[mythtv-users] Patches that improve mythcommflag accuracy

[Karl Newman]

On Thu, Nov 20, 2014 at 10:37 PM, faginbagin <mythtv at hbuus.com> wrote:

> On 11/18/2014 1:24 PM, Carl Hunter wrote:
> > On 10/29/2014 6:48 AM, Carl Hunter wrote:
> >>     Yes, I still get the numerous decoding errors not just the one at
> >>     the end.  My HD recordings show one error at the end but still
> >>     detect commercials fine.  I'll look into changing the recording
> >>     settings some more.  Your point about different kernels has me
> >>     questioning things too.  I have a test box running Mythbuntu 11.10
> >>     with Myth 0.24 on it.  I'll see if I can update the kernel on that
> >>     one and compare results.
> >>
> >>     Yes, I'm using HVR-1600's.  Sorry for the typo.  When using the
> >>     analog side of the card mythcommflag fails the same way on those
> >>     recordings.  I also record using the S-Video and RCA inputs
> >>     depending on the different set-ups I've got, not the "cable" input.
> >>     Not sure if that makes a difference with my recordings either.  I
> >>     wonder if the part that "combines" the audio and video on these
> >>     cards has changed with new kernel drivers.
> >>
> >>     Thanks
> >>
> >>     Carl
> >>
> >>
> > I've been using these patches ever since your PVR-150 typecast fix was
> added to 0.27-fixes and have only seen positive results.  My testing is
> only "watching" recordings.  HD recordings still seem to be fine but SD
> recordings are much better.  Where I wasn't getting any commercial flags
> even after running the rebuild on the recordings I'm now getting the right
> number of flagged commercials.  Not all "marks" are perfect but they're
> definitely on par with Myth 0.24 if not better.  So what's the next step to
> get this added to the 0.27-fixes branch?  Have you seen any negative
> results?
> >
> > Thanks again for all your work.
> >
> > Carl
>
> Hi Carl,
>
> I'm glad my patches are working well for you. They are being reviewed by
> one of the devs. I believe his initial testing has been mostly positive,
> although he's got one recording where accuracy dropped by about half. I've
> shared a patch that helps that one recording, but doesn't help others. So
> ...
>
> Anyone else have feedback on the patches?
>
> Regards,
> Helen
>

I think they are a definite improvement for my PVR-500 recordings. I don't
think it's quite back to the accuracy it had in 0.24, but that's a high bar
to clear. Comm flagging struggles a bit with The Daily Show (even in 0.24
it had both false positives and negatives), but that may be a challenge
anyway due to the format of the show. By the way, on a lot of channels the
logo extends into the letterbox bars; I know one of your patches adjusts
the border for the logo detection; I didn't quite understand the formulas
you had for the different resolutions though. For my 480i recordings, I
think it ends up being like 2 pixels (but maybe that applies to the
low-resolution decode used for comm flagging, if I understand correctly).

Karl
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