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Novice Q – bit rates on HPX500/900
So I’m doing an edit in the next week, matching some HPX500/900 footage. I was delivered an HDD loaded with files from these two cameras. The footage from the 900 was pushed through a nanoflash during production, and from that cam I’ve got loads of MOVs. The clips from the 500 are still in their original MXF wrappers. No problems there, I did some test loads of these clips into final cut, they play fine, etc.
My question is, the footage in FCP is listed at 12/14 mbps respectively, and I was expecting all the clips to be at 100 mbps. So, either the DPs messed up on set with their file settings, or, more likely, the 100 mbps footage is in the clips, but FCP just downconverts when it imports? So how do I get at the footage in its full quality?
One thing that worries me is – the total size of the files I was delivered is 65GB. At 100mbps, that would only be, what, 10 minutes of footage? Instead, I’ve got more like 70 minutes of footage – and at 100mbps, I should have something like 400GB right? Maybe I can get the MXFs in 100 mb/s but I’m screwed on the MOVs?
Anyway, I really appreciate any help anyone can shine on this. Thanks in advance.
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9 Replies
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The files are at their highest settings now – don’t worry about it.
Chris Tompkins
Video Atlanta LLC -
Meaning, they’re not going to get any higher quality than 12 and 14 mbps? If so that’s kind of problematic because we were looking for a higher quality. Do you think they have files at 100 and just exported low bit-rate versions?
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Hopefully someone else can chime in here about the data rate FCP shows. It’s not something to worry about.
The footage was shot DVCPRO HD. This is the highest setting those cameras shoot. There is no lower or higher data rate option.
Chris Tompkins
Video Atlanta LLC -
Yeah, the problem is that the footage is for local HD broadcast news, so I was hoping to get around 25 at a minimum (typical hd broadcast comes in at around 20 I believe). Of course the footage looks good and all, but the mbps I have here (unless I’m missing something) is a great deal lower than we (the dps, producer and I) had agreed upon.
It’s just really curious to me because both of the DPs have a ton of experience and both explicitly mentioned they were shooting at 100. And I know the cameras are capable of doing just that, so it leaves me wondering. I Might have to have a conversation with our producer, but I don’t want to do that and then find out I’m just being a dope and missing something obvious.
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DVCPRO HD by nature IS a 100mb format.
DV25
DV50
DV100 (DVCPRO HD)Don’t worry about that column in FCP.
Chris Tompkins
Video Atlanta LLC -
FCP and data rates:
Chris Tompkins
Video Atlanta LLC -
Hey, thanks a lot Chris. It looks like you’re right. I did some more looking into the metadata and found that the bit rate is listed as 102,304. And then I checked out the manual for our Io HD (not because we’re using it fr this particular job, but because I remembered it had a section on codecs/recording formats and their data rate. Anyway, it listed dvcpro hd at 6-14 MB/second, which fits with your above info.
But my question then is, what the??? I mean, obviously this is one of those things where the metrics just differ a little. But do you know much about the relationship of that 100 mbps bit rate of dvcpro 100 and the actual 10/14 MB/second throughput?
In the end, it’s kind of fortunate because we don’t have the storage solution necessary to support true 100 MB/second video, but do you know how it is that this works out?
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Well. I feel stupid. Got the answer. 100 mbps = ~12.5 MB/s
1 megabit = 0.125 megabyte
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No I don’t. But people here do.
Your Hard Drives speed throughput should be far north of a 100mb/s
Chris Tompkins
Video Atlanta LLC
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