Version 4.1

• New functions to design FIR filters were developed.
• New Wavelet Transform functions were developed. They support transform for vector length with power of 2 (WtInit) as well as arbitrary length (WtInitLen).
• New functions Min and Max have been optimized to return the min and max values in a vector. The functions MinExt and MaxExt also return the indices of the element found.
• New logical functions for integer data were added to the library, such as And, Xor, Or, and Not functions. Bit operation functions, such as ShiftL (shift data left) and ShiftR (shift data right) were added as well.
• Performance of the FFT transform functions was improved for all data types.
• Accuracy of 1D convolution function was improved for the the integer data type.
• New example programs, including the Frequency Analyzer, Windows device driver, and Multithreading support, were added.
• Microsoft Visual J++ support was added for Java* programming.
• The calling convention for all library functions has been changed from cdecl to stdcall (this change is required for support of other programming languages such as Delphi and Visual Basic).
• Almost all of the library functions have been optimized either in C source code or in assembly language. In this release, special attention has been paid to the optimization for the Pentium II processor family. Please refer to the performance sheet for the updated benchmark numbers.
• New optimized library to support the Intel Pentium III processor

Version 4.0 - 11/97

• Optimized for additional processors, including the Pentium Pro and Pentium II processors.
• New functions - DCT, Wavelet, Power Spectrum, Norm, and Normalize (optimized to improve performance on all Intel Architecture processors, especially the Pentium Pro and Pentium II processors)
• Improved accuracy of the integer filter API by using internally a 32-bit delay line and accepting floating point taps, the accuracy of the integer filter functions is significantly improved. This change affected the function prototypes of the IIR, FIR, and LMS filter functions. Refer to the Intel Signal Processing Library Reference Manual for details.

Version 3.0 - 11/96

• Added support for 16-bit integer data types, for the Pentium processor with MMX technology
• Added a custom DLL to minimize the memory footprint.

Version 2.0 - 9/95

• Added processor-specific, dynamically linked libraries (DLLs). A DLL detects the processor type at the time the DLL is loaded and loads a processor-specific DLL that is optimized for either the Intel486 processor, the Pentium processor, or the Pentium Pro processor.

Version 1.0 - 6/95

• The first public release of the Signal Processing Library (originally released to alpha sites in mid-March of 1995). It consisted of a Pentium processor-optimized static library form of the functions.