A/V sync issues on DVB Live TV and Recording Playback

Hissing Shark

Hi,

I'm just about there with my Kodi/Tvheadend setup on the Rpi2.

The only issue now is the sync between audio and video. I'm in the UK and this affects SD and HD channels and their recordings.

With live tv it doesn't happen every time, but most of the time. I will start a channel and the audio will continue without problem, but the video will appear to surge/fast-forward for a moment early on, taking it out of sync.

With recordings they may be fine, but if I jump forward that will often break the sync too.

Viewing the recordings on a laptop running VLC under Mint Linux works fine, skipping forward no problem, although after watching a few different files it seems to hang (may be a completely unrelated issue).

I have tried repackaging the SD recordings from a.ts to a.mp4 using ffmpeg and that seems to "fix" them.
I cannot do this with the HD recordings as it gives an error:

http://pastebin.com/raw/fiQbhn9m

I've tried running ffprobe on the recordings.
SD:

http://pastebin.com/raw/yuMUR21G

HD:

http://pastebin.com/raw/tR5YvL0j

I think I've tried all the different Kodi/PVR settings but I may be missing something.

Tvheadend itself is using the default protocol settings of HTSP -> LiveTV and Pass -> Recording.

Originally I was recording to the microSD card and HD recordings were terrible and corrupted, SD ok, even if I transferred them to another device for viewing. I'm now recording to a NAS which has fixed that. Bandwidth doesn't seem a problem having successfully recorded 3 simultaneous HD channels from one tuner/multiplex and 2 HD channels from different tuners.

Any other glitches in live tv, particularly HD were cleaned up my using a powered booster/splitter for my coax. According to my freeview box the signal quality was always 100%, but the booster took the strength up from 22% to 50%.

My setup:
* RPi2 with mpeg2 codec license.
* Sandisk 8GB class 10 microSD (verified with F3)
* Arch Arm Linux
* tvheadend 4.0.8-9~gce82e79 (compiled from AUR)
* kodi-rbp 15.2 (from repo)
* kodi-addon-pvr-hts (compiled from AUR)
* Augustint T210 DVB (on a powered hub)
* PCTV 290e (on a powered hub)
Can anyone please help me jump this final hurdle?

Hissing Shark

I never managed to fix this per se.

I tested OpenElec as I thought it was meant to work "out of the box" and it's true! No audio sync problem!

Couldn't get to the bottom of what made their setup work. But I couldn't stay there either because I use my Rpi for coding, WOL and Retroarch and OE is totally locked down.

Then I tested OSMC. I thought it was just a variation on a theme, but it's not! It's a no frills Debian, but nothing stopping you from adding the packages you need to extend its purpose. Wish I'd realised the difference between OE and OSMC 18 months ago! Although my time on ArchArm has been educational.

I've since put Tvheadend on my headless Rpi2 under RaspianLite and my Kodi/gaming frontend setup is OSMC on an Rpi3.

Job done.

Hiro Protagonist

Have you tried recording as .mkv instead of .ts ?

Brain Ma

It must be a frustrating experience that audio is not synchronous with the video while watching movies or videos. In general, most of the audio sync problem arises from the time axis damage. To fix sync issue, you can transcode the video file (e.g. transcode mkv to mp4) with 3rd party software. http://www.videoconverterfactory.com/tips/audio-sync-problem.html