ymax+1)>>1, &sub_x, &sub_y, 1.0);
> +        xmin = FFMAX(xmin, 2*sub_x - 4);
> +        xmax = FFMIN(xmax, 2*sub_x + 4);
> +        ymin = FFMAX(ymin, 2*sub_y - 4);
> +        ymax = FFMIN(ymax, 2*sub_y + 4);
> +    }
> +
> +    for (y=ymin; y<=ymax; y++) {
> +        for (x=xmin; x<=xmax; x++) {
> +            float score = compare(foc->haystack_frame[pass], foc->needle_frame[pass], x, y);
> +            av_assert0(score != 0);
> +            if (score < best_score) {
> +                best_score = score;
> +                *best_x = x;
> +                *best_y = y;
> +            }
> +        }
> +    }
> +    return best_score;
> +}
> +
> +static void cover(FOCContext *foc, AVFrame *in, int offx, int offy)
> +{
> +    int x, y, p;
> +
> +    for (p=0; p<3; p++) {
> +        uint8_t *data = in->data[p] + (offx>>!!p) + (offy>>!!p) * in->linesize[p];

> +        uint8_t *src  = foc->cover_frame->data[p];

please make it const

> +        int w = foc->obj_frame->width  >> !!p;
> +        int h = foc->obj_frame->height >> !!p;

FF_CEIL_RSHIFT or not relevant?

> +        for (y=0; y<h; y++) {
> +            for (x=0; x<w; x++) {
> +                data[x] = src[x];
> +            }

> +            data += in->linesize[p];
> +            src += foc->cover_frame->linesize[p];

i've seen gcc derping a lot on this; you might want to check if taking
these dereferencing out of the loop helps

> +        }
> +    }
> +}
> +static void blur(FOCContext *foc, AVFrame *in, int offx, int offy)
> +{
> +    int x, y, p;
> +
> +    for (p=0; p<3; p++) {

> +        int ox = offx>>!!p;
> +        int oy = offy>>!!p;

FF_CEIL_RSHIFT?

> +        int stride = in->linesize[p];
> +        uint8_t *data = in->data[p] + ox + oy * stride;
> +        int w = foc->obj_frame->width  >> !!p;
> +        int h = foc->obj_frame->height >> !!p;
> +        int iw = in->width  >> !!p;
> +        int ih = in->height >> !!p;
> +        for (y=0; y<h; y++) {
> +            for (x=0; x<w; x++) {
> +                int c = 0;
> +                int s = 0;
> +                if (ox) {
> +                    int scale = 65536 / (x + 1);
> +                    s += data[-1 + y*stride] * scale;
> +                    c += scale;
> +                }
> +                if (oy) {
> +                    int scale = 65536 / (y + 1);
> +                    s += data[x - stride] * scale;
> +                    c += scale;
> +                }
> +                if (ox + w < iw) {
> +                    int scale = 65536 / (w - x);
> +                    s += data[w + y*stride] * scale;
> +                    c += scale;
> +                }
> +                if (oy + h < ih) {
> +                    int scale = 65536 / (h - y);
> +                    s += data[x + h*stride] * scale;
> +                    c += scale;
> +                }
> +                data[x + y*stride] = (s + (c>>1)) / c;
> +            }
> +        }
> +    }
> +}
> +
> +static int filter_frame(AVFilterLink *inlink, AVFrame *in)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    FOCContext *foc = ctx->priv;
> +    float best_score;
> +    int best_x, best_y;
> +    int i;
> +
> +    foc->haystack_frame[0] = av_frame_clone(in);
> +    for (i=1; i<foc->mipmaps; i++) {
> +        foc->haystack_frame[i] = downscale(foc->haystack_frame[i-1]);
> +    }
> +
> +    best_score = search(foc, 0, 0,
> +                        FFMAX(foc->xmin, foc->last_x - 8),
> +                        FFMIN(foc->xmax, foc->last_x + 8),
> +                        FFMAX(foc->ymin, foc->last_y - 8),
> +                        FFMIN(foc->ymax, foc->last_y + 8),
> +                        &best_x, &best_y, 1.0);
> +
> +    best_score = search(foc, 0, foc->mipmaps - 1, foc->xmin, foc->xmax, foc->ymin, foc->ymax,
> +                        &best_x, &best_y, best_score);
> +
> +    for (i=0; i<MAX_MIPMAPS; i++) {
> +        av_frame_free(&foc->haystack_frame[i]);
> +    }
> +
> +    if (best_score > foc->threshold) {
> +        return ff_filter_frame(ctx->outputs[0], in);
> +    }
> +

> +    av_log(ctx, AV_LOG_DEBUG, "Found at %d %d score %f\n", best_x, best_y, best_score);

found what?

> +    foc->last_x = best_x;
> +    foc->last_y = best_y;
> +
> +    av_frame_make_writable(in);
> +
> +    if (foc->mode == MODE_BLUR) {
> +        blur (foc, in, best_x, best_y);
> +    } else {
> +        cover(foc, in, best_x, best_y);
> +    }
> +    return ff_filter_frame(ctx->outputs[0], in);
> +}
> +
> +static av_cold void uninit(AVFilterContext *ctx)
> +{
> +    FOCContext *foc = ctx->priv;
> +    int i;
> +
> +    for (i=0; i<MAX_MIPMAPS; i++) {

nit: pleasefixthestyle

> +        av_frame_free(&foc->needle_frame[i]);
> +        av_frame_free(&foc->haystack_frame[i]);
> +    }
> +
> +    if (foc->obj_frame)
> +        av_freep(&foc->obj_frame->data[0]);
> +    if (foc->cover_frame)
> +        av_freep(&foc->cover_frame->data[0]);
> +    av_frame_free(&foc->obj_frame);
> +}
> +
> +static av_cold int init(AVFilterContext *ctx)
> +{
> +    FOCContext *foc = ctx->priv;
> +    int ret, i;
> +
> +    if (!foc->obj_filename || (!foc->cover_filename && foc->mode == MODE_COVER)) {
> +        av_log(ctx, AV_LOG_ERROR, "object or cover filename not set\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    foc->obj_frame = av_frame_alloc();
> +    if (!foc->obj_frame)
> +        return AVERROR(ENOMEM);
> +

> +    if ((ret = ff_load_image(foc->obj_frame->data, foc->obj_frame->linesize,
> +                             &foc->obj_frame->width, &foc->obj_frame->height,
> +                             &foc->obj_frame->format, foc->obj_filename, ctx)) < 0)
> +        return ret;

Can you use the dualinput mechanism to load the image instead? See
paletteuse for a typical 1 frame load case. This will avoid a libavformat
and libavcodec dependency to the filter (which you forgot to add to
configure), as well as clumsiness with the file path into the filtergraph.

> +
> +    if (foc->obj_frame->format != AV_PIX_FMT_GRAY8) {
> +        av_log(ctx, AV_LOG_ERROR, "object image is not a grayscale image\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    foc->needle_frame[0] = av_frame_clone(foc->obj_frame);
> +    for (i=1; i<foc->mipmaps; i++) {
> +        foc->needle_frame[i] = downscale(foc->needle_frame[i-1]);
> +        if (!foc->needle_frame[i])
> +            return AVERROR(ENOMEM);
> +    }
> +
> +    if (foc->mode == MODE_COVER) {
> +        foc->cover_frame = av_frame_alloc();
> +        if (!foc->cover_frame)
> +            return AVERROR(ENOMEM);
> +
> +        if ((ret = ff_load_image(foc->cover_frame->data, foc->cover_frame->linesize,
> +                                &foc->cover_frame->width, &foc->cover_frame->height,
> +                                &foc->cover_frame->format, foc->cover_filename, ctx)) < 0)
> +            return ret;
> +
> +        if (foc->cover_frame->format != AV_PIX_FMT_YUV420P && foc->cover_frame->format != AV_PIX_FMT_YUVJ420P) {
> +            av_log(ctx, AV_LOG_ERROR, "cover image is not a YUV420 image\n");
> +            return AVERROR(EINVAL);
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static const AVFilterPad foc_inputs[] = {
> +    {
> +        .name         = "default",
> +        .type         = AVMEDIA_TYPE_VIDEO,
> +        .config_props = config_input,
> +        .filter_frame = filter_frame,
> +    },
> +    { NULL }
> +};
> +
> +static const AVFilterPad foc_outputs[] = {
> +    {
> +        .name = "default",
> +        .type = AVMEDIA_TYPE_VIDEO,
> +    },
> +    { NULL }
> +};
> +
> +AVFilter ff_vf_findandcover = {
> +    .name            = "foc",
> +    .description     = NULL_IF_CONFIG_SMALL("Find and cover a user specified object"),
> +    .priv_size       = sizeof(FOCContext),
> +    .init            = init,
> +    .uninit          = uninit,
> +    .query_formats   = query_formats,
> +    .inputs          = foc_inputs,
> +    .outputs         = foc_outputs,
> +    .priv_class      = &foc_class,

> +    .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,

Where is the support of this handled then?

> +};

-- 
Clément B.
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