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probable race condition initializing HTML5 video




Audio/Video: Playback
2 years ago
2 years ago


(Reporter: Rich Franzen, Unassigned)


38 Branch

Firefox Tracking Flags

(Not tracked)





2 years ago
User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0
Build ID: 20150513174244

Steps to reproduce:

Display page at http://r0k.us/rock/memoriam.html .  Scroll down to "from Danna" section (or click Danna menu item in upper right).  You should see an embedded YouTube video ready to play, and just below that, an HTML5 video entitled "The Surprise".

Code to display video:
<video width="480" height="270" controls preload="metadata">
   <source src="images/TheSurprise.mp4" type="video/mp4">
   Your browser does not support the video tag.

Actual results:

Intermittently, video support will not load, and the video frame contains an error message:

"No video with supported format and MIME type found",
with a big X in the middle (above that message).  Refreshing the browser window will often get rid of the error, and the video becomes playable.

Minor: Even when video support loads properly, often the pre-click (initial) frame does not show until video is started.

Note, the problem occurs frequently on relatively low power CPU systems, and possibly not at all on higher power systems.  My sister's desktop experiences it frequently.  She runs msWindows 7.0 Home Premium 64-bit, and has an  Intel (R) Core (TM) i3-2120 CPU @ 3.30 GHz.  I see it very occasionally.  Same OS, with an AMD Phenom(tm) II X6 1035T @ 2.6 GHz.

Expected results:

Video is ready to be played, every time.

Minor: the initial frame from video should show in frame before clicking


2 years ago


2 years ago
Component: Untriaged → Video/Audio
Product: Firefox → Core


2 years ago

Comment 1

2 years ago
I copied HTML page to file with this bug's name, so I could keep editing page without possibly changing the symptoms.
Component: Audio/Video → Audio/Video: Playback
WFM. Can you still reproduce the issue?
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