[FFmpeg-devel] [PATCH] avfilter: Add reverse filter

Paul B Mahol onemda at gmail.com
Thu Jul 16 21:55:39 CEST 2015


Dana 16. 7. 2015. 20:43 osoba "Clément Bœsch" <u at pkh.me> napisala je:
>
> On Thu, Jul 16, 2015 at 05:43:59PM +0000, Derek Buitenhuis wrote:
> > Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
> > ---
> > The design is how ubitux requested. Use trim with it or risk using ALL
THEM MEMORY.
>
> ;)
>
> > ---
> >  doc/filters.texi         |   4 ++
> >  libavfilter/Makefile     |   1 +
> >  libavfilter/allfilters.c |   1 +
> >  libavfilter/version.h    |   2 +-
> >  libavfilter/vf_reverse.c | 145

Missing Changelog entry.
+++++++++++++++++++++++++++++++++++++++++++++++
> >  5 files changed, 152 insertions(+), 1 deletion(-)
> >  create mode 100644 libavfilter/vf_reverse.c
> >
> > diff --git a/doc/filters.texi b/doc/filters.texi
> > index 3b4ec2c..7b0410a 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -8247,6 +8247,10 @@ pixels will slow things down on a large logo.
> >  This filter uses the repeat_field flag from the Video ES headers and
hard repeats
> >  fields based on its value.
> >
> > + at section reverse
> > +
> > +Reverses a clip. Requires memory to buffer the entire clip, so
trimming is suggested.
>
> We use infinitive form, so "Reverse".
>
> You might want to print "Warning: this filter requires ..."
>
> Can you add an example to make sure users don't membomb too much their
> OS?
>
> > +
> >  @section rotate
> >
> >  Rotate video by an arbitrary angle expressed in radians.
> > diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> > index 058b9e9..1638ae8 100644
> > --- a/libavfilter/Makefile
> > +++ b/libavfilter/Makefile
> > @@ -185,6 +185,7 @@ OBJS-$(CONFIG_QP_FILTER)                     +=
vf_qp.o
> >  OBJS-$(CONFIG_REMOVEGRAIN_FILTER)            += vf_removegrain.o
> >  OBJS-$(CONFIG_REMOVELOGO_FILTER)             += bbox.o lswsutils.o
lavfutils.o vf_removelogo.o
> >  OBJS-$(CONFIG_REPEATFIELDS_FILTER)           += vf_repeatfields.o
> > +OBJS-$(CONFIG_REVERSE_FILTER)                += vf_reverse.o
> >  OBJS-$(CONFIG_ROTATE_FILTER)                 += vf_rotate.o
> >  OBJS-$(CONFIG_SEPARATEFIELDS_FILTER)         += vf_separatefields.o
> >  OBJS-$(CONFIG_SAB_FILTER)                    += vf_sab.o
> > diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> > index b0d8410..5e2a322 100644
> > --- a/libavfilter/allfilters.c
> > +++ b/libavfilter/allfilters.c
> > @@ -200,6 +200,7 @@ void avfilter_register_all(void)
> >      REGISTER_FILTER(REMOVEGRAIN,    removegrain,    vf);
> >      REGISTER_FILTER(REMOVELOGO,     removelogo,     vf);
> >      REGISTER_FILTER(REPEATFIELDS,   repeatfields,   vf);
> > +    REGISTER_FILTER(REVERSE,        reverse,        vf);
> >      REGISTER_FILTER(ROTATE,         rotate,         vf);
> >      REGISTER_FILTER(SAB,            sab,            vf);
> >      REGISTER_FILTER(SCALE,          scale,          vf);
> > diff --git a/libavfilter/version.h b/libavfilter/version.h
> > index 618c626..d22b2c5 100644
> > --- a/libavfilter/version.h
> > +++ b/libavfilter/version.h
> > @@ -30,7 +30,7 @@
> >  #include "libavutil/version.h"
> >
> >  #define LIBAVFILTER_VERSION_MAJOR  5
> > -#define LIBAVFILTER_VERSION_MINOR  22
> > +#define LIBAVFILTER_VERSION_MINOR  23
> >  #define LIBAVFILTER_VERSION_MICRO 100
> >
> >  #define LIBAVFILTER_VERSION_INT
AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
> > diff --git a/libavfilter/vf_reverse.c b/libavfilter/vf_reverse.c
> > new file mode 100644
> > index 0000000..00512be
> > --- /dev/null
> > +++ b/libavfilter/vf_reverse.c
> > @@ -0,0 +1,145 @@
> > +/*
> > + * Copyright (c) 2015 Derek Buitenhuis
> > + *
> > + * 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 "avfilter.h"
> > +#include "formats.h"
> > +#include "internal.h"
> > +#include "video.h"
> > +
> > +#define DEFAULT_LENGTH 300
> > +
> > +typedef struct ReverseContext {
> > +    const AVClass *class;

Apparently not needed.

> > +
> > +    int nb_frames;
> > +    AVFrame **frames;
> > +    unsigned int frames_size;
> > +    unsigned int pts_size;
> > +    int64_t *pts;
> > +    int flush_idx;
> > +} ReverseContext;
> > +
> > +static av_cold int init(AVFilterContext *ctx)
> > +{
> > +    ReverseContext *s = ctx->priv;
> > +
> > +    s->pts = av_fast_realloc(NULL, &s->pts_size,
> > +                             DEFAULT_LENGTH * sizeof(*(s->pts)));
> > +    if (!s->pts)
> > +        return AVERROR(ENOMEM);
> > +
> > +    s->frames = av_fast_realloc(NULL, &s->frames_size,
> > +                                DEFAULT_LENGTH * sizeof(*(s->frames)));
> > +    if (!s->frames) {
> > +        av_freep(&s->pts);
> > +        return AVERROR(ENOMEM);
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static av_cold void uninit(AVFilterContext *ctx)
> > +{
> > +    ReverseContext *s = ctx->priv;
> > +
> > +    av_freep(&s->pts);
> > +    av_freep(&s->frames);
> > +}
> > +
> > +static int config_output(AVFilterLink *outlink)
> > +{
> > +    outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
> > +    return 0;
> > +}
> > +
> > +static int filter_frame(AVFilterLink *inlink, AVFrame *in)
> > +{
> > +    AVFilterContext *ctx = inlink->dst;
> > +    ReverseContext *s    = ctx->priv;
> > +
> > +

Extra newline.

> > +    if (s->nb_frames + 1 > s->frames_size / sizeof(*(s->frames))) {
> > +        void *ptr;
> > +
> > +        ptr = av_fast_realloc(s->pts, &s->pts_size, s->pts_size * 2);
> > +        if (!ptr)
> > +            return AVERROR(ENOMEM);
> > +        s->pts = ptr;
> > +
> > +        ptr = av_fast_realloc(s->frames, &s->frames_size,
s->frames_size * 2);
> > +        if (!ptr)
> > +            return AVERROR(ENOMEM);
> > +        s->frames = ptr;
> > +    }
> > +
> > +    s->frames[s->nb_frames] = in;
> > +    s->pts[s->nb_frames]    = in->pts;
> > +    s->nb_frames++;
> > +
> > +    return 0;
> > +}
> > +
> > +static int request_frame(AVFilterLink *outlink)
> > +{
> > +    AVFilterContext *ctx = outlink->src;
> > +    ReverseContext *s = ctx->priv;
> > +    int ret;
> > +
> > +    ret = ff_request_frame(ctx->inputs[0]);
> > +
>
> > +    if (ret == AVERROR_EOF && !ctx->is_disabled && s->nb_frames > 0) {
>
> is_disabled suggest a timeline support. You could add that if you feel
> like it. That way, "reverse=enable='between(t,30,40)'" would reverse only
> between t=30 and t=40 and pass through the rest of the time.
>
> > +        AVFrame *out = s->frames[s->nb_frames - 1];
> > +        out->pts     = s->pts[s->flush_idx++];
> > +        ret          = ff_filter_frame(outlink, out);
> > +        s->nb_frames--;
> > +    }
> > +
> > +    return ret;
> > +}
> > +
> > +static const AVFilterPad reverse_inputs[] = {
> > +    {
> > +        .name         = "default",
> > +        .type         = AVMEDIA_TYPE_VIDEO,
> > +        .filter_frame = filter_frame,
> > +    },
> > +    { NULL }
> > +};
> > +
> > +static const AVFilterPad reverse_outputs[] = {
> > +    {
> > +        .name          = "default",
> > +        .type          = AVMEDIA_TYPE_VIDEO,
> > +        .request_frame = request_frame,
> > +        .config_props  = config_output,
> > +    },
> > +    { NULL }
> > +};
> > +
> > +AVFilter ff_vf_reverse = {
> > +    .name        = "reverse",
> > +    .description = NULL_IF_CONFIG_SMALL("Reverse a clip."),
> > +    .priv_size   = sizeof(ReverseContext),
> > +    .init        = init,
> > +    .uninit      = uninit,
> > +    .inputs      = reverse_inputs,
> > +    .outputs     = reverse_outputs,
> > +};
> > --
> > 1.8.3.1
> >
>

Rest looks good.

> --
> Clément B.
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>


More information about the ffmpeg-devel mailing list