[FFmpeg-devel] [PATCH] aac: Clip large (legal) PNS/IS values

Alex Converse alex.converse
Fri Oct 9 18:38:17 CEST 2009

On Fri, Oct 9, 2009 at 9:37 AM, Robert Swain <robert.swain at gmail.com> wrote:
> 2009/10/6 Alex Converse <alex.converse at gmail.com>:
>> Large intensity stereo and PNS indices are legal. Clip them instead of
>> erroring out. A magnitude of 100 corresponds to 2^25 so the will most
>> likely result in clipped output anyway.
>> None of the conformance streams fall in the range that need to be clipped.
> Looks OK to me as long as it isn't arbitrary clipping but rather
> something needed/allowed within and specified by the specification.

The clipping is semi-arbitrary. It was designed such that after the
third patch the ranges are the same as regular scalefactors. However
these large vales (even when clipped) should cause cause output
clipping on any streams that aren't purely academic exercises.

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