Is Uncompressed Video Format Compressed?

[Alec Gitelman]

so how does “uncompressed” format compare to “none”? is “none” a 4:4:4 YUV format or RGB?

also, my observation, “uncompressed” limits you to a 720×486 frame. if you’re exporting 720×480 dvcpro footage the extra 6 lines may cause a number of issues for you, especially when doing compositing and graphics.

[Russell Lasson]

Yes, what is that “none” thing about?

The default size for uncompressed is 720×486, but you can change that to 720×480 by selecting custom on an export or just changing your sequence compressor.

-Russ

[Graeme Nattress]

Yes, “uncompressed” is compressed in the sense that it only records 2 out of every 4 chroma samples, but it’s uncompressed in the sense that it does not throw away any of the data it records.

No point going 4:4:4 with DVCproHD or HDCAM though – no benefit at all, really. I don’t think any of those decks will do 4:4:4 anyway – you’d have to go to D5 or HDCAM SR for that.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Rafael Amador]

[Graeme Nattress] “Yes, “uncompressed” is compressed in the sense that it only records 2 out of every 4 chroma samples, but it’s uncompressed in the sense that it does not throw away any of the data it records”
That the point. What is the difference in between 8b Unc and DVCPro50? The two of them are 8b, 422. The two of them record the half of the chroma information, but DVCPro50 apply some other kind of compression (DFT or DCT or so, I’m not sure about now) to get smaller files. 8b Unc it writes all this information as it is without applying any other form of compression.
Cheers,
rafael

[Martin Baker]

QuickTime None codec is 8 bit 4:4:4

Martin
Digital Heaven, London UK
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[Petteri Evilampi]

We all know that dv, dvcam and dvcpro are highly compressed, 4:2:0, 4:1:1.
Doesn

[Graeme Nattress]

Yes, the 4 implies a full resolution luma, or Y. I’ve found that old film on DV PAL looks very nice indeed, but it all depends what format you got it telecined to.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Peter Dewit]

Compression isn’t jsut the chroma subsampling. Uncompressed footage will also give you a higher datarate and thus better quality. That being said capturing uncompressed isn’t going to eliminate any compression that was there to start with. DV footage, for example, is already highly compressed on the tape itself. The DV codec in FCP is designed to match that compression method thus really nothing is lost loading DV footage in as DV. Likewise you really aren’t going to gain anything loading DV in uncompressed since there isn’t enough information on the original tape to provide that quality anyway. There may be other reasons to bring it in using the Uncompressed codec like mixing DV with other tape formats and titling. I’m not sure but I think effects might look a bit better on an uncompressed timeline too.

For your film project it really depends on the format you are getting telecined too. If you go to a higher quality format like Digibeta loading in uncompressed might be worthwhile.

[Russell Lasson]

[Russell Lasson] “So, is there a loss when you go from a 4:1:1 or 4:2:2 compressed format to 4:2:2 uncompressed? Will uncompressed 4:2:2 through away half of the color information or will the program doing the converting figure that it doesn’t need to because the color space is less than or equal to the uncompressed format and just translate (not compress) the current values into the uncompressed format, thus not losing anything?”

-Russ

[Rafael Amador]

Yes but the quetion of Russ haven’t been answer. Supose that we had telecined a B&W film. We record it in 8b Unc. Then we make a copy in DV. Would be any difference in between the two movies?
In theory, I think, it shouldn’t be any difference. If so, as Russ says, working in DV would save a lot of space in his HDs and the quality of the final movie would be exactly the same.
Russ, probably the best is if you make some tests. I would suggest you to apply a CC filter and put the saturation all the way down. just to make sure that there is not any remaining Chroma. This i would do it just because I’ve got no idea about telecining:-)
Cheers,
rafael