[FFmpeg-devel] [PATCH] atrac decoder

[Michael Niedermayer]

On Tue, Jun 09, 2009 at 02:30:11PM +0200, Benjamin Larsson wrote:
> Michael Niedermayer wrote:
>> On Tue, Jun 09, 2009 at 11:00:38AM +0200, Benjamin Larsson wrote:
>>   
>>> Michael Niedermayer wrote:
>>>     
>> [...]
>>   
>>>>         
>>>>> +
>>>>> +    ff_imdct_calc(mdct_context,out,spec);
>>>>>             
>>>> cant imdct_half be used?
>>>>         
>>> If you/someone explain what imdct_half does. I need the complete output 
>>> from the imdct per my understanding.
>>>     
>>
>> the complete output is the half output twice
>> see ff_imdct_calc_c()
>>
>>   
>
> Ok, now I get it. The actual transform has symmetries but the complete 
> output isn't calculated at the time. So that job is passed on to 
> vector_fmul_window which does what the last part of imdct_calc did before. 
> But this change needs a complete mdct window so I won't be able to remove 
> the multiplication by 0 and 1. It should cut the size of the windows in 
> half though. Is that good enough ?

maybe ...

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The educated differ from the uneducated as much as the living from the
dead. -- Aristotle 
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