[mythtv] SI/PSIP Parser

Kenneth Aafløy lists at kenneth.aafloy.net
Fri Sep 24 19:25:34 EDT 2004


On Wednesday 22 September 2004 20:19, Daniel Thor Kristjansson wrote:
> ]On my set top ATSC box I have to re-scan from time to time because they
> ]are always changing what minor channels exist and what not, so I
> ]suspect there may be a need for some sort of Auto-PID code instead of
> ]caching PIDs in the DB (Which I don't like the idea of caching PIDs
> ]since it takes almsot no time to get and parse the PAT and PMT).
>
> I've done some timings on this and it only takes a few milliseconds to
> get the PAT & PMT, while it takes 200-300 ms to get the first GOP.
> Unfortunately if you wait for the TVCT that also seems to take 200-300
> ms to come in. This argues for caching the TVCT info in the database.
> We don't want to wait 600 ms just to BEGIN writing the recording to
> disk.
>
> But caching the TVCT isn't so bad since the broadcasters are discouraged
> from changing the subchannel<->programID mapping very often.

Completly agree with you on this, MythTV's tuning/channel changes is slow 
already, and adding to this delay is just lame.

Kenneth


More information about the mythtv-dev mailing list