E-PL1 and E-P2 video bitrate and buffer speed

Discussion in 'Filmmaking' started by julienrl, Jul 28, 2010.

  1. julienrl

    julienrl Mu-43 Regular

    100
    Jul 28, 2010
    Ottawa, Ontario
    There are a few threads out there about class of memory cards and all, but class does not equal the actual speed of the card. You can see benchmarks for cards here for example So what I would like to know is

    1-does the E-PL1 have a variable bitrate video encoding or does it have a fixed size at max and every image fits in it
    2- what is the bitrate (if it is fixed) and what is the RAGE of bitrates (if it is variable)
    3-does anyone know what the speed of the buffer is? (to know what is the max speed of card we can even benefit from)

    The reason I want to know this is because I have the choice of the Lexar Platinum II 32GB for 99.99 or the Lexar Pro 16GB for 99.99.


    I know this is a fairly technical request, so thanks to anyone who can help!

    J.
     
  2. antithetic

    antithetic Mu-43 Regular

    150
    Jun 7, 2010
    City of Angels
    I took a look at a few of the video files taken on my E-PL1 with MediaInfo. It doesn't explicitly tell me that the video bit rate is constant but from the half a dozen video files, the bit rate stayed in the 33.1 to 33.7 Mbps. The audio bit rate is constant at 411.2 Kbps. The overall bit rate is ~34-35 Mbps.

    This were recorded on an SanDisk 16GB Class 6 card.
     
  3. julienrl

    julienrl Mu-43 Regular

    100
    Jul 28, 2010
    Ottawa, Ontario
    Thanks for checking!

    I understand, but some class 4 (like the Lexar Platinum II 32GB) have 10BMps write speeds.

    So if we over estimate that bitrate to 40Mbps to leave some headroom, that gives us 5MBps (8 bits in a Byte). So all we need are cards that can sustain that 5MBps + speed.
     
  4. julienrl

    julienrl Mu-43 Regular

    100
    Jul 28, 2010
    Ottawa, Ontario
    so does anyone know what the speed of the buffer is in the E-PL1?
     
  5. Rider

    Rider Mu-43 Regular

    139
    Oct 14, 2010
    Thanks--very helpful. It seems a Class 4 would struggle to keep up with video, unless the Class 4 is slightly faster than specs.
     
  6. julienrl

    julienrl Mu-43 Regular

    100
    Jul 28, 2010
    Ottawa, Ontario
    checkingout benchmarks takes care of that. Many class 4 are high than spec because there was already a need for faster cards before the class 6 standard was made official. Any class 4 that is at bare minimum specs would be just under what is needed (by 1-2megabits) so anything even marginally higher than the minimum would work. To be quite frank the REAL advantage of a faster card is for bursting.