Latest post Wed, Dec 28 2016 11:08 AM by Phil Norris. 4 replies.
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  • Wed, Dec 7 2016 8:06 AM

    JPEG 2000

    Hi,

    Just testing Avids Jpeg 2000 codec for the first time and I get metadata back from FFMPEG like this.

     

     

    Metadata:

       product_name    : Avid Media Composer 8.2.6

       company_name    : Avid Technology, Inc.

       timecode        : 03:43:19:20

    Duration: 00:00:07.36, start: 0.000000, bitrate: 61549 kb/s

       Stream #0:0: Video: jpeg2000, yuv422p10le, 1920x540, SAR 1:2 DAR 16:9, 25 tbr, 25 tbn, 25 tbc

     

    So this must be wrong right?

    Maybe not - 10bit JPEG2K file sizes are approximately HALF of 8bit 50Mbit/XDCAM MPEG2 - which would work out logical if the material is indeed 1:2 SAR with a resolution of 1920x540. Half the info was trashed.

    If the Media Composer JP2K was 1920x1080 - then I would expect files at roughly the same size, as the codec is more advanced it can logically pack 10 bits of information into files at roughly the same size as 8bit XDCAM.

    But these files are 1/2 the size and Media Composer reports 10bit 1920x1080 - what's going on with JPEG 2K in MC? where are the specs?

  • Mon, Dec 19 2016 12:12 PM In reply to

    Re: JPEG 2000

    No takers?

    It looks like Media Composer is either telling me that I have full 10bit HD at half the file sizes of 8bit HD - or it's not telling me the whole truth about Jpeg2K.

     

  • Mon, Dec 19 2016 12:29 PM In reply to

    • mjolnarn
    • Top 10 Contributor
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    Re: JPEG 2000

    They have lowered the speed and quality of the J2K encode , it was far better when it first was introduced

    Mac: 17" Macbook Pro i7 2,66 ghz with 8Gb Ram, 500gb 7200rpm drive___ PC_NEW Win10 Pro Mbo Asus Rampage IV Black CPU Ivy Bridge-E 4960X ( = 12 x 4... [view my complete system specs]

    Tomas 

     

  • Thu, Dec 22 2016 2:03 PM In reply to

    • knejmann
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    • Århus, Denmark
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    Re: JPEG 2000

    Is this interlaced material? That could explain the half height part as the fields would be encoded separately.

    Media Composer 2020.12.6 - Windows 10 - Dell 8520 - Blackmagic Decklink Studio 4K - Interplay and NEXIS storage - Avid Artist Color. [view my complete system specs]

    Kåre Nejmann

    Danish Broadcasting Corporation - DR
    Aarhus, Denmark 

  • Wed, Dec 28 2016 11:08 AM In reply to

    Re: JPEG 2000

    Hi Kåre,

    knejmann:

    Is this interlaced material? That could explain the half height part as the fields would be encoded separately.

     

    Exactly! I found it too - it's J2K fields as per ticket - https://trac.ffmpeg.org/ticket/1102 - it's actually 2X as effective file size wise + it's 10bit to boot :)

    A worthy intermediary maybe - fancy throwing it around in grading and see how it holds up?

     

     

     

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