11 January 2011, 11:56

Hi,

One of our users will be uploading a lot of video content, and I wondered if the Mahara team or anyone else had looked at converting uploaded videos into a common format which could be played by the flash player - ie. using ffmpeg.

I guess this could put a load on the system - could the conversion process be devolved to a media server?

She also asked about playing back video fullscreen. I guess this depends on the player/plugin technology. I think it should be possible with .flvs - any other formats?

Thanks for any thoughts.

Mike

11 January 2011, 16:36

Hi Mike,

We have played with video transcoding already and you are right that it can put a lot of load on the server. The trick here is to queue the transcoding jobs so that there is a hard limit on the number of transcoding tasks happening at any one time.

Then if it takes too long to transcode video, you can allocate more resources (e.g. a dedicated transcoding server) to processing the tasks.

With regards to fullscreen mode, this is already available, but disabled by default in all versions of Mahara. If you want to enable it, open htdocs/artefact/file/blocktype/internalmedia/lib.php and change this line within the flow_player function:

PluginBlocktype {
                           time:false,
                           stop:false,
                           playlist:false,
-                          fullscreen:false,
+                          fullscreen:true,
                           scrubber: true,
                           autoHide: '.$autohide.'
                       }'.$audio.'

I'll make sure that functionality is enabled by default on 1.4.

Cheers,

Francois

12 January 2011, 3:30

Thanks Francois,

If we try to integrate transcoding no doubt I will have more questions for you.

Best wishes,

Mike

12 January 2011, 5:56

Hi Mark

A transcoding option for video media in Mahara has already been mostly developed and should hopefully make it into core for the 1.4 release.

FFMpeg is being used for the transcoding which can be applied to video files already in a users portfolio or to new videos on upload.  The issue of load has been dealt with by the development of a queuing system which can be configured by an admin user to increase/decrease the stress on the server. Also being discussed is an API to have the transcoding load pushed to a separate dedicated server, although that is not currently looking likely for the initial release.

Good to know that there is demand for the feature as that will make it more likely to appear quickly.

Cheers

12 January 2011, 7:39

That's good news. I'll hold off with a local implementation then. Will videos uploaded with the current options still be accessible though, once the new feature is in place - or will they have to be transcoded?

Mike

13 January 2011, 5:35

Yes, existing video handling will be maintained, this is more of an add on.  You will still be able to access all existing videos and continue to be able to upload videos in the exisitng formats if that's what you wish.

13 January 2011, 10:49

OK, thanks.

I'm not having much luck with SWFs at the moment - is the Flash Player working? Nothing appears on the Page, and the link to the file takes me to a blank page.

The Flow Player seems OK with MP4s.

I'm using Mahara 1.4 dev version.

Mike

13 January 2011, 16:12

Hi Mike,

It was working fine for .swf (which doesn't use the flow player), flv (flowplayer) and mp4 (flowplayer) last time I tried it.

If you submit a bug report on the tracker and attach the SWF file you are having problems with, we'll have a look at it.

Cheers,

Francois

17 January 2011, 3:33

I think the SWF I was testing was designed to run inside a Flash movie player. It probably had a stop action in the first frame. I tried another one and it worked OK. So user error. : P