Changeset 264299 in webkit

Timestamp:

Jul 13, 2020, 6:03:22 AM (6 years ago)

Author:

aboya@igalia.com

Message:

[MSE][GStreamer] Discard PTS-less samples
​https://bugs.webkit.org/show_bug.cgi?id=214252

Reviewed by Philippe Normand.

In some cases GStreamer demuxers emit PTS-less samples with metadata
at the beginning of the container. These are fortunately not necessary
for playback, and in fact incompatible with the way MSE works, where
you should be able to start playing a stream from the middle.

This patch skips these frames in the AppendPipeline so they don't
pollute other parts of the MSE codebase.

Since these frames were not necessary and were later overwritten,
this patch is just a cleanup introducing no notable behavior changes.

• platform/graphics/gstreamer/mse/AppendPipeline.cpp:

(WebCore::AppendPipeline::appsinkNewSample):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/gstreamer/mse/AppendPipeline.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2020-07-13  Alicia Boya García  <aboya@igalia.com>
+
+        [MSE][GStreamer] Discard PTS-less samples
+        https://bugs.webkit.org/show_bug.cgi?id=214252
+
+        Reviewed by Philippe Normand.
+
+        In some cases GStreamer demuxers emit PTS-less samples with metadata
+        at the beginning of the container. These are fortunately not necessary
+        for playback, and in fact incompatible with the way MSE works, where
+        you should be able to start playing a stream from the middle.
+
+        This patch skips these frames in the AppendPipeline so they don't
+        pollute other parts of the MSE codebase.
+
+        Since these frames were not necessary and were later overwritten,
+        this patch is just a cleanup introducing no notable behavior changes.
+
+        * platform/graphics/gstreamer/mse/AppendPipeline.cpp:
+        (WebCore::AppendPipeline::appsinkNewSample):
+
 2020-07-13  Carlos Garcia Campos  <cgarcia@igalia.com>
 

trunk/Source/WebCore/platform/graphics/gstreamer/mse/AppendPipeline.cpp

@@ -461 +461 @@
     }
 
+    if (!GST_BUFFER_PTS_IS_VALID(gst_sample_get_buffer(sample.get()))) {
+        // When demuxing Vorbis, matroskademux creates several PTS-less frames with header information. We don't need those.
+        GST_DEBUG("Ignoring sample without PTS: %" GST_PTR_FORMAT, gst_sample_get_buffer(sample.get()));
+        return;
+    }
+
     auto mediaSample = WebCore::MediaSampleGStreamer::create(WTFMove(sample), m_presentationSize, trackId());