Adjusting Audio/Video Sync

In some cases you may find that the video player cannot get accurate lip-sync. There can be multiple reasons for this:

• The video has broken lip-sync.
• The audio driver that is used for sound playback does not report the audio latency correctly.

In these cases one has to adjust the audio synchronization parameters manually to get the best lip-sync. This is done globally with the environment variable RESONANT_LATENCY, which should be set to numeric value representing the amount of required latency compensation in milliseconds. Typically one needs to figure out this value through experimentation. Typical values are in the range 10-200 milliseconds.

To set the latency compensation to 130 milliseconds, you can use:

Windows command line:
set RESONANT_LATENCY=130

OS X/Linux:
export RESONANT_LATENCY=130

In theory one can also use negative compensation values, but compensation values below zero are not tested or supported.