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ProRes HQ 24P playback / output issues FCP 6.0.2
Hi All,
I am editing a project using ProPrez 422 (HQ) source material at 23.98fps. Individual clips play back fine off my internal eSATA drive on my Mac Pro Quad Core off the HD with no stutter full frame at 24P. I tested my drive with the AJA Kona System Test app and I have plenty of speed. When editing, in FCP 6.0.2 the footage also plays back fine, although at “dynamic rez” but at full frame rate (24P) when I play the timeline.
My clips and my sequence settings match exactly. (ProRes 422 (HQ) 1280×720 at 24 FPS)
Now, the problem is if I render the cut and play back in FCP I get frame stutter that looks more like 15-18 FPS. Also, if I export in various ways ( I tested ProRes normal, ProRes HQ and uncompressed 8bit at 24 FPS ) the video plays back choppy even though the Quicktime info panel tells me 24 FPS playback.
Any idea why? The data rate is still within the range of trouble free playback. I tested an export with ProRes Normal (not HQ) to see if it was a data rate issue and it’s not (play back is around 35mBits/sec). Is this some kind of a pull-down problem? Why wouldn’t a Prores clip that plays back fine as a clip in Quicktime when rendered out at the same specs not play back properly? What other tests should I perform and is there a workaround or some sort of a solution? Is this a known issue?…
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Point Zero Pictures
<https://www.pointzeropictures.com> -
7 Replies
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are you working in a 24.0fps timeline? or 23.98?
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Hm…. Why are you editing with “Dyanmic Res”? When you render, is it because you’re using filters on the footage? What filters?
You should have zero problems with ProRes on your machine. there’s probably something simple hidden away that we need to find
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After some testing I’ve come to the conclusion that there is a problem with Apple’s ProRes rendering.
I have a huge problem as I have a 30 min film I edited that I can’t export into any kind of a format even if I try uncompressed, a non-ProRes codec.
I have 2K (2048×1152) 23.98 FPS source material coming from Cineform codec (shot with the SI-2K camera) that I transcoded into ProRes 422 (HQ) 23.98 FPS using After Effects at the same frame size – I didn’t scale it at all – just a straight transcode into ProRes. At the time there was no support for the Cineform codec on the Mac and there was no other way I could edit the film with FCP.
I then bring this into FCP and edit on a 1280×720 / 23.98FPS ProRes (HQ) timeline, that’s my output format. One of the reasons I chose this is to be able to pan and scan within a frame for reframing action (vertical editing.)
My tests confirmed that rendering out from this timeline produces a frame stutter problem, uneven playback, even though the Quicktime player tells me it’s playing back at 23.98 FPS. Apparently it’s a bug in the codec. Seems that if editing ProRes encoded source at a different frame size produces this problem.
My 1280×720 Prores clips have a data rate of less than 100 mBits/ sec and my system is able to handle that playing back full frame rates. It plays back clips double that date rate without a hitch.
What I tested is starting a fresh project with ProRes 422 (HQ) settings, bringing in a fresh clip that is (2048×1152) 23.98 FPS source material. Created a new sequence from a Prores easy set-up. I dragged this source clip into the sequence, at which point I get a warning that the sequence settings don’t match, so I make them match. If I export this clip it renders out fine and plays back fine at 23.98 FPS. Not so with a different sequence set to 1080×720 using the same source clip (2048×1125) I get the frame stutter problem.
So it seems that unless I use the SAME ProRes frame size as the source clips FCP / ProRes doesn’t like it. Again, everything else matches, especially the frame rate, except the frame size between the sequence and the clip.
BTW: I have no problem playing back (2048×1152) 23.98 FPS source material clips in Quicktime at 200 mBits / sec so it’s not a system or drive speed issue. It plays clean at full frame rate. A smaller frame: 1280×720 at 90mBits is not a problem.
Apple should test it like I did and find a solution to the problem. I haven’t been able to find a workaround and it’s a serious issue.
Can anybody chime in with a different experience?
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Point Zero Pictures
<https://www.pointzeropictures.com> -
Hm. I’m going to bet it’s because you’re using a non-standard frame size. That is, 2k is not a format FCP is “familiar” with and it’s causing some bug when you render…. or there’s a bug with ProRes that is freaking out on the non-standard frame size.
Have you tried trascoding your 2k to 1080 w/ ProRes? You won’t lose much res compared to 2k.
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No I haven’t tried that yet, but I continue to test this. You may be right about the 2K being “too much for ProRes to deal with. It looks beautiful though… It would be a major headache if I have to re-transcode all my clips at 1920×1080.
B4 I do that I need to test to make sure it’s not a general bug in ProRes where it doesn’t like to be scaled or cropped into and then rendered.
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Point Zero Pictures
<https://www.pointzeropictures.com> -
I am having the same problem with Pro Res HQ using 1080i footage . For me there is a stutter when I have a dissolve beteen 2 images. Anyone figure out hhow to resolve this?
Best, Connie
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