[mythtv-users] Channel changing pause

[Ed W]

> I'm using a 1Gb Athlon with 512 memory as a frontend/backend system. 
> nVidia 5200 graphics card and 2 Nova-T's.
>   


- Myth currently seems to parse the over the air data when tuning, this 
may add a delay while it finds the correct params for a channel (not sure)
- The DVB-T cards usually tune in between 0.1 and 0.5 of a second. 
- Myth then spools the incoming stream to disk
- The spooled video is then piped to the frontend (if it's network 
transfer then you have some buffers in the network layer as well).  
There are a couple of buffers to fill here and myth likes to have these 
buffers so that it can cope with temporary glitches in the supply of data

So the issue is really one of a few millisecs here and there which all 
add up to a fairly sizable delay overall.  To fix it you need to start 
instrumenting the code and figure out where the pauses are.  When I last 
checked there were some chunks of code which were blocking unnecessarily 
and also several buffers could be reduced in size considerably in the 
case of a local frontend. 

However, you need to instrument the code to take this further

Ed W