[mythtv] FYI Tuning patch

[Jim]

Thanks again!
FYI - testing using patch6 against revision 7306 using default 
signal/channel timeouts

recording/playback/scanning - digital/analog - working well.
Live tv tuning between on-air channels now consistenly 5-6s
Tuning from viewing an off-air channel to an on-air channel now ~17s, 
occasionally 22 or 30+s - again no obvious correlation between the 
channels involved and the timings.

Two minor bugs:
a) the UK currently has two channels with apostrophes embedded in the name 
picked up by the scan - (UKTV Br'tIdeas & Teachers' TV)  the code in 
TVRec::DoGetNextChannel  now uses ' in the select statement which breaks 
with the embedded ' 
b) channels can only be changed in one direction, this seems to be because
TVRec::TuningFrequency calls GetNextChannel using a direction computed 
from the channum string after stripping out  "NextChannel"
int dir = channum.right(channum.length() - 15).toInt();
I think this should be 
int dir = channum.right(channum.length() - 11).toInt();


Its harder to get consistent timings at the moment because front-end cpu 
load has increased (<~35% at 6910 to > 84% now) to the extent that the 
code in NuppelVideoPlayer::DisplayNormalFrame
invoking "playing slower due to falling behind..."  is now being invoked.

( The effect here is probably not what was intended because cpu load 
reduces a little when it plays slower so the "Playing at normal speed from 
falling behind..." is triggered - which takes cpu load up and we go round 
again :)  - which also means the osd displaying the timing is almost 
always visible. 
A secondary consequence is that the only way to exit is to change channel 
as the exit request is ignored whilst the above is happening)


This was on:- 2.6.12-rc4, Avermedia 771 = bt8xx, pvr250, epia 10k, 
frontend/backend on same box.