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February 9th, 2008, 11:47 AM | #16 |
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Opps, I stand corrected.
H1 SDI - no embedded audio. I had read a few posts that said they where using a XL H1 SDI out w/ embedded audio. May be they where mistaken and where actually using the firewire out. So, I did more research on the subject. Also, its interesting that Canons pages on the H1 make no mention of it either. |
February 9th, 2008, 03:28 PM | #17 |
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Hd-sdi
So then what is H1 recording to tape, then out via SDi to an uncompressed timeline? Bypassing firewire, is there less compression going into the computer? I can see better results on a Blu-ray disc when compared to HDV workflow. Can this be explained?
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February 11th, 2008, 02:47 AM | #18 |
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Newby clearing head
Please forgive me jumping in but even after reading the first page - with GOP's and 4.2.2's (whatever they are) I am still unsure if the picture taken from an H1 is better from the tape or out of the SDI to a hard drive.
Is there a definitive on this one? Thanks Dave
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February 11th, 2008, 08:20 AM | #19 |
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hd-sdi vs. tape
I will give a crack at it. This is my guess. If I take a photo in 8 bit mode and convert it to 16 bit mode before editing and then take it back to 8 bit mode the histogram will look good w/out verticle lines running thoughout. This might be somewhat true regarding video. If the Chroma and Luninance are being subsampled to 4:2:0 to tape (compression) and then sent to the hard drive via the firewire and finally to a compressed codec timeline like pro rez or hdv, then color correcting will become very restrictive on how far one would be able to push cc or added effects. Mind you alot of effects can hide the clipping and so on by implying that it was intentional.
Now in my experience, when comparing this same footage shot on tape was instead sent out to computer via SDI (BNC Cable) to an UNCOMPRESSED 8 OR 10 bit timeline I got better results. It has a much greater tolerance with cc and effects before smooth tonal gradations are compromised. Now what is going on, I don't have a clue. Is the signal still 4:2:0 but a full 1920x1080 or even 4:2:2 1920x1080 compared to 1440x1080 4:2:0 by way of firewire. Now on the field with a proper set up like Matrox with a hd break-out box, one can be sure its' a full 4:2:2 1920x1080 subsampled signal. Keeping this signal pure by putting it in a HD project on an 8bit Uncompressed timeline takes all the guess work out of it. You would have the best the Canon H1 can do. Now here is the most important part for me,"final output". Taking that large data file, the Matrox AVI 8bit Uncompressed file and loading it in Encore CS3, I can produce a HD Blu-ray disc that has absolutely no banding or artifacts due to the fact that it was not compressed twice. I hope this helps as this is only my opinion and experience with my workflow. |
February 13th, 2008, 12:40 AM | #20 |
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Is 24F out of the HD-SDI port imbedded into a 60i stream or is it 23.976 fps?
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February 13th, 2008, 01:56 PM | #21 |
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Lets clear a few things up...again
Here is some facts to save you from searching through several earlier posts.
1. HDSDI out of H1 is 10bit 4:2:2 @ 1920x1080 HDV is 8bit 4:2:0 @ 1440x1080 1a. 24f is output from HDSDI embedded in 1080i 29.97 2. HDSDI gives a much better grading format and effects work clip to work with. 3. HDSDI gives you true 1080p...not 1440x1080 like HDV recorded to tape 4. HDV (that which has been recorded to tape and directly recorded through the firewire port) is heavily compressed long GOP (like a DVD) format. It REALLY SLOW to render on an old computer. PERIOD. It is horribly blocky for greenscreen work. It is pleasing to the eye...but don't try to modify it! 5. Recording to HDV and then outputing HDSDI does not magically make the video better...garbage in - garbage out. Once it is recorded to HDV the show is over. 6. Is HDSDI better? YES. 7. Is HDSDI more economical? NO. 8. Should I shoot HDSDI in the field? Not unless you have a good sized crew and do extensive testing with a "foolproof" system. You can even record HDV and do a second system capture to uncompressed or ProRes and just slate each shot if you want better quality and safety at the same time. 9. Should I consider a different camera/format if 10bit 4:2:2 is what I want? YES. hope that helps
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February 13th, 2008, 02:06 PM | #22 |
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*Applause* Thank you very much! I aware of all of that, except that it applies pulldown.
BTW, one thing that might not be clear for G1 and XL-H1 users is those cameras will output 8-bit color packaged in 10-bits. It's not 10-bit color, even though it's in an HD-SDI 10-bit stream. |
February 13th, 2008, 02:41 PM | #23 |
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Feel free to repost and correct....I am exhausted from typing all that.
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February 14th, 2008, 08:46 AM | #24 |
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hd-sdi vs. tape cont.....
Good Morning Will,
Recording to tape is exactly what? I know output from the tape via firewire is a compressed 1440x1080 4:2:0 signal. In fact in ppro cs3 the file is stated as just that. Now, again when that same recording from tape is sent to the computer using the SDI then in fact the signal is stated as 1920x1080 and the file is much much larger, better quality and impossible to visually see the difference when compared to pure HD-SDI recording to computer before and after editing the same for both. The key in the workflow is keeping it in an uncompressed timeline. I know all this to be true because I have tested this again and again. My question is does the chroma and luma stay subsampled to 4:2:0 or does it in fact output at 4:2:2 via the SDI while at 1920x1080? Pro rez is better than HDV in my opinion but not better than 1920x1080 from tape to computer via SDI (to an uncompressed timeline) Matrox AVI Bottom line is that the higher resolusion from tape using the SDI instead of the firewire does give a much better file to edit with and produces a much much better Blu-ray disc. Thanks |
February 14th, 2008, 10:10 AM | #25 | |||||
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Quote:
Quote:
to 1920x1080 when coming from tape, unlike live capture of HDSDI which yields more resolution, better dynamic range(lots more info in the shadows), and less compression artifacts. Quote:
It's kinda like dropping a GIF into a TIFF or PSD file in photoshop. The file says 24bit color and no compression, but the GIF obviously wasn't!! Quote:
like I mentioned before, you have already saved the footage as HDV and are just converting from that to uncompressed and not actually shooting uncompressed. Quote:
1920x1080. It could look marginally better and is obviously easier to edit and deal with (other than the file size). I'm not arguing that. I'm just saying that a live ProResHQ or Uncompressed capture from HDSDI during the shoot looks MUCH better than capturing from tape in any format.
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February 14th, 2008, 10:42 AM | #26 |
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hd-sdi vs. tape cont.....
Thanks Will,
The clouds are starting to roll back. Just one more thing, are you absolutely sure that the mini tape in the Canon cannot receive the full 1920x1080, if not then how is the camera capable of uprezing the file? I though what's on the tape is analog until it is digitized out either by SDI or Firewire. Also isn't the sensor a full 1920x1080, wouldn,t that be sent to tape? I really appreciate this Will. Is there anything from Canon to substantiate this? Regards, troy |
February 14th, 2008, 10:51 AM | #27 | |||
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Quote:
Quote:
Quote:
Yes. Their website and documentation.
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February 15th, 2008, 11:53 AM | #28 |
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hd-sdi vs tape
Hello Will,
Maybe I am missing something, but it seems to me that Canon is silent on the color space other that HD-SDI out. I cannot find any detailed info on what you have stated. Can you point me in the right direction. Thank you for your time, I really appreciate this Troy |
February 15th, 2008, 01:23 PM | #29 |
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If it is 1080/60i HDV it is 4:2:0 in any camera.
That is the HDV standard. http://news.sel.sony.com/hdvcamcorde...ology_book.pdf
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February 16th, 2008, 07:27 AM | #30 | |
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Quote:
HDV is always what the XL-H1 records to tape. HDV is always 1440 pixels wide, not 1920. It displays as 1920 during playback because the pixels are stretched to cover the same width that 1920 pixels would. That is why you'll hear it said that HDV uses rectangular or anamorphic pixels. What's on the tape is never analog. It's digital. And it is compressed to meet the HDV standard. I would do some searches on HDV. It is not just a vague term, but rather a very specific way of compressing a digital video and audio signal. What comes out of the HD-SDI port is not compressed. Finally I believe the sensor is not 1920, but rather 1440. So the camera is "uprezing" the width when the signal comes out of the HD-SDI port. HTH ;). P.S. I have no dobut that HDV uprezed by the camera and stored as ten bits instead of eight will give a better result than capturing w/o the uprezing. But I also have no doubt that, like Will said, uncompressed will look much better. So: HDV captured via Firewire < HDV captured via HD-SDI <<< Uncompressed HD-SDI. |
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