Actually fix caps negotiation issue (I hope)

It seems to be some sort of race condition/flakiness with nvh264dec.
valadaptive · Nov 2, 2024 · 6599522 · 6599522
1 parent 3a77cce
commit 6599522
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Showing 2 changed files with 12 additions and 5 deletions.
diff --git a/crates/gui/src/gst_utils/init.rs b/crates/gui/src/gst_utils/init.rs
@@ -37,5 +37,13 @@ pub fn initialize_gstreamer() -> Result<(), GstreamerError> {
         sink.set_rank(gstreamer::Rank::NONE);
     }
 
+    // nvh264dec is flaky and seemingly creates spurious caps events with memory:CUDAMemory late in the caps negotiation
+    // progress, causing caps negotiation to fail (see
+    // https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/2644). This doesn't occur all the time and points to
+    // some sort of race condition.
+    if let Some(dec) = gstreamer::ElementFactory::find("nvh264dec") {
+        dec.set_rank(gstreamer::Rank::NONE);
+    }
+
     Ok(())
 }
diff --git a/crates/gui/src/gst_utils/ntsc_pipeline.rs b/crates/gui/src/gst_utils/ntsc_pipeline.rs
@@ -246,6 +246,9 @@ impl NtscPipeline {
                                 gstreamer_video::VideoOrientationMethod::Auto,
                             )
                             .build()?;*/
+                            let video_rate = gstreamer::ElementFactory::make("videorate")
+                                .name("video_rate")
+                                .build()?;
 
                             let video_scale = gstreamer::ElementFactory::make("videoscale")
                                 .name("video_scale")
@@ -261,10 +264,6 @@ impl NtscPipeline {
                             let caps_filter = gstreamer::ElementFactory::make("capsfilter")
                                 .name("caps_filter")
                                 .build()?;
-
-                            let video_rate = gstreamer::ElementFactory::make("videorate")
-                                .name("video_rate")
-                                .build()?;
                             let framerate_caps_filter =
                                 gstreamer::ElementFactory::make("capsfilter")
                                     .name("framerate_caps_filter")
@@ -274,9 +273,9 @@ impl NtscPipeline {
                                 &video_queue,
                                 //&video_flip,
                                 &video_convert,
+                                &video_rate,
                                 &video_scale,
                                 &caps_filter,
-                                &video_rate,
                                 &framerate_caps_filter,
                             ];
                             pipeline.add_many(video_elements)?;