[Theora] will there be theora_decode_RGBout() ?

Markus Meyer meyer at mesw.de
Thu Jun 30 11:39:19 PDT 2005


When I experimented with Theora, I used the discussion on

http://www.fourcc.org/fccyvrgb.php

to build my own formulas, which worked well. This is actually the first 
search result on Google when you search for "yuv to rgb conversion". Be 
sure to check out the link to Microsoft MSDN at the bottom, too. The 
page also has a good discussion on why there are sometimes different 
formulas used and what you can do to speed up calculation.


Markus

david kment schrieb:

>i allready looked at the 3 different players, and they all use SDL, displaying directly to a YUV surface.
>
>i allready have taken a look at some code to convert a plain YUV (YCbCr) pixel to RGB,
>but what confuses me is the information that uncompressed YUV is just half the size of 24 bit RGB
>(don't know whether this is correct).
>
>the problem is that my application cannot display YUV images, and converting to 24 bit RGB is essential.
>
>so, how can i access the yuv buffer, to get the right value for each single pixel, which then can be converted?
>is it simply Y & U & V representing a non-interleaved pixel series?
>
>thanks,
>
>---david
>
>
>Markus Meyer <meyer at mesw.de> schrieb am 30.06.05 13:51:35:
>  
>
>>Hi David,
>>
>>just look at the example player in Theora CVS, it should explain all 
>>important concepts.
>>
>>
>>Markus
>>
>>david kment schrieb:
>>
>>    
>>
>>>hi folks!
>>>
>>>i would like to know whether there will be some function to decode to some plain 24 bit RGB buffer in the future.
>>>
>>>i think this feature is sometimes important, especially when using different surface layers, or when modifying
>>>the buffer in realtime.
>>>
>>>if this feature will definitely not be, could someone tell me how i can convert to some RGB buffer in realtime?
>>>i already tried different example codes, but i did not succeed, since i do not seem to understand the way the YCbCr data works....
>>>
>>>thanks a lot in advance,
>>>
>>>
>>>---david
>>>
>>>
>>>
>>>
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>>>
>>>      
>>>
>
>
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