Welcome to Pinnacle Systems - Forums Sign in | Join | Help

Re: magic timewarp number?

  •  11-26-2009, 15:51

    Re: magic timewarp number?

    ....aahhh, you're forgetting that regardless of whether you shoot 50i or 59.94i (assuming we're talking DV or HDV) the data rate doesn't change - it stays constant at 25Mb/s. The amount of data used in each field/frame is NOT the same when using 50i or 59.94i. Therefore - logically - if you play back material that is shot at 50i at a frame rate of 59.94, you are increasing the data rate by a factor of (approx) 1.2. Therefore you are no longer within the specifications of DV or HDV. Also, when you've created a timeline, you've specified the render codec for that particular timeline. That codec also specifies the data rate to be used so, when you place your 50i footage on a 59.94i timeline, you're "speeding up" the footage, but you also need to reduce the data rate by a factor of 0.83 in order to now reduce 59.94i frames of 50i data into a 59.94i data stream... It's one thing to come up with a magic number to create a 1:1 frame correlation - it's something else entirely to fit it withing the constraints of the various codecs....

     .....and if your talking DV as opposed to HDV, you need to realise that there are a lot of calculations going on as everything is resized from 720x576 to 720x480....

     Personally, I think that forty-two sounds like a blazing-fast number....   Stick out tongue

View Complete Thread
Copyright © 2012 Corel, Inc.. Terms of Use | Privacy Policy