[FFmpeg-devel,14/16] vf_ssim: convert to framesync2.

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 605df917a3..b988cdcd4f 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -300,7 +300,7 @@  OBJS-$(CONFIG_SMARTBLUR_FILTER)              += vf_smartblur.o
 OBJS-$(CONFIG_SOBEL_FILTER)                  += vf_convolution.o
 OBJS-$(CONFIG_SPLIT_FILTER)                  += split.o
 OBJS-$(CONFIG_SPP_FILTER)                    += vf_spp.o
-OBJS-$(CONFIG_SSIM_FILTER)                   += vf_ssim.o dualinput.o framesync.o
+OBJS-$(CONFIG_SSIM_FILTER)                   += vf_ssim.o framesync2.o
 OBJS-$(CONFIG_STEREO3D_FILTER)               += vf_stereo3d.o
 OBJS-$(CONFIG_STREAMSELECT_FILTER)           += f_streamselect.o framesync2.o
 OBJS-$(CONFIG_SUBTITLES_FILTER)              += vf_subtitles.o
diff --git a/libavfilter/vf_ssim.c b/libavfilter/vf_ssim.c
index 371f6dba70..5f5bed7a0e 100644
--- a/libavfilter/vf_ssim.c
+++ b/libavfilter/vf_ssim.c
@@ -38,16 +38,16 @@ 
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
-#include "dualinput.h"
 #include "drawutils.h"
 #include "formats.h"
+#include "framesync2.h"
 #include "internal.h"
 #include "ssim.h"
 #include "video.h"
 
 typedef struct SSIMContext {
     const AVClass *class;
-    FFDualInputContext dinput;
+    FFFrameSync fs;
     FILE *stats_file;
     char *stats_file_str;
     int nb_components;
@@ -78,7 +78,7 @@  static const AVOption ssim_options[] = {
     { NULL }
 };
 
-AVFILTER_DEFINE_CLASS(ssim);
+FRAMESYNC_DEFINE_CLASS(ssim, SSIMContext, fs);
 
 static void set_meta(AVDictionary **metadata, const char *key, char comp, float d)
 {
@@ -282,13 +282,21 @@  static double ssim_db(double ssim, double weight)
     return 10 * log10(weight / (weight - ssim));
 }
 
-static AVFrame *do_ssim(AVFilterContext *ctx, AVFrame *main,
-                        const AVFrame *ref)
+static int do_ssim(FFFrameSync *fs)
 {
-    AVDictionary **metadata = &main->metadata;
+    AVFilterContext *ctx = fs->parent;
     SSIMContext *s = ctx->priv;
+    AVFrame *main, *ref;
+    AVDictionary **metadata;
     float c[4], ssimv = 0.0;
-    int i;
+    int ret, i;
+
+    ret = ff_framesync2_dualinput_get(fs, &main, &ref);
+    if (ret < 0)
+        return ret;
+    if (!ref)
+        return ff_filter_frame(ctx->outputs[0], main);
+    metadata = &main->metadata;
 
     s->nb_frames++;
 
@@ -320,7 +328,7 @@  static AVFrame *do_ssim(AVFilterContext *ctx, AVFrame *main,
         fprintf(s->stats_file, "All:%f (%f)\n", ssimv, ssim_db(ssimv, 1.0));
     }
 
-    return main;
+    return ff_filter_frame(ctx->outputs[0], main);
 }
 
 static av_cold int init(AVFilterContext *ctx)
@@ -343,9 +351,7 @@  static av_cold int init(AVFilterContext *ctx)
         }
     }
 
-    s->dinput.process = do_ssim;
-    s->dinput.shortest = 1;
-    s->dinput.repeatlast = 0;
+    s->fs.on_event = do_ssim;
     return 0;
 }
 
@@ -425,28 +431,25 @@  static int config_output(AVFilterLink *outlink)
     AVFilterLink *mainlink = ctx->inputs[0];
     int ret;
 
+    ret = ff_framesync2_init_dualinput(&s->fs, ctx);
+    if (ret < 0)
+        return ret;
     outlink->w = mainlink->w;
     outlink->h = mainlink->h;
     outlink->time_base = mainlink->time_base;
     outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
     outlink->frame_rate = mainlink->frame_rate;
 
-    if ((ret = ff_dualinput_init(ctx, &s->dinput)) < 0)
+    if ((ret = ff_framesync2_configure(&s->fs)) < 0)
         return ret;
 
     return 0;
 }
 
-static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
+static int activate(AVFilterContext *ctx)
 {
-    SSIMContext *s = inlink->dst->priv;
-    return ff_dualinput_filter_frame(&s->dinput, inlink, buf);
-}
-
-static int request_frame(AVFilterLink *outlink)
-{
-    SSIMContext *s = outlink->src->priv;
-    return ff_dualinput_request_frame(&s->dinput, outlink);
+    SSIMContext *s = ctx->priv;
+    return ff_framesync2_activate(&s->fs);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
@@ -466,7 +469,7 @@  static av_cold void uninit(AVFilterContext *ctx)
                s->ssim_total / s->nb_frames, ssim_db(s->ssim_total, s->nb_frames));
     }
 
-    ff_dualinput_uninit(&s->dinput);
+    ff_framesync2_uninit(&s->fs);
 
     if (s->stats_file && s->stats_file != stdout)
         fclose(s->stats_file);
@@ -478,11 +481,9 @@  static const AVFilterPad ssim_inputs[] = {
     {
         .name         = "main",
         .type         = AVMEDIA_TYPE_VIDEO,
-        .filter_frame = filter_frame,
     },{
         .name         = "reference",
         .type         = AVMEDIA_TYPE_VIDEO,
-        .filter_frame = filter_frame,
         .config_props = config_input_ref,
     },
     { NULL }
@@ -493,7 +494,6 @@  static const AVFilterPad ssim_outputs[] = {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_output,
-        .request_frame = request_frame,
     },
     { NULL }
 };
@@ -501,9 +501,11 @@  static const AVFilterPad ssim_outputs[] = {
 AVFilter ff_vf_ssim = {
     .name          = "ssim",
     .description   = NULL_IF_CONFIG_SMALL("Calculate the SSIM between two video streams."),
+    .preinit       = ssim_framesync_preinit,
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
+    .activate      = activate,
     .priv_size     = sizeof(SSIMContext),
     .priv_class    = &ssim_class,
     .inputs        = ssim_inputs,