[FFmpeg-devel] [PATCH] [PATCH] lavfi: add inverse telecine filter

Himangi Saraogi himangi774 at gmail.com
Mon Mar 16 20:14:07 CET 2015


On 14 March 2015 at 09:42, Michael Niedermayer <michaelni at gmx.at> wrote:

> On Wed, Mar 11, 2015 at 03:20:47AM +0530, Himangi Saraogi wrote:
> > This is an exact inverse of the telecine filter unlike previously
> existing
> > pullup and fieldmatch ones.
> >
> > The algorithm was briefly discussed with Carl. The algorithm is not
> completely
> > tested, though I do have a some sample suggestions and will be testing on
> > them soon. Documentation is yet to be added.
> > ---
> >  Changelog                   |   1 +
> >  libavfilter/Makefile        |   1 +
> >  libavfilter/allfilters.c    |   1 +
> >  libavfilter/vf_detelecine.c | 323
> ++++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 326 insertions(+)
> >  create mode 100644 libavfilter/vf_detelecine.c
>
>
>
> >
> > diff --git a/Changelog b/Changelog
> > index e88359d..341faca 100644
> > --- a/Changelog
> > +++ b/Changelog
> > @@ -3,6 +3,7 @@ releases are sorted from youngest to oldest.
> >
> >  version <next>:
> >  - FFT video filter
> > +- Detelecine filter
> >
> >
> >  version 2.6:
> > diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> > index b184f07..399072c 100644
> > --- a/libavfilter/Makefile
> > +++ b/libavfilter/Makefile
> > @@ -112,6 +112,7 @@ OBJS-$(CONFIG_DECIMATE_FILTER)               +=
> vf_decimate.o
> >  OBJS-$(CONFIG_DEJUDDER_FILTER)               += vf_dejudder.o
> >  OBJS-$(CONFIG_DELOGO_FILTER)                 += vf_delogo.o
> >  OBJS-$(CONFIG_DESHAKE_FILTER)                += vf_deshake.o
> > +OBJS-$(CONFIG_DETELECINE_FILTER)                += vf_detelecine.o
> >  OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o
> >  OBJS-$(CONFIG_DRAWGRID_FILTER)               += vf_drawbox.o
> >  OBJS-$(CONFIG_DRAWTEXT_FILTER)               += vf_drawtext.o
> > diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> > index 043ac56..2e4e2f6 100644
> > --- a/libavfilter/allfilters.c
> > +++ b/libavfilter/allfilters.c
> > @@ -128,6 +128,7 @@ void avfilter_register_all(void)
> >      REGISTER_FILTER(DEJUDDER,       dejudder,       vf);
> >      REGISTER_FILTER(DELOGO,         delogo,         vf);
> >      REGISTER_FILTER(DESHAKE,        deshake,        vf);
> > +    REGISTER_FILTER(DETELECINE,     detelecine,     vf);
> >      REGISTER_FILTER(DRAWBOX,        drawbox,        vf);
> >      REGISTER_FILTER(DRAWGRID,       drawgrid,       vf);
> >      REGISTER_FILTER(DRAWTEXT,       drawtext,       vf);
> > diff --git a/libavfilter/vf_detelecine.c b/libavfilter/vf_detelecine.c
> > new file mode 100644
> > index 0000000..ce9ba74
> > --- /dev/null
> > +++ b/libavfilter/vf_detelecine.c
> > @@ -0,0 +1,323 @@
> > +/*
> > + * Copyright (c) 2015 Himangi Saraogi <himangi774 at gmail.com>
> > + *
> > + * 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
> > + */
> > +
> > +/**
> > + * @file detelecine filter.
> > + */
> > +
> > +#include "libavutil/avstring.h"
> > +#include "libavutil/imgutils.h"
> > +#include "libavutil/opt.h"
> > +#include "libavutil/pixdesc.h"
> > +#include "avfilter.h"
> > +#include "formats.h"
> > +#include "internal.h"
> > +#include "video.h"
> > +
> > +typedef struct {
> > +    const AVClass *class;
> > +    int first_field;
> > +    char *pattern;
> > +    unsigned int pattern_pos;
> > +    unsigned int nskip_fields;
> > +
> > +    AVRational pts;
> > +    double ts_unit;
> > +    int occupied;
> > +
> > +    int nb_planes;
> > +    int planeheight[4];
> > +    int stride[4];
> > +
> > +    AVFrame *frame;
> > +    AVFrame *temp;
> > +} DetelecineContext;
> > +
> > +#define OFFSET(x) offsetof(DetelecineContext, x)
> > +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
> > +
> > +static const AVOption detelecine_options[] = {
> > +    {"first_field", "select first field", OFFSET(first_field),
> AV_OPT_TYPE_INT,   {.i64=0}, 0, 1, FLAGS, "field"},
> > +    {"top",    "select top field first",                0,
> AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "field"},
> > +    {"t",      "select top field first",                0,
> AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "field"},
> > +    {"bottom", "select bottom field first",             0,
> AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "field"},
> > +    {"b",      "select bottom field first",             0,
> AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "field"},
> > +    {"pattern", "pattern that describe for how many fields a frame is
> to be displayed", OFFSET(pattern), AV_OPT_TYPE_STRING, {.str="23"}, 0, 0,
> FLAGS},
> > +    {NULL}
> > +};
> > +
> > +AVFILTER_DEFINE_CLASS(detelecine);
> > +
> > +static av_cold int init(AVFilterContext *ctx)
> > +{
> > +    DetelecineContext *s = ctx->priv;
> > +    const char *p;
> > +    int max = 0;
> > +
> > +    if (!strlen(s->pattern)) {
> > +        av_log(ctx, AV_LOG_ERROR, "No pattern provided.\n");
> > +        return AVERROR_INVALIDDATA;
> > +    }
> > +
> > +    for (p = s->pattern; *p; p++) {
> > +        if (!av_isdigit(*p)) {
> > +            av_log(ctx, AV_LOG_ERROR, "Provided pattern includes
> non-numeric characters.\n");
> > +            return AVERROR_INVALIDDATA;
> > +        }
> > +
> > +        max = FFMAX(*p - '0', max);
> > +        s->pts.num += *p - '0';
> > +        s->pts.den += 2;
> > +    }
> > +
> > +    s->nskip_fields = 0;
> > +
> > +    av_log(ctx, AV_LOG_INFO, "Detelecine pattern %s removes up to %d
> frames per frame, pts advance factor: %d/%d\n",
> > +           s->pattern, (max + 1) / 2, s->pts.num, s->pts.den);
> > +
> > +    return 0;
> > +}
> > +
> > +static int query_formats(AVFilterContext *ctx)
> > +{
> > +    AVFilterFormats *pix_fmts = NULL;
> > +    int fmt;
> > +
> > +    for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
> > +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
> > +        if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
> > +              desc->flags & AV_PIX_FMT_FLAG_PAL     ||
> > +              desc->flags & AV_PIX_FMT_FLAG_BITSTREAM))
> > +            ff_add_format(&pix_fmts, fmt);
> > +    }
> > +
> > +    ff_set_common_formats(ctx, pix_fmts);
> > +    return 0;
> > +}
> > +
> > +static int config_input(AVFilterLink *inlink)
> > +{
> > +    DetelecineContext *s = inlink->dst->priv;
> > +    const AVPixFmtDescriptor *desc =
> av_pix_fmt_desc_get(inlink->format);
> > +    int i, ret;
> > +
> > +    s->temp = ff_get_video_buffer(inlink, inlink->w, inlink->h);
> > +    if (!s->temp)
> > +        return AVERROR(ENOMEM);
> > +
> > +    s->frame = ff_get_video_buffer(inlink, inlink->w, inlink->h);
> > +    if (!s->frame)
> > +        return AVERROR(ENOMEM);
> > +
> > +    if ((ret = av_image_fill_linesizes(s->stride, inlink->format,
> inlink->w)) < 0)
> > +        return ret;
> > +
> > +    s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(inlink->h,
> desc->log2_chroma_h);
> > +    s->planeheight[0] = s->planeheight[3] = inlink->h;
> > +
> > +    s->nb_planes = av_pix_fmt_count_planes(inlink->format);
> > +
> > +    return 0;
> > +}
> > +
> > +static int config_output(AVFilterLink *outlink)
> > +{
> > +    AVFilterContext *ctx = outlink->src;
> > +    DetelecineContext *s = ctx->priv;
> > +    const AVFilterLink *inlink = ctx->inputs[0];
> > +    AVRational fps = inlink->frame_rate;
> > +
> > +    if (!fps.num || !fps.den) {
> > +        av_log(ctx, AV_LOG_ERROR, "The input needs a constant frame
> rate; "
> > +               "current rate of %d/%d is invalid\n", fps.num, fps.den);
> > +        return AVERROR(EINVAL);
> > +    }
> > +    fps = av_mul_q(fps, av_inv_q(s->pts));
> > +    av_log(ctx, AV_LOG_VERBOSE, "FPS: %d/%d -> %d/%d\n",
> > +           inlink->frame_rate.num, inlink->frame_rate.den, fps.num,
> fps.den);
> > +
> > +    outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
> > +    outlink->frame_rate = fps;
> > +    outlink->time_base = av_mul_q(inlink->time_base, s->pts);
> > +    av_log(ctx, AV_LOG_VERBOSE, "TB: %d/%d -> %d/%d\n",
> > +           inlink->time_base.num, inlink->time_base.den,
> outlink->time_base.num, outlink->time_base.den);
> > +
> > +    s->ts_unit = av_q2d(av_inv_q(av_mul_q(fps, outlink->time_base)));
> > +
> > +    return 0;
> > +}
> > +
> > +static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
> > +{
> > +    AVFilterContext *ctx = inlink->dst;
> > +    AVFilterLink *outlink = ctx->outputs[0];
> > +    DetelecineContext *s = ctx->priv;
> > +    int i, len = 0, ret = 0, out = 0;
> > +
> > +    if (s->nskip_fields >= 2) {
> > +        s->nskip_fields -= 2;
> > +        return 0;
> > +    } else if (s->nskip_fields >= 1) {
> > +        if (s->occupied) {
> > +            s->occupied = 0;
> > +            s->nskip_fields--;
> > +        }
> > +        else {
> > +            for (i = 0; i < s->nb_planes; i++) {
> > +                av_image_copy_plane(s->temp->data[i],
> s->temp->linesize[i],
> > +                                    inpicref->data[i],
> inpicref->linesize[i],
> > +                                    s->stride[i],
> > +                                    s->planeheight[i]);
> > +            }
> > +            s->occupied = 1;
> > +            s->nskip_fields--;
> > +            return 0;
> > +        }
> > +    }
> > +
> > +    if (s->nskip_fields == 0) {
> > +        while(!len && s->pattern[s->pattern_pos]) {
> > +            len = s->pattern[s->pattern_pos] - '0';
> > +            s->pattern_pos++;
> > +        }
> > +
> > +        if (!s->pattern[s->pattern_pos])
> > +            s->pattern_pos = 0;
> > +
> > +        if(!len) { // do not output any field as the entire pattern is
> zero
> > +            av_frame_free(&inpicref);
> > +            return 0;
> > +        }
> > +
> > +        if (s->occupied) {
> > +            for (i = 0; i < s->nb_planes; i++) {
> > +                // fill in the EARLIER field from the new pic
> > +                av_image_copy_plane(s->frame->data[i] +
> s->frame->linesize[i] * s->first_field,
> > +                                    s->frame->linesize[i] * 2,
> > +                                    inpicref->data[i] +
> inpicref->linesize[i] * s->first_field,
> > +                                    inpicref->linesize[i] * 2,
> > +                                    s->stride[i],
> > +                                    (s->planeheight[i] - s->first_field
> + 1) / 2);
> > +                // fill in the LATER field from the buffered pic
> > +                av_image_copy_plane(s->frame->data[i] +
> s->frame->linesize[i] * !s->first_field,
> > +                                    s->frame->linesize[i] * 2,
> > +                                    s->temp->data[i] +
> s->temp->linesize[i] * !s->first_field,
> > +                                    s->temp->linesize[i] * 2,
> > +                                    s->stride[i],
> > +                                    (s->planeheight[i] -
> !s->first_field + 1) / 2);
> > +            }
> > +            len -= 2;
> > +            for (i = 0; i < s->nb_planes; i++) {
> > +                av_image_copy_plane(s->temp->data[i],
> s->temp->linesize[i],
> > +                                    inpicref->data[i],
> inpicref->linesize[i],
> > +                                    s->stride[i],
> > +                                    s->planeheight[i]);
> > +            }
> > +            s->occupied = 1;
> > +            out = 1;
> > +        } else {
> > +            if (len >= 2) {
> > +                // output THIS image as-is
> > +                for (i = 0; i < s->nb_planes; i++)
> > +                    av_image_copy_plane(s->frame->data[i],
> s->frame->linesize[i],
> > +                                        inpicref->data[i],
> inpicref->linesize[i],
> > +                                        s->stride[i],
> > +                                        s->planeheight[i]);
> > +                len -= 2;
> > +                out = 1;
> > +            } else if (len == 1) {
> > +                // fill in the EARLIER field from the new pic
> > +                av_image_copy_plane(s->frame->data[i] +
> s->frame->linesize[i] * s->first_field,
> > +                                    s->frame->linesize[i] * 2,
> > +                                    inpicref->data[i] +
> inpicref->linesize[i] * s->first_field,
> > +                                    inpicref->linesize[i] * 2,
> > +                                    s->stride[i],
> > +                                    (s->planeheight[i] - s->first_field
> + 1) / 2);
> > +                // TODO: not sure about the other field
> > +
> > +                len--;
> > +                out = 1;
> > +            }
> > +        }
> > +
> > +        if (len == 1 && s->occupied)
> > +        {
> > +            len--;
> > +            s->occupied = 0;
> > +        }
> > +    }
> > +    s->nskip_fields = len;
> > +
> > +    if (out) {
> > +        AVFrame *frame = av_frame_clone(s->frame);
> > +
> > +        if (!frame) {
> > +            av_frame_free(&inpicref);
> > +            return AVERROR(ENOMEM);
> > +        }
> > +
> > +        frame->pts = outlink->frame_count * s->ts_unit;
>
> the pts hadling looks wrong
> also simply testing as in
> ./ffplay matrixbench_mpeg2.mpg  -vf detelecine
> shows AV desync
>
>
Currently, ts_unit is set to inverse(fps * outlink->time_base) and used to
get the pts of the output frames as above. This is similar to the telecine
filter. I suppose outlink->time_base takes care of the input timestamps not
being guaranteed to start at 0.

Any suggestion on how this should be handled?


> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Everything should be made as simple as possible, but not simpler.
> -- Albert Einstein
>
> _______________________________________________
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> ffmpeg-devel at ffmpeg.org
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>
>


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