VDK Frequently Asked Questions (FAQ)

General Questions

Which features should I expect will be included in the next VDK releases?

To have up-to-date information about which features our engineers are working on and to know the planned delivery date of next releases, please have a look at the VDK Roadmap.

Under which Licensing Model VDK is distributed?

The licensing model of VDK is tightly based on VirtuaDev technology it uses: since every media streming sink/source is seen as a virtual device (it being a file, a VoIP call or a phisical audio device) you have to “connect” these devices together in order to create your application. VDK comes in three different packages (Basic, Premium and Gold) each of them differing from the other for the number of VirtualDevices that can be connected at the same time.

Some examples follow:

  • A simple phone call would require two “connects”: one to connect microphone to the VoIP line and one to connect the VoIP line to the speakers.
  • An answering machine would require just one connect: one to connect an audio file (containing our away message) to the line, then, after the message has been played, the file can be disconnected and the line can be connected to another file to store it on hard disk; Only one connection at a time was used

In addition Licenses are also related to the platform (single or multiple) under which VDK should run and to number of developers that will use the kit.

Which products and services are included in the VDK License I buy?

The Basic License includes Basic Package updates/support and separately bought Additional Packages support for one year. Additional Package updates are included in the Additional License.

How much does the VDK cost?

Pricing policies are detailed in the VDK Pricing List 2012 [307.88 kB].  In this page you can also find a clear and detailed explanation on Packages bundles and upgrades.

Technical Questions

Why nothing happens when i try to use registerSipAccount() or startAudioCall() methods?

Probably you forgot to call the setActiveSipAccount() method to tell VDK which account should be used at the time to perform SIP Requests. Since VDK allows multiple SIP accounts to be registered and active (for reception) at the same time, you should tell which one is to be used for sending.

On my Linux distribution I get a freeze whenever I try to connect my speakers, what’s up?

VDK depends on the external library portaudio to access the physical audio card installed on your PC, we ship a copy of it along with the VDK installer, however it might happen that this version of portaudio is slightly different from what your distribution expects. The simple fix is to install the portaudio package ditributed by your Linux vendor and use that instead of the one shipped with VDK.

Why do i get an error when i try to register my SIP account?

Probably this is because in version 0.9.6 there is an offset in the account numbering as specified in the vdk.ini configuration file and in VDK APIs like registerSipAccount() or setActiveSipAccount() which actually start the enumeration from 0. This was fixed in version 0.9.7 and the account numbering will start from 1 everywhere; the 0 will remain as an alias for account 1 but this is not a stable feature and might be changed in future releases.

Is there a way to get a sense from the VDK error codes?

Yes, this was a bug of version 0.9.6, the getErrorMessage() method was not made available in the public API. This was fixed in 0.9.7. Using getErrorMessage() and passing the error code as parameter, will give you the string corresponding to that error. We are very sorry for the inconvenience