#815 Poor Echo Cancellation

[Anonymous]

Originally created by: stephen....@gmail.com

Echo cancellation is significantly worse on beta csipcimple than with sipdroid.  I've enabled echo cancellation and turned the microphone sensitivity as low as possible while allowing called party to still hear me.  They report that echo is still annoying on regular headset call and unbearable when I put them on speaker phone.

I'm bummed about this because there is no echo problem with sipdroid, even on speaker phone, but the audio quality of the call is significantly better with csipsimple.

[Anonymous]

Originally posted by: r3gis...@gmail.com

Usually this issue is linked to the device/manufacturer audio driver implementation.

So :
* What is your device?
* Did you try the FAQ audio workarounds?

Status: Need-Details

[Anonymous]

Originally posted by: r3gis...@gmail.com

Last point, if your device has an armv7, it could be interesting to activate speex echo cancellation mode (it's an accoustic echo canceller). (you have to switch to ExpertSettingMode to try it ;) ).

[Anonymous]

Originally posted by: stephen....@gmail.com

Thank you for responding.  My device is an LG Optimus V.  Quick System Info app reports the CPU is an ARMv6 rev 5.  I didn't mention the hardware initially because I thought the large difference between sipdroid having no perceivable echo and csipsimple having significant echo meant the problem lies in the app's algorithm as apposed to the device's audio drivers.

I saw the FAQ at https://code.google.com/p/csipsimple/wiki/FAQ but do not see any information related to echo.  There is no difference in echo when the screen is on/off so I did not think that entry was related.

Yes, I did try enabling the Speex echo cancellation, but it did not have any noticeable effect.  I then reordered the codec preference to use the Speex codec before trying G729 and G711.  The audio quality was slightly worse, but there was not much improvement on the echo problem.

[Anonymous]

Originally posted by: r3gis...@gmail.com

In the FAQ you should try "Audio Troubleshooting" section. It's about audio routing, but sometimes in fact the way the device interpret the routing deeply impact how hardware is opened and sometimes changing it can help to open hardware a way echo cancellation is reduced by hardware.

If it's armv6 do not try speex echo cancellation mode.
Could also be interesting to test with latest dev versions.

FYI, android audio api prior to 2.3 is just awful and each manufacturer has his own interpretation of what it should do. As consequence in term of audio device is EXTREMELY important. There is no issue at all on Nexus One for example. Cause the default way to open audio hardware on csipsimple match the way HTC and google understand the audio API. But on other devices it's by far worse. For example on the Samsung Galaxy S there is usually a big echo. But... with a Samsung galaxy S with android 2.3 CM7 on it.. miracle... Cyanogen mod works just perfectly cause Cyanogen guys did great work.
So in this kind of problem usually it's really really linked to the manufacturer and it make things extremely hard for developpers to have something working good on all devices... Fortunately it sounds better in newer android 2.3 api.

[Anonymous]

Originally posted by: stephen....@gmail.com

Thanks for the information.  I downloaded and installed the latest nightly build.  It really tickles me how you can switch the settings menu between "Advanced Mode" and "Expert Mode".

My phone is running the 2.2 froyo that shipped on it.  I'll update to 2.3 as soon as the carrier makes it available.  I did many tests with the routing options, the echo cancellation method, the echo tail setting, and other items.  None of them had an effect.

But THEN, I had the bright idea to turn off echo cancellation.  When I did that, there was a significant echo of my voice on my end.  Which made me realize, perhaps the echo cancellation algorithm is only being applied when I'm speaking.  It needs to also be applied when the other party is speaking.  That would explain why I don't hear the echo but they do.

[Anonymous]

Originally posted by: stephen....@gmail.com

I'm not sure how I missed it, but my problem may be the same as bug 119 - I swear I searched for echo before I filed this.