Audio out of sync with video while transcoding

I am currently running tvheadend version 4.2.7-42~gac839c6. While using the saved stream profiles i.e webtv-vp8-vorbis-webm or webtv-h264-aac-mpegts, the audio is out of sync with the video i.e. it starts well then ends up slowing down past the video and remains out of sync.

Is there a way out of this?