[MPlayer-users] mythtv "adjust" filter in mplayer?

Michael Doerrie [mplayerhq.hu] cap-x6V4KnGCB0BwcDASvhdEhffq at doerrie.us
Thu Oct 14 17:24:25 CEST 2010


On 10/14/2010 07:24 AM, Lobster wrote:
>  On 14/10/2010 6:46 p.m., Michael Doerrie [mplayerhq.hu] wrote:
>> Can anyone on this list tell me if there is a way to run a string of 
>> filters in mplayer equivalent to running an "adjust" filter in 
>> mythtv?  I have a bt848 card with washed-out colors and need to 
>> correct it.  However, I don't want to record, but need to display in 
>> near real time for playing a video game console, so mythtv can't be 
>> used.  Is this possible?
>
> you will never get the image to display "real time" enough to play a game
> console properly.
Actually the bt848 is very responsive.  I've played many video games on 
it under Windows.  When I bought the card and tested it though Windows, 
there was no noticeable delay when separating the audio/video channels 
and playing one live on a TV.  The only problem I'm having now is 
correcting colors in Linux when using mplayer.
>
> If I was you I would give up and get a proper TV to display it on.
>
> In answer to the filter question, read the manpage under the -vf section.
I had already done so in that I have skimmed the filter descriptions on 
the man page.  The problem is that I'm not an expert on the terminology, 
and can't find any direct term overlap between the description of the 
"adjust" filter for MythTV and any of the Mplayer video filters.  The pp 
filter doesn't appear to have the options I need, and I can not find any 
information about adjusting luma and chroma settings in mplayer.

 From MythTV.org Manual:

    The "adjust" filter

    This filter adjusts the digital values for luma and chroma to ensure
    that they will fall within the ranges specified in the ITU-R601
    standard. By default, this corrects a known problem for the luma
    range used by bt8x8 chips which causes video to look washed out. If
    parameters are passed, there need to be exactly six. However,
    passing a single parameter of "-1" will disable the filter.

    1: luma minimum input value (int) 2: luma maximum input value (int)
    3: luma gamma correction (float) 4: chroma minimum input value (int)
    5: chroma maximum input value (int) 6: chroma gamma correction (float)

    The default bt8x8 correction values are equivalent to
    "16:253:1.0:2:253:1.0". Output ranges are fixed at ITU-R601 values
    (16-235 luma, 16-240 chroma).

How can I set this in mplayer?  Do I need to do this somehow in V4L2?

Michael Doerrie


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