Author Topic: 60D Raw Video - Transfer Rate Workaround Idea?  (Read 2924 times)

JavaMoose

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60D Raw Video - Transfer Rate Workaround Idea?
« on: February 02, 2014, 09:55:35 PM »
I might be way out in left field here, but I would be interested if this is possible.  We all know about the 60D (and others) SD card transfer speed limit (~20MB/s), which seriously hampers RAW video recording on these cameras. 

What I'm wondering is, since the 60D supports tethered shooting, and USB2.0 maxes out at around 60MB/s, would it be possible to code ML to hijack the USB out to do tethered RAW recording, bypassing the buffer/SD card?  Canon software supports tethered shooting to PC/Mac, in the field, using an iPad would be would be amazing (or an Android tablet?); if there was a way to do USB tethered RAW video capture.

So, those in the know, would this even be possible to enable?  Given the (ahem) magic the ML team has pulled off, I am hoping it's not a total pipe dream...

Audionut

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Re: 60D Raw Video - Transfer Rate Workaround Idea?
« Reply #1 on: February 02, 2014, 10:00:24 PM »
This has been discussed before.  I can't recall what the outcome was and I'm to tired to search the result for you.

Short answer:  Not at the moment.

JavaMoose

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Re: 60D Raw Video - Transfer Rate Workaround Idea?
« Reply #2 on: February 02, 2014, 10:14:45 PM »
Ah, sorry.  I tried searching, but wasn't coming up with anything.

Audionut

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Re: 60D Raw Video - Transfer Rate Workaround Idea?
« Reply #3 on: February 02, 2014, 10:50:09 PM »
Yeah, something like this might be a little difficult to search for.

A good tip for something like this is to narrow down the search results from a developer.

http://www.magiclantern.fm/forum/index.php?topic=6128.0

dmilligan

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Re: 60D Raw Video - Transfer Rate Workaround Idea?
« Reply #4 on: February 03, 2014, 05:19:08 PM »
480Mb/s (60MB/s) is only the theoretical burst rate, the theoretical sustained rate is half that, and the actual real-world rate is lower than that, and the actual speed of the camera's USB controller is even slower than that. I think I remember reading it's something like ~10MB/s. So while you could offload some of the writing to USB and get an effective rate of maybe 30MB/s, it would be rather difficult to implement and continuous 720p still wouldn't be possible, so probably not worth the effort. (Think about how hard it would be to manage the load balancing and also figure out how to reconstruct the data being stored to two different locations)