[mythtv-users] Troubleshooting video problems on my combined FE/BE

[Michael T. Dean]

On 03/13/2015 11:41 AM, Mike Perkins wrote:
> On 13/03/15 15:22, Hika van den Hoven wrote:
>> Friday, March 13, 2015, 4:10:44 PM, you wrote:
>>> On Thu, Mar 12, 2015 at 4:29 PM, Mark Perkins wrote:
>>>>
>>>> I'm finding that constant swapping between progressive and 
>>>> interlaced very
>>>> odd. Do you get those messages on the non-stuttering frontend? Does 
>>>> the
>>>> recording play stutter free on the main frontend if you use another 
>>>> player
>>>> like VLC? What does mediainfo say about the file?
>>>>
>>>> It is not uncommon for the format to change at commercial breaks 
>>>> and the
>>>> like but the messages above seem to indicate it is changing every few
>>>> seconds and sometimes every few frames!
>>>>
>>> I began writing this email about two hours ago with all of my efforts.
>>> Basically, when I hooked up my FE/BE to my analog KVM and then 
>>> directly to
>>> my usual computer monitor, the stuttering went away in all programs I
>>> tried.  I was getting stuttering in Kodi, Plex Home Theater, Myth 
>>> videos,
>>> I'm sure everywhere else, too.
>>> I finally started looking at settings on the TV.  I wound up 
>>> changing the
>>> Game Mode setting to On.  The TV says there is a reduction in image
>>> quality, but I can't see it.  The stuttering seems to have gone 
>>> away.  I
>>> can't find it now, so I am satisfied.
>>> So if you have a Samsung later model TV and you experience 
>>> stuttering, try
>>> setting Game Mode to On.
>>> Should I put this in the wiki somewhere?
>>> Thanks to Mark and Hika for the help!
>>
>> It sounds logical, gaming needs faster response.
>> As far as I can think, the only thing that could get changed this way
>> is your resolution and possibly the refresh rate. I guess it now sends
>> other edid info to the computer.
>>
> In theory it should also eliminate overscan, which is a feature that 
> belongs in the analog age.
>
> When your incoming signal is a known 720 or 1280 digital signal, and 
> the tv is flat-screen digital with individual pixel addressing, why on 
> Earth did anybody think overscan was a good idea?
>

On Samsung TVs, setting Game mode eliminates the TV's processing of the 
signal--so you get exactly the output that X/MythTV gives without your 
TV screwing it up (to "make it better").  The processing goes quite a 
bit farther than just overscan, so it's a very noticeable difference.  
As a matter of fact, if you're sensitive to sync issues and you're using 
something other than the TV speakers for audio output, you may even see 
an A/V sync difference because of all the time the TV spends processing 
the video before displaying it.

Mike