videoaggregator: don't do caps processing that is not overridable

Allows the subclass to completely override the chosen src caps.

This is needed as videoaggregator generally has no idea exactly
what operation is being performed.

- Adds a fixate_caps vfunc for fixation
- Merges gst_video_aggregator_update_converters() into
  gst_videoaggregator_update_src_caps() as we need some of its info
  for proper caps handling.
- Pass the downstream caps to the update_caps vfunc

https://bugzilla.gnome.org/show_bug.cgi?id=756207

1 files changed, 62 insertions, 26 deletions

diff --git a/gst/compositor/compositor.c b/gst/compositor/compositor.c
index d015d85e1..c5b1a9abf 100644
--- a/gst/compositor/compositor.c
+++ b/gst/compositor/compositor.c
@@ -216,9 +216,9 @@ gst_compositor_pad_set_property (GObject * object, guint prop_id,
 
 static void
 _mixer_pad_get_output_size (GstCompositor * comp,
-    GstCompositorPad * comp_pad, gint * width, gint * height)
+    GstCompositorPad * comp_pad, gint out_par_n, gint out_par_d, gint * width,
+    gint * height)
 {
-  GstVideoAggregator *vagg = GST_VIDEO_AGGREGATOR (comp);
   GstVideoAggregatorPad *vagg_pad = GST_VIDEO_AGGREGATOR_PAD (comp_pad);
   gint pad_width, pad_height;
   guint dar_n, dar_d;
@@ -241,13 +241,10 @@ _mixer_pad_get_output_size (GstCompositor * comp,
 
   gst_video_calculate_display_ratio (&dar_n, &dar_d, pad_width, pad_height,
       GST_VIDEO_INFO_PAR_N (&vagg_pad->info),
-      GST_VIDEO_INFO_PAR_D (&vagg_pad->info),
-      GST_VIDEO_INFO_PAR_N (&vagg->info), GST_VIDEO_INFO_PAR_D (&vagg->info)
-      );
+      GST_VIDEO_INFO_PAR_D (&vagg_pad->info), out_par_n, out_par_d);
   GST_LOG_OBJECT (comp_pad, "scaling %ux%u by %u/%u (%u/%u / %u/%u)", pad_width,
       pad_height, dar_n, dar_d, GST_VIDEO_INFO_PAR_N (&vagg_pad->info),
-      GST_VIDEO_INFO_PAR_D (&vagg_pad->info),
-      GST_VIDEO_INFO_PAR_N (&vagg->info), GST_VIDEO_INFO_PAR_D (&vagg->info));
+      GST_VIDEO_INFO_PAR_D (&vagg_pad->info), out_par_n, out_par_d);
 
   if (pad_height % dar_n == 0) {
     pad_width = gst_util_uint64_scale_int (pad_height, dar_n, dar_d);
@@ -292,7 +289,8 @@ gst_compositor_pad_set_info (GstVideoAggregatorPad * pad,
       gst_video_colorimetry_to_string (&(wanted_info->colorimetry));
   best_chroma = gst_video_chroma_to_string (wanted_info->chroma_site);
 
-  _mixer_pad_get_output_size (comp, cpad, &width, &height);
+  _mixer_pad_get_output_size (comp, cpad, GST_VIDEO_INFO_PAR_N (&vagg->info),
+      GST_VIDEO_INFO_PAR_D (&vagg->info), &width, &height);
 
   if (GST_VIDEO_INFO_FORMAT (wanted_info) !=
       GST_VIDEO_INFO_FORMAT (current_info)
@@ -310,8 +308,8 @@ gst_compositor_pad_set_info (GstVideoAggregatorPad * pad,
         width, height);
     tmp_info.chroma_site = wanted_info->chroma_site;
     tmp_info.colorimetry = wanted_info->colorimetry;
-    tmp_info.par_n = vagg->info.par_n;
-    tmp_info.par_d = vagg->info.par_d;
+    tmp_info.par_n = wanted_info->par_n;
+    tmp_info.par_d = wanted_info->par_d;
     tmp_info.fps_n = current_info->fps_n;
     tmp_info.fps_d = current_info->fps_d;
     tmp_info.flags = current_info->flags;
@@ -403,7 +401,8 @@ gst_compositor_pad_prepare_frame (GstVideoAggregatorPad * pad,
    *     width/height. See ->set_info()
    * */
 
-  _mixer_pad_get_output_size (comp, cpad, &width, &height);
+  _mixer_pad_get_output_size (comp, cpad, GST_VIDEO_INFO_PAR_N (&vagg->info),
+      GST_VIDEO_INFO_PAR_D (&vagg->info), &width, &height);
 
   /* The only thing that can change here is the width
    * and height, otherwise set_info would've been called */
@@ -498,7 +497,8 @@ gst_compositor_pad_prepare_frame (GstVideoAggregatorPad * pad,
     GstCompositorPad *cpad2 = GST_COMPOSITOR_PAD (pad2);
     gint pad2_width, pad2_height;
 
-    _mixer_pad_get_output_size (comp, cpad2, &pad2_width, &pad2_height);
+    _mixer_pad_get_output_size (comp, cpad2, GST_VIDEO_INFO_PAR_N (&vagg->info),
+        GST_VIDEO_INFO_PAR_D (&vagg->info), &pad2_width, &pad2_height);
 
     /* We don't need to clamp the coords of the second rectangle */
     frame2_rect.x = cpad2->xpos;
@@ -883,17 +883,26 @@ set_functions (GstCompositor * self, GstVideoInfo * info)
 }
 
 static GstCaps *
-_update_caps (GstVideoAggregator * vagg, GstCaps * caps)
+_fixate_caps (GstVideoAggregator * vagg, GstCaps * caps)
 {
   GList *l;
   gint best_width = -1, best_height = -1;
-  GstVideoInfo info;
+  gint best_fps_n = -1, best_fps_d = -1;
+  gint par_n, par_d;
+  gdouble best_fps = 0.;
   GstCaps *ret = NULL;
+  GstStructure *s;
 
-  gst_video_info_from_caps (&info, caps);
+  ret = gst_caps_make_writable (caps);
 
-  /* FIXME: this doesn't work for non 1/1 output par's as we don't have that
-   * information available at this time */
+  /* we need this to calculate how large to make the output frame */
+  s = gst_caps_get_structure (ret, 0);
+  if (gst_structure_has_field (s, "pixel-aspect-ratio")) {
+    gst_structure_fixate_field_nearest_fraction (s, "pixel-aspect-ratio", 1, 1);
+    gst_structure_get_fraction (s, "pixel-aspect-ratio", &par_n, &par_d);
+  } else {
+    par_n = par_d = 1;
+  }
 
   GST_OBJECT_LOCK (vagg);
   for (l = GST_ELEMENT (vagg)->sinkpads; l; l = l->next) {
@@ -901,9 +910,13 @@ _update_caps (GstVideoAggregator * vagg, GstCaps * caps)
     GstCompositorPad *compositor_pad = GST_COMPOSITOR_PAD (vaggpad);
     gint this_width, this_height;
     gint width, height;
+    gint fps_n, fps_d;
+    gdouble cur_fps;
 
-    _mixer_pad_get_output_size (GST_COMPOSITOR (vagg), compositor_pad, &width,
-        &height);
+    fps_n = GST_VIDEO_INFO_FPS_N (&vaggpad->info);
+    fps_d = GST_VIDEO_INFO_FPS_D (&vaggpad->info);
+    _mixer_pad_get_output_size (GST_COMPOSITOR (vagg), compositor_pad, par_n,
+        par_d, &width, &height);
 
     if (width == 0 || height == 0)
       continue;
@@ -915,17 +928,40 @@ _update_caps (GstVideoAggregator * vagg, GstCaps * caps)
       best_width = this_width;
     if (best_height < this_height)
       best_height = this_height;
+
+    if (fps_d == 0)
+      cur_fps = 0.0;
+    else
+      gst_util_fraction_to_double (fps_n, fps_d, &cur_fps);
+
+    if (best_fps < cur_fps) {
+      best_fps = cur_fps;
+      best_fps_n = fps_n;
+      best_fps_d = fps_d;
+    }
   }
   GST_OBJECT_UNLOCK (vagg);
 
+  if (best_fps_n <= 0 || best_fps_d <= 0 || best_fps == 0.0) {
+    best_fps_n = 25;
+    best_fps_d = 1;
+    best_fps = 25.0;
+  }
+
+  gst_structure_fixate_field_nearest_int (s, "width", best_width);
+  gst_structure_fixate_field_nearest_int (s, "height", best_height);
+  gst_structure_fixate_field_nearest_fraction (s, "framerate", best_fps_n,
+      best_fps_d);
+  ret = gst_caps_fixate (ret);
+
   if (best_width > 0 && best_height > 0) {
-    info.width = best_width;
-    info.height = best_height;
-    if (set_functions (GST_COMPOSITOR (vagg), &info))
-      ret = gst_video_info_to_caps (&info);
+    GstVideoInfo v_info;
 
-    gst_caps_set_simple (ret, "pixel-aspect-ratio", GST_TYPE_FRACTION_RANGE,
-        1, G_MAXINT, G_MAXINT, 1, NULL);
+    gst_video_info_from_caps (&v_info, ret);
+    if (!set_functions (GST_COMPOSITOR (vagg), &v_info)) {
+      GST_ERROR_OBJECT (vagg, "Failed to setup vfuncs");
+      return NULL;
+    }
   }
 
   return ret;
@@ -1059,7 +1095,7 @@ gst_compositor_class_init (GstCompositorClass * klass)
 
   agg_class->sinkpads_type = GST_TYPE_COMPOSITOR_PAD;
   agg_class->sink_query = _sink_query;
-  videoaggregator_class->update_caps = _update_caps;
+  videoaggregator_class->fixate_caps = _fixate_caps;
   videoaggregator_class->aggregate_frames = gst_compositor_aggregate_frames;
 
   g_object_class_install_property (gobject_class, PROP_BACKGROUND,