Blank spots recording Skype

[steve]

This is when you use Skype without even recording it?

Yes.

I thought mobile and VoIP offered full-duplex emulation ( http://en.wikipedia.org/wiki/Duplex_%28 ... _emulation ) so that theoretically, parties should be able to speak simultaneously.

"Full duplex" allows bidirectional data simultaneously. "Emulation" fakes a similar effect. Time division duplexing (TDD) is one way to emulate full duplex, but it isn't full duplex. There are different forms of TDD including "half-duplex" (like a walkie-talkie ... "over"...), Code division multiple access (CDMA), and others. Duplexing can be emulated quite convincingly when the data is digital and can be compressed, by alternating "packets" of data (several different standards for doing this).

Regardless of the duplexing method (and I don't know the details for cell phones), the communication flow is managed. Many cell phones can be used on a "speaker phone" setting. If it were not managed it would certainly produce an audio feedback loop. To prevent that, at each end, either the speaker or the mic is active, but not both at the same time, so each end is either "transmitting" or "receiving" but not both simultaneously.

On top of that, Skype (by default) dynamically adjusts the mic level with a form of automatic gain control (AGC). There's a lot that can go wrong, and Skype's claim to fame is that they've got it all to work pretty well by tightly controlling the entire system, but that does not lend itself to easy recording.

[Gale Andrews]

Yes I've heard feedback on mobile phones when two people are trying to talk at the same time. I don't think I have heard dropouts of one party or the other when both talk together, though since one or or the other tend to stop talking that can be hard to judge.

I have never heard or recorded a complete dropout of both parties when recording Skype with Audacity or other tool, where two people are talking at the same time.


Gale

[steve]

I have never heard or recorded a complete dropout of both parties when recording Skype with Audacity or other tool, where two people are talking at the same time.

I've not had a complete drop-out either, but I have had the recorded volume go very low for a short time immediately after a loud noise (until the AGC catches up), and (of course) I've had one side of the conversation much quieter than the other, and I've had drop-outs on my old machine because it struggled to keep up with running Skype and Audacity at the same time.

I've not had much success recording Stereo Mix with hardware playthrough (Win XP) enabled on my mic (though apparently some people record that way), but I can imaging that causing the local mic to cut out while the other person talks.

In short, there's a lot of things that can go wrong when trying to record Skype with Audacity.
On the other hand I've had Skype Call Recorder work flawlessly on my current machine, and both Pamela and SoundLeech work flawlessly on my old Windows machine.

[kozikowski]

Given enough time I can find the controlled recordings I did with two computers where the two ends were able to interrupt each other. I did not hear switching or ducking. Perhaps he system knows when it's unstable which leads me to...

I still think this is a feedback problem. The recording was made with the system in borderline unstable feedback and either party getting loud resulted in using a non-linear portion of its range, or clipping. I have no trouble imagining a watchdog system which mutes if it senses that happening.

Koz

[Enver]

I'm running on Vista and in my Sounds settings all I have is Playback and Recording, and I can't find any communications tab on there.


Yeah it's totally a volume thing. When someone gets louder, it's like it filters that out of the recording, but if someone is talking soft and don't get loud and start talking non stop (or two people talking together) it won't happen at all.

I don't audacity is the problem at all. I think there must be some filter deep in the computer settings. I see Windows 7 has more options.

Could it be the stereo mix properties? I have it set at 2 channel 16 bit 48000 Hz (DVD Quality) and same for playback.

There is a setting called "Exclusive mode" with two tabs for "allow applications to take exclusive control of this device" and "give exclusive mode applications priority". So if that's the filter, I'll uncheck the boxes and try.

[Enver]

I've not had a complete drop-out either, but I have had the recorded volume go very low for a short time immediately after a loud noise (until the AGC catches up), and (of course)

This happened to me a couple times, where things all of a sudden get really loud right when someone is hanging up.

[kozikowski]

I'm going to predict the past. You're going to find a combination of tools and adjustments and techniques which allow Audacity to record both sides of the Skype call with minimum distortion and problems. Skype will then be unusable because of bad or missing echo cancellation.

"What did you do to Skype? I can hear my voice coming back and it's really annoying."

Koz

[Gale Andrews]

Could it be the stereo mix properties? I have it set at 2 channel 16 bit 48000 Hz (DVD Quality) and same for playback.

There is a setting called "Exclusive mode" with two tabs for "allow applications to take exclusive control of this device" and "give exclusive mode applications priority". So if that's the filter, I'll uncheck the boxes and try.

Are you hearing these dropouts when you record?

The sample rate you are choosing is not excessively high and not relevant unless your machine is so slow that it can't even cope with a sensible rate like that without dropouts.

I think we are of the opinion that the droputs are due to Skype volume management and not lack of computer resources. Have you followed my suggestion to read https://support.skype.com/en/faq/FA1033 ... -windows-7 ?

Look at the section "Make sure your your audio settings are correct in Skype". Try changing the settings for microphone volume and speakers volume. Experiment with different volume settings and most importantly, experiment with checking and unchecking "Automatically adjust microphone settings" and "Automatically adjust speaker settings".

The settings you are looking for are not likely to be in Windows Sound given you have no Communications tab there.

Exclusive Mode is highly unlikely to be relevant. It does not even have any effect in Audacity unless you choose Windows DirectSound host in Device Toolbar . If you want to experiment with that, leave the Exclusive Mode boxes checked and change to Windows DirectSound in Device Toolbar. Then there will be no sample rate changes between the sound device and Audacity, but I don't think it will make any difference.

You should use a dedicated Skype recording app, and stop trying to use Audacity. All the issues you say you have with Skype recording apps are easily fixed by editing in Audacity (as already described). If you adjust volume levels or turn off volume management in Skype ( as already described at https://support.skype.com/en/faq/FA1033 ... -windows-7 ) you may very likely solve the problems you have with those other apps.


Gale

[Enver]

I clearly told you guys that I had the same problem with other recording programs, including one made by Adobe. I'm pretty sure it's not Audacity, and is a computer problem.

I'm going to predict the past. You're going to find a combination of tools and adjustments and techniques which allow Audacity to record both sides of the Skype call with minimum distortion and problems. Skype will then be unusable because of bad or missing echo cancellation.

"What did you do to Skype? I can hear my voice coming back and it's really annoying."

Koz

I have never had that problem before.

[Gale Andrews]

I clearly told you guys that I had the same problem with other recording programs, including one made by Adobe. I'm pretty sure it's not Audacity, and is a computer problem.

And we clearly told you that you would not have this problem if you used an application intended for recording Skype. Adobe Audition is not meant for recording Skype. We have listed applications meant for recording Skype.

Have you looked at the volume settings in Skype or not? If not, I strongly suggest you do so.


Gale