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FCP 5 native “lossless” HDV editing? – Part Two
As I mentioned in my former post, – the question was not whether HDV is a “professional” usable format or not (compared to HDCAM, Varicam, etc.) but whether the new FCP5 is able to treat native HDV quality lossles not only with hard cuts but also while rendering like in apples statement: https://www.apple.com/finalcutstudio/finalcutpro/quicktours/native_HDV.html
So I did a simple camparison test:
I captured a sample HDV scene to FCP, then encoded it with MPEG StreamClip to as well as 10 bit uncompressed (136 Mbit/sec.) and likewise as a DVCPRO HD sequence – which should be a far better codec (12 Mbit/sec.) than the original mpeg2-transport-stream (3,6 Mbit/sec.)Both sequences had been equally treated with 3 filters and rendered in Final Cut Pro 4.5.
Then only for web application both sequences had been exported as Photo Jpeg files (100% quality) from which via PC the downloadable .wmvHD files (1920×1080) had been encoded.
While the result of the 10 bit editing shows nearly no visible artifacts, the editing with the
compressed DVCPRO codec shows heavy banding and color artifacts especially in the blue sky
where a gradient filter and a color enhancement filter were used.This simple test confirms the fact, that apparently only uncompressed editing doesn`t alter the visible image quality while rendering – independent from the used codec (even HDCAM is compressed). That is even more important when a heavy compressed format like HDV is used as source material – with the intention to rescue all residuary quality while editing.
This may be a disillusionment for all who hoped for lossles native HDV-editing in FCP5.To download the samples click:
https://www.rtv-studio.de/editsamples.htm
Regards
Roman Teufel
RTV-STUDIO -
12 Replies
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Roman,
It is impossible for there to be lossless quality in an HDV codec timeline when you render an effect. I think there has been a misunderstanding. Nobody is expecting that. Even a DVCPRO HD timeline will be lossy.
-Christopher
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Hi Christopher,
I agree to your opinion, but then apple shouldn`t talk about “lossless HDV editing while using filters etc”.
In my understanding it -
Apple doesn’t state “lossless HDV editing while using filters etc”. They say, which it true to HDV, DV and any other “lossy” format, that you edit the footage in it orignal codec, making “lossless editing” t/f the camera. However, as with any lossy codec, modifiying the image WILL give you a quality reduction (one generation loss). Staight cuts in FCP 5 should however keep the quality captured from tape.
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Apple tells in the “Native HDV” quick tour movie:
“… video quality is totally lossless, because the media is never converted or transcoded. It
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There is a substantial render process involved when going back out to HDV. The people at NAB are very reluctant to talk about it, but it sounds like it’s a long wait. Unless you have a board that will support real-time output.
All the best,
Tom
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Yes, it could be missunderstood… But the “lossless editing” thing has been talk about since DV came, and that’s also “wrong”.
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Hi Eric,
so as a conclusion it means finally:
If I want to save all possible quality out of originally HDV, – I have to use at least 10 bit uncompressed 1080i in conjunction with a Blackmagic Decklink HD card and a fast disk array like the Apple Xserve Raid, – the conventional, classical and professional way for HD-postproduction.
For us it is an important matter of decision, because we are at the beginning of the post of a large documentary filmed with HDV and we are very interested in conserving all possible resources of this “poor mans HD-format”. I -
Aloha Roman,
Am I correct in understanding that you think that all of the effects are being done in RGB color space versus YUV? And if so, is this conversion the big culprit rather than simple decompression and recompression?
Staying in YUV color space is why we opted to work in uncompressed SDI for SD editing and now it appears that the same thing maybe true for HD.
By the way, your shots are really nice.
Aloha,
Ken
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Hi Ken,
it
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OK. I want to admit out front that I am not an expert. But, I am extrapolating from other Apple functions like; exporting FCP to DVD Studio Pro. So when I hear that Apple is saying; “Lossless HDV editing”, I surmise that this means, I am getting the same results as if I converted the HDV to an uncompressed format, added filters and such and whatever else, and then exported. I think that is definitely possible. You might SEE artifacts in the timeline while you edit, but when you render out the file, it will render from the original. So this saves you time and drive space.
The same thing happens when you export to DVD Studio Pro. Compressor grabs the original images and applies effects and transformations in FCP, or grabs the original file if just a cut is made. You don’t get any better than what the original file was, but you don’t get worse either.
I think the big question is; what is the color space that FCP composites in. When laying RGB graphics on a YUV timeline… you would get horrible results in FCP 4.5. If you used Calligraphy or LiveType, you would get much better results because those packages actually pre-composite in a full 24 bit RGB colorspace and then output back to whatever your timeline is set at–giving you better results. My guess is (and hope) is that Apple composites everything in 32 bit space. Currently, that colorspace has a big effect on diminishing projects that I’ve done in YUV with the 4.1.1 colorspace.
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