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-   -   HD200/250 Feedback? (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/85162-hd200-250-feedback.html)

Ronald Wilk February 1st, 2007 12:11 AM

Sticky details
 
I am glad to hear that you have not noticed that particular defect but, nevertheless, I understand that the motion recording issue that others have noticed has been addressed and rectified in the HD 200/250 series.

Ron

Jonathan Nelson February 1st, 2007 02:16 AM

Quote:

Originally Posted by Ronald Wilk
I am glad to hear that you have not noticed that particular defect but, nevertheless, I understand that the motion recording issue that others have noticed has been addressed and rectified in the HD 200/250 series.

Ron

Fascinating, I must have miscalculated the acuteness of this defect.

I recall reading about it exclusively in Adam Wilt's Texas Shootout.

Now, I am interested in becoming well versed in the new Prohd revisions. The assertions of improved noise reduction and other enhancements have compelled me to consider the investment of a hd 200/250 in the immediate future.

Is there a website that can elaborate more on the Prohd improvements featured in hd 200/250?

Werner Wesp February 1st, 2007 08:03 AM

Fragments that 'stick' are always a concern with MPEG-2 streams, however I have never noticed it out of my HD101 - and trust me, I've been looking for it at times. 'defect' is a strange word to use for such a thing. 'Limitation' or 'budget' might come into mind.

MPEG-2 encoders become better and better over time, so any artifact of lower quality should lower in time. However, it needs to be said that the GOPs are longer with the new series (200/250), and that is the usual reason for MPEG-2 artifact such as this - because there's just 1 refreshed I-frame every 12 frames, instead of 6. Those 12 frames are covered with the same amount of data as the 6 frames in the previous encoder. Movements between frames is lower of course, but still, it would be a feat in itself to maintain the quality of 6-frame-GOP-25p-video, while coding it in 12-frame-gops (50p). My point is: the encoder needed to be improved to maintain the same image quality. And I can't really say the overal image quality has improved (even less 'dramatically').

Of course the new 14-bit DSP is more precise, but that's another subject...


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