1150857 - Turning off main thread composition causes HTML5 video scaling to fail

Status: VERIFIED DUPLICATE of bug 1141433

(Core :: Audio/Video, defect)

Description

[u529383]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.118 Safari/537.36

Steps to reproduce:

Open about:config

Change layers.offmainthreadcomposition.enabled to false

Cold restart Firefox

Play any HTML5 video (in this case YouTube video)


Actual results:

The videos don't scale correctly. The HTML5 player changes size, but the video content inside the player stays in its original file size.

For example: If I am watching a 1280x720p video in a HTML5 player that is bigger than the video's native resolution then the video will not fill the player's available space. The same thing happens in reverse, if the video's native resolution is bigger than the player's size then the video will stay "zoomed" inside the smaller player.

Screenshot examples as provided by others that faced the same issue:

 http://i.imgur.com/Bq2vVFR.png

 https://05642170577473949014.googlegroups.com/attach/fcfd74a4886b9312/20140802sRAkF1JRd1pC7Rd2_MUK0j_large.jpeg?part=0.1&view=1&vt=ANaJVrE97TlVoTZFfA0R4PLbwTH_gCg09fONHXEVqRxqtL-xkLmK2AjeCt8fCYgqVBe44Xz7qMgklrG2D7z8EFUZZWl6KpzHePtkiXRDKs9ToZNeZcZmFO8


Expected results:

The video should fill the available player space like it does when  layers.offmainthreadcomposition.enabled is set to true.

Comment 1

[(not currently active) Ted Mielczarek]

Jeff, Anthony, the bug filer here is from /r/firefox, I asked them to file this bug.