[mythtvnz] reasonably effective commercial detection silence.preset for NZ?

[Adam Bennetts]

On Mon, May 7, 2018 at 3:00 PM James Walker <james.walker.nz at me.com> wrote:

> The tooling I have setup is per this wiki page:
> https://www.mythtv.org/wiki/Commercial_detection_with_silences

> The processing seems to be reasonably light weight and pretty fast. I do
have a quad core backend master sever that just shrugs when 2 such jobs are
processing.  However on older kit I can see how it might be more pushed.

> As to effectiveness - the wiki page “advertises” it as working/workable
in NZ, hence my question to the community.  However having analysed some of
the shows on various channels I can see how tough it will be to get
consistent “okay” results. The methods for fading between shows and
commercials are all over the place.

> I’ve been using the skip facilities for years so no issue returning to
that.  I was just hoping to achieve some processing magic  :-)

> Cheers,
> James.


I had a configured slience.preset but seem to have lost it.... Given I
hadn't noticed it probably wasn't much better than the defaults which I
find much better than nothing. Works reasonably well on prime time shows on
three and prime, Dukes not too bad. 2 is the worst, particularly half hour
shows. Not so great on news shows. It can be disabled per show or channel
but I've never bothered. As with all ad detection routines it is not
perfect, some shows it will pick up all ad breaks, some shows only one or
two. The worst is when it gets an ad break completely wrong and skips some
of the show. if you have auto skip on you need to jump back obviously.

The fading doesn't really matter as much as the number of silences in an ad
break. Short ad breaks are the hardest to deal with, and shows like the
news which have silence between short segments. Most pre-recorded shows
don't have real silences that are clustered like an ad break.

Having the OSD 'ad skip' show up just before an auto ad skip starts works
well with it as it tends to make it more obvious if a skip is too long - I
can't remember the name of this setting.

It doesn't take much effort to install or get working so I'd suggest giving
it a go and see if it works on the shows you watch.

Debug mode gives a lot of info if you want to attempt to configure it.

I use it on an atom based combined backend/frontend and the silence
detections routines take 1 minute to process a 30 minute recording.

Cheers,
Adam.