[Ffmpeg-devel] [RFC] IMC decoder

Benjamin Larsson banan
Mon Oct 30 15:25:47 CET 2006

Kostya skrev:
> On Mon, Oct 30, 2006 at 10:39:24AM +0100, Benjamin Larsson wrote:
>> [...]
>> First thanks for cleaning up my code. And here are some comments.
> I learned a bit more of lavc doing this so thanks for opportunity ;)

Wanna learn some more ? The DTS decoder is not yet completly ported :)

> [...]
>> This looks alot like the ffmpeg imdct function with the exception of the 
>> postrotation, window and reorder part. The thing that can be tried is to 
>> like the do_imdct_512 function in the soc ac3 decoder. If that doesn't 
>> work then the transforms aren't identical and the code can't be replaced.
> Well, two issues stopped me:
> a) different prerotating coefficients (and signs)
> b) windowing and output also involve last_fft_im (with updating) and
> untangling it is not trivial to me
> Anyway, feel free to convert it to imdct. I just not dare to do this.

I think it's another MLT based transform if the rotation coefficients 
differ. It looks like they rolled their own MLT transform like cook.

Benjamin Larsson

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