[mythtv-users] Using the transcoder to cut commercials...

[hayward at slothmud.org]

I've noticed that many people have asked about cutting commercials without 
re-encoding (looking in the archives), but I didn't see a real solution 
being discussed there.

Then I noticed that the misc section of the MythTV documentation says:
==================================================
The transcoder can be used in two ways:

    * Automatically re-encode every file once it has completed recording
    * After marking commercials, the transcoder can be run manually to 
delete the commercials from the file (thus further saving space)

[...]

The second method can be used on files that have already been transcoded 
(or files which were are already in the correct format), so only the 
frames immediately following a cut section will be re-encoded, resulting 
in a very minimal loss of quality.
==================================================

How large of a section after a cut is re-encoded? (e.g. how many 
frames?)

I understand that I must load the cut list (M, Z - then adjust the 
cutpoints to be correct).  Then I understand that I use "X" to queue the 
program for transcoding...

But how do I ensure transcoding wont' re-encode the whole thing?  The 
mythtv Transcoder is a bit of black-magic to those who aren't really that 
familiar with it.

There are two profiles (mpeg4/mpeg2) for the MythTV transcoder, how do I 
make sure it uses the correct one and doesn't re-encode my mpeg2 to mpeg4?

Do I have to make sure the MPEG2 Transcoder settings are correct, or will 
the fact that the file is already ANY form of MPEG2 keep it from 
re-encoding the file?

Also - The audio format is set to MP2 Layer 3.  I don't want MP3 audio - 
but if I'm not going to have the entire file transcoded, does it matter 
what it's set to?

Thanks,
Brian Hayward