[FFmpeg-devel] Indeo3 replacement, part 2

[Maxim]

Reimar D?ffinger schrieb:
> On Tue, Sep 22, 2009 at 12:09:23AM +0200, Maxim wrote:
>   
> [...]
>> /**
>>  *  Average 4/8 pixels at once without rounding using softSIMD
>>  */
>> #define AVG_32(dst, src, ref)   AV_WN32((dst), ((AV_RN32(src) + AV_RN32(ref)) >> 1) & 0x7F7F7F7F)
>> #define AVG_64(dst, src, ref)   AV_WN64((dst), ((AV_RN64(src) + AV_RN64(ref)) >> 1) & 0x7F7F7F7F7F7F7F7F)
>>     
>
> Are all of src, dst, ref unaligned in general? If not, you should be
> using casts instead of AV_RN*
>   

Could someone skilled in the art explain me the difference between a
cast and an AV_RNxx?
I don't see any because the AV_RNxx macros use casts as well...
The code above looks more readable for me when using those macros than
smth like this:

#define AVG_64(dst, src, ref) \
        *((uint64_t *)(dst)) = ((*((uint64_t *)(src)) + *((uint64_t
*)(ref))) >> 1) & 0x7F7F7F7F7F7F7F7F

Regards
Maxim