Kodi Community Forum

Full Version: accelerated playback with external audio devices?
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Pages: 1 2
Hello,

All nightlies and the current rc1 of gotham 13.0 result in vastly accelerated and chopped up playback of all video files for me. This discussion leads me to believe that it has to do with external audio interfaces.

I run a 2012 Mac Mini with 10.9.2 and all my sound runs through a Metric Halo 2882 +DSP. I installed xbmc through the downloadable .dmg files. No other applications exhibit this behaviour.

Please find the debug log here: http://pastebin.com/4pGT2Tek

If there's any other information you need, please tell me how to produce it.

Best and thanks for xbmc,
dergit
1. Your device claims it has a single channel. I presume this isn't correct? How many channels does it have?

2. You need to run the builds that Memphiz made available with additional debugging, such as:

http://mirrors.xbmc.org/test-builds/osx/...x86_64.dmg

and grab another Debug Log.
(2014-05-03, 00:57)jmarshall Wrote: [ -> ]1. Your device claims it has a single channel. I presume this isn't correct? How many channels does it have?

This question isn't very easy to answer as it has a DSP processor with very variable routing. My default home use setup just has one stereo output but it can have many more (8 analog ins and outs + various digital ones via ADAT, S/PDIF, AES etc.).

(2014-05-03, 00:57)jmarshall Wrote: [ -> ]2. You need to run the builds that Memphiz made available with additional debugging, such as:

http://mirrors.xbmc.org/test-builds/osx/...x86_64.dmg

and grab another Debug Log.

Thanks for the test build. The good news: the accelerated playback is gone. The bad news: If I set the output to 2.0 I only get sound on the left side. As far as I can gather from the debug log, xbmc only recognises the left channel ("FL" instead of "FL, FR" like with the other audio devices in that log). If I set it to 2.1, playback stutters and I get no sound at all.

Here's the debug log: http://xbmclogs.com/show.php?id=191956

I tried setting up two mono rather than one stereo channel as outputs in the DSP of my interface but the result was the same.

Not sure I've said this before... but it seems worth noting that this behaviour does not occur in 12.3 or any other software.

Thanks for the quick reply,
dergit
I suspect this device requires planar audio (so that the 18 identical streams it's presenting to CoreAudio are likely a single channel each, some of which could be input) but without hardware we're just guessing.

I doubt there'll be any changes to get things working to be honest unless you're prepared to build and debug things yourself. If so, we can give suggestions, but that's about it.

EDIT: Just in case a shot in the blind works, try this branch: https://github.com/jmarshallnz/xbmc/tree/ca_planar

Build will be available on mirrors.xbmc.org under test-builds in about 30mins.

Gotham uses a lower-level API than does Frodo (and most other software) so that we can provide better access for passthrough and the like. This has problems for particular devices such as this which doesn't seem to provide the expected responses to the lower-level CoreAudio interface.

You'll find the default analog output, optical output and HDMI output will all work without issue.

Cheers,
Jonathan
That is very sad news indeed. Sad
Sorry I'm away on business for a few days. I'll try it as soon as I get back (probably Thursday) - thanks for the quick stab in the dark tho! Highly appreciated!
Dear jmarshall,

Thanks for the test build, unfortunately I still get the accelerated playback. Here's the debug log: http://xbmclogs.com/show.php?id=198991

I hope this helps and there's still a chance for me and others using higher end external audio interfaces?
It seems to be working, if it wasn't for the late-night coding snafu... Have fixed. Build is on the way.

EDIT: Here's the fixed build: http://mirrors.xbmc.org/test-builds/osx/...x86_64.dmg

If that works, we'll look at refining it (it's rather hacked in at present!)
Good news first: It's working!
Bad but somewhat unrelated news: it's crashing: http://pastebin.com/wvRVrvvw

Thank you so much for your efforts. I was starting to think I'd have to abandon xbmc if there was no fix for rare cases like mine (I'll admit, audio interfaces at that price point aren't that wide spread).

Just to clarify - does this mean I'll have to skip Gotham and stick with 12.3 until the first release candidates of 14 come out or is there a chance your fix will be implemented into Gotham?

Thanks again,
dergit
Good news is the crash is entirely unrelated to audio. As that's a v14 build, it could be related to the new ffmpeg merge or some such.

The changes will be merged into Gotham 13.2 most likely. The beta for that will come out about a week or so after 13.1 comes out (hopefully 1.5 weeks).

There's a couple more OSX audio related changes, so once they're ironed out we'll merge them into a Gotham branch and get some testing going. That would be your best bet for playing with it, as that'll be Gotham 13.1 + audio fixes.
Saw that crash aswell unrelated to audio - definitly related to swscale/ffmeg.
Very good news - thanks for all your efforts. I'll stick with 12.3 for a little longer then and see what comes.

If you need someone to test anything specific to setups with external audio interfaces, hit me up!
Sorry to bump this back to the top but with the current nightlies (14 alpha 3) I get decelerated playback now... it sound slowed and pitched down a fair bit.
debug log (wiki)
Pages: 1 2