[mythtv-users] Lossless Cut and keyframes

[Doug Vaughan]

Ian,
Most of your questions are answered in detail in the wiki:

1) Lossless Cut is totally dependant on accurate keyfames for the 
recording. Database records are written at record time which have those 
keyframevalues.  This means if you did any processing (transcoding) on 
the recorded file after it was recorded by MythTV then the keyframes are 
inaccurate.
2) Use of Keyframe Adjust:
http://www.mythtv.org/wiki/Lossless_Cut#Keyframe_Adjustment_of_Cut_and_Skip_Lists
3) There are three ways to use Lossless Cut and two are non-destructive. 
That means you can happily adjust you cut points and re-cut endlessly. 
Unfortunitely it sounds like youused the "-r" replace option which is a 
one way trip. The cut points in the DB and some other records are no 
longer valid for a replaced video file so they are removed.
Please read these two wiki sections:
a) Suggested workflow: 
http://www.mythtv.org/wiki/Lossless_Cut#Lossless_Cut_Work_Flow
b) The three method of applying a Lossless Cut: 
http://www.mythtv.org/wiki/Lossless_Cut#Loss_Less_Cut_user_jobs

I have one user with aHDHomerun who has had Lossless Cut issues with 
recordings from specific channels but never had issues with the cuts not 
being accurate. Read and apply the references above. If you still get 
innacurate cuts from an unchanged/modified recording then file a bug 
report with me:
See: http://www.mythtv.org/wiki/Lossless_Cut#Bug_Reporting

Thanks

Doug