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Old Jun 5, 2010, 3:48 AM   #991
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Thanks fish for the quick reply,
I will try your suggestions for using ZI8 as a PMP.


MOVIES ARE IN .MOV FORMAT.
STILL PICTURES ARE IN .JPG FORMAT.


Low light testing (room illuminated by 18W CFL lamp at night) results,

1280x720,30 fps,1 min,56.12 MB
1920x1080,30 fps,1 min,99.97 MB
848X480,30 fps,1 min,29.99 MB

Day light (sunny) under shade,

1920x1080,30 fps,1 min,99.97 MB
1280x720,60 fps,1 min,74.43 MB
1280x720,30 fps,1 min,90.05 MB
848X480,30 fps,1 min,53.90 MB

Still pictures (taken all 5 of them in day light),

3072x1728
1.67 MB,2.12 MB,2.30 MB,2.18 MB,1.94 MB.

8 GB TRANSCEND SDHC CARD DATA TRANSFER SPEEDS ASESSED BY CONNECTING ZI8 TO PC VIA FLEXIBLE USB PORT (NOT USING MEMORY CARD READER),

WRITE SPEED (TRANSFER FROM PC TO CARD) 998 MB IN 5 MINUTES 12 SECANDS.
READ SPEED (TRANSFER FROM CARD TO PC) 998 MB IN 2 MINUTES 55 SECANDS

THEREFORE THE READ SPEEDS ARE ALMOST DOUBLE THE WRITE SPEEDS.

NOTE ,IN A VIDEO:

1080p=1920x1080 pixels
720p=1280x720 pixels
WVGA=848x480 pixels
FPS=NUMBER OF FRAMES CAPTURED IN A SECAND (EG. 60 FPS AND 30 FPS.)
MP=MEGAPIXEL (NUMBER OF PIXELS SENSED BY THE SENSOR, I THINK MEGA HERE REFERS TO I MILLION).
HENCE MEGAPIXEL COUNT IS DIRECTLY PROPORTIONAL TO THE VIDEO RESOLUTION.
THE LARGER THE SENSOR THE BETTER THE LOW LIGHT PERFORMANCE. SO POCKET CAMCODERS HAVE A POOR LOW LIGHT PERFORMANCE DUE TO SMALL SENSORS USED TO SAVE SPACE.

8 GB class 6 (faster read/write speeds enables video to be recorded at a high bit rate with out hiccups) SDHC card is cheap and ideal because if 1080p or 720p/60fps mode video will consume 100 MB space in a minute then it will record 8000 MB (roughly 8 GB because 1 GB=1024 MB) in 80 minutes which is the time the battery lasts (90 minutes) after a single complete recharge. In case you are buying a cheap additional spare battery (like pentax) then 16 GB card would be better for you.

Finally, fishy i just want to ask you that has the rolling shutter defect some thing to do with video decoder used ? I found that when the video (.mov 720p/60fps and 1080p) was played in VLC 1.0.5 it showed the rolling shutter defect (1-2 horizontal lines slowly moving down) but i found no trace of this defect when the same video was played in arcsoft media player. More over the video is very well stabilised in the 720p/60fps mode!




Last edited by drramkishorehs; Jun 5, 2010 at 5:25 AM.
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Old Jun 5, 2010, 6:41 AM   #992
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Kodak Zi8 bitrate issue.

Hi! I'm owner of the device. The device is great, but there is a bitrate issue. I've recorded some test video and have got video with various compression artefacts. It looks very ugly on 42'' LCD. I think, it happens because of poor bitrate: 5,7 Mbit/s average - 720p/60 and 4,7 Mbit/s average for 720p/30. Could anyone help me to solve the problem?

Kodak Zi8, fw 1.06

UPD: Bitrate in 1080p mode looks ok. Its between 11 Mbit/s and 16 Mbit/s. Picture quality seems to be good. So, the bitrate issue is in 720p mode. Some tests shows, that bitrate of 720p mode is in range from 3 to 6 Mbit/s.

UPD2: Bitrate in WVGA mode is in the range from 1 to 2 Mbit/s. Picture quality is poor with many compression artefacts.

It looks like constant quality compression preset in firmware. How to connect with Kodak software engineers with the issue? I m sure, that they should let users to choose picture quality manually.

Last edited by petunder; Jun 5, 2010 at 8:30 AM.
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Old Jun 5, 2010, 9:30 AM   #993
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Quote:
Originally Posted by Wayne12 View Post
I humbly submit these suggestions for the future model for Kodak. Please feel free to comment or suggest more:

Water proofing (seriously, why does the top model not have water proofing). With encrypted radio Mic.

Macro and wide angle lens on all models (or at least a mount on the camera). The lens could be molded side by side and rotated, or slid, across the sensor to select.

Better lowlight/noise, more latitude, better rolling shutter.

3D (24mbs+).

FULLHD 60 and 50p.

Super HD resolution sensor (for photos, proper pixel binning for low light and noise, and interpolation to fullHD and 720p), bigger than 1/2.3 of an inch.

High speed shooting modes (even FULLHD/720p 100/120/240p in 24mb/s+). It would be good to have it in SHD, for preshoot buffering in stills mode, like the Casio F1 did).

Multiple channel external mic (in camera stereo at least).

Live HDMI out feed at 10bit+.


GPS tagging, with focus/iris lens in the top model.

If the top end model had all these features, looked like a digital still camera, had performance within reach of the HX5/HD2000 and cost $299US, I would not mind .


The following could be added as a firmware upgrade to the existing zi8 camera as well:

The normal 25 and 50 frame a second modes that non NTSC countries use (many countries out side of the US and Japan). The picture would display better on PAL TVs, and it helps with better quality at lower data rates.

More advanced options: EV control and an advanced settings menu for shutter, gain, focus and iris (if it has iris and focus in future), to lock them down at values. Mosaic effect and mosaic + luminance large pixel effect (4:4:4, 960*540). A more advanced menu feature set, like the Samsung U10 has, apart from the normal easy mode.

One touch auto exposure lock, and manual override.

The rolling shutter and latitude techniques of the Aptina sensors.


Altogether, the zi8 is a beautiful camera for the low end already. Thank you Kodak.
Wow & Yes, those features would make Zi8 best "simple" cam in the world, BUT, now it will costs US$28,896,465.99 and... my wife would'nt be able to use it!
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Old Jun 5, 2010, 12:41 PM   #994
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Quote:
Originally Posted by petunder View Post
Kodak Zi8 bitrate issue.

Hi! I'm owner of the device. The device is great, but there is a bitrate issue. I've recorded some test video and have got video with various compression artefacts. It looks very ugly on 42'' LCD. I think, it happens because of poor bitrate: 5,7 Mbit/s average - 720p/60 and 4,7 Mbit/s average for 720p/30. Could anyone help me to solve the problem?

Kodak Zi8, fw 1.06

UPD: Bitrate in 1080p mode looks ok. Its between 11 Mbit/s and 16 Mbit/s. Picture quality seems to be good. So, the bitrate issue is in 720p mode. Some tests shows, that bitrate of 720p mode is in range from 3 to 6 Mbit/s.

UPD2: Bitrate in WVGA mode is in the range from 1 to 2 Mbit/s. Picture quality is poor with many compression artefacts.

It looks like constant quality compression preset in firmware. How to connect with Kodak software engineers with the issue? I m sure, that they should let users to choose picture quality manually.
Which SDHC card are you using (class 4/class 6)? You might have a slower SDHC card.I would suggest you getting the Transcend class 6 SDHC card to resolve the bitrate issue (the bit rate should match the write speed of the card). Else it would either stop recording or record with hiccups.

Next thing to check out is the firmware version of your ZI8 because in the firmware version 1.06 version it is reported to have solved the vertical lines issue (priorly considered to be a sensor defect). If you have a lower firmware version then you might need a firmware upgrade. Firmware can be downloaded from KODAK official website.The megaupload links to download any firmware version of ZI8 is listed in first page of this thread. Thanks to guy who uploaded it. Remember you can only upgrade your firmware (follow manifactorer instructions to void warrenty) though you can downgrade your firmware using unofficial methods (listed in this thread) at your own risk.

Further to continue, compression artifacts and low bit rate issues result from encoding. Excessive compression of the video (to decrease the file size and save disk space) would result in compression artifacts. It relates to the processing (encoding) power of the chip used. In 720p/60fps mode image seems to better stabilised due to addition of more frames and video plays smoother. Therefore, lower the bit rate the more the possibility of compression atrifacts.

I never had any issues regarding compression artifacts or vertical lines issue with my ZI8 (firmware version 1.06). But i could find lot of noise in indoor low light conditions (720p/60fps is a good choice here). In ZI8 the video is encoded in .MOV format (less compression) which has a higher bit rate compared to .MP4 (higher compression) used in some other camcoders.

My CANON IXUS 100IS digital camera records video in 720p format but they have sacrificed the file size for achieving a high bit rate. 2 GB card can record only 10 minutes of 720p video. Video quality is very sharp and very well stabilised due to optical image stabilisation. Hence the battery life is very short.

This is all about balancing the file size,video quality and battery life. So we never know which is the best configuration to achieve it.

I hope this serves your concern!

Why dont you re-encode the video at a higher bit rate with a free video processing software (like virtualdub or avidemux) but beware this is gonna increase the video size a lot!



Last edited by drramkishorehs; Jun 5, 2010 at 12:59 PM.
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Old Jun 5, 2010, 5:04 PM   #995
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Thank you, drramkishorehs!

I use Kingston Class 10 SDHC card. ALso, I've changed this card to Apacer SDHC Class6 8Gb, there no difference.

Firmware version is 1.06.

You told good example - CANON IXUS encodes 10 min 720p video to 2Gb. Its equal 25 Mbit/s bitrate. Zi8 encodes 60 min 720p video to 2 Gb.

Kodak engineers didnt care about customers, that may want to tune compression levels. They implemented the simpliest algo in firmware - constant quality. But I want to improve quality (of course, it increase file size), but I have not any interface in Zi8 to tune it.
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Old Jun 6, 2010, 12:02 AM   #996
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Quote:
Originally Posted by petunder View Post
Kodak Zi8 bitrate issue.

Hi! I'm owner of the device. The device is great, but there is a bitrate issue. I've recorded some test video and have got video with various compression artefacts. It looks very ugly on 42'' LCD. I think, it happens because of poor bitrate: 5,7 Mbit/s average - 720p/60 and 4,7 Mbit/s average for 720p/30. Could anyone help me to solve the problem?

Kodak Zi8, fw 1.06

UPD: Bitrate in 1080p mode looks ok. Its between 11 Mbit/s and 16 Mbit/s. Picture quality seems to be good. So, the bitrate issue is in 720p mode. Some tests shows, that bitrate of 720p mode is in range from 3 to 6 Mbit/s.

UPD2: Bitrate in WVGA mode is in the range from 1 to 2 Mbit/s. Picture quality is poor with many compression artefacts.

It looks like constant quality compression preset in firmware. How to connect with Kodak software engineers with the issue? I m sure, that they should let users to choose picture quality manually.
This sounds strange, we measured 24mb/s in the zi8 before in 1080p. I was surprised at the time, that Kodak would put that in the Zi8, and suspect. I was suspect the playsport might throttle it back, it might be possible they have done this int he zi8. So, did I carry some calculation out the wrong way or something (I think others have find), or were the rendered clips we measured rendered up to 24mb/s (which I asked about). I am trying to find the mercedes clip again to remeasure it (not the best clip to measure).

Did you guys try it on normal active walk around scenes? The ambarella codec is (normally) very variable, and will drip down drastically in datarate if you film a blank wall, static scene, if it is too dark, or you have night mode (slow shutter) on. On my Aiptek if it is too dark, it virtually turns the shutter off and records sound at hundreds of kilobits per-second or less in WVGA.

As far as artifacts in normal conditions (not being tossed for a spinner around the room), if you see it, it is mediocre.

Thanks


Wayne.
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Old Jun 6, 2010, 1:39 AM   #997
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OK, I have tested an number of clips, and they are roughly up to 24mb/s for 1080p, I found one pool swimming scene in 720p60 over 20mb/s but generally they tend to be below 16mb/s (unfortunately not the same as 1080p). I have reread the posts, my reading is not up to it today) and I agree, meant top ask last time. Another problem is that people can output the video from the editor at 24mb/s, but will not get any more quality, or try to output at a smaller size and get less quality. The mercedes clips was smaller, probably re-encoded and in the dark, I remember the previous version was at a higher data-rate.

The real way to test is short unedited clips saved straight from the camera. The following types of scenes can help determine the quality of a camera for everyday situation: They maybe clinical, but they give real ideas of how the camera is behaving.

For noise, nighttime inside (dimly lit, with bulb type and strength) and outside, and inside daytime scene on a sunny day. With the inside daytime scene you also have a chance to show how the camera handles exposure changes and how it handles shooting the inside of a room and what's outside the background widow at the same time, by starting still, then sweeping slowly to the window, so it fills some of the screen.

Outside on a bright day (+gloomy days as well, if they happen). In this shot you can pickup a number of things. If you start still shooting a complex scene, with things in shadows and things in the sunlight, and bright white/shinny things, you can see how it handles latitude/exposure outside, and hopefully not any noticeable noise. If you then move the camera about and sweep you test motion compression, and move about image stabilisation. If grass, plants, not smooth brick and concrete, and smooth contrasty lines (such as chrome trimming around car windows in the background) are in the scene you can see how it handles detail, interpolation and anti-aliasing problems. Gratuitous framed shots of a tree with wind blowing the leaves, and choppy/wavy water are also a good torture test for compression motion artifacts.

A still video shoot of a plain dim flat light colored surface/wall inside can also reveal other things, like banding, over compression leading to this banding and blocking (forget the term for it). Luckily the good cameras we have been seeing have not been having problems with this in recent years.


Most cameras will fail at least at some stage in these tests.
see roughly the same amount of pixels per second)..

However, enough testing has been done for the zi8, apart from the issue of how much data rate the camera is actually recording files at, not much more testing is really needed on it. I prefer not to download any more 24mb/s clips over my 56K dial up .
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Old Jun 6, 2010, 4:00 AM   #998
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Hi Wayne12!
I ve tryed to record complex scene, f.e. "the trees are sighing", bitrate in 1080p was 13,6 Mbit/s. Simple scenes, like a light room with little movement, takes 9,6 Mbit/s in 1080p.

But in 720p/60 bitrate is critically low. Car record takes only 5 Mbit/s!!! Thats exactly why quality of the record is very poor on 42'' LCD. Definitely, that Zi8 records looks fine in Yotube small window. But the issue is in big screens. When you connect Zi8 to HDMI LCD (Plasma), you will be disappointed because of compression artefacts.

I have 32 Gb SDHC and I want to increase quality and, of course, increase file size. But there is no interface...

Please, calculate bitrate for records, with video length more than 10 minutes. Use the file size in bytes, then divide it on video length (seconds) and multiply on 8 bits.
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Old Jun 6, 2010, 7:09 AM   #999
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Hd720P60F will not be exact, especiall when you film @ low level or extreme low level, the cam will Drop its Framerate of 60 -to-30frames.

The cam Works fine for me, plays fine for me on a LCD 42 inch and its not plasma, are you saying lcd is plasma ? confused?

Youtube, vimeo, are both not a HD, Hid definitions site, they are a flash driven Hd hi definition site, anddo not play the correct file you placed up.

HDWEBTOWN.COM is not a flash driven site , but a Hi definition site and will play the exact file of the cam in HD.

The ZI8, since we're in this topic Does not have Nightshot mode, i has a Auto ISO up to 800, so others do not get confused.
I tend notto worry boutthe Little things, that may be Bigto others,

The cam does its job, and does it well.

I have two clips:

hd720p 30 8.51 mbits 9 mb daytime train
hd720p60 9.5ish mbits 9 mb
hd720p60 12.5ish mbits 6 mbs close up window

As I shot about 8 vids, the first vid or two were lower, then the others most the vids are @ 12.90mbits

I just wanted to say that.
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Last edited by fishycomics; Jun 6, 2010 at 7:22 AM.
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Old Jun 6, 2010, 2:46 PM   #1000
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Guys, Petunder got it bulls eye!

How did they name the new release a "PLAY-sport" when they did'nt offer us enough functions to play with. JUST KIDDING!

ZI8 was targeted at mass consumers by its simplicity to use and that file sizes are smaller making it possible for people to use it with low volume memory card (reduces cost).

I too was very surprised when i found how simple was its settings menu interface. Thats why ZI8 was constantly out of stock at amazon,cruthfield etc due to an increased demand. Trust me 70-80% of the ZI8 owners would be basic and not advanced.

Overall it seems to be an advanced (HD) camera for a beginner due to simplicity to operate.

But I am a guy who likes to fiddle with my gadgets trying to get it to perform to its actual potential. For example i overclocked my outdated pc. In the Process sometimes i ended ruining my stuff.

I have found that electronic gadgets are designed to perform to about 90% of its actual potential and a grey area of 10% is leaft out for advanced users to capitalise and explore with. During the voyage we learn a lot of stuff and keeps us anxious.

I surely would'nt sacrifice quality for quantity. There should be some high end camcoders that would capture the video in raw uncompressed AVI format but large sized hard drives with a very high write speeds are required making them very expensive.

I am content with my ZI8 performance provided the price at it which it was purchased and keeping in mind its close rivals like flip,RCA wonder,cerative vado HD etc.

Some body in near future could probably hack the firmware making it possible for us to alter its codecs-compression. KODAK guys take note of this and its better that you act instantaneously and keep hackers away from the buisness.

Another request is that guys when you describe the bit rate issue, please give the values in MB(mega bytes)/secand than Mb(mega bits)/secand. This would avoid confusing a lot of people all over the world who are following this thread. Most of people are familiar with bytes than bits!

1MB=8Mb

Last edited by drramkishorehs; Jun 6, 2010 at 3:44 PM.
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