Re: [Asterisk-Users] Bounty! For help with echo cancellation code.
[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. It might help if you identify what your actual goal is :-\ Steve ___ 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
Re: [Asterisk-Users] Bounty! For help with echo cancellation code.
On Wed, Jul 14, 2004 at 10:14:19AM -0700, Bob Knight wrote: [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. Almost 20 years ago I wrote my own digital spectrum analyzer code which I then used to do my research. Provided that SMAART can fully utilize the transfer function (do convolutions etc) it would may be useful, but spectrum analysis is not the hard part. Controlling and getting the data out of zaptel.o is the hard part and help with that is what is requested in the Bounty! echo -- Bob Knight [-w] the work option [EMAIL PROTECTED] 925-449-9163 ___ 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 ___ 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
RE: [Asterisk-Users] Bounty! For help with echo cancellation code.
Please post it at http://www.voip-info.org/wiki-Asterisk+Bounty I'm ready to cover some of the costs. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, July 13, 2004 10:29 PM To: [EMAIL PROTECTED] Subject: [Asterisk-Users] Bounty! For help with echo cancellation code. 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. [EMAIL PROTECTED] ___ 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 ___ 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
Re: [Asterisk-Users] Bounty! For help with echo cancellation code.
[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. -- Bob Knight [-w] the work option [EMAIL PROTECTED] 925-449-9163 ___ 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
Re: [Asterisk-Users] Bounty! For help with echo cancellation code.
[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
Re: [Asterisk-Users] Bounty! For help with echo cancellation code.
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? It probably would not help, but it sure is fun to play with. SMAART compares any 2 signals. If you pump a signal into a black box and then compare the output to the input, it can show you what the black box did to the signal in both time and frequency domain. It will show you phase response, impulse response and transfer func. Bad news, it is not open source and does not run on linux. They do have a free 30 day demo version you can download and play with. It can make real pretty pictures on the screen. -- Bob Knight [-w] the work option [EMAIL PROTECTED] 925-449-9163 ___ 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
[Asterisk-Users] Bounty! For help with echo cancellation code.
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. [EMAIL PROTECTED] ___ 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
