From f5a02639e1ae0f8e828d47a8788d4fc886265782 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Mon, 27 Jul 2020 18:55:35 +0300
Subject: [PATCH] audioaggregator: Only check downstream caps when handling
 CAPS events if we didn't negotiate with downstream yet

If we already negotiated with downstream there is not point in checking
if the caps are supported. We already know that this is the case.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/768>
---
 gst-libs/gst/audio/gstaudioaggregator.c | 44 +++++++++++++------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/gst-libs/gst/audio/gstaudioaggregator.c b/gst-libs/gst/audio/gstaudioaggregator.c
index 546c9a02f7..5bc0cbd426 100644
--- a/gst-libs/gst/audio/gstaudioaggregator.c
+++ b/gst-libs/gst/audio/gstaudioaggregator.c
@@ -869,20 +869,9 @@ gst_audio_aggregator_sink_setcaps (GstAudioAggregatorPad * aaggpad,
 {
   GstAudioAggregatorPad *first_configured_pad =
       gst_audio_aggregator_get_first_configured_pad (agg);
-  GstCaps *downstream_caps = gst_pad_get_allowed_caps (agg->srcpad);
-  GstCaps *rate_caps;
   GstAudioInfo info;
   gboolean ret = TRUE;
-  gboolean downstream_supports_rate;
-
-  /* Returns NULL if there is no downstream peer */
-  if (!downstream_caps)
-    downstream_caps = gst_pad_get_pad_template_caps (agg->srcpad);
-
-  if (gst_caps_is_empty (downstream_caps)) {
-    ret = FALSE;
-    goto done;
-  }
+  gboolean downstream_supports_rate = TRUE;
 
   if (!gst_audio_info_from_caps (&info, caps)) {
     GST_WARNING_OBJECT (agg, "Rejecting invalid caps: %" GST_PTR_FORMAT, caps);
@@ -893,11 +882,28 @@ gst_audio_aggregator_sink_setcaps (GstAudioAggregatorPad * aaggpad,
    * because offsets will have to be updated, and audio resampling
    * has a latency to take into account
    */
-  rate_caps =
-      gst_caps_new_simple ("audio/x-raw", "rate", G_TYPE_INT, info.rate, NULL);
-  downstream_supports_rate =
-      gst_caps_can_intersect (rate_caps, downstream_caps);
-  gst_caps_unref (rate_caps);
+
+  /* Only check against the downstream caps if we didn't configure any caps
+   * so far. Otherwise we already know that downstream supports the rate
+   * because we negotiated with downstream */
+  if (!first_configured_pad) {
+    GstCaps *downstream_caps = gst_pad_get_allowed_caps (agg->srcpad);
+
+    /* Returns NULL if there is no downstream peer */
+    if (downstream_caps) {
+      GstCaps *rate_caps =
+          gst_caps_new_simple ("audio/x-raw", "rate", G_TYPE_INT, info.rate,
+          NULL);
+
+      gst_caps_set_features_simple (rate_caps,
+          gst_caps_features_copy (GST_CAPS_FEATURES_ANY));
+
+      downstream_supports_rate =
+          gst_caps_can_intersect (rate_caps, downstream_caps);
+      gst_caps_unref (rate_caps);
+      gst_caps_unref (downstream_caps);
+    }
+  }
 
   if (!downstream_supports_rate || (first_configured_pad
           && info.rate != first_configured_pad->info.rate)) {
@@ -913,13 +919,9 @@ gst_audio_aggregator_sink_setcaps (GstAudioAggregatorPad * aaggpad,
     GST_OBJECT_UNLOCK (aaggpad);
   }
 
-done:
   if (first_configured_pad)
     gst_object_unref (first_configured_pad);
 
-  if (downstream_caps)
-    gst_caps_unref (downstream_caps);
-
   return ret;
 }