Bug 259915

Summary:	[WPE][Debug]: fast/mediastream/captureStream/canvas3d.html crashes with error gst_sample_get_caps: assertion 'GST_IS_SAMPLE (sample)' failed
Product:	WebKit	Reporter:	Diego Pino <dpino>
Component:	New Bugs	Assignee:	Philippe Normand <philn>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	philn, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Diego Pino 2023-08-07 21:23:45 PDT

https://build.webkit.org/results/WPE-Linux-64-bit-Debug-Tests/266663@main%20(6300)/fast/mediastream/captureStream/canvas3d-crash-log.txt

STDERR: (WPEWebProcess:76043): GStreamer-CRITICAL **: 18:47:01.803: gst_sample_get_caps: assertion 'GST_IS_SAMPLE (sample)' failed
STDERR: WPEWebProcess terminated (pid 76043) for reason: crash

Thread 1 (Thread 0x7fd586f62ec0 (LWP 76043)):
#0  g_logv (log_domain=0x7fd58d9529ae "GStreamer", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=<optimized out>) at ../glib/gmessages.c:1422
#1  0x00007fd58db05c53 in g_log (log_domain=log_domain@entry=0x7fd58d9529ae "GStreamer", log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, format=format@entry=0x7fd58db69ff7 "%s: assertion '%s' failed") at ../glib/gmessages.c:1460
#2  0x00007fd58db06e6d in g_return_if_fail_warning (log_domain=log_domain@entry=0x7fd58d9529ae "GStreamer", pretty_function=pretty_function@entry=0x7fd58d977920 <__func__.8.lto_priv.35> "gst_sample_get_caps", expression=expression@entry=0x7fd58d975644 "GST_IS_SAMPLE (sample)") at ../glib/gmessages.c:2930
#3  0x00007fd58d911c26 in gst_sample_get_caps (sample=<optimized out>) at ../gst/gstsample.c:209
#4  gst_sample_get_caps (sample=<optimized out>) at ../gst/gstsample.c:207
#5  0x00007fd5a02e4b5e in WebCore::VideoFrameGStreamer::create(WTF::GRefPtr<_GstSample>&&, WebCore::FloatSize const&, WTF::MediaTime const&, WebCore::VideoFrameRotation, bool, std::optional<WebCore::VideoFrameTimeMetadata>&&, std::optional<WebCore::PlatformVideoColorSpace>&&) (sample=..., presentationSize=..., presentationTime=..., videoRotation=WebCore::VideoFrameRotation::None, videoMirrored=false, metadata=..., colorSpace=...) at /app/webkit/Source/WebCore/platform/graphics/gstreamer/VideoFrameGStreamer.cpp:222
#6  0x00007fd5a02d9edc in WebCore::MediaPlayerPrivateGStreamer::videoFrameForCurrentTime() (this=0x7fd57d561780) at /app/webkit/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:3870
#7  0x00007fd5a0137426 in WebCore::MediaPlayer::videoFrameForCurrentTime() (this=0x7fd57d129c60) at /app/webkit/Source/WebCore/platform/graphics/MediaPlayer.cpp:1144
#8  0x00007fd59e1c65c8 in operator()(WTF::RefPtr<WebCore::HTMLVideoElement, WTF::RawPtrTraits<WebCore::HTMLVideoElement>, WTF::DefaultRefDerefTraits<WebCore::HTMLVideoElement> >&) const (__closure=0x7ffcc8113cd0, video=...) at /app/webkit/Source/WebCore/Modules/webcodecs/WebCodecsVideoFrame.cpp:190

I think the issue might be that the `convertedSample` in https://searchfox.org/wubkat/source/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp#3868 is not sample anymore.

Comment 1 Philippe Normand 2023-08-08 01:06:04 PDT

This bot has no GPU I guess?
Setting GST_DEBUG=3 should show the relevant error, most likely from gst_video_convert_sample() returning NULL.

I cannot reproduce this here, but this code should be more error-prone. I'll send a PR.

Comment 2 Philippe Normand 2023-08-08 01:08:36 PDT

Pull request: https://github.com/WebKit/WebKit/pull/16470

Comment 3 EWS 2023-08-09 05:31:33 PDT

Committed 266723@main (6204c3532ecc): <https://commits.webkit.org/266723@main>

Reviewed commits have been landed. Closing PR #16470 and removing active labels.

Comment 4 Radar WebKit Bug Importer 2023-08-09 05:32:14 PDT

<rdar://problem/113624573>