Keep in mind that RGB is the superset of all other colorspaces. Assuming the RGB system has enough bit depth to handle the signal, there is virtually no loss converting anything else into RGB. I would prefer an editor that can handle the largest colorspace possible while fading, adding effects, etc. Working in straight YUV will suffer more color loss since it's not as robust a format as RGB is.

That may be true but if the dv signal on my dv tape is in a YUV color space what advantage do I have in converting it to RGB ? I'm also not sure why YUV would suffer more color loss, according to Apple color accuracy is one of the reasons Final Cut pro uses YUV. Avid also boast that their programmes work in YUV color space, it seems to be a selling point. surely top end programmes like these would work in RGB if it was better to do so.

Regards

Berti

>> This can cause unintended changes to the color and brightness of video processed by Vegas.

To color: Yes, but only in very rare cases.
To brightness: No. Vegas does NOT change brightness by YUV to RGB conversion. Luminance range is precisely kept by Vegas after render.

I would never switch from Vegas to any different NLE only because of the RGB rendering.
Premiere was told to have YUV rendering since Premiere Pro. But this was not (and still is not) true.

Yes, Edius preview is pretty fast and in many cases there is no rendering needed depending on what hardware you use there. If you're heading a realtime-system then Edius is a nice choice. Vegas never claimed to be a realtime-system but the Vegas workflow beats the rest in many cases even without realtime fx handling.

Marco

YUV is an artificial system. Nothing 'sees' in YUV and nothing displays YUV. The system was developed because of technical limitations when TV was first designed. Yes there can be issues in the RGB<->YUV conversion, lots of nasty looking maths involved.
Blackmagic have decided to ditch support for FCP, they claim one reason being that more and more customers are demaning to work in a RGB space. Also RGB can display a wider gamut than YUV, sometimes this can work against you, you can create colors that YUV cannot handle but then again far from all media these days is delivered in YUV over television transmission.

Question: I thought Edius only works with Canopus hardware cards.

The latest version - Edius 2 - also works with common OHCI cards.

Marco

Just a quick comment:

As I understand it, YUV was developed not because of technical limitations, but rather as a very clever way to reduce the amount of data that needed to be transmitted in order to create a color image. Indeed, the first color TV systems operated by sending Red, Green, and Blue images sequentially (I think the CBS system operated at 144 fields/sec). Big drawbacks were (1) lack of compatibility with the then-existing NTSC monochrome standard, (2) "rainbow" effect from fast-moving objects (for example, a golf club would appear as a series of RGB clubs during the swing, and (3) poor image resolution due to huge bandwidth needed. YUV was developed because researchers discovered that the human eye sees sharpness in monochrome, not color, so by extracting the gray-scale "Y" component out of an RGB image one could then derive U and V (or originally I and Q) channels of greatly-reduced bandwidth and send that information instead. In the receiver the YUV (YIQ) components would recreate the RGB signals feeding the CRT.

Perhaps what was meant by "technical limitations" was the limited bandwidth available for color signals. Also, please forgive me if I'm simply restating the obvious.

Yes, Edius2 Real Time features are very impressive (full DV quality with OHCI version) and I really hope Sony will improve vegas RT features.
But Edius2 still have gaps:
-cannot copy/paste several events
-cannot add only video (or audio) on Time Line
-no sequence… like Vegas :(((
-audio features very limited

I cannot tell about YUV/RVB conversion, I never had any problem with that.

I have both Edius and Vegas. The strengths of Edius are its realtime capabilities, titler and chroma keying. (The strengths of Vegas are much more than this, but I think the members of this forum know that already).

Compared to Vegas, Edius can do smoother realtime preview on external monitor, however there is a limited playback buffer and when this is exhausted the video stutters badly. Depending on what filters you use, this is not as bad as it sounds - some effects play back without depleting the buffer at all. Others, like the XPlode effects, choke up almost straight away.

Edius comes with TitleMotion, and since the titles play back realtime, including crawls and rolls, this allows you to create moving titles on video very quickly (but if you try to apply video effects to titles the alpha channel gets screwed up, so there are some constraints here).

The Edius chroma keying is very good, this has always been a strong Canopus feature. (I think it could be because they upsample 4:1:1 video to 4:2:2 for processing, but I might be wrong on this.)

While there are certain Edius features that are impressive, some of the basic workflow would make you weep with frustration. After you have become used to quickly bashing 2 events together in Vegas to create an easily adjustable crossfade, the steps involved to perform the same basic task in Edius are so complicated and non-intuitive that I will never use this program for everyday work. In Edius, even selecting and dragging clips is not straightforward unless you are prepared to use shortcut keys for everything. There is also a serious delay in response whenever you want to adjust a clip or transition edge.

It is a mystery to me that a company could produce a new NLE program with such a poorly designed user interface.

Another bugbear (for me) with Edius is its lack of keyframing for most of the effects and filters. In Vegas, you can keyframe almost everything and it means that everything is customisable to help you achieve the effect you want. In Edius, most of the keyframing only allows you to fade the effect in and out, there is no way to adjust effect parameters (e.g. motion blur length) over time. (To be fair, there is an effect called 3D PIP that has good keyframing, but this is only a small fraction of the effects provided).

I would recommend anyone in the market for a SW-only NLE to try out Vegas before considering Edius (or anything else). Edius has some good points, especially when it is teamed with a Storm card, but it simply cannot tackle the wide range of editing jobs that are possible with Vegas.

(By the way, although I have a Storm card, my comments above about Edius are based on running it just with an OHCI 1394 card. Another disadvantage of a hardware-dependent solution - my Storm broke in January and it was almost 3 months before I got it back working again. Luckily I have Vegas to depend on!)

Richard Hunter

"Keep in mind that RGB is the superset of all other colorspaces. Assuming the RGB system has enough bit depth to handle the signal, there is virtually no loss converting anything else into RGB."

Hi Chienworks. I don't think this is actually correct. I don't have the conversion formulas handy at the moment, but I believe some legal YUV values translate into negative or >255 RGB values which are obviously out of gamut. When these YUV values are converted to RGB by the editing program some clipping takes place. How much practical effect this has on the image quality I am not very sure, since I have not tried it out for myself.

Richard Hunter