This is the process by which MythTV detects commercial breaks in recorded shows and marks jump points in the database so that such breaks can be skipped (or later cut out of the recording during transcoding).
Commflagging can be configured within the 'General' page of 'Utilities/Setup > Setup > TV' in mythfrontend.
Setting the 'Commercial flag new recordings' tickbox enables commflagging for all subsequent recordings that take place on channels which are not set to 'commercial free'.
Commercial skip method: A variety of different methods can be used to detect commercial breaks.
- Blank Frame Detection - is used to determine when a programme fades to black (this invariably happens between show segments)
- Blank Frame & scene change detection - as above but tries to determine that a large amount of the picture has changed
- Scene change detection - tries to determine that a large amount of the picture has changed
- Logo detection - looks for a part of the picture that does not change during a recorded show - i.e. an onscreen logo. Logos are usually removed for the duration of commercial breaks, making them 'easier' to spot.
- All - use all commercial detection methods at the same time
An additional option - 'Strict Commercial Detection' - tightens up the rules used to detect commercials. This should be disabled if commercials are not being detected & marked.
Note: 'Automatically flag commercials' in a show's recording options must be enabled for any method other than 'blank frame detection' to work. That is to say, only blank frame detection flagging will work if commflagging is run as a job at a later date.
Once recordings in MythTV have been flagged for commercials (commflagged), ad-breaks can be skipped.
The End or Z key (by default) jump to the next commercial break marker. The Home or Q (by default) key will jump back to the previous commercial break marker.
Commercial skipping can be enabled on a show-by-show basis by bringing up the OSD menu during playback and selecting a commercial skipping option. Choices given are:
- None - i.e. do nothing when markers are reached
- Notify but do not skip - indicate that a commercial marker has been reached
- Skip automatically - skip between markers automatically
As a default option
Within the 'TV playback' section in mythfrontend's setup menus, there is a 'Commercial Skip' settings page.
Here the options for default actions on commercial flagged recordings can be set:
- Automatically Skip Commercials: None, Notify but do not skip, Skip Automatically
- Commercial skip auto-rewind amount: automatically rewind 'x' seconds after performing a commercial skip
- Commercial skip notify amount: announce a commerial marker has been detected 'x' seconds before the marker
- Skip blank frames after commercials: Automatically skip past the blank frames at the end of a commercial break