Command line converter for VoH and ViQ

For streaming media is not generated real-time as it would heavily reduce the number of concurrent sessions the service would be able to serve, rather the to be streamed content is pre-generated and stored in Verba proprietary media format.

The vmfconverter.exe command line tool shipped with Verba is the conversion tool to generate the streaming optimized media files from any standard MP4 video clips.

It generates the following streams from which the most desired one is selected by the streaming service at call setup based on capabilities of remote video endpoints/phones and available bandwidth advertised:


    • H.264 1080p - 4 mbps
    • H.264 720p - 2.5 mbps
    • H.264 720p - 1.5 mbps
    • H.264 288p - 512 kbps
    • H.264 288p - 256 kbps


    • Opus 48 KHz stereo
    • G.722.1 32 KHz
    • G.722
    • G.711 u/a
    • G.729

Video streams will be generated only for those resolutions from the above list which are less or equal of the input video stream's resolution, ie. if a 720p MP4 file is converted then 1080p video stream will not be generated.


 Processing video files is highly CPU and disk intensive task, running it on any production Verba node might overload the server and interfere with other Verba services. It is recommended to run the tool either on Media Repository or non-Verba PC.

The tool can be started on any Windows 7/Windows 2008R2 or newer machine by copying verba_install\bin\vmfconverter.exe and libsiren.dll

The tool has the following cmd syntax:

vmfconverter.exe input.mp4 output.vmf (where input/output is either a full or relative path of the media files)

During processing the tool provides progress information and estimated time to finish processing.


Please note due to many resolutions and bitrates of video streams the processing of media is quite slow. It is ~1/4-1/10 of real-time, which means processing 60-second video might take 600 seconds or more depending on hardware, number of available CPU cores