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

Michael Niedermayer michaelni at gmx.at
Sat Mar 14 05:12:08 CET 2015


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

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
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