Constant audio stutter when using OpenSL ES on Nexus 10

[neatchee]

Greetings!

Just wanted to report that I'm experiencing a constant audio stutter/clicking/crackle when using OpenSL ES audio output on the latest ARMv7 nightly build (03/09/2013). Interestingly, both Native and Java audio output work flawlessly. Hardware accelerated decoding is enabled, but disabled seems to make no difference. I am on a Nexus 10 (Samsung Manta) running the latest CyanogenMOD 10.1

I only use VLC for Android for video, so I have not tested on audio-only files.

The issue appears to be effecting all sources (mkv, avi, dts, aac, any combination of audio/video codecs, both local and network sources)

Logcat is here: https://dl.dropbox.com/u/11321922/log.txt

Let me know if you need any additional information or debugging steps and I'll be happy to provide anything you want.

[neatchee]

Hey guys, it's been almost a week. Can I get either confirmation that this is a known issue, or some indicator as to next steps I should take to narrow down the problem?

Thanks

[funman]

Hello,

Unfortunately nothing suspicious stands out in your log so I don't know what to suggest.

I have a HP Touchpad running CM10 which works fine with OpenSL ES, and another developer has a Nexus 7 which is reported to work fine.

Can you record the output so we have an idea of the artifacts?

dmesg shows something maybe?

[neatchee]

Hi funman,

Thanks for the feedback.

Here is the recording of the audio stutter: https://dl.dropbox.com/u/11321922/clicking.mp3
That was recorded via a network stream (DLNA) of Wreck-It Ralph, x264 at 720p

Here is the dmesg: https://dl.dropbox.com/u/11321922/dmesg.txt
That was taken after attempting to play a local file (Psych S07E03) which also had the stuttering audio. I wanted to make sure I was ruling out any network problems when grabbing the dmesg.

That dmesg seems very telling, considering all the wm8994 errors (the wolfson audio hub)

I should also note here that builds since, I'd guess, 03/10 or so have been showing decreased performance when decoding HD videos. I'm seeing frame drops/video stutter every 5-15 seconds. I would have to go back through the old builds to determine exactly when it started. HW decoding is enabled, and the behavior gets significantly worse without it. With HW decoding disabled, the stuttering has the same frequency, but far more frames are dropped when it happens. I'm fine with addressing the audio issues first and dealing with this secondarily.

Thanks

[funman]

Can you report it to the CM developers?

I looked in linux.git and can not find the messages that you get, I see wm8994* files in drivers/{mfd,gpio,regulator} and I'm not sure which one to look

[neatchee]

I've requested help from the CM guys but there's one thing I want to be sure of...

Are you running CM10 or CM10.1 on your Touchpad? I know that there were some very drastic changes to the audio subsystems in CM10.1, so I want to make sure I'm pointing the CM guys in the right direction.

Thanks

[neatchee]

Hey funman,

I've just confirmed that this issue exists on the STOCK Nexus 10 ROM as well, so this is definitely a VLC or chipset issue and NOT a CM issue.

[funman]

For the record, I would expect a problem in the kernel (which would be shared between google's build and CM's build)