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Vegas – Sony YUV Codec – Decklink – Impressions so far…
Thought I’d post this for those folks who are using Vegas, and thinking about a BMD Decklink Card. If anyone has results that are contrary to the ones below, by all means please let me know!
Thoughts so far:
If you acquire footage from DV, and plan on outputting it through the Decklink card, your best bet is to stick with 720×480 projects. I haven’t found a good solution for using 480 media, in a 486 timeline (field order appears out of wack). It also eliminates some rendering, until the final output. (If anyone has any suggestions on how to use 480 media in a 486 timeline without it looking like crap, please let me know!)
Print to tape works great – I’m using a non-approved P4 setup, and so far haven’t had a single problem with previewing, or printing to tape through the Decklink card. The odd lockup in Vegas since the installation of the card, but that’s about it. The only issue I’ve found so far, is you’ll have to play with pre-roll and offsets a bit – the deck is (inconsistently) about 2 seconds off. For most things, not a big deal – but can be a big pain.
Sony YUV Codec is terrible – So far, I’ve been less than impressed using the Sony YUV Codec for anything… especially for Graphics. Color gradients look worse than rendering with DV. If you’re doing any kind of processing of your video, don’t use the YUV Codec… Especially, it seems, if you’re working with DV Source material (because it is already compressed so heavily). 90% of our commercial projects are processed quite a bit in post (converted to 24p, gamma corrected, color corrected etc.), and the YUV codec is murder on the video. So far, with my comparisons anyway, DV in Vegas actually looks better than re-rendered YUV. (Again if anyone has any experience to the contrary, I’d love to hear it.) If you make a color grad in Vegas, or even Photoshop then ‘pre render’ it to DV – it looks way cleaner than ‘pre rendered’ to Sony YUV.
Here’s the workflow I’m using now, which is producing the best results (using DV source material). Do your basic editing in a 720×480 timeline, do your color correction, legalize your levels etc. Then render to 24p uncompressed AVI files. Start a new project (29.97 fps), import your rendered media – do whatever finishing you need to (insert slates, titles, etc.), then print your entire project to tape using the BMD 4:2:2 10bit codec. It will have to re-render the entire timeline (to take the 24p media, to 30i). Lots of rendering – but using regions, and the batch render options in Vegas it’s not too bad. Set it up at night, come back in the morning and you’re good to finish.
Obviously, for say a documentary, this workflow is less than ideal… For commercials and short-run projects, it works great. Few extra steps, but the final results take flat boring video, and gives it a nice look.
MY biggest worry with using Vegas and the Decklink, at least from the results I’ve been seeing with the YUV codec, is if you capture through the Decklink to Sony YUV – then do any kind of post processing of your footage, it’s going to completely fall apart… color correct etc. Each pass through the YUV codec, seems to make things that much worse. So I haven’t found a good way to work with the footage that doesn’t require rendering the entire timeline (which is going to make it terrible for longer projects).
I’m going to experiment further to see what kind of results I get capturing from SP with the YUV Codec, then printing it back… I think if you’re just doing a straight capture, edit, and print back to tape it should be OK (essentially one pass through the YUV Codec). But, if you’re Mr. Picky Pants like me, and want to color correct or do any kind of post-processing, it could be nasty…
I’ll post more results when I get a chance to experiment more.
Michael Linton
http://www.centricproductions.com -
4 Replies
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[mikelinton] “if you capture through the Decklink to Sony YUV – then do any kind of post processing of your footage, it’s going to completely fall apart…”
Michael,
Why would you want to capture DV through ANY codec? I would think the starting point is simply to get the DV onto the hard drive with no processsing.
Also, please tell us more about wanting to work with 486.
Gary Kleiner
Learn Vegas and DVD Architect
http://www.VegasTrainingAndTools.com
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Sorry, perhaps I wasn’t clear. If you are capturing footage with the Decklink card, its coming into Vegas in the Sony YUV Format. If your source material is DV, you’re going to capture it through firewire.
In other words, if you are using SP as acquisition in the field, capturing with Vegas to YUV (the only option you have), then do any kind of color correction, which will then require ANOTHER render using the YUV Codec, the footage starts to fall apart… Graphics completely fall apart… Regular video looks ok (because there is enough other information there), but so far my experience using generated media, graphics, animation etc. is the YUV codec just tears it apart – especially gradients, or solid colors. I was just playing around rendering DV to YUV, and then re-rendering it again and it seems my assumptions were correct. Albeit less obvious than graphics, there is a decline in subtle color details (banding, etc.) more so than rendering DV-DV. I haven
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Well thats really dissapointing to hear the Sony YUV codec is worse than DV.
But you can always render to BMD 10-bit and not have the problems right?
BMD 10-bit still looks better than DV re-rendered correct?The reason 480 and 486 timelines don’t work is that the pixel image aspect
is slightly off (the 6 lines).Rendering 486 graphics to a 480 timeline will cause tearing while 480 graphics
to 486 will cause aliasing problems. (sigh) -
Well. All in all, it’s good… now that I’ve tested it more, and played a bit – it’s not as bad as I had originally thought. But, still not as good as I would’ve hoped for.
I think at the end-of-the-day, if you keep your graphics/animations as uncompressed AVIs and then render them down at the last print-to-tape phase, it will be great. But, if you render your graphics to YUV and then again in the print-to-tape phase, it certainly isn’t pretty. And that’s easy enough to have happen – especially if your graphics aren’t quite legal, and you’re using Vegas to change levels etc. for output to BetaCAM you’ll be re-rendering it again.
The BMD 10 Bit Codec doesn’t ADD anything – i.e. you put in 8bit, you’re gonna essentially get 8bit (because Vegas only processes in 8bit).
Also, one of my earlier comments isn’t quite accurate – you CAN’T print to tape using the BMD 10bit codec from Vegas. You can render it to a file, then use the BMD Control Panel tool to print it to tape. You can pre-render your timeline to it, no problem. But you can’t print it. Vegas only gives you the option of using templates that use the Sony YUV Codec at 29.97 fps. Anything else, it ignores.
Colors also play a role in how good the output is. Our company logo is green, for example – so we often use that color for slates etc. And the YUV codec seems to do a lousy job rendering it… it’s essentially a color gradient that ‘rotates’ around the screen slowly as the program info is displayed. I rendered the animation of the gradient background to a file, then overlay the program text on top, then had to render it again to print to tape. The 2nd pass through the YUV codec just destroyed it. The first pass was OK – you could see some banding in it, but it wasn’t horrific (DV creates some too). Wasn’t as smooth as DV or uncompressed, but still acceptable. Did the same thing with a blue, and it looks fine – hardly any difference between DV, YUV, or uncompressed. Rendering the same background to uncompressed, doing the text overlay, then rendering to YUV produced much cleaner results (basically the same as the first pass through the YUV codec).
And from the video files I’ve processed to death, render them to YUV, BMD, DV – and the end of the day, video files look fine. That is – anything that had banding in YUV, also had it with the BMD Codec, and the DV codec – just different degrees, and different places. It
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