[mythtv] Problem with Via VLD XVMC display and DVB recordings in current CVS: Gaps in video and audio

Terry Barnaby terry1 at beam.ltd.uk
Sat Apr 9 05:41:43 UTC 2005

Ivor Hewitt wrote:
> On Thursday 07 Apr 2005 21:06, Terry Barnaby wrote:
>>The current MythTv CVS version of MythTV has a stange problem with
>>display on my Via M10K box which uses Via VLD XVMC hardware MPEG decode.
>>The Via M10K box is a simple client with a separate server containg DVB
>>Myth CVS after 2005.03.30 has this problem.
>>MythTV CVS before 2005.02.20 is Ok.
>>If I watch an old recording, all is fine.
>>If I watch live TV or a new recording the video and audio seems to
>>have continuous gaps (about 4 per second) resulting in unwatchable/
>>unlistenable output. This results in a start/stop display.
>>There are no special messages from mythfrontend.
>>Watching using another system using software MPEG decode and Xv output
>>all is fine.
>>Could some change to the DVB code have resulted in an MPEG stream that
>>the Via MPEG hardware cannot decode correctly ?
> Hi Terry,
> I've finally updated the code on my epia to current cvs (I've been too busy 
> doing the unichrome-pro drivers, that's my excuse anyway)
> Anyhow I'm getting the same at the moment.
> Changing to record TS reduces the problem slightly, but not much. Can  you 
> confirm if you're recording PS or TS.
> Also I only see this on some transmissions, are you sure that all old 
> recordings are fine and all new recordings are broken?
> Most transmissions are just fine but a specific example is Eastenders which 
> exibits this problem (hey I don't watch it ok!). Could it be some sort of 
> problem with the type of sound stream?
> Regards,
Hi Ivor,

I am recording PS streams.
You are right, it only seems to affect certain channels/transmissions.
BBC1 (at the moment) is affected but BBC2/ITV1 is Ok.

I don't know if "all" my old recordings are fine (I have 400G of
them !), but I think that they are. Also new recordings taken with
the older 2004-02-20 software are fine.

I think the problem must lie with the DVB system, this had a major
change in MythTv at this time. I note some mail-list entries about
"Re: [mythtv] Re: DVB fix?", I wonder if this is related ?
I would have thought that the DVB input system would just record
the PS stream without mods, but maybe it plays around with it ?


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