60fps acquisition with Epiphan DVI2USB 3.0

[Karl-Philippe]

Hi,

I am willing to record a stereo endoscope with an Epiphan DVI2USB 3.0 at a resolution of 1920x1080 and 60Hz.

I previously tested recording with the Epiphan, and I was able to record 60Hz videos using the Epiphan Capture Tool software.

However, when acquiring with Plus (configuration file below), the acquisition rate drops to about 40fps, which is equivalent to what I observed to be the display frame rate in the Epiphan Capture Tool when the display format is 'RGB 24 bit per pixel.'

Is it possible to change the codec to lower the color depth in Plus (the Epiphan can also record with the IYUV codec), or to improve the current Plus configuration to increase the frame rate? Or does anyone know what could be the bottleneck?

Thanks,

 <PlusConfiguration version="2.1">
  <DataCollection StartupDelaySec="1.0" >
    <DeviceSet 
      Name="PlusServer: Epiphan video capture device - color"
      Description="Broadcasting acquired video through OpenIGTLink"
    />
    <Device
      Id="VideoDevice" 
      Type="Epiphan"
      AcquisitionRate="60">
      <DataSources>
        <DataSource Type="Video" Id="Video" PortUsImageOrientation="MF"  ImageType="RGB_COLOR"/>
      </DataSources>      
      <OutputChannels>
        <OutputChannel Id="VideoStream" VideoDataSourceId="Video" />
      </OutputChannels>
    </Device>
    <Device
      Id="CaptureDevice"
      Type="VirtualCapture"
      BaseFilename="RecordingTest.igs.mha"
      EnableCapturingOnStart="FALSE"
      AcquisitionRate="60"
      RequestedFrameRate="60"
      BufferSize = "300">
      <InputChannels>
        <InputChannel Id="VideoStream" />
      </InputChannels>
    </Device>
  </DataCollection>
  <CoordinateDefinitions>
    <Transform From="Image" To="Reference"
      Matrix="
        0.2 0.0 0.0 0.0
        0.0 0.2 0.0 0.0
        0.0 0.0 0.2 0.0        
        0 0 0 1" />
  </CoordinateDefinitions>
  
  <PlusOpenIGTLinkServer 
    MaxNumberOfIgtlMessagesToSend="1" 
    MaxTimeSpentWithProcessingMs="50" 
    ListeningPort="18944" 
    SendValidTransformsOnly="true" 
    OutputChannelId="VideoStream" > 
    <DefaultClientInfo> 
      <MessageTypes> 
        <Message Type="IMAGE" />
      </MessageTypes>
      <ImageNames>
        <Image Name="Image" EmbeddedTransformToFrame="Reference" />
      </ImageNames>
    </DefaultClientInfo>
  </PlusOpenIGTLinkServer>
</PlusConfiguration>