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Technology Stocks : Qualcomm Moderated Thread - please read rules before posting -- Ignore unavailable to you. Want to Upgrade?

To: JGoren who wrote (58965)	1/24/2007 4:02:38 PM
From: waitwatchwander	Respond to of 197246

The conversion of DCT into the Integer variant is also covered in Richardson's book. It involves "factorising" the required matrix multiplications into a strict integer format. The result of this new variant is converted to the result one would get from a DCT calculation by a "scalar" matrix multiplication. This is similar to multiplying something a constant. In order to transform the DCT method, two numbers are rounded up. The bottom line is best stated by Richardson "This transform [ie going from DCT to Integer DCT] is an approximation to the 4x4 DCT but because of the change to factors d and b, the result of the new transform will not be identical to the 4x4 DCT. I am not 100% sure but I think Qualcomm's patent was based on an 8x8 block. That might be another "minor" difference. Someone here mention the importance of lossiness in video compression. This is just such a case. The problem that Broadcom has is that they probably need to pay royalties not only to Qualcomm but also to the parties that figured out the "factorizing". One can't improve a process until one has a process. Sorry about all the confusion. Trevor