[mythtv-users] confused newbie

Trever Furnish t+mythtv at wondious.com
Wed Aug 18 01:30:33 EDT 2004

Thanks, Cedric, that at least got me started.  Still a bit confused 

Cedric Tefft wrote:

>> The transcode package is installed (although it was NOT installed 
>> when mythtv was compiled) and mythtranscode exists in /usr/local/bin 
>> with the rest of the MythTV binaries.
> This sounds a little suspicious.  I compiled myth 0.15.1 from source 
> and mythtranscode was installed automatically.  What did you have to 
> do to get it installed on your system? 

I compiled 0.15.1 from source, but at the time I hadn't yet installed 
any of the actual transcode package (if that matters).

>> When I select "Begin Transcoding", the menu item changes to "Stop 
>> Transcoding", as though the transcoding process has begin, but it 
>> never changes back, and there's no transcode (or mythtranscode) 
>> process running.
> On my system, it takes several seconds for mythtranscode to appear in 
> the process table.  My assumption is that there's a transcode queue 
> somewhere that's polled periodically by an internal process.  I would 
> check the output of your backend's output for any entries that have to 
> do with transcoding.  Here's a bit of mine (for comparison):
> myth:/var/log/mythtv > grep -i transcod backend
> 2004-08-14 22:53:04 Transcoding from 
> /data/video/store/1240_20040814224600_20040
> 814224600.nuv to 
> /data/video/store/1240_20040814224600_20040814224600.nuv.tmp
> 2004-08-14 22:54:22 Transcoding 
> /data/video/store/1240_20040814224600_2004081422
> 4600.nuv done

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 
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

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) 

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?

> Also, BTW, you didn't mention which TV tuner card you're using.  Does 
> it generate RTJPEG streams?  If it's generating MPEG2 streams, you 
> need to set up the other transcoding profile.
Ah, sorry - Hauppage PVR-250.

>> Maybe the problem is that I'm not understanding how to use the 
>> recording profiles.  I see that I can have multiple recording 
>> profiles, but how do I tell Mythtv to actually use one of the profiles?
> See advanced options when you set up a recording.  There is a 
> 'profile' field.

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

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

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