[joshuass]

I've been testing the latest SVN releases. They are looking really good.

I have one problem that I can't seem to figure out.

I have videos that crawl to a very choppy 7-9fps during playback with pretty much any SVN build version I have tried (3 so far) that were built after 22516 (GL versions only).

It occurs specifically during the opening song/credits because of subtitle movement. Though, playback seems a bit choppy over all (just not nearly as bad).

I've run logs, and can't seem to see anything that indicates theres a problem. I probably need more background into how subtitling works I guess.

Anyways, here's a debug log:
http://pastebin.com/f5250718b

I played two videos, the first one plays no problem at all.

The second movie however, becomes unwatchable as described above.

Its a tough problem to explain. I'm gonna be inspecting the vidoes (they are mkv's, btw.) to see what the differences are.

Has anyone else had this problem?

[joshuass]

Reading the change logs again, I noticed that quite a bit of updates are being done to address font caching and things for subtitles.

Perhaps my issue isn't with XBMC perse as it is with the libraries it uses to render the subs?

I looked at the mkv's that I opened when building the debug log with mkvtoolnix and nothing seemed out of the ordinary. Though, I did not dive too deeply into it (extracting the subs and viewing them) because, frankly, I wouldn't know what to look for.

Also note, choppiness wasn't due to a pegged CPU because during playback, the CPU was around 60 to 70% in use. I saw 40-50% usage when playing the known good file.

Finally, the only other file dependency problem I saw in the log was for MSVCR90.dll. Would placing a copy of that in the system folder for XBMC fix that issue? I installed the VC++ 2008 x86 and x64 runtime redistributables, but that didn't work. VC++ 2005 was already installed for the AMD ATI drivers to function.

[qnox]

Im getting the same issue with latest (r23946) SVN build for Karmic Ubuntu - when I'm playing video with subtitles from text file video seems to be low FPS, wne disabling subtitles I get smooth playback. Audio goese all the time without a problem.

[joshuass]

This is most likely due to libass. Have you tried a previous build?

I noticed that this problem only rears its head with ASS/SSA styled subs, which libass renders for XBMC.

Earlier builds after 22516 had this problem. Its all gone away by 23796 that I'm using right now.

[elupus]

I've seen it.. some ass subs really kill video playback performance. The problem is that they can end up being a really huge upload if you run at high resolution and they cover a large portion of the screen.

[joshuass]

Another thing to probably consider is if you are using VDAPU for linux, how does that rendering and decoding pipeline handle styled subs. I've done a ton of reading on the Windows side of things and all my research suggests that any sort of inserting of styled subs into the rendering pipeline is a no-no. SRT and other text based subs work, but not the fancy ones that use the SSA/ASS specifications.

[qnox]

First of all - thank you for answers!

Normally I'm running MB with IGM HD4200 and for that hardware I've got this issue: no mater what format I have subtitles and no mater is movie is SD/HD. Also I doubt its performance issue, becouse on my hardware playing 1080p MKV I've got 70% on one core, 20% on second.

Today I've putted spare NVIDIA 9400GT card into my HTPC and I've do some testing - it seems, that no mater if I use VDPUA or not, for NVIDIA card subtitles are dispalying without any impact on video FPS.

So it's look like ATI driver issue - I'm sure that it was OK some time ago, but unfortunetly I'm not used to watch movies with subtitles, so I discover that problem when my wife complains about some tvshow she's watching