card spanning for video

[70MM13]

Has anyone given much thought to doing card spanning on models with dual slots such as my 5d3?
I'm finding that dual iso video, even at 10 bits, is too demanding for shots longer than about 10-20 seconds depending on compressibility of the content.  If card spanning could improve this by any amount, it could be a life saver!

just curious...

[Danne]

Feature already exists for mlv_rec. You could have a go porting it to mlv_lite.

[70MM13]

I'm not a coder.
I'd help however I can...

[Danne]

No one here was born a coder
Just sayin...

[70MM13]

Is there really no one interested in this?

I'm sure I will be attacked for asking, beyond the ridicule I already received, but I would just like to know the opinion of anyone who knows the details of what would be involved in making it work...

Surely there are others out there who would benefit from increased recording times?

...reaches for his flak jacket.

[timbytheriver]

@70MM13 Hey. I'd be interested in this – but I thought the speed of the SD card cannot sustain the bit rate required? Or am I confused...? 

[70MM13]

My uninformed guess would be that it's all about stopping the buffer from running out, so when the first card stops keeping up, the camera writes to the second card until that one can't keep up, by which time the first card has written more data and can maybe take a bit more again.  It wouldn't last very long but even a few seconds extra could save a shot!

[Danne]

Code is in mlv_rec. Porting this to mlv_lite combined with the sd_uhs hack should do a significant improvement. If g3gg0 or a1ex would take an interest here it's doable. Or else I would advise you to look for some skilled c-coder elsewhere instead of double post which most likely will lead to - nothing...