Include only half the blank frames between commercial breaks

[Jim Stichnoth <stichnot@…>]

When the commercial skiplist is created, I prefer to include a blank interval between program sections (CommSkipAllBlanks=0). Sometimes, though, a small piece of the commercial break gets included. A pretty good compromise is to include half of the blank interval. This patch adds that as a CommSkipAllBlanks option.

Note: The patch addresses all places where the skiplist is adjusted according to the blank sections, but I have only tested the portion in BuildAllMethodsCommList().

[Jim Stichnoth <stichnot@…>]

Updated with commflag_split_blanks_v2.patch after libmythui-osd branch merge.

[Jim Stichnoth <stichnot@…>]

Updated with v3 patch. Following the discussion on the dev list, this version removes the CommSkipAllBlanks setting altogether, and always includes half the blank interval in the non-commercial segment, up to a maximum of MAX_BLANK_FRAMES frames (arbitrarily defined to be 60).

[sphery]

(In [27389]) Show half the blank frames before and after the commercial break.

This allows MythTV to better handle those shows with trailing/leading audio that extends into blank frames. Thanks to Jim S. for this patch, which simplifies configuration and gives a more sensible behavior than either of the previously-selectable behaviors.

Only new recordings/newly-commercial-flagged recordings will be affected by this change.

Closes #8522 by applying patch from Jim S.