Latest post Wed, Apr 27 2022 5:21 PM by andym. 1 replies.
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  • Fri, Dec 3 2021 4:40 PM

    AMT3 for uncompressed linked alpha channel

    Hi All


      I am trying to use AMT3 (version 5.2.2) to write an uncompressed video file to be used as an alpha channel for a video file.  I have found a number of MADs that are accepted by the AMT interface, but none of them allow me to actually write the uncompressed frames.  I am initially trying to setup for 'DNxUncompressed Standard Format' or 'Uncompressed' 8 bit YUY2 4:2:2 format.  The sample in the SDK uses "Uncompressed" and when I extract a MAD from a MC AAF, it uses "DNxUncompressed Standard Format".  In either case, the data is the same.  The closest I have gotten still gets an exception after adding a few frames

    Microsoft C++ exception: GH14::Av::Generic::Exceptions::InvalidFormat at memory location

    and in the extended debug, it has 

    DEBUG - Unable to compute common estimated essence size for Unknown picture type

    and this is using the 'DNxUncompressed Standard Format' MADs.  Any thoughts would be greatly appreciated.



  • Wed, Apr 27 2022 5:21 PM In reply to

    • andym
    • Not Ranked
    • Joined on Thu, Jan 13 2011
    • Posts 128
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    • Avid Developer Moderator

    Re: AMT3 for uncompressed linked alpha channel

    In AMT3 there is a difference between essence description and target/encoding settings. 'DNxUncompressed Standard' is the description of a specific encoded essence format. As target/encoding format setting, only the label "Uncompressed" is supported. This works as expected on our side. 

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