fdk-aac

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Jean-Michel Trivi ed247dfa54 Encoder quantizer fix AAC Encoder: Saturate quantizer shift value to prevent undefined behaviour. In very rare cases the shift value 'totalShift = (16-4)-(3*(totalShift>>2))' can be greater than accu data width. If you apply a shift with more then 31 bit the result depends on the architecture and is not defined in C. For certain platforms zeros are shifted in. That would be our desired behaviour. On other platforms the shift will be applied as modulo. For example >>34 would be applied as >>2. To prevent this discrepancy the shift value is limited/saturated to DFRACT_BITS-1. 'accu >>= fixMin(totalShift,DFRACT_BITS-1)'. Bug 9428126 Change-Id: I27177654c4dc22cf899bc35dad9cdd040dccb02d	2013-08-20 15:01:21 -07:00
..
include	Disclaimer update, lib version increment	2013-08-20 14:38:55 -07:00
src	Encoder quantizer fix	2013-08-20 15:01:21 -07:00

Jean-Michel Trivi ed247dfa54 Encoder quantizer fix

AAC Encoder: Saturate quantizer shift value to prevent
  undefined behaviour.

In very rare cases the shift value 'totalShift = (16-4)-(3*(totalShift>>2))'
 can be greater than accu data width. If you apply a shift with more then
 31 bit the result depends on the architecture and is not defined in C.
For certain platforms zeros are shifted in. That would be our desired behaviour.
On other platforms the shift will be applied as modulo. For example >>34
 would be applied as >>2. To prevent this discrepancy the shift value
 is limited/saturated to DFRACT_BITS-1. 'accu >>= fixMin(totalShift,DFRACT_BITS-1)'.

Bug 9428126

Change-Id: I27177654c4dc22cf899bc35dad9cdd040dccb02d

2013-08-20 15:01:21 -07:00

include

Disclaimer update, lib version increment

2013-08-20 14:38:55 -07:00

src

Encoder quantizer fix

2013-08-20 15:01:21 -07:00