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PPro CS6 multicam question
Hello,
We’ve recently switched to Premiere Pro from FCP 7, and I had a quick question regarding the way multicam works in CS6 Premiere Pro:
Does PPro constantly stream the video from all cameras, regardless of what angle is selected, or whether you’re editing or rendering? Or is it smart enough to know that, for example, CAM 1 is “on air”, so don’t stream CAM 2 and CAM 3?
Right now, we’re multicam’ing a project with 2 streams of C300 and 1 stream of H264 (I believe it’s a 5D), and while the multicam works OK to actually do the intitial cut & trim, we’re getting a pretty significant performance hit during final rendering, especially once we have colour correction and LUTs applied (via LUT Buddy). I suspect that this is because PPro is streaming all angles and processing all the different codecs, even though it really has to only stream/render the 1 angle which is “on air”. The situation isn’t helped by the fact that we need to render to DVCProHD as our final master, but I’m still surprised by the magnitude of the performance hit.
Does anyone know if this is actually how PPro operates? While I would expect that all 3 streams need to be present during editing, but are all 3 being streamed during rendering/output as well? And has this been changed/improved in the CC version?
Thanks!
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5 Replies
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Doesn’t sound like a multicam issue.
Lut buddy is pretty intenstive…I assume you are seeing red render bars in the sequence
when adding it?It would help to know what sort of system you have, and your storage connection.
And if you have a qualified GPU. these all have a tremendous impact on performance.
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Yes, we do get red render bars with the LUT Buddy. But even without any effects, it just seems that the conversion from C300 and/or H264 to the DVCProHD is taking an inordinate amount of time. This is why I was wondering if PPro was processing/transcoding all the streams of the multicam, even though only 1 is visible.
The system is pretty beefy. I don’t have the exact specs with me, but these are new Dell workstations, with the nVidia K5000 for acceleration, and we have 32GB of RAM and I believe it’s a 12 core CPU.
We’re connected to a SAN for storage, with a 10gig pipeline, so throughput shouldn’t be an issue.I also notice that CPU usage seems quite low when rendering.
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how do you mean conversion? export time? how long are the sequences?
ya sounds like you have a more than adequate screaming fast system.
I just realized you said CS 6. I know I had a few issues with CS 6
and multicam, but exporting times seemed reasonable. -
The sequences are 1/2 hour interview shows, so we have about 20 minutes of multicam in each episode (the rest is titles, credits, etc).
Because we need to do a final output to DVCProHD .MOV for delivery, we use DVCProHD sequences for editing.
Doing the actual multicam is not the problem, the problem is that when we add LUT Buddy and/or colour correction, we get red render bars, and the render takes a long time to crunch through.
My thought (and I may be wrong about this) was that – even though only 1 camera is “on air” at any given time – PPro is still reading all 3 video streams, and converting from either C300 or H264 (depending on the camera angle) to DVCProHD (the sequence codec), even though it really only has to convert 1 stream (whichever camera angle is visible).
I guess I could re-phrase the question to ask, if there was a way to commit or collapse (as we would say in FCP 7) a multicam sequence so that only the final chosen clips are used on the timeline, would our render times be significantly faster?
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the multicam sequence is collapsed. you only see one video track and 2 audio tracks.
I doubt it’s going any slower because of accessing other clips (same as you pointed out)
you might try copying the contents of the edited sequence and pasting it into a new
sequence.then export and see if it takes less time. That was something I had to do occasionally
with cs 6 to get an export out.
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