Matt Moore

C++

Linux » Audio/Video Playback Too Fast In Linux (Ubuntu 14.04)

Sep 21, 2014

I just discovered an issue with audio/video playback (including during gaming): setting the audio output to HDMI speeds up the audio/video playback by 10%-20% (I'm guessing about the exact percent here as I didn't actually measure it. I'm just going by my ear).

Apparently this is due to changes in the Linux kernel related to Intel chipsets. The issue appears to be fixed in kernel 3.16, but that's not available yet in Ubuntu 14.04 (as of this post). To fix the timing issue, you can disable the new power features until 3.16 is available - or until Ubuntu 14.10 or possibly 14.04.2. Launch the command prompt and edit /etc/default/grub:

$ sudo vim /etc/default/grub

Go to the line that contains "GRUB_CMDLINE_LINUX_DEFAULT". At the end you should see "quiet splash". Right after splash (include a space after splash) enter the following:

i915.disable_power_well=0

Your line should look something like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.disable_power_well=0"

Save the file and then run this command:

$ sudo update-grub

Now reboot your machine. The "HDMI chipmunk" issue should be resolved. Audio/video should play back properly.