[Coco] CoCoFEST! 2009 256-color slideshow (now dithered!)

[Joel Ewy]

Gene Heskett wrote:
> On Sunday 10 January 2010, Joel Ewy wrote:
>   
>> Gene Heskett wrote:
>>     
>>> On Sunday 10 January 2010, Joel Ewy wrote:
>>>       
>>>> John W. Linville wrote:
>>>>         
>>>>> So I learned how to dither images.  Now my 256-color slideshow looks
>>>>> a lot better...
>>>>>
>>>>> 	http://www.youtube.com/watch?v=Tm9yB3xVfbs
>>>>>
>>>>> Enjoy!
>>>>>
>>>>> John
>>>>>           
>>>> That looks really good, John.  The dithering really does help.
>>>>
>>>> JCE
>>>>         
>>> Is the flickering border part of this 256 color mode, or do I have a
>>> viewer problem?
>>>       
>> The flickering border is not intrinsic to the 256 color mode.  John must
>> have put that in there for fun, or to demonstrate that the CoCo can do
>> other things while displaying pictures in this mode, because it is a
>> single, ordinary 640x200 screen, with no palette switching or anything
>> else.  All the colors are artifact colors in the manner of the old PMODE
>> 4.  FWIW, my slideshow doesn't do anything with the borders, and 'view'
>> just makes them black.
>>
>>     
> I get a fairly clear picture for about 15 seconds of each new pix, then the 
> flickering border starts, flashing all colors of the rainbow, while random 
> sections of the image dance a pixel or so in random directions for the final 
> 15 seconds or so.  This is on linux, and I have NDI what decoder is actually 
> in use when I'm watching these.
>
>   

You're watching the YouTube video I assume...  I get the same thing you 
do.  I'm running Ubuntu 8.04 on this machine.  Youtube uses a Flash 
player to play videos.  I have the (nonfree) Adobe flash player 
installed on Ubuntu.  I've never gotten Gnash to work with YouTube 
(which is a shame, because I have a dual G4 Mac running Ubuntu 9.10, and 
there ain't no official Adobe Flash player for Linux PPC, those 
miserable so-and-so's).  It looks the same in Wingdohs XP and Google Chrome.

I suspect the dancing pixels are an artifact (to overload a term) of the 
video compression algorithm.  But this mode looks rock solid on a real, 
honest to gosh NTSC monitor.  Well, as rock solid as 60Hz ever gets.

JCE