[mythtv-users] PDA Transcode: new install featureforpdatranscode.pl

[David Fishburn]

> > I've just uploaded a new version of my "pdatranscode.pl" 
> > script that now includes code for handling the MySQL 
> updates needed to 
> > set up a User Job.
> > Setting up pdatranscode.pl to run as a User Job now can be 
> as easy as 
> > running
> >   pdatranscode.pl --install-job-number 1
> > 
> > I've updated the wiki with more info
> >   http://www.mythtv.org/wiki/index.php/Transcoding_for_the_PDA
> > and the script, as usual, is here:
> >   http://www.tux.org/~peterw/linux/pdatranscode.pl.txt
> > 
> 
> Peter, I was just reading through your changes to the wiki:
> 
> ***
> Then I create a script call "pdatranscode" and put it in 
> "/usr/local/bin". I have two methods to transcode here. The 
> first one uses mythtranscode's low quality transcoder (number 
> 29 on my system). I have low quality set to 320x240 with a 
> 300k bitrate. An hour long show came out to 136M. The second 
> method uses mencoder. Mencoder produced a show 145M in size. 
> Uncomment whichever you prefer to use.
> ***
> 
> I am trying to automatically transcode these shows for a Sony PSP.
> I was hoping to automatically cut the commericials before I transcode.
> 
> You mention above you set mythtranscode low quality to 300k bitrate.
> I see you can do this by moving the slider down to 300 from 
> Utilities -> Setup -> TV -> Recording Profiles -> Transcoders 
> -> Low Quality
> 
> You also mention you have low quality set at 320x240.  This 
> is not part of the transcoding pieces, so it must be part of 
> (in my case) MPEG-2 Encoders (PVR-500).  But I thought this 
> setting would change the actual recording, rather than the 
> after the fact transcoding.

Okay, after a bit more digging around I also see:
Utilities -> Setup -> TV -> Recording Profiles -> Transcoders -> Low Quality

If you check the "Resize Video while transcoding" the next screen allows you
to choose a size.  So again, aiming for my PSP with a 16:9 aspect ratio I
choose:  368x208.

Video
Codec: MPEG-4
Bitrate: 300
Max quality: 0
Min quality:1
Max quality diff: 1
Scale bitrate: 0
Enabhel high quality: 0
Enable 4MV: 1
Enable Interlaced DCT: 0
Enable Interlaced motion: 0

Audio
Codec: MP3
Sampling rate: 32000 (lowest setting)
MP3 Quality: 1
Volume: 100%


On the website you say:
> The first one uses mythtranscode's low quality transcoder 
> (number 29 on my system)

So I fired up PHPAdmin and browsed the recordingprofiles table and see:
id   	 name   	 videocodec   	 audiocodec   	 profilegroup
29  	Low Quality  	MPEG-4  	MP3  	6

Looking at 6, I went to profilegroups:
id   	 name   	 cardtype   	 is_default   	 hostname
6 	Transcoders 	TRANSCODE 	1 	NULL


So it looks like I also need to use 29 for my mythtranscode line as well.

Next I did the following:
mythtv at myth:~$ mythcommflag --gencutlist --file 1050_20061214153000.mpg
2006-12-15 22:40:03.108 Using runtime prefix = /usr
2006-12-15 22:40:03.455 New DB connection, total: 1
2006-12-15 22:40:03.532 New DB connection, total: 2

mythtranscode --infile 1050_20061214153000.mpg --outfile pda/M4V00006.mp4 -l
-p 29 --showprogress

And I compared this against my mencoder line:
mencoder -aid 0 -oac lavc -ovc lavc -of lavf -lavcopts
aglobal=1:vglobal=1:vcodec=mpeg4:acodec=aac -af lavcresample=24000 -vf
harddup -lavfopts
format=psp:i_certify_that_my_video_stream_does_not_use_b_frames -vf
scale=368:208  -o /media/mythtv/pda/M4V00007.mp4
/media/mythtv/1050_20061214153000.mpg

Here are the size differences:
1,165,664,256 2006-12-14 16:00 1050_20061214153000.mpg
840,593,395 2006-12-15 16:56 M4V00006.mp4
198,335,598 2006-12-15 17:13 M4V00007.mp4

So how are your settings different from mine that gives you these results:
> I have low quality set to 320x240 with a 300k bitrate. 
> An hour long show came out to 136M. 
> The second method uses mencoder. 
> Mencoder produced a show 145M in size. 


Thanks,
Dave