[Ffmpeg-devel] [PATCH] Vorbis decoder

Mike Melanson mike
Thu May 12 18:26:36 CEST 2005


Balatoni Denes wrote:
> It is a somewhat twisted idea that a perceptual audio codec with 16 bits 
> precission would need so many bits. In the case of Vorbis the spec. allows 48 
> bits of precision, and in fact tremor uses an optimized floating point 
> implementation (the idea: many numbers share the same exponent). In practice 
> however (looking at the current encoder) 32 bits are more than enough for the 
> decoder, but this could change. 

	I fail to remember which step in the decoding recipe mentions it (dot 
product?), but I know that the Vorbis decoder spec notes that the 
product of one particular multiplication can overflow a 32-bit variable.

-- 
	-Mike Melanson





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