[mythtv] Commercial Detector questions
Paul Andreassen
paulx at andreassen.com.au
Sat Dec 10 06:02:52 EST 2005
On Sat, 10 Dec 2005 05:45 am, Chris Pinkham wrote:
> > - Australia doesn't have blanks between ads so changed MAX_COMM_LENGTH
> > to match MAX_COMM_BREAK_LENGTH (is this the right thing to do?)
> I think that would accomplish what you want yes. In SVN, you could use
> the undocumented 'CommDetectMaxCommLength' setting in the DB.
Will this ever be a mythtv-setup option, instead of undocumented? Or better
yet autodetected.
> > - Patches to match my global record before of 5 minutes and after 10
> > minutes - Pick format from 5 minutes to last 10 minutes
> > - Move Logo detecting 6 minutes in and if not detected try in 15 minutes
> > in (it maybe more sensible to reduce my before time to 1 minutes)
> With current SVN, we now have the ability to know the program's scheduled
> start and end times in addition to the actual recording's start and end
> times. I think that post-0.19, we could make mythcommflag look inside the
> scheduled timeperiod for the format and logo and not at the actual
> recording start since we may have started recording early. I made a note
> on my TODO to look into this unless you want to take a look at it.
See attached commflag-svn_start_stop_times.patch. This patch hasn't been
compiled so probably has bugs. I'm not sure that the macro MAX is acceptable
MythTV coding style.
> The 6 vs 15 minute thing would have to be able to handle in-progress
> recordings also, so it wouldn't try them unless we were far enough behind.
> For in-progress recordings, we could delay until requiredHeadStart seconds
> past the actual program's scheduled start time to handle the logo
> detection.
I've dropped the second attempt at logo detection because during testing it
wasn't any more successful. It was actual worse on my test video. Even a
third test was useless.
> > Does it make sense to +10 score when format matches? My understanding is
> > format matches mean either show or ad. And format non matches mean ad.
> For this, are you thinking take out the +10 when formatMatch >
> (fbp->frames * .90) and leave in the -10 when formatMatch <
> (fbp->frames * .10)?
>
> Your logic makes sense, we are more sure that something is not part of the
> show if it's format does not match the show so we can -10 there, but
> we aren't as sure what it is if the format does match so why +10 in that
> case. I made a note about this also.
See attached commflag-svn_format-aspect.patch. This patch hasn't been
compiled so probably has bugs. I did test this on 18.1 and it works much
better for my recordings. Aspect changes untested because I don't have them.
The difference in score due to frame block size is because the larger blocks
are more meaningful for this test. Are they?
> Just to give you an idea of what other things I may be looking into
> shortly, here are a few things from my TODO:
>
> * Keep track of min/max brightness found during logo detection so we can
> use that information later to determine what is really a blank screen and
> what is not. (ie, if the min is only 50, we might want to try to
> compensate in some of our other thresholds)
>
> * Fade detection, checking the last X number of frames to see if the
> brightness is constantly increasing or decreasing.
>
> * Better logo detection. I looked into this for a while but haven't messed
> with that code at all recently. Detecting the logo is easy using
> something like sobeil, checking for the logo in each frame after you've
> found what the logo looks like that is the part that is a bit harder since
> we're dealing with video.
I did some basic image processing a uni but nothing like this. Its hard for
me to write code for svn when I'm using 18.1.
Thanks,
Paul
--
-------------- next part --------------
A non-text attachment was scrubbed...
Name: commflag-svn_start_stop_times.patch
Type: text/x-diff
Size: 5698 bytes
Desc: not available
Url : http://mythtv.org/pipermail/mythtv-dev/attachments/20051210/32c3ba7f/commflag-svn_start_stop_times-0001.bin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: commflag-svn_format-aspect.patch
Type: text/x-diff
Size: 4724 bytes
Desc: not available
Url : http://mythtv.org/pipermail/mythtv-dev/attachments/20051210/32c3ba7f/commflag-svn_format-aspect-0001.bin
More information about the mythtv-dev
mailing list