facebook pixel MediaMaster latency test on the A10 Media Server | ArKaos Pro
By ArKaos Team
on 02 Apr 2010 12:00 AM
  • mediamaster
  • optimization
  • synchronization
  • troubleshooting
  • video

On the support, we sometimes have to answer questions about the latency between the live input and output on computers running MediaMaster. We know this a concern for most users but actually, there’s no straight answer since the amount of latency you will get will depend on a lot of different hardware and software parameters and therefore will vary depending on your own setup.

In a perfect world, we would have zero frame delay but unfortunately this is not possible with current computer hardware; the simple fact that a computer is processing video already adds one frame of input delay, that frame is needed for the computer to store the complete image before having it processed by the video card. Then you can add another frame of output delay, caused by the video card processing the image. Before or after that, each device that is added to the pipeline – such as a camera, a mixer, a LED controller or a projector – will add some delay into the processing. In the end, if the delay becomes too big you will notice that the sound and the video are out of sync, for example you will hear the voice of the speaker before his lips start moving on the screen.

If we cannot tell what the latency will be with your setup, we can however provide you with a point of comparison by measuring how many frames are needed to process a live input on an ideal setup: MediaMaster running on one of our A10 Media Servers that are specially built and configured to get the most out of our software.

Here is how we proceeded: we’ve setup a MacBook Pro with DVI/HDMI output connected to the Blackmagic Intensity Pro input card from the A10 Media Server which was set to an input resolution of 720P 60Hz. Then we started a frame counter movie on the MacBook Pro and launched the live input from MediaMaster full screen on the A10 Media Server. Finally, we put the monitors next to each other and took a picture so we can see the difference between the frame counter on both screens.

As you can see in the movie, when we took the picture the MacBook Pro was at frame count 24429 and the output of the A10 Media Server was at 24424: there is a 5 frames delay between the counter from the laptop and the counter from the server. Since our whole setup was running at 60Hz, this means that the processing delay equals 83 milliseconds (1 second divided by 60 frames = 16.6 milliseconds per frame, 5 times 16.6 milliseconds equals 83 milliseconds).

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