1011400 - [Tarako][Video] Disable preloading for "pick" activities. by setting "preload" to "none".

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Gaia::Video, defect)

Description

[Andrew Sutherland [:asuth] (he/him)]

In bug 1010701 on attachment 8422946 [details] the email app is OOM'ing when an activity is attempting to attach a video at the bottom of the log.  There are a large number of logcat entries on SPRDAVCDecoder and SprdSimpleOMXComponent that strongly imply that the video is being loaded (to my untrained eye).

From simple grepping it appears that in v1.3t the video app only ever sets the "preload" attribute to "metadata" when explicitly set.  And https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video implies that if unset, it should default to "metadata" anyways.

Anywho, the email app would like to avoid getting dead and appreciates all help in this, so I figured I'd propose this for consideration.  I am going to do some other investigation into the memory use too.  (And indeed a bigger concern on bug 1010701 is that the activity was triggered while the email app was actively slicing/dicing another attachment which :digitarald's firewatch graphing app has shown causes wild swings in memory usage across the email process and the system process.  I will investigate that, but every little bit helps, especially since it appears that many of our problems are due to fragmentation/heap growth.)

Comment 1

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

Hi John, would you be able to look at this bug please?

Comment 2

[John Hu [:johnhu][:johu][:醬糊小弟]]

(In reply to Andrew Sutherland (:asuth) from comment #0)
> In bug 1010701 on attachment 8422946 [details] the email app is OOM'ing when
> an activity is attempting to attach a video at the bottom of the log.  There
> are a large number of logcat entries on SPRDAVCDecoder and
> SprdSimpleOMXComponent that strongly imply that the video is being loaded
> (to my untrained eye).

This is because the first frame is decoded. It is required when user taps the video and gets the first frame of video.


> From simple grepping it appears that in v1.3t the video app only ever sets
> the "preload" attribute to "metadata" when explicitly set.  And
> https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video implies that
> if unset, it should default to "metadata" anyways.

We depends on "preload='metadata'" or "video been loaded" for two purpose:
1. to fetch the size and duration of video
    We already have them during metadata parsing. It is easy to use information our stored metadata.

2. to set the currentTime to show the correct video frame to user.
    We may not have a large enough image for showing as a poster. We only have a 210x120 thumbnail for the video list. That means we need to generate a larger image for it.

I think it is possible to do it. But we need to change the procedure of showPlayer().


BTW, the default value of preload attribute is "none" in b2g: 
http://dxr.mozilla.org/mozilla-central/source/b2g/app/b2g.js#315

This is in master branch, and I don't know if we change this default value to metadata in v1.3t.

Comment 3

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

I think if I am looking at this right, it's the same : 
http://mxr.mozilla.org/mozilla-b2g28_v1_3/source/b2g/app/b2g.js#283 ?

Comment 4

[BMO Automation]

Firefox OS is not being worked on