[mythtv-users] LiveTV Channel Browsing Speed (New angle !)

[Scott D. Davilla]

>On Mar 20, 2008, at 10:04 PM, Josh Mastronarde wrote:
>
>>  2)  In parallel, record the current channel to disk as usual
>
>I don't think you would have much luck accessing /dev/video or /dev/
>dvb or whatever in parallel.
>You also have to keep in mind that some people don't have these 
>outrageous delays of a couple of seconds when changing channels. I 
>know mine isn't nearly that bad. I have to wait for the external 
>channel change script to execute and have the satellite box respond.
>After that, it's half a second at most.

My channel change is almost immediate to a Disk301 receiver using the 
PRV-150 blaster. But it takes 1-2 seconds for the video file to 
appear in the storage group directory, then 1-2 seconds more for the 
backend to find it again and then the frontend to buffer and start 
displaying. If the backend flushed the video file immediately rather 
than waiting for it's buffer to fill (direct io for LiveTV on the 
backend), this would eliminate the first 1-2 second delay.

We have to do this for our x-ray spectrum imaging application that 
pulls events from networked hardware or you get a few seconds delay 
before seeing the x-rays on the host.

Just a thought.

Scott