Author Topic: Low bit-rate on 60D with Sandisk Extreme 32G UHS-1  (Read 2377 times)

in03

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Low bit-rate on 60D with Sandisk Extreme 32G UHS-1
« on: February 28, 2013, 07:38:23 AM »
Hey Guys,

I have a Canon 60D, Magic Lantern 2.3 and a Sandisk Extreme 32G UHS-1 SD card. It's blazingly fast, except, it seems, when it comes to video mode. Often the buffer will fill and the recording will simply stop after 10 seconds or so on firmware default bitrate settings. I've been able to get Q-scale at about -2 with the buffer floating around 50%, but it usually won't tolerate it. I've seen people with older cameras and slower cards using Q-scale -10. Am I over expecting? Or is something playing up?

a1ex

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Re: Low bit-rate on 60D with Sandisk Extreme 32G UHS-1
« Reply #1 on: February 28, 2013, 08:03:59 AM »
Don't forget that VBR means variable bitrate (and it varies by orders of magnitude). It's not unusual to have recording stopping at QScale +4, or record at QScale -16 on a class 2 card.

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Re: Low bit-rate on 60D with Sandisk Extreme 32G UHS-1
« Reply #2 on: February 28, 2013, 04:37:07 PM »
I'd guess for 60D you'd need a build with g3gg0's video hacks working so you can write the buffer out faster. Might as well try with CBR as it dynamically adjusts that "qscale" value. I don't know if extending 4gb limit really worked on 60D so real high rates will give you like 4 minutes of recording time. CBR can get you some 60-80MB/s with fast cards which is mostly enough.