Hello, I''m still facing the old problem of major A/V skew when changing to HD or Full HD channel.
Encountered on USB DVB-T receiver, using LAV codec for audio and video decoder, Prog demultiplexer. If I switch to any HD channel, audio starts to play first, then 2s pause following video stream. The video delay stays. I tried change many settings but not found one that helps or improves the synchronization. Have anybody any idea how to make it work. I'm fine with SD channels, there video starts immediately just as HD sync is ok with TV card vendor's player (AverTV). Because it I still think the out of sync is problem of ProgDVB or it's wrong settings.

Try watching channel over stream (over Prog Media Server). Try it first with VLC player.
Open Prog Media Server Home (in 'Service' menu) and then click on button with label "Open" just up from button "Close".
Then click on channel that you want to test and download .m3u8 file and open it with VLC.

1. Check CPU usage.
2. Check File->Input traffic->packet lost.

Also possible need other audio codec or audio renderer.

I did check. CPU usage not trespass 12% when switching to HD channel
Minimum lost packets are 0 or very low number.
I think that the audio and video streams get out of sync immediately after switching to HD channel.
Could ProgDVB perform forced A/V streams synchronisation immediately after audio and video buffets fill in and playback starts. There's noticeable video delay on switch while audio starts play almost immediately. Another problem encountered while HD payback is occasional outage of audio stream. Not happening with SD playback.

What makes the trouble harder traceable is that sometimes when switching to HD channel the sync starts almost accurate.