Hello All: I am working on ADPCM G.726 Coder for dual channel. After completeing coding and testing sucessfully , MIPS(MCPS) performance is found to be around 15( for full duplex). The assembly code is fully optimized as it's almost completely serial and without any software pipeling. I wanted information from anyone who has worked on this before as to how many MIPS that had done it in. Also Radisys Comm.,claims to have done ADPCM in 7.5MCPS (full duplex)!!!!!!!!!!!!!. Any suggestions on how I can improve on the performance figures. Thanks in advance Arvind |
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G726 on TMS320C62xx
Started by ●February 2, 2001
Reply by ●February 5, 20012001-02-05
Arvind wrote: > I am working on ADPCM G.726 Coder for dual channel. > After completeing coding and testing sucessfully , MIPS(MCPS) > performance is found to be around 15( for full duplex). > The assembly code is fully optimized as it's almost completely serial > and without any software pipeling. > I wanted information from anyone who has worked on this before as to > how many MIPS that had done it in. Also Radisys Comm.,claims to have > done ADPCM in 7.5MCPS (full duplex)!!!!!!!!!!!!!. > Any suggestions on how I can improve on the performance > figures. Am I right to recall that g726 is almost the same as g721 but with a selection of rates? If not, ignore the rest of this message. A couple of years ago, I wrote a g721 for a processor almost the same as a 320c55. It took about 4.5 mips, duplex. I can't tell you details of the tricks I used because the work was done for a client who now owns all the detailed implementation information. However, there is one general point: I spent nearly a month fiddling with C code for the algorithm before going near an assembler. This mostly consisted of experimenting with different ways of performing the arithmetic, checking which alternatives were possible without breaking the bit-exactness. I always write my own C code, even when code already exists as part of the standard. I think it's the only way of getting sufficiently familiar with the algorithm. Tim. ------------------------ Tim Thorpe Tel: +44 1223 240366 Fax: +44 1223 414402 ------------------------ |