From ada6752eae951396cc216b95934fc0d299252f9e Mon Sep 17 00:00:00 2001
From: Jim Broadus <jbroadus@gmail.com>
Date: Tue, 30 Mar 2021 21:31:55 -0700
Subject: [PATCH] gstengine: Don't modify caps when pipeline is running

When the decoder bin's src pad is added, only set caps to use the native
bit depth if the the pipeline is not already running.
---
 src/engines/gstenginepipeline.cpp | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/src/engines/gstenginepipeline.cpp b/src/engines/gstenginepipeline.cpp
index 56cabd1d9..97ef1aaa1 100644
--- a/src/engines/gstenginepipeline.cpp
+++ b/src/engines/gstenginepipeline.cpp
@@ -15,6 +15,9 @@
    along with Clementine.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+// To turn on logging of bus callbacks, run Clementine with:
+// --log-levels GstEnginePipelineCallbacks:3
+
 #include "gstenginepipeline.h"
 
 #include <QCoreApplication>
@@ -878,18 +881,23 @@ void GstEnginePipeline::NewPadCallback(GstElement*, GstPad* pad,
   GstCaps* caps = gst_pad_get_current_caps(pad);
   if (caps) {
     gchar* caps_str = gst_caps_to_string(caps);
-    qLog(Debug) << "Current caps:" << caps_str;
+    qLog(Debug) << "Initial decoder caps:" << caps_str;
     g_free(caps_str);
 
-    QString fmt = GetAudioFormat(caps);
+    if (instance->pipeline_is_initialised_) {
+      qLog(Debug)
+          << "Ignoring native format since pipeline is already running.";
+    } else {
+      QString fmt = GetAudioFormat(caps);
 
-    // The output branch only handles F32LE and S16LE. If the source is S16LE,
-    // then use that throughout the pipeline. Otherwise, use F32LE.
-    if (fmt != "S16LE") {
-      GstCaps* new_caps = gst_caps_new_simple("audio/x-raw", "format",
-                                              G_TYPE_STRING, "F32LE", nullptr);
-      g_object_set(instance->capsfilter_, "caps", new_caps, nullptr);
-      gst_caps_unref(new_caps);
+      // The output branch only handles F32LE and S16LE. If the source is S16LE,
+      // then use that throughout the pipeline. Otherwise, use F32LE.
+      if (fmt != "S16LE") {
+        GstCaps* new_caps = gst_caps_new_simple(
+            "audio/x-raw", "format", G_TYPE_STRING, "F32LE", nullptr);
+        g_object_set(instance->capsfilter_, "caps", new_caps, nullptr);
+        gst_caps_unref(new_caps);
+      }
     }
     gst_caps_unref(caps);
   }
@@ -1134,11 +1142,6 @@ void GstEnginePipeline::TransitionToNext() {
 
   ignore_tags_ = true;
 
-  // Reset the caps filter
-  GstCaps* new_caps = gst_caps_new_any();
-  g_object_set(capsfilter_, "caps", new_caps, nullptr);
-  gst_caps_unref(new_caps);
-
   if (!ReplaceDecodeBin(next_.url_)) {
     qLog(Error) << "ReplaceDecodeBin failed with " << next_.url_;
     return;