Skype Call Recorder

FAQ

If you have a question that isn’t answered here, feel free to contact me.

1. General notes

1.1 Can I record conference calls? If you are not hosting the conference, then you can record it just fine. However the file name will only reflect the hoster and not any other participants. If you are yourself the host of the conference, then recording will not work properly. This is a limitation of Skype Call Recorder that I hope to fix, but Skype’s API documentation isn’t very abundant about this, so it’s not yet clear to me how it should work. Any help is welcome. Update: Latest git versions might work a lot better with regard to conference calls.

1.2 Which desktop environments are supported? KDE 3, KDE 4, Gnome and Xfce work fine. Any environment that implements the System Tray Protocol Specification should work and if it also implements the Desktop Menu Specification it should automatically appear in your menu. If you use a desktop environment other than KDE/Gnome/Xfce, I’d be interested in hearing how it works for you. When Skype Call Recorder is started in an environment that does not provide a system tray, it will complain about this after 10 seconds and propose to open a small main window to give you access to the menu. This is not an ideal solution, but it works. Note that Gnome 3 may not have a visible system tray by default; pressing Win+M makes it appear.

1.3 Are 64-bit platforms supported? Yes. Version 0.5 fixed a bug that caused it to crash on at least Ubuntu/amd64, but any later version should work fine.

1.4 Which versions of Skype will work? Skype Call Recorder has mainly been developed with Skype 2.0.0.68 and also works with any newer version that I know of. Older 1.x versions are now obsolete and are not supported.

2. Installation notes

2.1 Using the binary package for Ubuntu, the dependencies do not resolve, why? Skype Call Recorder depends on the package libmp3lame0 (or liblame0 on older Ubuntus) being installed, which is in the category ‘multiverse’. If you don’t have multiverse enabled, it won’t be able to resolve this dependency. This can happen if you’re running an Ubuntu Live CD, or if you live in a restricted country, where downloading some software might be problematic. You can enable and disable multiverse under “Software sources”. Please refer to the Ubuntu help resources for more information.

2.2 Using the binary package for Debian, the dependencies do not resolve, why? Skype Call Recorder depends on the package libmp3lame0 being installed, which is in the multimedia repository. See debian-multimedia.org for details.

3. Usage notes

3.1 What’s this stereo thing? The default setting is to record in stereo mode, each side of the conversation on its own channel. This can be convenient for later editing, for example in the case of an interview. If you prefer, you can inverse the channels or choose any mix in between. For example, if you do not plan to edit the recordings, it can be more pleasant to listen to them later if you record them with a 80% / 20% mix: The left channel will contain 80% of your microphone and 20% of the other person’s microphone and the right channel the opposite. You can also record to a mono files if you prefer. The configuration for this are available in the “File format” tab of the preferences dialog.

3.2 What are good settings for Ogg Vorbis and MP3? The default settings are most probably good enough for you and higher quality settings will only make your files get larger for no real gain. If you have been using MP3 files before, you might wonder why the default bitrate is set to 64 kbps, even though other MP3 files encoded at 128 kbps have audible artifacts. The important thing here is that Skype calls operate at 16kHz which is much lower than the 44.1kHz that are used on CDs and many MP3 files you’ll find. This is why 64 kbps is plenty enough for Skype calls and results in a better encoding quality than a CD ripped at 128 kbps. If you’re recording to mono files, even 32 kbps will be enough.

3.3 What if Skype Call Recorder doesn’t detect Skype? If the connection to Skype cannot be established, the system tray icon will remain gray. Note that this is normal as long as you haven’t logged into your Skype account. If you are logged in and it stays gray, then one possible reason for this is that you downloaded one of the two static versions of Skype. Unfortunately, these do not include support for D-Bus and cannot work with Skype Call Recorder. Try using one of the dynamic versions.

4. Bugs / Known problems

4.1 I think I found a bug! Great! Contact me and report it. You might want to run Skype Call Recorder from a shell to see its debug output which might contain information that are helpful in tracking down the bug/problem. Redirect this output to a file and send it to me, or at least copy suspicious lines in your message. Of course you should remove any personal information from that file first. If it crashes, then a stack backtrace would be very useful. You can get one by compiling in debug mode (change build type from ‘RELEASE’ to ‘DEBUG’ in CMakeLists.txt) and run inside gdb; when it crashes, type ‘bt’ to get the backtrace.

4.2 On long calls, the two channels get out of sync. This is a known problem in version 0.2 and earlier. Version 0.3 and later try to resynchronize the streams when they get out of sync. So far, this synchronization feature seems to work quite well.

4.3 The recorded call is missing a bit of the beginning. One unlikely reason for this is that it can take Skype Call Recorder up to 5 seconds to notice that you signed into Skype. Thus, if you manage to sign in and make a successful call, all within 5 seconds, then the first few seconds might not be recorded. This is due to a bug in Skype’s API for linux. However, it’s very difficult to be that fast, so this is hardly ever a problem. The much more likely problem is that your system was under heavy load when the call started and Skype Call Recorder was too slow requesting the audio data from Skype and therefore didn’t get the first bit.

4.4 It says it can’t start because no system tray was detected. Version 0.3 and earlier would complain if you use a desktop environment or window manager that doesn’t implement the System Tray Protocol Specification, i.e. you do not have a system tray. Upgrade to the latest version which will notice this after 10 seconds and then propose to open a small main window, so that you can still access the menu. It’s not an ideal solution, but it works.

5. Development

5.1 Is there a version for Microsoft Windows? Short answer: no. Longer answer: I’m working on it. First successfully recorded calls have been made.

5.2 Is there a version for Mac OS X? No. I’d like to because I know of no free alternatives, but I can’t because I do not own a Mac to develop this on. It wouldn’t be very difficult to port Skype Call Recorder to Mac OS X and you’re welcome to try if you’re interested. Contact me if you need help.

5.3 Is there a public repository with the development sources? Yes, there is a public git repository now. See the compiling instructions.

5.4 Can we have support for FLAC files? I’ve been asked this quite a few times and the answer is no. Skype transfers the audio stream using its own lossy voice compression codecs, which means that your audio has already suffered lossy compression. Add packet loss and other artifacts that reduce the audio quality and suddenly it makes no sense anymore to store that audio stream using a lossless codec. That said, since WAV files are supported, you can always encode to FLAC manually.

2010-07-21/jlh