1462967 - autoplay doesn't work for blobURIs

Status: RESOLVED DUPLICATE of bug 1457661

(Core :: Audio/Video: Playback, enhancement)

Description

[Kaiido]

Attachment: autoplay.html

Autoplay doesn't work for downloaded media served through a blobURI.

Note that media generated from a MediaRecorder do autoplay, but the ones fetched or gotten from user's input won't.


mozregression points to this commit: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=772fef647fd7750f8c87dfd4f55bbd85046a555a&tochange=821560cd716d50fbb0c49d0170bd351255e55bc3

Comment 1

[Jean-Yves Avenard [:jya]]

Sound the same as bug 1457661

Comment 3

[benmbenjamin]

Is this the same? The referenced duplicate (1457661) doesn't mention anything about autoplaying media, and it doesn't appear that the autoplay attribute and requires canplaythrough to be true to function properly?

Comment 4

[Jean-Yves Avenard [:jya]]

per spec:
https://html.spec.whatwg.org/multipage/media.html#ready-states

"If the new ready state is HAVE_ENOUGH_DATA

    If the previous ready state was HAVE_CURRENT_DATA or less, the user agent must queue a task to fire an event named canplay at the element, and, if the element's paused attribute is false, notify about playing for the element.

    The user agent must queue a task to fire an event named canplaythrough at the element.

    If the element is not eligible for autoplay, then the user agent must abort these substeps.
"

if the attribute autoplay is set, playback will only start once readyState == HAVE_ENOUGH_DATA which will cause canplaythrough to be fired.

Here we never reach readyState == HAVE_ENOUGH_DATA, as such canplaythrough isn't fired, and autoplay attribute has no effect.

so yes, the two things are extremely related.