[Speex-dev] Performance of the acoustic echo canceller

[William Zhang]

Hi All, I am working on my master project to port the Speex Acousic Canceller to FPGA. But I am not able to get a satisfied result in its performance whenI integrated it to a SIP softphone as my first step.  The SIP softphone calls to a PSTN gateway and lands to my land line phone.  I can hear the echo of my every word while I talks on the land line phone.   I am using G.711 codec, frame_size 80 and both 1024 and 2048 tail length. The code was compiled as floating point and fixed point in the PC. But noneof them help. I made sure the the synchronization between echo_frame and input_frame was stable and the delay is consistant about 10ms. The echo return lossis around 20db but output_frame and input_frame signal is about the same.  I even tried Jean-Marc's latest mdf.c from the subversion but no luck. Has anyone test the performance in any other softphones and how well does it work?   I have the recording files, anyone would be interesting in taking a look? I wonder if there is something wrong with my input, setup...BTW: did anyone ever try to port the algorithm to hardware?  I will do some profiling and implement the most compuation expensive function in the Xilinx FPGA.I would really appecriate if anyone can share some  experience or provide adavise and suggest!  I like to contribute my work to the Speex project if my project turns out to be good end.  Regards,William
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