On Tue, Feb 28, 2012 at 05:31:27AM -0800, Mashiat Sarker Shakkhar wrote:
> 
> 
> ----- Original Message -----
> > From: Christophe Gisquet <[email protected]>
> > To: libav development <[email protected]>
> > Cc: 
> > Sent: Tuesday, February 28, 2012 7:09 PM
> > Subject: Re: [libav-devel] [PATCH] Windows Media Audio Lossless decoder
> > 
> > 2012/2/28 Mashiat Sarker Shakkhar <[email protected]>:
> >>  https://github.com/shahriman/libav/tree/wmall
> > 
> > I was in the process of profiling it. A very quick analysis (I'm
> > sparing you the details) show that
> > first code blocks of lms_update and lms_predict account for more than
> > 60% of the decoding time, while the rest is scattered without clear
> > candidates.
> 
> 
> The code is not really as optimized as it could be, because optimizing
> it wasn't really the first priority and I am not terribly experienced
> at that.
> 
> > 
> > Most operations seems to involve int16_t, so dspizing should not be
> > very difficult (famous last words).
> 
> Intermediate operations require 32-bit integer according to the spec,
> (that is, Pred is int32_t). Ref-code uses 64-bit for some reason that
> I don't understand.

it's hard to understand reference decoder indeed
 
> I don't have experience with SIMD, but will try to write some if that's
> necessary. Priority for now is to implement 24-bit.

Yes, you don't have to worry about SIMD.
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