[mythtv-users] Viktor's Bob deint patch for interlaced modelines

[Michael T. Dean]

On 03/22/2008 02:39 PM, Seth Daniel wrote:
> On Sat, Mar 22, 2008 at 11:43:08AM -0400, Tom Dexter wrote:
>   
>> On Tue, Jan 29, 2008 at 6:43 PM, Seth Daniel <mythtv.org at sethdaniel.org> wrote:
>>     
>>> On Tue, Jan 29, 2008 at 05:15:02PM -0500, Tom Dexter wrote:
>>>  [...snip...]
>>>
>>>       
>>>> By the way...do you know offhand if that patch still works in trunk?
>>>>         
>>>  > If there's no better alternative when 0.21 comes out I'd still like to
>>>  > use it.
>>>
>>>  Viktor's patch works on trunk.  I'm using it on trunk now.
>>>
>>>       
>
> [...]
>   
>> I'm replying to an older post here.  I'm waiting for a stable Gentoo
>> 0.21 ebuild before I upgrade.  I was reading about playback profiles
>> here:
>>
>> http://www.mythtv.org/wiki/index.php/Playback_profiles
>>
>> Currently on 0.20.2 (using the above patch) I'm using libmpeg2 (no
>> XvMC) and bob deinterlacing outputting at 1080i.  Once I upgrade I
>> have no reason I'm aware of of to use anything more complex in the way
>> of profiles.  If I create a profile group with a single playback
>> profile using a resolution "> 0 0", libmpeg2, xv-blit, and bob
>> deinterlacing, should it just work like my current configuration?
>> Some of the things I'm reading here, especially regarding performance
>> etc have me a little concerned.
>>     

Wow.  You did read that page as you even have the terminology (playback 
profile groups vs playback profiles) correct.  :)

In short, though, yes--assuming you choose the right settings and that 
your system is actually using what you think it's currently using.

> I run HEAD so my setup isn't _exactly_ like yours.  Should you upgrade to
> 0.21 the first thing you will probably want to do is get rid of all of
> the new playback profiles that are created.

Actually, better would be to do as suggested on the wiki page--leave the 
example profile groups for reference and create a new profile group 
(i.e. 'Custom XvMC Simple' or whatever).

>   Why?  Well, I discovered
> that new profiles were created: High Quality, Low Quality, ...  The old
> profiles still existed also: cpu++, cpu--, etc...  I kept updating cpu++
> assuming it was the profile being used...I was wrong.  I started seeing
> a performance degradation in my playback and it turns out this was
> because the 'High Quality' profile was being used.

If your profile group specifies no valid profiles, Myth will fall back 
to using whatever will work (which may, in fact, be similar to the 
setting in High Quality).

>   The 'High Quality'
> profile uses the 'Linear Blend' deinterlacer which, as I'm sure you
> know, doesn't work well with our setup.  We need to use Bob (or possibly
> Yadif, but I haven't tried that yet).  Anyway, I deleted *all* the
> profiles and created a single new profile that had all the correct
> settings (xv-blit, bob(2x), etc...).
>
> Read this thread if you have not done so already:
> http://www.gossamer-threads.com/lists/mythtv/users/323483?search_string=WTF;#323483
>
> It explains about the new profiles.  If I had not read that I never
> would have known what to do to fix my playback issues.

Just to mention, some of that info has gone into the Playback Profiles 
wiki page.

>> Also, would there be any advantage to using ffmpeg over libmpeg2?  For
>> example, does ffmpeg support closed captions?  That's one of the few
>> downsides of libmpeg2 I've run into.
>>     
> I've never used anything other than ffmpeg.  I can't comment on CC since
> I've never used that.  Sorry.  Occasionally I've briefly switched from
> ffmpeg to libmpeg2 but I never can tell a difference between the two.
>   

ffmpeg supports CC, libmpeg2 doesn't.  Plus, libmpeg2 may require more 
resources on some systems and is much less stable than ffmpeg.  I highly 
recommend ffmpeg (and a processor sufficiently powerful to use it ;).

Mike