[mythtv-users] commercial flagging questions

[Fred Squires]

On Thu, Mar 27, 2008 at 2:49 PM, Dan Ritter <dsr-myth at tao.merseine.nu> wrote:
> On Thu, Mar 27, 2008 at 11:05:54AM -0700, Yeechang Lee wrote:
>  > bungle <nabble.e.wuuza at xoxy.net> says:
>  > > According to my latest results, [comskip] seems less than twice as
>  > > fast, so skipping every other frame (which probably wouldn't miss
>  > > much) could easily account for a lot of that.
>  >
>  > The skip-every-other-frame idea does sound interesting; in this
>  > non-coder's mind it sounds like an easy way to significantly improve
>  > performance on a task that doesn't seem to require that every single
>  > frame be examined. Heck, even one frame per second or half second
>  > sounds usable. Or am I missing something obvious? It's not like
>  > mythcommflag's performance is really lacking anything as things stand,
>  > at least on my setup.
>
>  Indeed, is it reasonable to examine every Nth frame, and if it
>  looks like a transition has occurred, move back N frames and
>  examine every one for the break?

That might work.  I don't think only examining once per second or half
second would be a good choice.
Usually if I manually cut commercials skipping by seconds will find a
blank frame, and if not half seconds will, but sometimes the blank
frames at the beginnings and ends of commercial breaks are only a few
frames long or even as little as a single frame.  That might not mess
up all the detection methods but I don't think blank frame detection
would like it very much.

-- 
It was supposed to be so Easy.