avfilter: Add repeatfields filter (Port of mp=softpulldown)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

LICENSE.md

@@ -46,6 +46,7 @@ Specifically, the GPL parts of FFmpeg are:
     - vf_pullup.c
     - vf_sab.c
     - vf_smartblur.c
+    - vf_repeatfields.c
     - vf_spp.c
     - vf_stereo3d.c
     - vf_super2xsai.c

configure

@@ -2613,6 +2613,7 @@ phase_filter_deps="gpl"
 pp_filter_deps="gpl postproc"
 pullup_filter_deps="gpl"
 removelogo_filter_deps="avcodec avformat swscale"
+repeatfields_filter_deps="gpl"
 resample_filter_deps="avresample"
 sab_filter_deps="gpl swscale"
 scale_filter_deps="swscale"

doc/filters.texi

@@ -7418,6 +7418,11 @@ much, but it will increase the amount of blurring needed to cover over
 the image and will destroy more information than necessary, and extra
 pixels will slow things down on a large logo.
 
+@section repeatfields
+
+This filter uses the repeat_field flag from the Video ES headers and hard repeats
+fields based on its value.
+
 @section rotate
 
 Rotate video by an arbitrary angle expressed in radians.

libavfilter/Makefile

@@ -169,6 +169,7 @@ OBJS-$(CONFIG_PSNR_FILTER)                   += vf_psnr.o dualinput.o framesync.
 OBJS-$(CONFIG_PULLUP_FILTER)                 += vf_pullup.o
 OBJS-$(CONFIG_QP_FILTER)                     += vf_qp.o
 OBJS-$(CONFIG_REMOVELOGO_FILTER)             += bbox.o lswsutils.o lavfutils.o vf_removelogo.o
+OBJS-$(CONFIG_REPEATFIELDS_FILTER)           += vf_repeatfields.o
 OBJS-$(CONFIG_ROTATE_FILTER)                 += vf_rotate.o
 OBJS-$(CONFIG_SEPARATEFIELDS_FILTER)         += vf_separatefields.o
 OBJS-$(CONFIG_SAB_FILTER)                    += vf_sab.o

libavfilter/allfilters.c

@@ -184,6 +184,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(PULLUP,         pullup,         vf);
     REGISTER_FILTER(QP,             qp,             vf);
     REGISTER_FILTER(REMOVELOGO,     removelogo,     vf);
+    REGISTER_FILTER(REPEATFIELDS,   repeatfields,   vf);
     REGISTER_FILTER(ROTATE,         rotate,         vf);
     REGISTER_FILTER(SAB,            sab,            vf);
     REGISTER_FILTER(SCALE,          scale,          vf);

libavfilter/vf_repeatfields.c

@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2003 Tobias Diedrich
+ *
+ * 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/imgutils.h"
+#include "avfilter.h"
+#include "internal.h"
+
+typedef struct RepeatFieldsContext {
+    const AVClass *class;
+    int state;
+    int nb_planes;
+    int linesize[4];
+    int planeheight[4];
+    AVFrame *frame;
+} RepeatFieldsContext;
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    RepeatFieldsContext *s = ctx->priv;
+
+    av_frame_free(&s->frame);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pixel_fmts_eq[] = {
+        AV_PIX_FMT_GRAY8,
+        AV_PIX_FMT_YUV410P,
+        AV_PIX_FMT_YUV411P,
+        AV_PIX_FMT_YUV420P,
+        AV_PIX_FMT_YUV422P,
+        AV_PIX_FMT_YUV444P,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pixel_fmts_eq));
+
+    return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    RepeatFieldsContext *s = inlink->dst->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    int ret;
+
+    if ((ret = av_image_fill_linesizes(s->linesize, 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 void update_pts(AVFilterLink *link, AVFrame *f, int64_t pts, int fields)
+{
+    if (av_cmp_q(link->frame_rate, (AVRational){30000, 1001}) == 0 &&
+         av_cmp_q(link->time_base, (AVRational){1001, 60000}) <= 0
+    ) {
+        f->pts = pts + av_rescale_q(fields, (AVRational){1001, 60000}, link->time_base);
+    } else
+        f->pts = AV_NOPTS_VALUE;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in) {
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = inlink->dst->outputs[0];
+    RepeatFieldsContext *s = ctx->priv;
+    AVFrame *out;
+    int ret, i;
+    int state = s->state;
+
+    if (!s->frame) {
+        s->frame = av_frame_clone(in);
+        if (!s->frame)
+            return AVERROR(ENOMEM);
+        s->frame->pts = AV_NOPTS_VALUE;
+    }
+
+    out = s->frame;
+
+    if ((state == 0 && !in->top_field_first) ||
+        (state == 1 &&  in->top_field_first)) {
+        av_log(ctx, AV_LOG_WARNING, "Unexpected field flags: "
+                                    "state=%d top_field_first=%d repeat_first_field=%d\n",
+                                    state, in->top_field_first, in->repeat_pict);
+        state ^= 1;
+    }
+
+    if (state == 0) {
+        AVFrame *new;
+
+        new = av_frame_clone(in);
+        if (!new)
+            return AVERROR(ENOMEM);
+
+        ret = ff_filter_frame(outlink, new);
+
+        if (in->repeat_pict) {
+            av_frame_make_writable(out);
+            update_pts(outlink, out, in->pts, 2);
+            for (i = 0; i < s->nb_planes; i++) {
+                av_image_copy_plane(out->data[i], out->linesize[i] * 2,
+                                    in->data[i], in->linesize[i] * 2,
+                                    s->linesize[i], s->planeheight[i] / 2);
+            }
+            state = 1;
+        }
+    } else {
+        for (i = 0; i < s->nb_planes; i++) {
+            av_frame_make_writable(out);
+            av_image_copy_plane(out->data[i] + out->linesize[i], out->linesize[i] * 2,
+                                in->data[i] + in->linesize[i], in->linesize[i] * 2,
+                                s->linesize[i], s->planeheight[i] / 2);
+        }
+
+        ret = ff_filter_frame(outlink, av_frame_clone(out));
+
+        if (in->repeat_pict) {
+            AVFrame *new;
+
+            new = av_frame_clone(in);
+            if (!new)
+                return AVERROR(ENOMEM);
+
+            ret = ff_filter_frame(outlink, new);
+            state = 0;
+        } else {
+            av_frame_make_writable(out);
+            update_pts(outlink, out, in->pts, 1);
+            for (i = 0; i < s->nb_planes; i++) {
+                av_image_copy_plane(out->data[i], out->linesize[i] * 2,
+                                    in->data[i], in->linesize[i] * 2,
+                                    s->linesize[i], s->planeheight[i] / 2);
+            }
+        }
+    }
+
+    s->state = state;
+
+    av_frame_free(&in);
+    return ret;
+}
+
+static const AVFilterPad repeatfields_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+        .config_props = config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad repeatfields_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_repeatfields = {
+    .name          = "repeatfields",
+    .description   = NULL_IF_CONFIG_SMALL("Hard repeat fields based on MPEG repeat field flag."),
+    .priv_size     = sizeof(RepeatFieldsContext),
+    .uninit        = uninit,
+    .inputs        = repeatfields_inputs,
+    .outputs       = repeatfields_outputs,
+    .query_formats = query_formats,
+};