[mythtv-users] Is there a good guide on recording profiles somewhere?

[Michael T. Dean]

On 08/29/2004 02:03 PM, Jay R. Ashworth wrote:

>On Sat, Aug 28, 2004 at 07:39:26PM -0400, Dave Bush wrote:
>  
>
>>     I'm getting ever so close to being able to say "Done!" and
>>replace my Tivo with my MythTV box. One thing I've Googled for, but I
>>must not be looking for the right thing, is configuration examples of
>>recording profiles. Specifically I'm looking for ideas on setting up
>>the different recording profiles for use with a PVR-350. Right now
>>they're on the default, and the resulting files are a little large,
>>but space isn't a problem yet.
>>
>>     Ultimately I'd really like to have a low quality setting that
>>uses 1 GB per hour or less, and a higher quality setting that uses 2
>>GB per hour or whatever people recommend.
>>    
>>
>I'll second this.  We're pretty happy with our Default, but less so
>with our Low Quality... and some suggestions on good mpeg2->4
>transcoding parameters would be nice too.
>
>I've put up a couple of pages at MythTV.info that people can post their
>parameters and comments on; they're underneath
>
>http://www.mythtv.info/moin.cgi/UserManual_2fTechnicalDetailsAppendix
>
>It's pretty much a copy and paste kind of thing.
>
>All contributions welcome.  :-)
>  
>
Haven't yet set up an account on the wiki, so I'm posting here.

I've noticed a lot of people using high bitrates with the PVR-x50's, but 
I'm using a pretty low bitrate and getting what I consider to be 
excellent results.  I will admit that I'm coming from about 5 years of 
having only watched TV after recording everything to VHS in EP mode, so 
I'm not the best judge of quality (anything beats an EP VHS recording 
:).  Also, I have a satellite signal piped to the PVR-350 via S-Video 
(but I'm using nVidia GF4MX440 for output for OpenGL and Xv support), so 
signal noise/bad signal quality aren't a problem.

Anyway, I was wondering what someone with a discriminating eye might 
think of my settings.  I'm using a bitrate of 2200 and max bitrate of 
9800 and it seems to give me the best of both worlds--small files and 
good quality.  I'm averaging about 1 1/4 GB/hr.  I've heard that having 
a large range of bitrates tends to stress the encoder, but I got 50 
episodes and 174 hours of Olympics without problems.  Also, I'm using 
640x480, but I can't tell a difference in quality between 480x480, 
640x480, and 720x480.  I might be switching to 720x480 to make DVD 
authoring easier, but...

Also, I'm wondering if the poor quality people have mentioned is 
actually noticeable on the TV or only when transcoding for/playing back 
on a computer (or other progressive display).

BTW, at the bottom is a nice little query that can summarize your 
recording profile information in a compact cross-tab format.  I'm 
posting my data in the standard tabular format because the long-lines of 
the cross-tab don't go well with  text-based mail readers...  (Oh, and 
you should probably stretch your terminal window when running the query.)

+--------------+-------------------+-----------+
| Profile      | name              | value     |
+--------------+-------------------+-----------+
| Default      | width             | 640       |
| Default      | height            | 480       |
| Default      | mpeg2streamtype   | DVD       |
| Default      | mpeg2aspectratio  | 4:3       |
| Default      | mpeg2bitrate      | 2200      |
| Default      | mpeg2maxbitrate   | 9800      |
| Default      | samplerate        | 48000     |
| Default      | mp3quality        | 7         |
| Default      | mpeg2audtype      | Layer II  |
| Default      | mpeg2audbitratel1 | 448       |
| Default      | mpeg2audbitratel2 | 256       |
| Live TV      | width             | 640       |
| Live TV      | height            | 480       |
| Live TV      | mpeg2streamtype   | DVD       |
| Live TV      | mpeg2aspectratio  | 4:3       |
| Live TV      | mpeg2bitrate      | 2200      |
| Live TV      | mpeg2maxbitrate   | 9800      |
| Live TV      | samplerate        | 48000     |
| Live TV      | mp3quality        | 7         |
| Live TV      | mpeg2audtype      | Layer II  |
| Live TV      | mpeg2audbitratel1 | 448       |
| Live TV      | mpeg2audbitratel2 | 256       |
| High Quality | width             | 720       |
| High Quality | height            | 480       |
| High Quality | mpeg2streamtype   | DVD       |
| High Quality | mpeg2aspectratio  | 4:3       |
| High Quality | mpeg2bitrate      | 4400      |
| High Quality | mpeg2maxbitrate   | 9800      |
| High Quality | samplerate        | 48000     |
| High Quality | mp3quality        | 7         |
| High Quality | mpeg2audtype      | Layer II  |
| High Quality | mpeg2audbitratel1 | 448       |
| High Quality | mpeg2audbitratel2 | 384       |
| Low Quality  | width             | 480       |
| Low Quality  | height            | 480       |
| Low Quality  | mpeg2streamtype   | DVD       |
| Low Quality  | mpeg2aspectratio  | 4:3       |
| Low Quality  | mpeg2bitrate      | 2200      |
| Low Quality  | mpeg2maxbitrate   | 4400      |
| Low Quality  | samplerate        | 48000     |
| Low Quality  | mp3quality        | 7         |
| Low Quality  | mpeg2audtype      | Layer II  |
| Low Quality  | mpeg2audbitratel1 | 448       |
| Low Quality  | mpeg2audbitratel2 | 192       |
+--------------+-------------------+-----------+


  SELECT recordingprofiles.name as Profile,
         max(if(codecparams.name = 'width', codecparams.value, '')) as 
Width,
         max(if(codecparams.name = 'height', codecparams.value, '')) as 
Height,
         max(if(codecparams.name = 'mpeg2streamtype', codecparams.value, 
'')) as StreamType,
         max(if(codecparams.name = 'mpeg2aspectratio', 
codecparams.value, '')) as AspectRatio,
         max(if(codecparams.name = 'mpeg2bitrate', codecparams.value, 
'')) as AvgBitrate,
         max(if(codecparams.name = 'mpeg2maxbitrate', codecparams.value, 
'')) as MaxBitrate,
         max(if(codecparams.name = 'samplerate', codecparams.value, '')) 
as AudioSampleRate,
         max(if(codecparams.name = 'mp3quality', codecparams.value, '')) 
as MP3Quality,
         max(if(codecparams.name = 'mpeg2audtype', codecparams.value, 
'')) as MPEG2AudioType,
         max(if(codecparams.name = 'mpeg2audbitratel1', 
codecparams.value, '')) as AudioBitrateL1,
         max(if(codecparams.name = 'mpeg2audbitratel2', 
codecparams.value, '')) as AudioBitrateL2
    FROM recordingprofiles, codecparams
   WHERE recordingprofiles.id = codecparams.profile
     AND codecparams.name IN ('width', 'height', 'mpeg2streamtype',
                            'mpeg2aspectratio', 'mpeg2bitrate',
                            'mpeg2maxbitrate', 'samplerate', 'mp3quality',
                            'mpeg2audtype', 'mpeg2audbitratel1',
                            'mpeg2audbitratel2')
GROUP BY codecparams.profile;