[mythtv-users] I'm in....

[Boyd II, Willy]

>-----Original Message-----
>From: Torsten Schenkel [mailto:torsten.schenkel at web.de] 
>Sent: Friday, November 14, 2003 9:07 AM
>To: Discussion about mythtv
>Subject: Re: [mythtv-users] I'm in....
>
>
>On Fri, 2003-11-14 at 15:50, bpierce815 at charter.net wrote:
>> On Fri, 14 Nov 2003 06:27:01 -0800 (PST)
>>   Peter Greis <peter_greis at yahoo.com> wrote:
>> >Greetings All,
>> 
>> Greetings
>> 
>> >One observation is that it takes an eternity (4-5
>> >seconds) to change channels. Is anyone else seeing
>> >this ?
>> 
>> I also see that it takes a long time to change channels, I
>> was attributing mine to the slow cpu(C3 Nemiah).  But I am 
>> not sure that this is correct. 
>
>No, the channel change can't be instantaneous. What you are 
>watching is a stream that's been recorded to disk and is 
>played from there. You are usually 3-4 seconds behind, so 
>it'll take this time to change channels. There might be a 
>possibility with playing the first minute a bit slower to 
>accumulate the 4 second buffer, but I don't think I'd like that.
>
>Hint: Use the browse mode! 

One thing I'm still trying to figure out is how this 3,4-second buffer is
determined.  Is it variable, and depending mainly on speed of hardware?  I
know a buffer must exist, not disputing that.  Just wondering about how the
size of the buffer is determined.  Is it simply a matter of the player will
play as soon as it sees data, and 3-4 seconds is the best we can do?  Or is
it stored in some variable in the code, and 3-4 seconds worth of data seemed
reasonable for most systems?  (And I'm actually one that promised to look
through the code and figure this out :-D  I have to admit I haven't gotten
beyond a few basics timing tests in my spare time, so not trying to be a
hypocrite)  Does anyone with a Tivo or ReplayTV see a 3-4 second delay?  For
a hardware encoder, and therefore just a simple player off of /dev/video0,
with modern hardware, I'm surprised that 3-4 seconds is the smaller buffer
that will play reliably.  For software encoding I realize that's a different
story...  but if the buffer is designed around a catch-all solution, maybe
it can be shortened for hardware encoder systems?  

- Willy

>
>> I am also seeing video and
>> audio get a little jumpy when the OSD comes up.  Are you 
>> seeing this as well? What hardware are you running?
>
>This is due to the slow hardware. ME6000 on this side. Got 
>lots better with the pvr350 though.
>
>Torsten
>-- 
>Config files for pvr350 tv-out and framebuffer: 
>http://www-isl.mach.uni-karlsruhe.de/>~hi93/ivtv-pvr-350-conf.tgz
>
>