[maemo-developers] Help with YV12->YUV420 converter

[From: Simon Pickering]

Hi Buck,

> I have not looked at your code, so forgive me if I say something obvious.
>
> The one thing that bit me was the fact that the DSP/toolchain did not
> handle access to data objects larger than 64k, due to 16 bit
> restrictions on the DSP.  My understanding is that later toolchains
> removed those limitations (although I do not know if they ever became
> freely available).   I wrote very ugly workarounds to handle cases
> where pointer values crossed 16bit boundaries.  I worked, but overall
> my code was horribly slow.  If this is news to you, I can provide more
> details.

I'd be interested to see what you did.

When I first started looking at accessing large regions of shared  
memory I may have run up against that 64k limit (I certainly had some  
weird errors). I was advised to never attempt to access memory as an  
array (i.e. ptr[n]) but to always use pointer arithmetic directly  
(i.e. *(ptr + n)) and it seems to have worked thus far.

Cheers for the advice,


Simon