GH5 - 400 Mbps recording

Discussion in 'Panasonic Cameras' started by 012abc, Jul 16, 2017.

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  1. 012abc

    012abc Mu-43 Regular

    27
    Jul 1, 2017
    I'm just doing market research on the camera right now.

    - First of all, the firmware enabling this feature has not been released yet. Is this correct?

    - Secondly, when this mode is enable, the camera can do the recording and storing of the video internal? I did a quick calculation and 400 megabit comes out to be 50 mega-byte. The fastest uhs-1 (sdxc uhs-1 u3 v30) card can write at ~90 megabyte per second.

    - If my calculation is right, then what's the point of needing a uhs-ii class card? These uhs-ii card can write up to 150 megabyte per second based on official spec. (Bus Speed (Default Speed/ High Speed/ UHS) - SD Association)

    Thanks.
     
  2. Wasabi Bob

    Wasabi Bob Mu-43 Top Veteran

    One reason the firmware update has not been released is likely due to the delay in getting faster media to market. So my question is, what truly justifies recording at 400 Mbps?
     
  3. DanS

    DanS Mu-43 Top Veteran

    822
    Mar 8, 2016
    Central IL
    Current cards are advertising maximum read/write speeds. The V designations are guaranteed sustained minimum write speeds. If the write speed drops below the video bitrate, you can have all kinds of issue. You could drop frames, or even completely corrupt the file.

    • v30 = 30 MB/s write minimum
    • v60 = 60 MB/s write minimum
    • v90 = 90 MB/s write minimum
    The 400mbps setting will use an ALL-i compression algorithm, the other modes use IPB compression. ALL-i is orders of magnitude easier to edit than IPB.

    All-I vs IPB - What do they mean? | DSLR Video College
     
    • Informative Informative x 1
  4. 012abc

    012abc Mu-43 Regular

    27
    Jul 1, 2017
    For those who do post production, the more information that there is in the footage, the more latitude we have in making changes to the file.
     
  5. 012abc

    012abc Mu-43 Regular

    27
    Jul 1, 2017
    Ahh, so really, what's important is the V rating. They should just drop all the other labels on the card and just have V rating!

    Wow, thanks!
     
  6. tkbslc

    tkbslc Mu-43 Hall of Famer

    The camera's error handling just ends the video when the video buffer fills (because it can't clear to card fast enough). Which means you end up being able to take a max 15 second clip, etc., instead of having a bad/corrupt video file.
     
  7. DanS

    DanS Mu-43 Top Veteran

    822
    Mar 8, 2016
    Central IL
    Yes, but 400mbps All-I does not guarantee you more information in post that 150mbps IPB. The compression algorithms are completely different, so its apples and oranges. We won't be able to tell if 400mbps all-i is actually better till the firmware is released, and someone does side by side comparisons.
     
    • Agree Agree x 2
  8. DanS

    DanS Mu-43 Top Veteran

    822
    Mar 8, 2016
    Central IL
    Panasonic's error handling is better than other manufactures then. I had seen all kinds of funkiness over the years.
     
  9. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    This is exactly right.

    Assuming that a different 400mbps codec is better by default than the current 150mbps one is a mistake just because it takes up more space. It will certainly be easier to edit, so if you do a lot of post-work with your video, it will likely be a big boon since it won't necessarily require transcoding. But definitely don't make any assumptions about quality.
     
    • Like Like x 1
  10. DanS

    DanS Mu-43 Top Veteran

    822
    Mar 8, 2016
    Central IL
    As a side note, I'm personally waiting to see how the open gate feature pans out. if it actually materializes, and is supported by most NLEs, it will be a game changer.