[mythtvnz] occasionally i get no sound recorded

[Håkon Alstadheim]

Rick Hudson wrote:
> On 7/07/2008 9:53 a.m., Mark van Dijk wrote:
>
>   
>> Help!!  Very occasionally (once every couple of weeks or so) a show will 
>> be recorded without sound!  I will try to play the show later and i 
>> can't hear anything.  playing other shows work fine, and watching live 
>> TV (through MythTV) works fine, but the show itself was recorded without 
>> sound.
>>  
>> The odd thing is that I was recording another show at the same time on 
>> the other channel, and it worked fine (sound and everything).
>>  
>> I have a PVR-500 and am running Mythbuntu 8.04
>>     
>
> I don't know if this is the same thing but I used to have this problem with my 
> PVR-250 and it turned out to be a subtle tuning problem. It seems it's 
> possible to tune to the nominal channel frequencies and always get a good 
> picture but occasionally it won't pick up the sound carrier. Sometimes the 
> sound would chime in part way through the recording, sometimes not at all.
>
> What I did was find out the actual frequencies of the channels and tweak them 
> in steps of 50 kHz or so. I think you can also tell myth to use the nominal 
> frquency by its channel number then fine tune it from there.
>
>   
Same experience here. Problem is worse when the signal is weak, and 
worse under heavy cpu-utilization. I have mostly solved the issue by 
using lower resolution and simpler image-processing, thereby freeing up cpu.