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General HD (720 / 1080) Acquisition
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Old December 22nd, 2012, 12:00 AM   #16
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Re: Need Help and clairty

Quote:
Originally Posted by Leon Kolenda View Post
How do you know that none of the bit rates are constant 20 Mbps, it seems to me that if I choose 1080/60I then I can choose HD FX (24) Mbps is this spec not constant?
Yes, but its better to shoot with the highest quality 28 mbps PS mode.
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Old December 22nd, 2012, 11:26 AM   #17
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Re: Need Help and clairty

So are you saying that if I shoot in the PS mode on my Sony VG-20 (1080/60p) and I render out (PPro CS6)
to their spec, (1080i/29.97 mpeg-2, Constant 20-Mbps Quality -4, Upper Field first), that I won't see a slower playback? I have never done any slow motion or any redering out to a different FPS than what the Original shoot was.
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Old December 22nd, 2012, 01:11 PM   #18
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Re: Need Help and clairty

If you use 60p, it CAN be used for slo-mo, but it does not HAVE to be.

Frames per second, bitrate, and the other specs have nothing to do with playback speed of the clip. They are "industry" ways to express the technical quality of the data in the clip.

What Eric is saying is to capture at the highest quality, edit at the highest quality, THEN when it's time to render it out, you choose the needed settings, and let the NLE convert to the needed output format in the render.

One of the problems here is that you are confusing many of the settings, where they are applicable, and struggling with what they are and how they might affect the video.

Take a little time to google (or just search DVi!) each of the words and get a handle on what they mean, and you'll be in a LOT better shape here... right now all the terms and concepts being thrown around probably seem like gibberish because you don't "speak the lingo"... need to learn the lingo, THEN your queries will either have been answered, or will be easier to answer... so far you're "challenging" the answers or coming to wrong conclusions from an incomplete grasp of the subject matter.

Frames have already been well explained, I think you've got resolution (sort of)...

Bitrate is a bit of a tricky thing - it is how much data is available per second of video playback - less data=lower quality, more data=better quality. There are lower limits, below which your image will look like poo (technical term <wink>), and upper limits beyond which the playback will stutter or freeze as the data rate overloads the buffers in the playback equipment, or exceeds the capabilities of the media.

Bitrates have been increasing with faster processors in cameras and faster computers to edit footage. As your camera will warn you, as you go higher on the bitrate, you limit your media options for playback. Higher bitrates will also make editing more of a challenge if your computer is old or slow... 17Mbps was the "high" setting for many cameras, just 2-3 generations of cameras ago!


Shoot at the highest setting, import into your editing program at the best setting IF your computer can handle it... WHEN you get to rendering the final output, do one render for SD, one for HD, using the specs your broadcasters tell you they need/want, and deliver the files via whatever method they prefer. You should find all or most of the settings either in a preset or a customizable menu when you go to render, learn them as best you can beforehand so you don't have to render too many times while sorting it out.
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Old December 22nd, 2012, 11:46 PM   #19
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Re: Need Help and clairty

Thanks Dave, that helps a lot.

So far I have what I think is a pretty fast computer, I built it myself.
WIn7 64 Pro, Intel i7-4.0 Ghtz. 24 gigs of DDR3 fast memory, Nvidia GTX460 GPU, Cuda compatible to Adobe software, 1 Gig of GPU Ram, 480mb Corsair SSD drive, used for OS and Apps.
12 Terabyte WD Raid 5 NAS. 1 Terabyte 7200RPM WD Black Caviar for scratch disk. Does not break a sweat.

Oh yes, If you shoot in the 1080/60P which is a 28 Mbps, is that a constant? The Station here's Spec is calling for a 20 Mbps constant.
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Old January 12th, 2013, 04:24 PM   #20
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Re: Need Help and clairty

Quote:
Originally Posted by Leon Kolenda View Post
Oh yes, If you shoot in the 1080/60P which is a 28 Mbps, is that a constant? The Station here's Spec is calling for a 20 Mbps constant.
Suggested workflow:

Shoot 1080/60p 28mbps->Edit->Render 1080/60i 20mbps constant

Alternative workflow:

Shoot 1080/60i 24mpbs->Edit->Render 1080/60i 20mbps constant

Shooting 60p will give more flexibility and quality, but in either case it is the render setting in your video editing software that needs to be 20mbps constant not the camera.
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