stuckat1

This is a really nice idea. I've done some research on the feasibility. Unfortunately, the view finder is actually an EPSON LCD with 1024 x 768 in resolution 4:3. (1024*768*3 = 2.36m, 3 is for R+G+B) using a LVDS interface. The camera outputs HDMI or composite. Because the HDMI is FHD (1920x1080) 16:9, one will need a LVDS to HDMI driver WITH A scaler to downscale. Unfortunately, while there are plenty of drivers, most do not downscale. For those that upscale/downscale none that I could find would actually adjust for different aspect ratios. You could theoretically replace the Epson LCD inside the viewfinder with a FHD one, but all those are a little larger but only do black and white video. Because of the larger LCD size, the optics might need to be upgraded or readjusted. The other option is to use composite video to either drive the viewfinder or a small external LCD monitor, say 4" or smaller. The problem with this is that composite can only generate up to 480i. This is probably not good to judge exposure or more importantly critical focus. Another option is to use the same 5" screen the BM Video Assist uses or a screen from a high resolution cell phone. Those screens use DSI protocol over LVDS. Right now, there are no boards that do HDMI to DSI for sale. There a two boards but they are not for sale ... yet. One can only keep dreaming.

Great comments!!! I do think all keyboards and mice using standard HID configurations that don't draw too much juice should work with all Android tablets (that have intact USB stack implementation) with USB host support and with a OTG cable. I imagine its completely possible that devices get shipped with little or no USB profiles other than mass storage. This is probably most likely for cheaper devices, under $100. Wacom and Acer Aspire devices are very interesting. Never seen them before. The Acer Aspire is so physically large and inexpensive that I think they just literally built an internal video switcher inside so the video isn't being processed by the OS. I watched a promotional Acer Aspire video that shows that the OS screen just vanishes when a HDMI cable is plugged in. A switcher probably only costs $5 to manufacture but you cannot record video from the source. Wacom is an interesting device but it does cost $800+. Wacom obviously designed special hardware to display the video feed inside its apps. This could definitely record video but the problem is that Wacom probably has no interest in making those APIs public. This means no third party support. Also this device is 13.3"!!! Also, the Wacom is designed to communicate with a PC using DCC, so it probably supports one or two display modes/resolutions. The tablet and PC negotiates bidirectionally how to display the best resolution/frequency. When you plug a monitor to a camera, the camera doesn't negotiate. It forces a resolution and refresh so if your HDMI recorder device can't support it, your S.O.L. Finally, when I meant frame rate support what I meant that USB/HDMI device needs to have a proper HDMI processor that supports a reasonable amount of video modes that most cameras output. The actual tablet device display frequency is independent of the HDMI feed. In terms of data plumbing, if your tablet can reasonably display YouTube videos using H.264 then the Inogeni device should work because UVC 1.5 protocol at its best resolution supports H.264. Again this assume you can shovel the HDMI bits into the tablet correctly and fast enough. The sad thing is that an 8" to 10" tablet with HDMI input will never be built. Its just too esoteric/ specialized. Large companies who make commodity devices with razor thin margins cannot afford adding such features. Look at the demise of Colby. However, a small company with a niche product like the Inogeni can gouge video enthusiasts with a $400 device.

Yep. Only a few tablets support USB 3, such as the new Asus ZenPad S 8. I imagine for 1K capture USB 2.0 should be sufficient. One can buy a ton of HD webcams on Amazon that use only USB 2.0. The OTG cable probably just needs to support USB: its like saying an Ethernet cable must support Skype. This device is dependent on Web Cam (aka UVC) support built into Android so there definitely no obvious need to root the device. The Android tablet would just run in Host mode. People have been able to plug in webcams to Android tablets for a while now. I've actually researched the feasibility of this setup a few weeks ago. There is no reason why a wired system wouldn't work reasonable well. The issue with WiFi based systems is not so much latency, which does matter, but the time outs and drops due to poor connectivity, radio interference and what not. Basically, this device is fancy web cam except that the built in camera is replaced by a HDMI cable input. There should be zero connectivity/drop out issues. Latency should be minimal. Companies actually sell silicon chips that are called web cam processors. These chips handle all the USB interfacing to the "computer." All the board designer needs to do is wire in a video camera. All webcams have this chip built inside. This particular adapter is just reading the data stream from the HDMI connector, writing this data into a memory/frame buffer and then shoveling that into the web cam processor. Pretty simple actually. Not $400 simple, more like $100 simple. Practicality is quite subjective. I think many people once thought shooting video on a DSLR was neither viable nor practical. Also, Canon Live View is proof that this idea is feasible because its basically doing the same thing. Also, I am not aware of single Android device that HDMI input. People already have tablets and huge phones. It would seem desirable to at least non-professionals to be able to reuse a nice 8" tablet for for framing if they already own the device and are probably carrying it anyway. That said, $400 seems crazy expensive. Storing video is another issue. Most tablets don't have SD slots. Also, micro SD media capacities aren't so great nor can you generally easily swap out a SD card on an Android device easily without rebooting the system. More of an annoyance. I would be concerned with really mundane stuff like does it handle 24p, 30p, 60p frame rates and 3:2 pull down properly. Even a "big" company like Black Magic is having issues with its Video Assist with HDMI out from Sony cameras. More importantly, is how is this video being recorded. The latest UVC 1.5 standard supports H.264 at best. Since Inogeni isn't supplying the software, what software does one use to record the video? Is it any good? Does it support a H.264 stream?

Probably a limitation of UVC protocol built into Android.