DLNA and Lip Sync problems

LucianH

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Please can any of you help me understand some of the basics of DLNA so I can work out why I've got some lip sync problems.

To start, my set up is:

- Panasonic BDT110 Blue Ray player
- Samsung 46" 7000 series LED TV connected to the BDT110 via HMDI
- A 10yr old Yamaha RX-V620RDS connected to the BDT110 via optical

I’ve disabled the HDMI audio output from the BDT110 and have determined that I need to set an 80ms audio delay to achieve lip sync when viewing BluRays. (I’m assuming that I need this to take into account video processing delays through the Samsung TV - is this correct?).

Now to the DLNA bit. I have a Windows XP PC and I’ve connected the BTD110 via a network cable to a Netgear Broadband Rx and Router. It should be noted that I really only want to use the DLNA function to view video files.

I’ve tried a few of DLNA servers including Samsung’s Allshare (extremely bloated and buggy) and Twonky (still appears bloated). I’ve ended up using Serviio which looks like it provides the basics that I need (the server functions).

Now the problem is that I’m getting lip sync problems when viewing video files via the BDT110 (the lip sync problem was the same between Twonky and Serviio). Now, what I don’t understand is why would there be different lip syncs when playing video files and BluRays through the BDT110.

It should be noted that I don’t have lip sync problems if I view the video files on the PC with Media Player.

This leads to a number of questions

What role does the DLNA server play when viewing video files? Does it just stream the “raw” mpeg data to the BDT110 or does it do any decoding/encoding stuff that could introduce lip sync problems?

Could there be different lip sync timings depending on the video file encoding method?

I know there are loads of threads related to lip sync probems so aplogies if this is covered elsewhere.

By the way, and just as an observation, I’ve tried using the “Smart TV” function of the Samsung TV (having connected it to my network via a cable) but found that the file viewing functions to be very poor – you can’t fast-forward or rewind for example.
 
The DLNA server if it supports transcoding will convert the video stream in real time so it plays on the device if it does not support the original codec, the loss of audio sync might be down to transcoding problems, perhaps the CPU on the PC cannot do it fast enough or there is some issue with the transcoded output the BDT110 has with it. What kind of CPU does your PC have ?

The fast forward rewind is a mess with Samsung they have their own version of DLNA (it's a horribly broken standard) if you apply the Samsung C/D series profile to the TV's IP address in Serviio (click generic DLNA profile text) I believe that will solve the fast forward/rewind issue.
 
nearly all forms of lip sync are to do with the tv's video processing, as you mention, if you can turn features off, or completely - to test - then this would rule this side of things out - if it does, then you can decide if going forward you are prepared to disable them/all to have sync

unfortunately, i always found that even if you narrow it down to the sets processing (ie, you keep the tv processing on, and adjust delay), that itself never seems to remain a constant, you can dial in your sources to compensate etc, but will eventually find something that evades that rule, so its constant game of cat and mouse (at least in my experience)

thats why i have disabled all processing, i can live without that looming over me and enjoy perfect video and lip sync, which research says you trust the story, plot and characters and enjoy the content more when lip sync is spot on, off slightly, although maybe not noticeable greatly, can undermine the material you watch on a subconscious level - very important thing

of course, as mentioned, it can be down to video files being wrong intrinsically, with delays hardcoded

i doubt dlna is the issue, certainly if its just streaming content without recoding, if recoding, and tv is ruled out then the server side software and hardware needs to be looked into
 

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