Still photo, to DV AVI challenge! - Page 2

mic · 24th August 2005, 22:08

Quote:

Originally Posted by trevlac

@Bobcat

I use Vegas and have a Laird DV device thru which I can pipe an s-video signal to an old Commodore monitor. From the timeline with monitor preview ... Vegas will encode the jpg to DV using the Sony codec, send it to the Laird, which will then turn it into an NTSC signal for the monitor. The monitor is just like a TV but has a higher horizontal resolution. I'll do this tonight and tell you what I see.

Out of curiosity, could you do a print to tape vs preview device comparison?

Oh, & how in the L do you still have a working Commodore monitor? Man that makes me feel old!

theReal · 24th August 2005, 22:32

Quote:

in the past I would watch big satellite dish wild feeds. They would play a recorded TV program that was to be downloaded by affiliate TV stations. They would often start, and end, the video feed with test patterns so the stations could calibrate their playback, and broadcasting equipment. Now my point is, these test patterns were the same as the one I linked to. The fine lines and all were not flickering when I watched them on my 70’s/80’s consumer TV’s, and the resolution was as good as the TV set I was playing them on.

The test patterns from satellite were most probably more compressed than DV (today MPEG2 is used for satellite connections, mostly with bitrates like on a DVD) - that means they were more blurry than DV...

Quote:

I don't think you're likely to see anyone using high bit rate mpg2 outside of HD

MPEG IMX from Sony uses I-frame-only MPEG2 compression for SD video. They say it's as good as DigiBeta... at least it's better quality than DV, at the same compression rate of 5:1.
I said that MPEG2 is a blurry mess compared to MPEG2 - I was referring to MPEG2 on DVDs, with long GOP and a maximum bitrate of 8-9mbit, not to some modified I-frame only high-bitrate MPEG2 like IMX!

Quote:

What this reinforced in my belief was that the NTSC DV codec is not a very high quality compression standard.

Oh really?

Why do you think everybody who can afford it is using DigiBeta or at least DVCPro 50?

mic · 25th August 2005, 00:12

Quote:

Originally Posted by theReal

MPEG IMX from Sony uses I-frame-only MPEG2 compression for SD video. They say it's as good as DigiBeta... at least it's better quality than DV, at the same compression rate of 5:1

Did it wind up catching on? Know it had good reviews a few years back, but hadn't heard anything. Doing a quick google couldn't find anything really recent?

trevlac · 25th August 2005, 01:44

Sony DV->Laird->commodore

Strike 1
Shakes like hell!

Mainly in the diagonals. The color lines also flicker. Some pure horizontals flicker.

So ... I thought ... maybe the pattern was not properly filtered. Maybe there are some funky edges in there. A few months back, I wrote a VDub filter that does a frequency analysis of an image. There is a link on this page: http://www.trevlac.us/FilterDocs/

I compared this image I pulled from the Avia disc vs bobcat's pattern. http://www.trevlac.us/pics/Resolution1.png

Strike 2My pattern has loads more aliasing! Bobcat's is fairly clean, but certainly higher than NTSC height can support.

So ... I thought ... let's try DVD.

Foul Ball The DVD also shakes like hell! The color lines are not as bad (but they were probably (properly) blurred going to 4:2:0) I made the mpeg from Vegas which uses main concepts.

==================================
Bottom line .... I failed the challange. HOWEVER my (unproven) conclusions are different about what is to blame. I say it is the NTSC interlaced signal / monitor that is the issue. The Vertical frequencies in the pics are higher than 240 scan lines can show. It could be the mpeg/DV codecs. They effectively compress by removing high frequencies. But logic tells me that because the image is not moving, the errors should also show on a progressive monitor. They do not show for me in VirtualDub from both a DV.avi and an mpg file.

I also think DV can not be blamed when using the camera to film a chart. The camera probably pulls 2 full frames and saves the fields before the codec sees the info. I doubt anything actually low pass filters. So again the crap V rez of NTSC is the problem.

But that is all theory stuff ...

trevlac · 25th August 2005, 02:04

Quote:

Originally Posted by theReal

MPEG IMX from Sony uses I-frame-only MPEG2 compression for SD video. They say it's as good as DigiBeta... at least it's better quality than DV, at the same compression rate of 5:1.

I'm as amature as they come

So I looked up the MSW-900P at B&H. $39,000.

Oh My God! Is the 4:2:2 really worth it? How bout HVR-Z1U for a mear $4k? I'm not really up on the specs of HDV but this really seems out of wack!

mic · 25th August 2005, 04:31

@bobcat56458

Grabbed pattern from link posted by trevlac -- if this grayscale is similar to what you guys were playing with, cool. Of course it won't show color effects of compression, but maybe do some good.

Had some minor issues with file color space of original, but nothing that would effect anything and tried orig & conversion anyway.

Compressed to mpg2 & DV, tested losses -- while detectable, not that significant. As I mentioned earlier, and maybe it's unusual, I've done a lot more with stills then video, so that's where I'm most comfortable when not trying to measure transients. The DV format showed very slightly more degradation then mpg2, with a very, very slight shift in red which I would have expected. The biggest difference was in the vert moire to the right in both cases.

Interpreted RGB output to small TV monitor was good, though a bit limited because just plugged composite in, with a slight bit of interlace flicker on horiz. lines in upper and lower moire. DV & mpg2 showed some degradation, DV was noticably worse on pattern in left lower circle -- right lower did not display properly in amy case, but again that was expected.

DVD test to TV with 600+ Horix. Lines Res. was interesting.

Everything checked out except 1 pixel wide horiz lines, again as expected. These would have mapped to alternate fields so moire did it's dance as I assume it was designed to with it's alternating bands of white etc., as explained here (Find the word "wedge" towards bottom of page):
http://download.microsoft.com/downlo...b45/MCEVid.doc

Don't know if that helps or not...

bobcat56458 · 25th August 2005, 12:56

Thereal: Lets try keep it real, when you state: “Oh really? Why do you think everybody who can afford it is using DigiBeta or at least DVCPro 50?” It reminds me of a professional that is shooting to 16mm film looking down on a guy that shoots to video, then there is the person that works in the IMAX format that looks down at the 16mm film person, can you see where I’m going with this? I see you are working at a local TV station, and making a career in the video field, naturally this would dictate that you would gravitate towards the tools of your chosen trade. But you must remember this is the “DV” forum and the majority of members here although much more knowledgeable than your average layman are using there consumer DV camcorders to archive family events, not the news at ten. We don’t want to lug around a shoulder mounted DigiBata professional camcorder to family events. We like the portability of our mini DV camcorders. We have no problems finding ways of spending money accessorizing our $350~$1500 consumer DV camcorders. Naturally given the type of person that hangs around a forum like this, we are always looking for ways to push to the limit what we can do with these consumer camcorders. We will spend countless hours between the times we are actually shooting a family event, searching forums, trying out new techniques, in the pursuit of this hobby. Which brings us back to the point of this thread. Making a calibration test tape for our consumer DV camcorders. Can we all focus on the topic at hand.

SeeMoreDigital · 25th August 2005, 13:17

Hi bobcat56458,

From time to time I make my own test cards too, using a little known application called JPGAvi which is available over at http://www.ndrw.co.uk

But I must admit I've not considered storing them onto DV tape!

Cheers

bobcat56458 · 25th August 2005, 14:33

SeeMoreDigital: I’ve had good results using a program called ProShow Gold for making slideshows or just MPEG2's from an image. It’s the program I used to make the MPEG2 file of my test pattern project. It made a MPEG2 that did not show any flickering, or color shift. It has an option to remove flicker that I do not see in the program JPGAvi. What ProShow can’t do is save a file as an AVI, an option that I wish it had for my project.

SeeMoreDigital · 25th August 2005, 14:47

Are you able to provide an short MPEG-2 sample so I/we can see how bad the flicker is?

Cheers

bobcat56458 · 25th August 2005, 15:37

SeeMoreDigital: There is no flickering on the MPEG2 file ProShow produced. If you are referring to the flicker on the DV AVI’s I’ve made yes there is. However I’m on the dreaded dialup, and am in an area which has no high speed internet available. So the most I’m able to upload is about 750Kb at maximum which would not be a long enough MPEG2 file to do you any good. The DV AVI flickering problem is a minor one, but when you want to produce something for testing purposes even that is unexceptable, sorry.

theReal · 25th August 2005, 18:13

Sorry bobcat56458, I didn't want to be rude (that's why I put a lot of smilies behind my statement). However when you say that this is an amateur DV forum (you're right), then you can't constantly demand professional standards from your amateur equipment... It appeared like this to me, so I wanted to point out you are right with your quality demands, on a professional level

Quote:

I'm as amature as they come So I looked up the MSW-900P at B&H. $39,000.
Oh My God! Is the 4:2:2 really worth it? How bout HVR-Z1U for a mear $4k? I'm not really up on the specs of HDV but this really seems out of wack!

The camcorders are in totally different leagues - the MSW-900P is a pro shoulder mounted 2/3" 3CCD. These camcorders are always horribly expensive, no matter what tape format they are. Quality differences are mostly the lenses, the 2/3" chips, the higher robustness - but almost nobody could afford something like this privately.

Quote:

Did it wind up catching on? Know it had good reviews a few years back, but hadn't heard anything. Doing a quick google couldn't find anything really recent?

I know that the German station WDR has just replaced all their Beta SP equipment with Sony XDCam, it's MPEG IMX on cartridged Blue-Ray DVDs. I think this one is catching on because of the tapeless recording.

mic · 25th August 2005, 19:17

Quote:

Originally Posted by theReal

I know that the German station WDR has just replaced all their Beta SP equipment with Sony XDCam, it's MPEG IMX on cartridged Blue-Ray DVDs.

Cool

Wasn't being smarta... when asked earlier

LocalH · 25th August 2005, 21:51

One problem is that the test card is already at video resolution, and thus the image was likely generated without taking interlace into account. Most actual professional test cards are at a much higher resolution and sampled by a camera, which will always output smooth and clean interlaced video. You could probably somewhat replicate this with a higher resolution test card that you downsample into an interlaced image. I'm not sure of a quick and easy way to get Avisynth to do this (it seems that the resize function treats the signal as progressive), but I'm pretty sure that Adobe After Effects can do such things, as I've used it quite a bit for producing local PSAs. Imported images are of excellent quality in a real-world broadcast situation, whether they be too small or of a good large size.

Basically, the best thing to do is always to use a higher-resolution image than you need and downsample to an interlaced frame. This should create the best possible results when viewed properly on an NTSC monitor, regardless of the compression used (except in an extremely bit-starved stream).

SeeMoreDigital · 25th August 2005, 22:28

Can some of you guys try the following MPEG-4 16.9 NTSC Test Cards please?

One has been encoded with 720x480 pixels and includes 16:9 DAR signalling, the other has been encoded with 854x480 pixels.

Cheers

trevlac · 30th August 2005, 18:28

@Bobcat

I was curious about your MPEG results ... and why they did not shake. So I took a look at my commercially produced Avia test TVL 200 resolution chart (I posted a copy above) using 4 different dvd players (apex,GE,Sony,Samsung) and 4 different monitors (commodore, 36" samsung, 25" GE, LCD TV). The apex and sony are s-video, the GE is composite, and the samsung is modulated with an F-connector.

All the images shake. Mainly on the diagionals as I mentioned before. The composite and F-connector introduce xtra color in the detail. The LCD actually shakes the least, but I think this is due to the bluring effect of the LCD monitor.

So ... my mpeg results don't match yours. And yours don't match a commercial test disc (no DV involved).

This of course does not meet your challange but I think it shows me that the display is the problem. Not DV.

@LocalH

"Basically, the best thing to do is always to use a higher-resolution image than you need and downsample to an interlaced frame."

I think this is good advice, but not the root of the problem. The important thing is HOW it was downsampled. If the downsampling does not lowpass filter the higher frequencies out ... the image will have artifacts. Lowpass filtering is bluring. The vertical resolution of any NTSC device is quite low. So if the downsampling blurs the vertical frequencies and then seperates the frame into fields, you might avoid the shake. This is of course theory ... guessing on my part.

BTW: A vertical blur probably does not reduce the value of the chart. The chart measures Horizontal resolution. Vertical resolution is the same for all NTSC devices.

@theReal

Ahh ... 2/3" CCDs. Yes i noticed that when I looked. I've wondered what depth of field tricks one could do with better CCDs. Anyway ... thanks for the comments on MPEG IMX. I never heard of that before.

@mic

Sorry I missed your comment on Tape vs Preview before. I'm not sure how I would do tape and be consistant. I'd have to play my tape from one of my cameras and I'm not sure if they are any good at making an NTSC signal. The Laird should be. I am quite sure if I copy to tape and back that there is no change.

The Commodore monitor is great. Someone on this forum gave me the tip. You can find them for about $25. I'm not sure I can fully trust it for colors, but it's resolution is way better than a TV, and I don't think it has overscan and such, so it works well as a production monitor. Much better than a TV.

mic · 30th August 2005, 19:16

@trevlac
Not to worry about tape vs preview -- thanks for reply to it

Basically I was just trying to add to experience and info on overlay render from preview vs print to tape which should cause render and use of avi file.

If it helps understanding...
Any image with 1 line or pixel height should dance on interlaced TV, and if it doesn't, then either the picture's being deinterlaced or blurred to take up 2 or more horizontal lines. How noticable it is can vary quite a bit.

Quote:

Originally Posted by trevlac

... All the images shake. Mainly on the diagionals as I mentioned before. The composite and F-connector introduce xtra color in the detail. The LCD actually shakes the least, but I think this is due to the bluring effect of the LCD monitor.

Earlier link:
http://download.microsoft.com/downlo...b45/MCEVid.doc might help or be of interest... If I read correctly, the still posted earlier is designed for testing deinterlacing on something like HTPC or MCPC, and should dance on anything interlaced. On LCD if fed progressive shouldn't see effects at all -- so if you used progressive player, might not be working as it should.

At any rate, it's supposed to shake on a TV. If you look at the image closely, you can see the alternating bands of white in lines that are one pixel tall. As player translates these one pixel lines to fields, and as one field is not refreshed, lines go away & reappear causing moire dance.

My wife loved it!

Quote:

Originally Posted by trevlac

Basically, the best thing to do is always to use a higher-resolution image than you need and downsample to an interlaced frame.

Actually as far as a PC is concerned, an image is an image, whether it shows effects resulting from being interlaced or not. Rendering an image to video most NLEs will record it pretty much as is -- on playback every other line will be taken as a field, or in the case of mpg2 23.976 or 24 p, pulldown will duplicate frames. It is better to use a slightly oversized image (Adobe.com lists recomended sizes) because that will produce better results during render with resampling to DV/DVD pixel aspect ratios.

The Commodore monitor sounds pretty decent.

FWIW, wonder if it's a bit like the old Amiga monitors. If so, think the color models are a bit different -- If I remember correctly there still are settings in some PC software to compensate for Amiga output.

bobcat56458 · 30th August 2005, 20:55

Trevlac: I’m surprised to hear that a commercial test DVD like the Avia shows flickering of the fine lines. If you had just used one DVD player, and one TV set to view this I would have been leery of your results, but you stated you tried this DVD with multiple DVD players, and TV sets, with different types of cables. If anyone else has this disk it would be interesting to hear if their results are the same as yours. To explain why the MPEG2 I made did not flicker may attest to the quality of the flicker filter in the ProShow Gold slideshow program that I used to make the MPEG2 video clip, I just wish it could output in the DV AVI format.

mic · 31st August 2005, 00:18

From: http://download.microsoft.com/downlo...b45/MCEVid.doc

Test 18: TV tuner/capture/encoder video bandwidth test
Goal: To measure the lines of video captured and compressed with the TV tuner device to ensure that video capture is delivering a detailed and accurate image.
Test Tools required: Avia Guide to Home Theater DVD and consumer electronics DVD player with S-Video output
Test Configuration: Set Media Center TV source to STB (S-Video) and connect DVD player output to TV capture card input via S-Video cable. Connect PC via VGA or DVI to ***high-resolution progressive scan display.*** Drive fixed pixel display at native resolution. Failure to drive display at native resolution will result in false failures on this test!

"Observe the moving resolution wedge closely and watch for any breakup in a smooth image. If the resolution wedge shows clear straight lines, the **deinterlacer** is properly running in film mode and is weaving. If the resolution wedge in the image shows distortion or aliasing artifacts such as a “valve” shape where straight lines should appear, the deinterlacer is running in video mode "

trevlac · 31st August 2005, 02:33

@bobcat

Yes ... 4 different setups. Too bad we can't see a still grabbed from that mpeg you make. Here is a filtered version of your image. It does not shake on my commodore via DV out. BUT i blurred it. Only in the Vertical direction. I was surprised that I needed to blur to about 2.5MHz. I thought around 3MHz would be ok. I basically used a truncated sinc filter so there is a bit of ringing in the image. i don't think one can see this on a TV. The image looks ok on a TV. Not as sharp as the origional, but not bad. On a PC, it is rotten. You can read the wedges and see that I blurred to around 200TVL vertical and not at all H. I sorta thought 240TVL Vertical would be ok. I'm not sure why it does not work.

http://trevlac.us/pics/bobcat.jpg

@mic

I'm not sure if your info is for me. I do not have a progressive dvd player and can't hook my LCD up via DVI. It's a bit old. The chart I was using could measure a few things. One thing I've used it for in the past is to measure horizontal resolution of capture devices. I posted a test link before.

BTW: My commodore is model 1702. Worth looking into.

25th August 2005, 01:44	#24 \| Link
trevlac budala Join Date: Oct 2003 Location: U.S. Posts: 545	Test Results Sony DV->Laird->commodore Strike 1 Shakes like hell! Mainly in the diagonals. The color lines also flicker. Some pure horizontals flicker. So ... I thought ... maybe the pattern was not properly filtered. Maybe there are some funky edges in there. A few months back, I wrote a VDub filter that does a frequency analysis of an image. There is a link on this page: http://www.trevlac.us/FilterDocs/ I compared this image I pulled from the Avia disc vs bobcat's pattern. http://www.trevlac.us/pics/Resolution1.png Strike 2My pattern has loads more aliasing! Bobcat's is fairly clean, but certainly higher than NTSC height can support. So ... I thought ... let's try DVD. Foul Ball The DVD also shakes like hell! The color lines are not as bad (but they were probably (properly) blurred going to 4:2:0) I made the mpeg from Vegas which uses main concepts. ================================== Bottom line .... I failed the challange. HOWEVER my (unproven) conclusions are different about what is to blame. I say it is the NTSC interlaced signal / monitor that is the issue. The Vertical frequencies in the pics are higher than 240 scan lines can show. It could be the mpeg/DV codecs. They effectively compress by removing high frequencies. But logic tells me that because the image is not moving, the errors should also show on a progressive monitor. They do not show for me in VirtualDub from both a DV.avi and an mpg file. I also think DV can not be blamed when using the camera to film a chart. The camera probably pulls 2 full frames and saves the fields before the codec sees the info. I doubt anything actually low pass filters. So again the crap V rez of NTSC is the problem. But that is all theory stuff ...

25th August 2005, 04:31	#26 \| Link
mic Registered User Join Date: May 2003 Posts: 410	In case it helps. @bobcat56458 Grabbed pattern from link posted by trevlac -- if this grayscale is similar to what you guys were playing with, cool. Of course it won't show color effects of compression, but maybe do some good. Had some minor issues with file color space of original, but nothing that would effect anything and tried orig & conversion anyway. Compressed to mpg2 & DV, tested losses -- while detectable, not that significant. As I mentioned earlier, and maybe it's unusual, I've done a lot more with stills then video, so that's where I'm most comfortable when not trying to measure transients. The DV format showed very slightly more degradation then mpg2, with a very, very slight shift in red which I would have expected. The biggest difference was in the vert moire to the right in both cases. Interpreted RGB output to small TV monitor was good, though a bit limited because just plugged composite in, with a slight bit of interlace flicker on horiz. lines in upper and lower moire. DV & mpg2 showed some degradation, DV was noticably worse on pattern in left lower circle -- right lower did not display properly in amy case, but again that was expected. DVD test to TV with 600+ Horix. Lines Res. was interesting. Everything checked out except 1 pixel wide horiz lines, again as expected. These would have mapped to alternate fields so moire did it's dance as I assume it was designed to with it's alternating bands of white etc., as explained here (Find the word "wedge" towards bottom of page): http://download.microsoft.com/downlo...b45/MCEVid.doc Don't know if that helps or not... Last edited by mic; 25th August 2005 at 05:27.

25th August 2005, 13:17	#28 \| Link
SeeMoreDigital Life's clearer in 4K UHD Join Date: Jun 2003 Location: Notts, UK Posts: 12,421	Hi bobcat56458, From time to time I make my own test cards too, using a little known application called JPGAvi which is available over at http://www.ndrw.co.uk But I must admit I've not considered storing them onto DV tape! Cheers __________________ \| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 \| My Network Layout & A/V Gear \| Last edited by SeeMoreDigital; 25th August 2005 at 13:48.

25th August 2005, 14:47	#30 \| Link
SeeMoreDigital Life's clearer in 4K UHD Join Date: Jun 2003 Location: Notts, UK Posts: 12,421	Are you able to provide an short MPEG-2 sample so I/we can see how bad the flicker is? Cheers __________________ \| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 \| My Network Layout & A/V Gear \|

25th August 2005, 21:51	#34 \| Link
LocalH Registered User Join Date: Mar 2005 Posts: 135	One problem is that the test card is already at video resolution, and thus the image was likely generated without taking interlace into account. Most actual professional test cards are at a much higher resolution and sampled by a camera, which will always output smooth and clean interlaced video. You could probably somewhat replicate this with a higher resolution test card that you downsample into an interlaced image. I'm not sure of a quick and easy way to get Avisynth to do this (it seems that the resize function treats the signal as progressive), but I'm pretty sure that Adobe After Effects can do such things, as I've used it quite a bit for producing local PSAs. Imported images are of excellent quality in a real-world broadcast situation, whether they be too small or of a good large size. Basically, the best thing to do is always to use a higher-resolution image than you need and downsample to an interlaced frame. This should create the best possible results when viewed properly on an NTSC monitor, regardless of the compression used (except in an extremely bit-starved stream). Last edited by LocalH; 25th August 2005 at 21:53.

25th August 2005, 12:56	#27 \| Link
bobcat56458 Registered User Join Date: Feb 2005 Posts: 76	Thereal: Lets try keep it real, when you state: “Oh really? Why do you think everybody who can afford it is using DigiBeta or at least DVCPro 50?” It reminds me of a professional that is shooting to 16mm film looking down on a guy that shoots to video, then there is the person that works in the IMAX format that looks down at the 16mm film person, can you see where I’m going with this? I see you are working at a local TV station, and making a career in the video field, naturally this would dictate that you would gravitate towards the tools of your chosen trade. But you must remember this is the “DV” forum and the majority of members here although much more knowledgeable than your average layman are using there consumer DV camcorders to archive family events, not the news at ten. We don’t want to lug around a shoulder mounted DigiBata professional camcorder to family events. We like the portability of our mini DV camcorders. We have no problems finding ways of spending money accessorizing our $350~$1500 consumer DV camcorders. Naturally given the type of person that hangs around a forum like this, we are always looking for ways to push to the limit what we can do with these consumer camcorders. We will spend countless hours between the times we are actually shooting a family event, searching forums, trying out new techniques, in the pursuit of this hobby. Which brings us back to the point of this thread. Making a calibration test tape for our consumer DV camcorders. Can we all focus on the topic at hand.

25th August 2005, 14:33	#29 \| Link
bobcat56458 Registered User Join Date: Feb 2005 Posts: 76	SeeMoreDigital: I’ve had good results using a program called ProShow Gold for making slideshows or just MPEG2's from an image. It’s the program I used to make the MPEG2 file of my test pattern project. It made a MPEG2 that did not show any flickering, or color shift. It has an option to remove flicker that I do not see in the program JPGAvi. What ProShow can’t do is save a file as an AVI, an option that I wish it had for my project.

25th August 2005, 15:37	#31 \| Link
bobcat56458 Registered User Join Date: Feb 2005 Posts: 76	SeeMoreDigital: There is no flickering on the MPEG2 file ProShow produced. If you are referring to the flicker on the DV AVI’s I’ve made yes there is. However I’m on the dreaded dialup, and am in an area which has no high speed internet available. So the most I’m able to upload is about 750Kb at maximum which would not be a long enough MPEG2 file to do you any good. The DV AVI flickering problem is a minor one, but when you want to produce something for testing purposes even that is unexceptable, sorry.

25th August 2005, 22:28	#35 \| Link
SeeMoreDigital Life's clearer in 4K UHD Join Date: Jun 2003 Location: Notts, UK Posts: 12,421	Can some of you guys try the following MPEG-4 16.9 NTSC Test Cards please? One has been encoded with 720x480 pixels and includes 16:9 DAR signalling, the other has been encoded with 854x480 pixels. Cheers __________________ \| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 \| My Network Layout & A/V Gear \|

30th August 2005, 18:28	#36 \| Link
trevlac budala Join Date: Oct 2003 Location: U.S. Posts: 545	@Bobcat I was curious about your MPEG results ... and why they did not shake. So I took a look at my commercially produced Avia test TVL 200 resolution chart (I posted a copy above) using 4 different dvd players (apex,GE,Sony,Samsung) and 4 different monitors (commodore, 36" samsung, 25" GE, LCD TV). The apex and sony are s-video, the GE is composite, and the samsung is modulated with an F-connector. All the images shake. Mainly on the diagionals as I mentioned before. The composite and F-connector introduce xtra color in the detail. The LCD actually shakes the least, but I think this is due to the bluring effect of the LCD monitor. So ... my mpeg results don't match yours. And yours don't match a commercial test disc (no DV involved). This of course does not meet your challange but I think it shows me that the display is the problem. Not DV. @LocalH "Basically, the best thing to do is always to use a higher-resolution image than you need and downsample to an interlaced frame." I think this is good advice, but not the root of the problem. The important thing is HOW it was downsampled. If the downsampling does not lowpass filter the higher frequencies out ... the image will have artifacts. Lowpass filtering is bluring. The vertical resolution of any NTSC device is quite low. So if the downsampling blurs the vertical frequencies and then seperates the frame into fields, you might avoid the shake. This is of course theory ... guessing on my part. BTW: A vertical blur probably does not reduce the value of the chart. The chart measures Horizontal resolution. Vertical resolution is the same for all NTSC devices. @theReal Ahh ... 2/3" CCDs. Yes i noticed that when I looked. I've wondered what depth of field tricks one could do with better CCDs. Anyway ... thanks for the comments on MPEG IMX. I never heard of that before. @mic Sorry I missed your comment on Tape vs Preview before. I'm not sure how I would do tape and be consistant. I'd have to play my tape from one of my cameras and I'm not sure if they are any good at making an NTSC signal. The Laird should be. I am quite sure if I copy to tape and back that there is no change. The Commodore monitor is great. Someone on this forum gave me the tip. You can find them for about $25. I'm not sure I can fully trust it for colors, but it's resolution is way better than a TV, and I don't think it has overscan and such, so it works well as a production monitor. Much better than a TV.

30th August 2005, 20:55	#38 \| Link
bobcat56458 Registered User Join Date: Feb 2005 Posts: 76	Trevlac: I’m surprised to hear that a commercial test DVD like the Avia shows flickering of the fine lines. If you had just used one DVD player, and one TV set to view this I would have been leery of your results, but you stated you tried this DVD with multiple DVD players, and TV sets, with different types of cables. If anyone else has this disk it would be interesting to hear if their results are the same as yours. To explain why the MPEG2 I made did not flicker may attest to the quality of the flicker filter in the ProShow Gold slideshow program that I used to make the MPEG2 video clip, I just wish it could output in the DV AVI format.

31st August 2005, 00:18	#39 \| Link
mic Registered User Join Date: May 2003 Posts: 410	So don't have to read doc :) From: http://download.microsoft.com/downlo...b45/MCEVid.doc Test 18: TV tuner/capture/encoder video bandwidth test Goal: To measure the lines of video captured and compressed with the TV tuner device to ensure that video capture is delivering a detailed and accurate image. Test Tools required: Avia Guide to Home Theater DVD and consumer electronics DVD player with S-Video output Test Configuration: Set Media Center TV source to STB (S-Video) and connect DVD player output to TV capture card input via S-Video cable. Connect PC via VGA or DVI to *high-resolution progressive scan display.* Drive fixed pixel display at native resolution. Failure to drive display at native resolution will result in false failures on this test! "Observe the moving resolution wedge closely and watch for any breakup in a smooth image. If the resolution wedge shows clear straight lines, the deinterlacer is properly running in film mode and is weaving. If the resolution wedge in the image shows distortion or aliasing artifacts such as a “valve” shape where straight lines should appear, the deinterlacer is running in video mode " Last edited by mic; 31st August 2005 at 00:20.

31st August 2005, 02:33	#40 \| Link
trevlac budala Join Date: Oct 2003 Location: U.S. Posts: 545	@bobcat Yes ... 4 different setups. Too bad we can't see a still grabbed from that mpeg you make. Here is a filtered version of your image. It does not shake on my commodore via DV out. BUT i blurred it. Only in the Vertical direction. I was surprised that I needed to blur to about 2.5MHz. I thought around 3MHz would be ok. I basically used a truncated sinc filter so there is a bit of ringing in the image. i don't think one can see this on a TV. The image looks ok on a TV. Not as sharp as the origional, but not bad. On a PC, it is rotten. You can read the wedges and see that I blurred to around 200TVL vertical and not at all H. I sorta thought 240TVL Vertical would be ok. I'm not sure why it does not work. http://trevlac.us/pics/bobcat.jpg @mic I'm not sure if your info is for me. I do not have a progressive dvd player and can't hook my LCD up via DVI. It's a bit old. The chart I was using could measure a few things. One thing I've used it for in the past is to measure horizontal resolution of capture devices. I posted a test link before. BTW: My commodore is model 1702. Worth looking into.

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