[FFmpeg-devel] [RFC] Channel layouts

Benjamin Larsson banan
Fri Aug 29 11:08:03 CEST 2008


Peter Ross wrote:
>> permutation table to match the internal FFmpeg channel order. I'm not 
>> sure how well that would fit for most decoders. One other option would 
>> be to decode in codec native order and then pass a channel permutation 
>> table via some means. I'll look into what would work best with dca.
>>     
> If that is correct then all decoders and encoder need a channel order
>
> Why not perform the permutation inside the decoder?
>   

Yeah, the issue I'm hinting at is that you might only know how to 
reorder after you decoded the samples and that you would need to do a 
memcopy to rearrange the order.


>   
>>> Is there any benefit to doing all the bit shifting of the flags or can
>>> we just do the usual 0x1, 0x2, 0x4, 0x8, 0x10, 0x20... that we use for
>>> other bit mask flags?
>>>   
>>>       
>> I think we just should add the relevant channel mask instead having this 
>> shifting.
>>     
>
> If you can suggest another method to associate an ascii name to each channel
> masks (for the purpose of user friendly i/o), then I am happy to change...
>   

Well we could just add another table. But that is not a large issue.

MvH
Benjamin Larsson






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