[mythtv] MPEG2: Picture start, but no GOP

John Patrick Poet john at BlueSkyTours.com
Sun Jul 11 19:51:13 EDT 2004

Jason Hoos wrote:

>>In trying to diagnose the problem, it looks to me like there is NEVER a 
>>GOP start indicator.  It looks like it does occationally see  a "Picture 
>>Start" indicator.  The notes at the top of hdtvrecorder.cpp indicate 
>>that Jason Hoos set it up such that a "Picture Start" indicator is "good 
>>enough", but it does not seem to work for my UPN/WB stations.
>>Jason, if you are still on this list, can you give me some  guidance on 
>>what to look for?
>I'm still around, although my time has been a bit limited. :(
>What I remember of this off the top of my head (and it has probably since
>been modified by Doug or Daniel), was that I made changes to the code that
>looked for the GOP frame so that if it didn't find a GOP within a certain
>amount of time, it would start using Picture Start indicators instead.  
>Looking through past mail, I recall that method survived for a while, and
>then mutated into a better method that looked for "Sequence Header Starts"
>instead.  Look for messages in the archives with the subject "better GOP
>detection for HDTV" to follow how things evolved.
>Meanwhile, I'm in the process of finally rebuilding my Myth box and diving
>back into some of this stuff soon...
I will try and track down that thread, thanks.  This really is not that 
critical for me, since the stations in question do not actually 
broadcast in HD yet, but I am curious why Myth has a problem with them.  
Mplayer plays the stream fine, so something is not right.

Welcome back to Myth!


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