After a couple of weeks of hard code tracing Coderat nailed the where/how of the bit rates for Nikon DSLR movies recording are set. The sad thing is the source of the bit rates is just a simple function that had been documented for a couple of years, the completeness of it’s effect was just not understood. Sigh.
But now we have patched in higher bit rates. To that end 34mbps and 54mbps have been tested on a D5100, and I’ve tested 34mbps, 49mbps and 64mbps on my D7000.
The online patch tool now lets to install these rates, on D5100 and D7000, and only at 1080p, but I’m sure more models/modes will follow as requested.
I had no record problems with 64mbps (really 60mbps as I had no sound being recorded), using both my slow Transcend Class 10 card, or my fast SanDisk Extreme Pro, which I purchased for these very tests back in 2012.
So if you want to test or talk about this come on over to the Nikon Hacker forums.