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-   -   Flash XDR Maximum Data Rate Recording Capability (https://www.dvinfo.net/forum/convergent-design-odyssey/476594-flash-xdr-maximum-data-rate-recording-capability.html)

Mark Job April 10th, 2010 07:47 PM

Flash XDR Maximum Data Rate Recording Capability
 
Hi Dan or Mike or Tommy:
I have a general tech question regarding the Flash XDR which is not related to beta testing results. What is the maximum recording capability possible using the fastest CF Card media approved with the XDR ? In other words, is it possible to record on the Flash XDR with a data rate higher than 280 Mbps in I-Frame mode ?

Dan Keaton April 10th, 2010 08:27 PM

Dear Mark,

We performed tests to determine the highest bit-rate we can support.

Then we back off a little to ensure reliability.

Please do not expect any serious advances in bit-rates.

Mark Job April 10th, 2010 10:01 PM

No Serious Advances in Bit Rate Recording on the XDR ?
 
Hi Dan:
Would this limitation be hardware based or CF Card Media based ?

Rafael Amador April 11th, 2010 12:58 AM

I guess that the higher the data rate you set, the easier for the XDR to process the signal, but more performance needed to write it.
Lower data rate means a bigger effort to properly compress the signal but less writing performance needed.
Personally I don't see the need of higher data rate.
The Sheer 8b Uncompress files are only some 10% bigger than the XDR/NANO files.
That means that we can consider the 280Mbps files virtually 8b Uncompress.
rafael

Mark Job April 11th, 2010 12:28 PM

Higher Data Rate Recording on the Flash XDR
 
Quote:

Originally Posted by Rafael Amador (Post 1512741)
I guess that the higher the data rate you set, the easier for the XDR to process the signal, but more performance needed to write it.
Lower data rate means a bigger effort to properly compress the signal but less writing performance needed.
Personally I don't see the need of higher data rate.
The Sheer 8b Uncompress files are only some 10% bigger than the XDR/NANO files.
That means that we can consider the 280Mbps files virtually 8b Uncompress.
rafael

Hi Rafael:
I agree with you that uncompressed is *not required for television production, but is very desirable for digital cinema origination for later output to film. The less compression in that case would be the better.

Mark Job April 11th, 2010 12:36 PM

2nd Pub Beta .MOV QT Files @ 220 Mbps I-Frame Recording
 
Hi Dan:
Very disappointing results were obtained from the second public XDR beta when I attempted Quicktime .MOV file recording using I-Frame codec scheme instead of Long GOP 180 Mbps. When recording files for QT .MOV using the I-Frame recording scheme @ 220 Mbps the resulting playback yielded.....

A) No Sound ! (I'm testing this further to be sure)
B) Glitchy, unsteady video, which breaks up and turns green !
C) Audio popping, screeching, and clicking !

I can confirm I had good audio during recording with proper VU meter modulation indication within proper limits for good 48 KHz 24 bit audio recording. I will re-test these results once again to confirm wether I can re-produce these anomalies. * CF Card playback via USB 2.0 reader in my iMAC yielded excellent playback picture quality but no audio signal. (Actually a loud hiss could be heard)

** Obstreperous Chris the Rex, I just realized I have posted this in the wrong thread, so if you see the cross post in the other thread, then please delete THIS ONE HERE. Thanks MJ.


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