Latest post Wed, Jan 8 2014 8:26 PM by bwilhelm. 9 replies.
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  • Wed, Jan 8 2014 4:44 PM

    • kmb23
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    Frame rate conversion issue - motion blur after transcoding

    Hey everyone,

    I'm working in a 1080p/23.976 project and have been trying to transcode a bin full of 1080p/25fps footage to my frame rate. 

    I set up a new 1080p/25 project for the new footage, consolidated, and then brought the bin into my 23.98 project for transcoding. 

     

    Here's what the footage is supposed to look like:

     

    Here's what it looks like after transcoding: This workflow has been working fine up until now. Just a few days ago I transcoded 1080i/50 footage that went off without a hitch. I've tried everything I can think of. Any suggestions would be great!

     

  • Wed, Jan 8 2014 4:50 PM In reply to

    Re: Frame rate conversion issue - motion blur after transcoding

    Those are terrible rates to convert between (23.976 / 24 / 25). Usually, it is done by slowing down or speeding up from one to the other. Going from P to I is slightly more forgiving, but it is not likely to give you broadcast acceptable results.

    If you AMA-link to 23.976p footage and transcode it to 25p, the 23.976->25fps conversion will be baked into the transcode, so it would be better to transcode in 23.976, then use the transcodes in a 25p project, as this will give you control over the type of motion adapters / timewarp. A FluidMotion Timwarp would probably be the best approach.

    Media Composer Symphony | PT Ultimate | Win10 HPZ | OSX MBP | ISIS5000 [view my complete system specs]
  • Wed, Jan 8 2014 4:56 PM In reply to

    • mjolnarn
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    Re: Frame rate conversion issue - motion blur after transcoding

    All good advices from Job.

    Last time I did this I ama linked in a project with the native framerate and opened up that project in my 25 p project, then promoted the motion adapter, selected fluidmotion and did a video mixdown, looked rather acceptable.

    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 

     

  • Wed, Jan 8 2014 5:25 PM In reply to

    Re: Frame rate conversion issue - motion blur after transcoding

    Except, I think, the OP is trying to get 25fps footage into a 23.976 project.  In that case, follow Job's advice, but the opposite...

    Transocde your 25fps material in a 25fps project, then bring it into your 23.976fps project.  Adjust motion adpaters accordingly for the best results.

    Symphony v2019 | OS 10.13.6 • Nitris DX • 12-core MacPro (Mid 2012) • 36 GB RAM • Facilis Terrablock 24EX [view my complete system specs]

    -- Kevin

  • Wed, Jan 8 2014 5:29 PM In reply to

    • mjolnarn
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    Re: Frame rate conversion issue - motion blur after transcoding

    Kevin Klimek:

    Except, I think, the OP is trying to get 25fps footage into a 23.976 project.  In that case, follow Job's advice, but the opposite...

    Ok, sorry, misread the initial post.

    Doing the same workflow although contrary should work however, so no transcode in that initial project, only ama link.

    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 

     

  • Wed, Jan 8 2014 6:44 PM In reply to

    Re: Frame rate conversion issue - motion blur after transcoding

    To the OP's original question as to why this workflow is exhibiting different results than in the past, it's because someone at Avid decided for v7 that we'd rather have frame blending in our transcodes as a default instead of not. This is pretty dumb in my opinion, and luckily you can revert the setting back to the way it was. In your settings, go to Render and UNCHECK the frame blending preference. Whew, back to normal.

     


    Mac OS X 10.9.5, MC/Symphony v8.4.2, Nitris DX, AJA ioExpress Sony HDCAM-SR SRW-5500 Panasonic AJ-3700HD D5 etc. [view my complete system specs]
  • Wed, Jan 8 2014 7:15 PM In reply to

    • bwilhelm
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    Re: Frame rate conversion issue - motion blur after transcoding

    Hi, just to clarify, the default enabled state for the "frame blending" setting (a feature introduced in v7.0.3), is intended to match the legacy behavior, which was to unconditionally use frame blending for non-trivial cross-rate conversions like this one (23<->25).  The default behavior shouldn't have changed in any version of MC7.  By disabling the setting, the user has elected to override this behavior - opting to use a temporal "pulldown" style of conversion as opposed to the spatial "blending" conversion.  Note that the setting applies to transcodes as well as to the creation of new motion adapters in any other scenario in MC.  Thanks!

  • Wed, Jan 8 2014 7:48 PM In reply to

    Re: Frame rate conversion issue - motion blur after transcoding

    My experience had been that ALL versions of Avid used frame blending when transcoding to different frame rates.  I like that we now have the option to change that, since the only other workaround was to transocde in a matched project and then adjust motion adpaters independently for each shot.

    Symphony v2019 | OS 10.13.6 • Nitris DX • 12-core MacPro (Mid 2012) • 36 GB RAM • Facilis Terrablock 24EX [view my complete system specs]

    -- Kevin

  • Wed, Jan 8 2014 8:15 PM In reply to

    Re: Frame rate conversion issue - motion blur after transcoding

    Hmm - my experience was that I always got a perfect (non-blended) added pulldown when transcoding 23.976p clips in a 59.94 project. So reading the readme here:

     

    Use frame blending in Motion Adapters: When clips of a different frame rate than the sequence are dropped on the Timeline, a motion adapter is automatically applied. Motion Adapter effects allow mixed rate clips to play at the project's frame rate and to have the correct field motion.

    The frame blending setting will give you some flexibility with mixed-rate media by offering a choice between temporal smoothness and spatial smoothness. It controls whether or not any new motion adapters use the Blended Interpolated render option.

    When this option is selected, the Blended Interpolated mode is used. The behavior is the same as previous versions of Media Composer, and uses Blended Interpolated for most motion adapters. When it is not selected, the Interpolated Field mode is used for interlaced clips, and Both Fields mode is used for progressive clips

     

    This made me believe that I would have to uncheck this new default option in order to not have blending for this conversion.

    And personally, for what it's worth, blending for any frame rate conversion is not my default preference, so I am glad at least that the option is there not to use it.

    Mac OS X 10.9.5, MC/Symphony v8.4.2, Nitris DX, AJA ioExpress Sony HDCAM-SR SRW-5500 Panasonic AJ-3700HD D5 etc. [view my complete system specs]
  • Wed, Jan 8 2014 8:26 PM In reply to

    • bwilhelm
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    Re: Frame rate conversion issue - motion blur after transcoding

    Mark Spano:

    Hmm - my experience was that I always got a perfect (non-blended) added pulldown when transcoding 23.976p clips in a 59.94 project.

    That is true, because the conversion from 23.976p to 59.94i doesn't fall in the "non-trivial" category.
    It will still continue to add 2:3 pulldown by default, regardless of the state of the new setting.
    Only in conversion cases when "blended" was used by default will disabling the setting have an impact on the behavior.
    I'll see if we can update the readme to express this more clearly - thanks!

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