1268694 - Widevine crash in mozilla::CDMCaps::AutoLock::AutoLock when using DASH.js player

Status: RESOLVED WORKSFORME

(Core :: Audio/Video: Playback, defect, P2)

Description

[Chris Peterson [:cpeterson]]

This bug was filed from the Socorro interface and is 
report bp-0c75d880-35cc-4d40-9481-aa97d2160428.
=============================================================

I hit this crash when trying to play MPD http://html5.cablelabs.com:8100/cenc/wv/dash.mpd (accessible from the DASH player's menu: Sample Streams > CableLabs Test Content > CableLabs Cenc Widevine) on DASH.js player http://dashif.org/reference/players/javascript/v2.1.1/samples/dash-if-reference-player/index.html.

0 	XUL 	mozilla::CDMCaps::AutoLock::AutoLock(mozilla::CDMCaps&) 	xpcom/glue/Mutex.h
1 	XUL 	mozilla::MediaDecoder::SetCDMProxy(mozilla::CDMProxy*) 	dom/media/MediaDecoder.cpp
2 	XUL 	mozilla::dom::HTMLMediaElement::FinishDecoderSetup(mozilla::MediaDecoder*, mozilla::MediaResource*, nsIStreamListener**) 	dom/html/HTMLMediaElement.cpp
3 	XUL 	mozilla::dom::HTMLMediaElement::LoadResource() 	dom/html/HTMLMediaElement.cpp
4 	XUL 	mozilla::dom::HTMLMediaElement::SelectResource() 	dom/html/HTMLMediaElement.cpp
5 	XUL 	mozilla::dom::HTMLMediaElement::SelectResourceWrapper() 	dom/html/HTMLMediaElement.cpp
6 	XUL 	nsRunnableMethodImpl<void (mozilla::dom::HTMLMediaElement::*)(), true>::Run 	xpcom/glue/nsThreadUtils.h
7 	XUL 	mozilla::dom::nsSyncSection::Run() 	dom/html/HTMLMediaElement.cpp
8 	XUL 	mozilla::CycleCollectedJSRuntime::ProcessStableStateQueue() 	xpcom/base/CycleCollectedJSRuntime.cpp
9 	XUL 	XPCJSRuntime::AfterProcessTask(unsigned int) 	js/xpconnect/src/XPCJSRuntime.cpp
10 	XUL 	nsThread::ProcessNextEvent(bool, bool*) 	xpcom/threads/nsThread.cpp
11 	XUL 	NS_ProcessPendingEvents(nsIThread*, unsigned int) 	xpcom/glue/nsThreadUtils.cpp
12 	XUL 	nsBaseAppShell::NativeEventCallback() 	widget/nsBaseAppShell.cpp
13 	XUL 	nsAppShell::ProcessGeckoEvents(void*) 	widget/cocoa/nsAppShell.mm

Comment 1

[Chris Peterson [:cpeterson]]

Blake, can an engineer on your team investigate this Widevine crash? We're encouraging video streaming services to switch from Silverlight to Widevine in Firefox 47. The crash is 100% reproducible with the steps in comment 0.

Comment 2

[JW Wang [:jwwang] [:jw_wang]]

I will take a look.

Comment 3

[JW Wang [:jwwang] [:jw_wang]]

Can't repro the crash on my MBP nightly.

I can play Sample Streams > CableLabs Test Content > CableLabs Cenc Widevine/ClearKey without any problem.
However, CableLabs Cenc Widevine didn't crash nor did it play at all.

Did I miss some setup for Widevine to play correctly?

Comment 4

[Chris Peterson [:cpeterson]]

Thanks for testing. I can no longer reproduce this crash, so I'm not sure what changed. I'll resolve this bug as WFM for now and retest later.

Comment 5

[Chris Peterson [:cpeterson]]

There is definitely some shutdown race condition that leads to some null pointer crashes in our Widevine code. I hit the following crashes (once each) when clicking the DASH.js player's "Load" button a couple times to reload the "CableLabs Cenc Widevine" manifest. When the crash happens, it always seems to happen within the first 1–2 button clicks.

[@ non-virtual thunk to mozilla::WidevineDecryptor::OnSessionClosed ]
bp-dcc4aefa-c837-490a-b026-aadbc2160505

[@ mozilla::SamplesWaitingForKey::WaitIfKeyNotUsable ]
bp-21904d1c-73aa-4ceb-b8f0-38dd82160505

I filed bug 1270607 for the WaitIfKeyNotUsable crash because there are 15 crash reports and most are from Amazon Video.