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Displaying Video from an external HMDI/DVI source on ODG Glasses

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Video data can be displayed in the glasses, transmitted over USB or WiFi.  The lower latency approach is to use UVC protocol over USB, mainly because data sent over IP over WiFi requires a video encode/decode; UVC can be uncompressed.  You will need a HMDI/DVI to USB Adapter, and a ODG battery pack for plugging in the adapter.  We've successfully used this adapter:

 http://inogeni.com/dvi-usb3-0/

and played video using this Android App:

https://play.google.com/store/apps/details?id=com.vaultmicro.camerafi

This works on both R-6 and R-7.

If transmitting video streams over IP, usually protocols like H.263 or H.264 are used (these have hardware based codecs on the platform).  There are many Android Apps that can play video from a standard stream.  VLC is the one we've used the most often. The latency for this approach is usually > 1/2 second, and can but up to 2-3 seconds depending on the size of the configured jitter buffer in the player.

Latency:

How you measure latency depends on what your video source is.  To give an example for the USB approach, using a Laptop as a video source with a stopwatch app running on it, an HDMI to USB converter, connected to the glasses, we measured ~ 220 - 250 milliseconds delay from the Laptop display to the glasses display. We estimate that the latency of the HDMI out of the laptop is ~ 80-100 milliseconds, and that the HDMI to USB converter, USB and UVC conversion and display in the glasses is ~ 140 milliseconds.  This was 720p 60 fps video.  

3D, Audio :

The Application that plays the video can be made to display both 2D and stereoscopic 3D video.  We think that most folks who have this use case are going to want to build their own player; the ones we've looked at don't currently natively support S3D.  Also note that the audio stream is accessible as well (the Inogeni adapter shows up as 2 USB devices - a camera and an audio source), but again, we have not found a off-the-shell player that plays audio with the video. [If you know of one, let us know!].

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    Bessam

    You didn't describe how to connect the INOGENI to the power hub. I have all the equipment you described in my lab but the INOGENI does not power up from the battery pack while it works perfectly when connected to a laptop. Any ideas?

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