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irenel36038886
Participant
October 1, 2018
Question

Bit Rate is too low when exporting from Premiere to MXF / OP1a

  • October 1, 2018
  • 1 reply
  • 1663 views

Hello,

I am trying to follow a spec sheet for a broadcast delivery to export a file from Premiere CC 12.0.1 - the broadcaster wants Op1a, 25 fps interlaced, minimum data rate 50 Mbps.

I have not made this kind of file before, but did some reading/ googling and everything has seemed relatively straightforward. I am using the MXF OP1a XDCAM HD 50 PAL 50i preset (which I thought is supposed to produce a data rate of 50 MBps?) and only adjusting the number of audio tracks (broadcaster wants 8 channels), otherwise using it as is.

But after I export the file and open it in Quicktime inspector to make sure all the specs are correct, it is showing me that the data rate is 9.22 MBps. I have done this export over and over again and the number is always the same. But there seems to be no way to adjust the data rate for the export—everything I have read says that you just pick the format and the right data rate should be automatic.

I don't want my file to be rejected for a data rate that is too low... not sure what is causing this and I don't see anywhere to adjust a setting to fix it. Help?

    This topic has been closed for replies.

    1 reply

    R Neil Haugen
    R Neil Haugen
    Legend
    October 1, 2018

    The 50i in that preset is for 50fps *interlaced* ... not anything about bitrate.

    If you're running a 25fps interlaced timeline select a preset to match the sequence then set the bitrates to match your needs.

    Neil

    Everyone's mileage always varies ...
    I
    irenel36038886Author
    Participant
    October 1, 2018

    I'm not sure that's correct.. the preset has the number 50 in it twice: It is XDCAM 50 PAL 50i

    I thought the 50i refers to framerate /interlaced, and I thought that the first 50 indicates the highest data rate (I can choose between XDCAM 25 / 35 / 50 presets).

    I am not able to select "match source" for export—it tells me "the course file's video stream is not compatible with this preset," and I have read in multiple places that the XDCAM 50 / 50i preset should be the correct one.

    This preset does not allow me to make any adjustments to data rate at all.

    And I don't think the timeline is an issue... when I export the same timeline to ProRes, I get a 169 MBps datarate. So this is happening in the export process.

    R Neil Haugen
    R Neil Haugen
    Legend
    October 1, 2018

    Thank you for catching that, I was 'remote' kicking into my editing rig from a laptop, and didn't catch the first fifty.

    And on getting to the editing rig, used that preset ... this is what MediaInfo sees of a test bit of RED media I used ...

    Which seems to be appropriate.

    On my Win10 machine, I can't load this into QuickTime player to view by Inspector.

    Neil

    Everyone's mileage always varies ...
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