[vorbis-dev] Suggestion for libvorbisfile: scaling

[Ian Walters]

On Thu, 3 Jan 2002 7:32 pm, Jack Moffitt wrote:
> > My suspicion is that floats are not used internally by ov_read(), and
> > there would be a speed penalty for using ov_read_float().
>
> Vorbis is natively float based.  ov_read_float will be quite a bit
> faster than ov_read, since it won't have the huge float->int conversion,
> etc (note that on x86, the float->int conversion is in assembler so it's
> pretty fast).

Which is a pity from the embedded perspective.  I had a look at porting 
Vorbis to the arm recently  and had no luck getting fast yet listenable 
playback.  I was only using float emulation stuff, not trying to remove 
floats from vorbis.  Unfortunately I won't be able to come back to this for a 
long time, but I was wondering how much the design of vorbis depends on 
floats.  It would be nice to have a audio format like vorbis in the pda arena.

>
> ov_read() 's conversion is still one of the slower functions on decode,
> especially on PPC it seems.
>
> jack.
>
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