[mythtv-users] Transcode script for pillar boxed SDTV broadcasts on HDTV

Patrick Wagstrom patrick at wagstrom.net
Tue May 29 19:17:49 UTC 2007

Steve Greene wrote:
> Everyone has probably seen pillarbox broadcasts on HDTV.  Because of the
> upsampling, they are still better than the analog broadcasts.  Does
> anyone have a script to eliminate the pillar box and create DVD-ready
> files?  Are the developers working on a solution for MythDVD?

see ticket 2581 for something quite related


I'm partial to this, because I wrote the patch and filed the bug. 
Basically, it allows you to define multiple transcoders that have a set 
aspect ratio.  For example, if you set the transcoder to be 4:3 ratio 
and if it gets 16:9 input, it will just take the middle portion of the 
screen and cut off the pillarboxes.  If it's 4:3 input, it leaves the 
ratio unchanged.  Likewise, it works in reverse and can compensate for 
letterboxed content broadcast in 4:3.

The videos are then transcoded just like any other video is transcoded 
within MythTV.  Just flag the commercials, then tell it to transcode 
using autodetect[1].  So, if DVD export works for MPEG4 on your system, 
then you'll get the correct aspect ratio.

I've been using it for the last 8 months on my system and my analog 
tuner is now idle most of the time, the SD over HD is just better.

Of course, as a downside, not everything is exposed in the UI, but it's 
a start.  I utilize a cronjob that periodically goes and changes the 
transcoders for shows that I know to be pillorboxed.  For other 
programs, I need to go in by hand and do some SQL hackery, but I can 
share the script if folks want it.  Here's hoping that mentioning it 
will give the patch another kick for the devs and other folks to look at it.


[1] Provided you've run the script I mentioned later in this email. I 
tried to hack up a UI that allows you to actually pick your transcoder, 
but at the time the transcoders were hardcoded and each had separate 
functions in the source.  It burned my eyes and I figured I could do it 
with a shell script faster.

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