: Xacti HD1, mediocre video quality maybe due to a bug

Posted on Fri Apr 07, 10:26 by another guest
Home Page:
Seriously, you mean all that fuss, was just about this little thing. We could have told you about the bug, if comments had been allowed to the article.

It has to be fixed, and seriously, they should have looked at 15/19/25Mb/s Mpeg4. But at 9Mb/s it fits on a DVD, that some Mpeg4 enabled players can play, at similar run lengths to a normal DVD, and at better codec quality and resolution then a normal DVD. It is also better than most HDTV transmissions I have seen for codec performance. In perspective, the HDTV's poor codec performance is probably going to wipe out a lot of the improved codec performance of the HC1 over a HDTV transmission. But HDV performance is goign to be better on HDDVD or Blu-ray. Plus the optical performance of the HD1 video just sucks, but what do you expect from the cheapest camera. They would have been better using Smalcamera autobrite sensor chip, very cheap, and wider aperture, should be closer to HDV camera's optical performance.

Something else that's interesting. Maybe you can get more out of HDV compared to 9Mb/s Mpeg4 in broadcasts in PAL/Secam HDTV countries then you can is NTSC countries. In NTSC countries they tend to have much narrower channels then in PAL/SECAM countries, that fit in only 19Mb/s Mpeg2. But, some broadcasters have been dividing up that limited bandwidth into lower quality sub channels. So the results are pretty poor. In PAL/Secam countries though, the channels can be upto more than 50% wider, I think, that allows much more bandwidth (though in Australia they have stuck to the 19Mb/s scheme) and some Europeans are trying better than Mpeg2 codecs (Mpeg4 I think, I don't know if they are trying H264).

But one experiment, throw a small pebble into a still pond, and record the ripples. I notice they are very jagged in HDV, but in the, limited footage I have seen from the HD1, there does not seem to be any. I wonder if Mpeg4 is better at handling curves in motion (except for the above HD1 error) then HDV.

Heard anything about the Ambarella H264 cameras yet, they were to announce last month? They may have better data rate too.