1920 X 1080?

[Gary Adcock]

[Pat McGowan] “Does anyone know if the DVCPRO HD codec used in the HVX900 is a native 1920 X 1080 frame? If not, what is it?”

The DVCPROHD compression for 1920 x1080 yields a 1280×1080 frame size in a 4:2:2 color space.

the codec also handles 1080 24 material as Psf that is fully compatible with the Sony format spec for progressively captured content that plays back as interlace (progressive segmented frame)

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL

[Pat Mcgowan]

How does that compare to HDCAM Gary?

[John Sharaf]

Pat,

You have to understand that there are differences both in the native imager and in the recording format that return us to the old 720p vs. 1080 PsF arguements. The Panasonic Varicam and HVX900 cameras are 720 “native” imagers, as distinguished from the Sony 1080 imager; the recording format is also 720 vs. 1080, so that the Panasonic is forced to “crossconvert” or as some might say “upconvert” the 720 signal to 1080 when directed to do so. That is not to say that it is any worse or better!

Many folks make the point that an particulat 720 field has more resolution than a 540 “field” in the HDCAM, and the ultimate quality assessment is very subjective, especially as regards use in television where transmission and HD display characteristics inly “dumb-down” the picture.

The only time this discussion really has any merit is when the intended use is for “film-out”, namely conversion to motion picture film for exhibition in a conventional cinema; here a native 1080 imager and recorder will show a slight benefit.

JS

[Pat Mcgowan]

So the native frame size for the HVX900 is 1280 X 720?

[Gary Adcock]

[Pat McGowan] “How does that compare to HDCAM Gary?”

if you could see the 1’s and 0’s on the Sony tape you would see something similar. Sony compresses the capture to 1440×1080 into a 3:1:1 color space,

Since Sony does not want everyone to see what it is doing– without an xspri system you will not be able to see the native version of the sony format (OK quantel can also see the native bits)

Everyone sacrifices something to get that 1.5 GBps to tape. part of the “squishing of the image” is like what happens in the days of anamorphic camera lenses — the attachment “compressed” the image horizontally to fit in to a standard 4:3 film frame then when the lens is rotated 90-degrees on playback the image is stretched back out.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL

[Gary Adcock]

[Pat McGowan] “So the native frame size for the HVX900 is 1280 X 720?”

the imager in the HDX 900 is 1280×720

the frames can be 1080 or 720

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL

[Pat Mcgowan]

I thought this only applied to Sony HDV, and now XDCAM. This is the prmiary reason that we are adopting the DVCPRO HD product with the purchase of a HDX900 camera and AJD1400 deck.

The 3:1:1 colourspace o the Sony offering vs. the 4:2:2 colourspace of the Panasonic offering was the deciding factor.

The fact that the image size is 1280 X 720 is not a deal breaker especially when you take the full frame progressive factor into account.

[Pat Mcgowan]

Thanks guys, original question is now answered.

[Tony]

Pat,

Don’t forget that the HDX-900 has to uprez the 720 to 1080i when recording to 1080.

Not the most ideal method to accomplish this in my opinion but one more reason why it is cheaper in price than a native 1920×1080 camera.

Tony Salgado

[Pat Mcgowan]

I guess that’s true but I think the HDX900 represents the kind of value we need without worrying about a 3:1:1 colourspace. Our compositing team is happier with this choice.