Last modified: 2014-05-17 18:54:49 UTC
Currently we're producing Ogg Theora (.ogv) transcodes at only 480p (or original size if smaller), while we produce a wider range of resolutions in WebM/VP8. Our current fallback when there is no WebM or Theora support natively is the Java Cortado applet which only plays back Theora, so on full SD or HD source videos it is stuck with a relatively large 480p version. A 360p video has about half the pixels to process as a 480p video, and a 240p video has half again. That makes a big difference in software decoding on a slow CPU or dynamic language VM! Note I'm also experimenting with JavaScript, and starting to look at Flash, for alternate fallbacks in the future as Java applets are increasingly difficult to use in recent versions. Both cases will probably also prefer Theora over WebM/VP8 because it is less demanding on the CPU.
Ugh, unfortunately the settings are kkinda hardcoded in TimedMediaHandler and it might be tough to add 240p. There is a preset for 360p and for 160p though... Ok changing this to requesting 360p and 160p. :) Actually 160p will be great for really slow devices...
Change 114507 had a related patch set uploaded by Brion VIBBER: Enable lower-res .ogv transcodes for fallback player on slow machines https://gerrit.wikimedia.org/r/114507
Change 114507 merged by jenkins-bot: Enable lower-res .ogv transcodes for fallback player on slow machines https://gerrit.wikimedia.org/r/114507
Note this config now appears to be live; waiting for some sample files to get through transcoding to confirm.
To be useful, wouldn't TMH have to actually default to that size in the situations your describe? I don't think it currently does.
Yeah, we'll have to check on that. I have to set up a machine or VM where the Java player actually works to confirm what it does right now... shouldn't be super hard to tweak once we get there, I hope.
As an update, we've discovered this is selecting the 160p version to show users even for people who should get big versions.
Let's revert this until we have a chance to fix the player to select good defaults...
Change 114761 had a related patch set uploaded by Brion VIBBER: Revert low-res .ogv transcode enable; player is picking too-small version by default https://gerrit.wikimedia.org/r/114761
Change 114761 abandoned by Brion VIBBER: Revert low-res .ogv transcode enable; player is picking too-small version by default Reason: replacing this with a proper fix https://gerrit.wikimedia.org/r/114761
Change 115094 had a related patch set uploaded by Brion VIBBER: Fix popup video size by ordering transcode settings properly https://gerrit.wikimedia.org/r/115094
All patches merged; resetting ticket status
As far as I can tell, nothing more to do here. 360p and 180p are both in the config. There may be some additional issues with jobs being "lost" (See also bug 47312), but I think that would be a separate bug. Similarly changing how TMH actually uses the options available to it should be a separate bug.
