[mythtv-users] confused newbie

Cedric Tefft cedric at phreaker.net
Sun Aug 22 03:55:39 EDT 2004

Trever Furnish wrote:

> Well, based on that I increased my logging to 'all' and found the 
> following in the log when I start a transcode:
> 2004-08-18 00:04:47 Transcoding from 
> /mnt/store//1059_20040808063000_20040808070000.nuv to 
> /mnt/store//1059_20040808063000_20040808070000.nuv.tmp
> Input #0, mpeg, from 
> '/mnt/store//1059_20040808063000_20040808070000.nuv':
>  Stream #0.0: Video: mpeg2video, 480x480, 29.97 fps
>  Stream #0.1: Audio: mp2, 48000 Hz, stereo, 384 kb/s
> Unknown video codec: 2004-08-18 00:04:48 Fast-Forwarding from 0 to 1255

This is probably nothing, but I noticed it's reporting the pathnames 
with two slashes '//' between 'store' and the file name.  Might check 
your setup for a trailing slash in your saved programs path.  Worth a 
check, but it's a way long-shot -- probably nothing at all.

> I'm guessing that "Fast-Forwarding from 0 to 1255" isn't a good thing, 
> although even that's a little confusing on a 30-minute (1800 second) 
> recording.

1255 might represent the frame number in which case it's only 
fast-forwarding 40-ish seconds into the program.  Another possibility is 
that it's a byte-offset.  Too lazy to go digging through the code to 
find out for sure.

> Anyone have any clue why it would say "Unknown video codec" given that 
> myth recorded the data and plays the file just fine, and understands 
> enough to create cut-points in the file?

Hmmm...  go into the transcoder recording profiles and make sure neither 
profile has auto-transcode enabled.  Also see 

> Ah, thank you!  So the 'default' profile defines the settings used 
> when the recording isn't started using the Advanced screen?  That 
> makes sense.

Not quite.  The default profile is what's used when you don't change it 
to something else.  The Advanced screen only provides you with the 
ability to view and change this setting.  It's there for every recording 
whether you use the Advanced screen or not.

> But then is there anything I can do to control the quality of the 
> video when watching live tv?  

Yes, change the "Live TV" recording profile.  If you like how your 
recordings look, copy the settings from the "Default" profile into the 
'Live TV' profile.

> The quality of the video from the PVR-250 is noticeably lower than 
> that from a simple tv set sitting next to it - I was hoping there was 
> just a higher-quality setting I had missed.

The main "quality" setting you can control directly is the bitrate, but 
keep in mind that you're never going to get the same quality from an 
analog capture device (like the PVR 250) that you do from the raw TV 
signal due to the extra A/D-->D/A conversion.

- Cedric

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