[FFmpeg-devel] [PATCH] extractplanes filter

Nicolas George nicolas.george at normalesup.org
Wed May 1 11:32:34 CEST 2013


Le primidi 11 floréal, an CCXXI, Paul B Mahol a écrit :
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavfilter/Makefile           |   1 +
>  libavfilter/allfilters.c       |   1 +
>  libavfilter/vf_extractplanes.c | 179 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 181 insertions(+)
>  create mode 100644 libavfilter/vf_extractplanes.c

Missing documentation.

> 
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index d4ecf95..3e8e5c5 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -120,6 +120,7 @@ OBJS-$(CONFIG_DESHAKE_FILTER)                += vf_deshake.o
>  OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o
>  OBJS-$(CONFIG_DRAWTEXT_FILTER)               += vf_drawtext.o
>  OBJS-$(CONFIG_EDGEDETECT_FILTER)             += vf_edgedetect.o
> +OBJS-$(CONFIG_EXTRACTPLANES_FILTER)          += vf_extractplanes.o
>  OBJS-$(CONFIG_FADE_FILTER)                   += vf_fade.o
>  OBJS-$(CONFIG_FIELD_FILTER)                  += vf_field.o
>  OBJS-$(CONFIG_FIELDMATCH_FILTER)             += vf_fieldmatch.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 97e558b..a193d4c 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -118,6 +118,7 @@ void avfilter_register_all(void)
>      REGISTER_FILTER(DRAWBOX,        drawbox,        vf);
>      REGISTER_FILTER(DRAWTEXT,       drawtext,       vf);
>      REGISTER_FILTER(EDGEDETECT,     edgedetect,     vf);
> +    REGISTER_FILTER(EXTRACTPLANES,  extractplanes,  vf);
>      REGISTER_FILTER(FADE,           fade,           vf);
>      REGISTER_FILTER(FIELD,          field,          vf);
>      REGISTER_FILTER(FIELDMATCH,     fieldmatch,     vf);
> diff --git a/libavfilter/vf_extractplanes.c b/libavfilter/vf_extractplanes.c
> new file mode 100644
> index 0000000..79363d8
> --- /dev/null
> +++ b/libavfilter/vf_extractplanes.c
> @@ -0,0 +1,179 @@
> +/*
> + * Copyright (c) 2013 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
> + */
> +
> +#include "libavutil/opt.h"
> +#include "libavutil/imgutils.h"
> +#include "libavutil/pixdesc.h"
> +#include "avfilter.h"
> +#include "internal.h"
> +
> +typedef struct {
> +    const AVClass *class;
> +    int flags;
> +    int map[4];
> +} ExtractPlanesContext;
> +
> +#define OFFSET(x) offsetof(ExtractPlanesContext, x)
> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
> +static const AVOption extractplanes_options[] = {
> +    { "planes", "set planes",  OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64=1}, 1, (1<<4)-1, FLAGS, "flags"},
> +    {      "y", "set luma",  0, AV_OPT_TYPE_CONST, {.i64=1<<0}, 0, 0, FLAGS, "flags"},
> +    {      "u", "set u",     0, AV_OPT_TYPE_CONST, {.i64=1<<1}, 0, 0, FLAGS, "flags"},
> +    {      "v", "set v",     0, AV_OPT_TYPE_CONST, {.i64=1<<2}, 0, 0, FLAGS, "flags"},
> +    {      "g", "set green", 0, AV_OPT_TYPE_CONST, {.i64=1<<0}, 0, 0, FLAGS, "flags"},
> +    {      "b", "set blue",  0, AV_OPT_TYPE_CONST, {.i64=1<<1}, 0, 0, FLAGS, "flags"},
> +    {      "r", "set red",   0, AV_OPT_TYPE_CONST, {.i64=1<<2}, 0, 0, FLAGS, "flags"},
> +    {      "a", "set alpha", 0, AV_OPT_TYPE_CONST, {.i64=1<<3}, 0, 0, FLAGS, "flags"},

Maybe "set x" -> "x plane" would be more correct, I am not sure.

> +    { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(extractplanes);
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> +    static const enum AVPixelFormat in_pixfmts[] = {
> +        AV_PIX_FMT_YUV410P,
> +        AV_PIX_FMT_YUV411P,
> +        AV_PIX_FMT_YUV440P,
> +        AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P,
> +        AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA422P,
> +        AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
> +        AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
> +        AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVA444P,
> +        AV_PIX_FMT_GRAY8A,
> +        AV_PIX_FMT_GBRP,
> +        AV_PIX_FMT_NONE,
> +    };
> +    static const enum AVPixelFormat out_pixfmts[] = {
> +        AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE,
> +    };
> +    int i;
> +
> +    ff_formats_ref(ff_make_format_list(in_pixfmts), &ctx->inputs[0]->out_formats);
> +    for (i = 0; i < ctx->nb_outputs; i++)
> +        ff_formats_ref(ff_make_format_list(out_pixfmts), &ctx->outputs[i]->in_formats);
> +    return 0;
> +}
> +
> +static int config_output(AVFilterLink *outlink)
> +{
> +    AVFilterContext *ctx = outlink->src;
> +    AVFilterLink *inlink = ctx->inputs[0];
> +    ExtractPlanesContext *e = ctx->priv;
> +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> +    int output;
> +
> +    sscanf(outlink->srcpad->name, "out%d", &output);
> +
> +    if (e->map[output] == 1 || e->map[output] == 2) {
> +        outlink->h = inlink->h >> desc->log2_chroma_h;
> +        outlink->w = inlink->w >> desc->log2_chroma_w;
> +    }
> +
> +    return 0;
> +}
> +
> +static int init(AVFilterContext *ctx)

Nit: init() before query_formats().

> +{
> +    ExtractPlanesContext *e = ctx->priv;
> +    int i;
> +
> +    for (i = 0; i < 4; i++) {
> +        char name[32];
> +        AVFilterPad pad = { 0 };
> +
> +        if (!(e->flags & (1 << i)))
> +            continue;
> +
> +        e->map[ctx->nb_outputs] = i;

> +        snprintf(name, sizeof(name), "out%d", ctx->nb_outputs);
> +        pad.name = av_strdup(name);

av_asprintf()

> +        if (!pad.name)
> +            return AVERROR(ENOMEM);
> +        pad.type = AVMEDIA_TYPE_VIDEO;
> +        pad.config_props = config_output;
> +
> +        ff_insert_outpad(ctx, ctx->nb_outputs, &pad);
> +    }

There is no check that the planes specified exist. For example, the user
could write "planes=r" and get the y plane instead if the input is yuv. But
I do not consider it blocking.

> +
> +    return 0;
> +}
> +
> +static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    ExtractPlanesContext *e = ctx->priv;
> +    int i, ret = AVERROR_EOF;
> +
> +    for (i = 0; i < ctx->nb_outputs; i++) {
> +        const int idx = e->map[i];
> +        AVFilterLink *outlink = ctx->outputs[i];
> +        AVFrame *out;
> +
> +        if (outlink->closed || !frame->data[idx])
> +            continue;
> +
> +        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> +        if (!out) {
> +            ret = AVERROR(ENOMEM);
> +            break;
> +        }
> +        av_frame_copy_props(out, frame);
> +
> +        av_image_copy_plane(out->data[0], out->linesize[0],
> +                            frame->data[idx], frame->linesize[idx],
> +                            outlink->w, outlink->h);

> +        ret = ff_filter_frame(outlink, out);
> +        if (ret < 0)
> +            break;

AVERROR_EOF needs to be handled separately, otherwise, the first closed
output will cause the whole filter to shut down.

> +    }
> +    av_frame_free(&frame);
> +    return ret;
> +}
> +
> +static void uninit(AVFilterContext *ctx)
> +{
> +    int i;
> +
> +    for (i = 0; i < ctx->nb_outputs; i++)
> +        av_freep(&ctx->output_pads[i].name);
> +}

Unrelated, but I believe this should be done automatically.

> +
> +static const AVFilterPad extractplanes_inputs[] = {
> +    {
> +        .name             = "default",
> +        .type             = AVMEDIA_TYPE_VIDEO,
> +        .filter_frame     = filter_frame,
> +    },
> +    { NULL }
> +};
> +
> +AVFilter avfilter_vf_extractplanes = {
> +    .name          = "extractplanes",
> +    .description   = NULL_IF_CONFIG_SMALL("Extract planes as grayscale frames."),
> +    .priv_size     = sizeof(ExtractPlanesContext),
> +    .priv_class    = &extractplanes_class,
> +    .init          = init,
> +    .uninit        = uninit,
> +    .query_formats = query_formats,
> +    .inputs        = extractplanes_inputs,
> +    .outputs       = NULL,
> +    .flags         = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
> +};

Good idea and good work, thanks.

Regards,

-- 
  Nicolas George
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