Several Unrelated Questions (From Newbie)

[thisiswells]

1) Is the WindowsXP operating system a bottleneck to DVCPRO-HD support over
Firewire with PC-based NLE, or is this something developers (such as Avid) could tackle independently?

2) Alternatively, if it is not possible to transfer data through Firewire with the 1200A
would the HD-SDI interface would be considered a suitable substitute?

3) Is there a visually discernable difference in quality when not using a native camera codec?

4) Do all Avid products transcode to an intermediate wavelet-based codec for editing?

5) Why?

Thank you very much, Michael, for taking time to answer these relatively basic
questions as I try to learn more about the Avid products.

Brian Wells

 

[MichaelP]

Hi Brian -

1) DVCPRO support was needed at the OS level in order to be captured directly over FireWire. This was delivered in the SP2 release of the Windows XP release last November. v.5.0 and later support direct capture and output of DV25, DV50, and DVCPRO 100. In the case of 24p versions, the applications will remove and add 2:3 pulldown (ADVANCED or NORMAL) on the fly for all formats without the need for a Mojo.

2) Capture over FireWire is fine.Avid uses the native codec when captured this way just as it does with DV25 and DV50. Capturing over HD-SDI decompresses the DVCPRO 100 stream to an uncompressed HD stream which can be captured in products like MC Adrenaline, DS Nitris and now Symphony Nitris as uncompressed or in any of the Avid DNxHD codecs for editing and mastering. This can be done as 8bit or 10 bit and in all cases is 4:2:2.

3) Avid offers; native codec, DNxHD renders or capture, or uncompressed. Depending on the amount of processing and effects rendering needed, working in uncompressed or DNxHD will retain the original quality of the image better than working in native DVCPRO 100. In the case of DV25, DV50, DVCPRO 100, etc. the frames need to be decoded, effect added, and rendered back as DV. Multiple generations of this can affect overall image quality. Avid allows the users to render as native DV or as DNxHD leaving the choice to the editor. If only rendering color correction, dissolves, etc. then working in DVCPRO 100 all the time will be fine.

4) Avids do not use wavelet based encoding, nor has it ever. Avids will work with native codecs for DV, and soon HDV or as DNxHD or as uncompressed depending on product. I suggest you read the Avid DNxHD white paper I wrote that is available on the Avid.com website.

http://www.avid.com/DNxHD/masteringQuality.asp

5) Answered in #4

Hope this helps.

Michael