> [EMAIL PROTECTED] wrote: > >>From the CLI and during a call I want to be able to: > > > > *** Pulse the outgoing line and record at least 50 ms of the incoming line. > > > > The pulse waveform must be specifiable as a series of amplitudes > > for each 1/8000 sec time slot. It would be best of these values > > could be read from a file specified on the CLI command line. > > > > Timing should be synced between the pulse and the echo so that the > > delay from the pulse to the echo can be accurately determined. > > > > Echo cancellation should be disabled during this operation. > > > > This would operate similar to the echo-training code that operates > > at the initiation of a call except that this could be done at > > any time. > > > > The initial pulse and any echoes can be combined and saved in a > > single channel. > > > > Output should go to a file and should be in a simple format that > > a program such as Audacity can read, display and play. > > > > > > *** Pulse the outgoing line and record at least 50 ms of the incoming line. > > > > Same as above EXCEPT echo cancellation would not be disabled during > > this test and the results of the echo cancellation operations should > > be recorded and saved in a separate channel. > > > > > > *** Change variables used to control echo cancellation. > > > > Only the code in mec2.h is of interest. > > > > I will help identify the variables and modify the mec2.h code as > > needed to accomplish this goal. > > > > There are a lot of parameters in mec2.h that may affect the quality > > of the echo cancellation. I want to be able to adjust them 'on the > > fly' and be able to immediately hear the results. > > > > > > I am open to alternative proposals which would accomplish the same goals. > > > > Name your price. > > How about being able to "see" the results real time? > I use a package called SMAART from siasoft.com. > It is a dual channel spectrum analyzer. > Run the output line as your reference channel > and the input line as your measurement channel. > > You can get great info from the impulse response > and transfer function. > > You could also use this to compare different codecs. > The impulse function will tell you how long it takes. > The transfer function will tell you just how good a > job it did at reconstruction the original audio.
At least one of us that have worked a fair amount with the echo problem tends to believe the issue is "system" related as opposed to pstn line issues. Off-list, we found that swapping motherboards "does" have a very noticable impact, and processor speed does not appear to be a consideration. (Kind of thinking the echo (or feedback loop) is actually internal to the system.) Would the SMAART package help if this is the case? Rich _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users