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(MPG4) Sanyo Xacti (all models)
A compact 720p MPEG4 digital media camera recording to SD Card.


 
 
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Old July 11th, 2006, 05:29 PM   #31
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Another fact is many foreign companies don't come in or gave up selling audio/visual products here because of frenzy competition here in Japan, for example, Philips.
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Old July 12th, 2006, 08:47 AM   #32
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OK, sorry for the delay, I have had to try to download most of clip three times, due problems, it being a plugin, and needing to be done in a single session (unlike a download).

Quote:
There was a large amount of macro blocking and bland details surfaces (so 19mb/s H264 is definitely needed). The h264 codec tries to cover this up by blurring the block borders, but this leaves blurry smudgy crawling blobs in many places and missed some blocks. The footage quality keeps stuttering, I didn't note if it was related to image gop or not.
The footage looks much better. H264 was blurring things out. The stuttering/shuddering of the original image is more obvious. The stuttering seems to be more gop like, with inter frames having compression problems, like speckled. Macro blocks are more obvious. Much more detail, the blurry blob problems of the first bend are cleared up considerably, replaced by real detail. Movement still works, looks strange, but for consumer it gets there. H264's features on h264 cameras should further improve the appearance of motion artifacting, but I think that 18Mb/s rate of AVCHD will be needed at 25/30fps to offer a worthy alternative to HDV.

If anybody wants to buy a H264 camera to look much better, I suggest using at least an bitrate that is equivalent to the one you are comparing too, bitrate is significant. I think this camera really needed 19Mb/s to let mpeg4 show up 19/mb/s Mpeg2.

Quote:
When the camera fell on the ground there was a lot of crawling detail as the exposure changed to compensate. I did notice some pixel crawl in the beginning bend.
The crawl is much less noticeable and finer. I looked at it quickly, with very little sleep, so I don't remember seeing any crawl on the first bend, it could well just have been because of the macro blocks at reduced resolution.

Unfortunately the clip finished just as you started filming your friend, where I was hoping to examine the pixelisation I saw there last time. I still saw some before it stopped. This pixelisation problem, we have seen from the baby clip on wards, it is one thing that mars the cameras performance.


New cameras:
I would like to outline some of the problems, and some work arounds, in case Sanyo is reading. I have posted links to various threads on another forum for a Sanyo rep. And why shouldn't Sanyo be a major video camera maker, delivering the best cameras they can.

Noise. We see there is a lot of noise in various clips filmed in less than ideal conditions. This kills compression performance, reducing quality, as noise is irregular and not very compressible. A solution would be, bigger aperture lens for low light, bigger sensor pad size better binning functions, higher bit-rates. After these are applied, noise removal/pixel restoration software working across pixels and frames would be effective.

The Jagged diagonal edges, from the blocking bug, and that pixelisation problem gone.

Latitude:
The sky is not white or yellow, when it is blue, shadows are not black. Multislope/autobrite senors, bigger sensor chips/pad size would help.

Motion problems:
Steals compression quality away. Higher bit-rates, better Mpeg4 support are two solutions. Better image modeling. Sacrificing quality in fast moving objects, while maintaining outline shape of the object and outline shape of inner details is preferable to blocking. It is preferable to maintain detail on static, or slow moving objects the eye can still track (obviously the speed level this can be supported to will have to be adjusted for bandwidth. This would be a graceful degradation in performance from motion compared to what happens in Mpeg2 cameras today. I believe that the camera already seems to support some shaping, because I have noticed round bubbles under magnification.

Focus/Zoom/exposure stepping. Needs to be smooth and seamless.


The suggestions so far are of minor cost, the following suggestions are still small cost but less so that the previous suggestions.

10 bit Uncompressed HDMI out, live USB uncompressed out, and camera control (yes, I would like to mount it on a tripod and use an external recorder, for live events or in studio, novel, but lovely). Would be nice if it could be used as a desk computer cam too.

Lanc jack, sync, microphones, or remote I could put on tripod handle with all Lanc functions (rec, stop, individual variable focus/zoom/aperture/gain etc).


Despite my objectivity, I don't think Sanyo will release a Mpeg4 handheld camera with a pro quality codec, that would require probably 36Mb/s Mpeg4. So, even if they go to 19 or 25 Mb/s, when things get moving it maybe just prosumer quality, but enough to keep many of us satisfied.


Actually, what about a Windows CE/Mobile version, even with phone, that would be cool, like the old Sharp viewcams. There seems to be a lot of media player/pocket digital TV devices around, those features could also be incorporated into one device.


Quote:
Thanks for the help Kaku.
Wayne Morellini is offline  
Old October 31st, 2007, 07:04 AM   #33
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Dear Kaku
Quote:
Originally Posted by Kaku Ito View Post
yeilds
"We're sorry but we can't find the iWeb page you've requested."
I would be very grateful if you would post it to Vimeo.
Tim
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Old October 31st, 2007, 07:12 AM   #34
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Here's the link for my old site.

http://xtream.ne.jp/kakugyo/affordab...eoPodcast.html
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Old October 31st, 2007, 07:16 AM   #35
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That was quick, thanks!
Tim
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Old October 31st, 2007, 07:21 AM   #36
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Kaku Ito

Wow, it's great to see a fellow DH'er on this site... i DH as well, my site (not as great as yours) can be located here:

http://downhillpics.googlepages.com/

i take my pictures with the Nikon D40, here are a few of me!

http://downhillpics.googlepages.com/...mDrop-full.jpg

http://i29.photobucket.com/albums/c2...s/DSC_0037.jpg

I Plan on taking my Sanyo HD2 out to the mountain very soon, can you do me a quick favor? can you take a picture of the HD1 connected to your bike so i can get an idea where to connect my HD2?

thanks!
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Old November 1st, 2007, 01:50 AM   #37
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David,

I had a lot more good stuff, but leaving links to this site ending up inviting hackers, so I stopped providing as much video clips.

Your shots at Diablo looks great! Let's get together at fujimi or takamineyama in the future!

Maybe I will show you more in the future (after InterBEE).

Answering to your question about the mount, I use Manfrotto SuperClamps and their attachments.

Anyhow, if you were to do it, probably better to tape or wrap the cam on your helmet. Make sure mount it well so it does not shake.

If you ever come to Tokyo, I will show you.
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Old November 1st, 2007, 02:00 AM   #38
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David,

Also, I see you use iWeb nicely, too. Congratulation.

My new site is here, too
http://www.onebikeguy.com

Go to Kakugyo and you will see more stuff there.
Kaku Ito is offline  
 

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