Interlaced MPEG2 at 352x288?

[SatStorm]

@flaninacupboard
Yes, canvas not carvas, who knows why this words end up in my mind as "carvas".
Some english words, are in my mind as "pictures", I never used them in real life. So, when a "picture" is broken in my mind, I repait the same mistake all the time. You can see that I do the same grammar mistakes all the time, untill someone correct me!
Thanks for this!

Just for those who don't really undestand my reaction in this treat:
There is a almost a 3 years background with Xesdeeni. It might look like an attack by me, but it isn't. I remind him that we have already discuss those things here and on doom9's forum. And he prooved more than once wrong.
The problem with him is that he "teach" the same subject, without updating his "lesson" with what the others manage to proove him over the years.
It's like talking to a deaf person. He gonna link you to some sites just to proove himself, and gonna reply to you in a way which for each sentance you need to open the dictionary.

Years ago, I used to say straight "Capture 352 x 576" for VHS. I was right, but others point me that this "rule" isn't always right, because of various things I didn't even know that exist. Mostly hardware stuff. It is a statement correct for the 60% of all cases for example, but not for the bt8xxx based cards.
So today, when I reply to someone in the question "how to capture VHS", I answer him with all the updates I have for this subject.
Xesdeeni doesn't do this when he "teach" about picture resolutions, framesizes, encodes, etc. It is like not even count what many others told him... It is only what he knows.
Well, I'm a practical person, not a theory one as he is.
I 'm not able to explain in english the theory behind 352 x 288 and why it looks like VHS, but I can point out how to test it and have your own thought about this subject.
And it is not an easy thing to do, because many standalones don't play 352 x 288 correct, unfortunatelly. But when it does, you are amazed with the results!
There are even DVB channels in europe transmitting interlace at 352 x 288 and look great. The music channel Magic TV Italy for example on Hotbird Satellite (13 East) is 352 x 288 with 1340 kb/s!

With NTSC and 352 x 240 you can't have VHS quality. You would, only if it was possible for 240 to be interlace. But this is not possible.
So, you can only emulate the canvas and end up 352 x 480. It is an overkill for VHS, but it is the only solution you have.

[vhelp]

TGIF peoples :P

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Well ... *cough* ... this thread is getting a tad out-of-control.

Let me say that I respect everyone in this thread. SatStorm, despite English not being his native language, has made many great posts here on this website. Xesdeeni is my hero for figuring out how to do PAL to NTSC long before ayone else did and his methods are still the best and I try to promote that all the time when I see people asking about such conversions. Last not not least LordSmurf has shown himself to also be extremely knowledgable and his website is a great resource.

And, lets not forget, he's the one that created the 411 filter for DV sources :P
And, I use it all the time :P :P
And, I too, am on everyones' side.

Cheers,
-vhelp

[lordsmurf]

junkmalle, I'd absolutely love to see that DVD and that tape if you still have them... I'm not sure I could repeat what you've done as accurately as you've done.

I still think there is more to the horizontal resolution, but I'd want to see your results with my own eyes to be sure. I'm guessing the 240 TVL is on the maximum side and not an average, and the lower resolutions on that range appear sharp, while the upper resoltuion spectrum that approaches 240 appears in more of a "sampled" pattern and bit fuzzy (though not corrupted like 540 TVL).

I'm glad you were able to respond to my chaotic madness from before. I sometimes lose focus when posting.

[junkmalle]

Lordsmurf,

I'd absolutely love to see that DVD and that tape

I might be able to post the source images here. The original BMP files are too big but converting to GIF shouldn't lose any detail. That will make them small enough to fit under the 50 KB limit.

I carefully converted the images to a DVD compatible (CBR, 6000 Kb/s) mpg. The mpg files looked clean when viewed on the computer. I extracted frames from the mpeg files to verify the compression maintained something close to the original images. I then burned to DVD without re-encoding the video stream. You should be able to repeat the process.

Let me know if you (or anybody else) are interested.

I still think there is more to the horizontal resolution, but I'd want to see your results with my own eyes to be sure. I'm guessing the 240 TVL is on the maximum side and not an average

That could be the case. Remember the resolution test used black and white lines (no color) which is a best case scenario for NTSC and VCRs. And this method can only determine that the VCR had more than 180 and less than 270 (1:1 picture dimensions) lines of horizontal resolution.

[junkmalle]

SatStorm,

352 x 288 can be interlace and this is a fact... There are even DVB channels in europe transmitting interlace at 352 x 288 and look great. The music channel Magic TV Italy for example on Hotbird Satellite (13 East) is 352 x 288 with 1340 kb/s!

I did a little searching around the net but didn't find any references to interlaced 288 line PAL video. Could you point to any authoritative source with information about this?

[SatStorm]

I don't bookmark anything (but sometimes when I speak to certain people I wish to have), so I don't have a link to offer you.
This is a very old discussion, anything related are deleted years ago from my PC.
Basicly, the interlace barrier is the 280 lines. PAL use 288 lines so it is lucky on this (and it really shows on TV).
Maybe some other forum users can point you on this.

[flaninacupboard]

junkmalle, if you can stick the images up or let us know a simple way of creating the images in photoshop the i'll certainly give it a go as well.

[energy80s]

Would a BBC Test Card be of any use to you?

[flaninacupboard]

that would be very useful! all i've got for calibrating things at the mo is the THX optimizer. which doesn't actually seem to give very good results, i end up with a very dark picture following it's instructions - not sure if they created a new one for PAL instead of NTSC?

[BJ_M]

PAL and NTSC calibration test images and video streams are on this ftp site

ftp.tek.com

/tv/test/streams/Element/MPEG-Video/

includes all the BBC cards and lots more

[junkmalle]

Here's my test image of vertical lines for examining the horizontal resolution of a device.

[Xesdeeni]

I did a little test. I created a 720x480 still image (uncompressed bitmap) of alternating black and white horizontal lines....The conclusion, VHS has a vertical resolution of 480 lines.

Excellent experiment. Everyone should try it.

Just for jollies, I did the same with alternating black and white vertical lines....720 lines...360 lines...240 lines...180 lines...144 lines....I recorded the DVD signal to VHS tape...The tape could only resolve the the lowest 3 resolutions (240, 180, and 144). So the horizontal resolution of my VCR is somewhere between 240 and 360 lines (over the entire width of a 4:3 image). That corresponds to between 180 and 270 vertical lines over a square (3:3) picture area. So the often quoted horizontal resolution of 240 for VHS is in the right ballpark. At least on my VCR.

Which hopefully shows the difference between the 240 (vertical) lines of resolution for an analog VHS VCR and the 240 (horziontal) lines of a VCD.

The problem with red shirt soccer players is oversaturation by the tv set, that's not a side-effect of the signal.

The biggest problem with color bleeding is that the way it was added to the color signal was a hack, so it would still be compatible with the black and white TVs still being used. As a result, the color gets screwed up very easily. And the color really gets screwed up when it's put on a video tape. If you want to see this at its worst, record from one VHS tape to another. The color then starts smearing and bleeding all over the place!

Xesdeeni

[flaninacupboard]

The biggest problem with color bleeding is that the way it was added to the color signal was a hack, so it would still be compatible with the black and white TVs still being used.

Not true of all transmission systems.....

[BJ_M]

The biggest problem with color bleeding is that the way it was added to the color signal was a hack, so it would still be compatible with the black and white TVs still being used.

Not true of all transmission systems..... :)

NTSC = Never The Same Color

[Xesdeeni]

The biggest problem with color bleeding is that the way it was added to the color signal was a hack, so it would still be compatible with the black and white TVs still being used.

Not true of all transmission systems.....

Perhaps, but for NTSC, PAL, and SECAM, I think it's pretty true.

SECAM is by far the worst. It is so bad that almost all SECAM video processing is done in PAL instead. Then the finished product is converted to SECAM just before broadcast. (This can be done since only the color encoding is different, but not the timing.)

NTSC has its share of issues, including "chroma crawl" and "color aliasing," which are caused by the color modulation interfering with the luminance (and vice-versa). And the "Never The Same Color" problems were due to phase alignment problems that showed up as green or red tinting of the picture. No wonder all NTSC TVs have a "tint" control.

And PAL suffers some issues as well. I just learned last week that PAL VHS VCRs include an additional line-to-line anti-crosstalk feature that causes the vertical resolution of the color information to be cut in half. It seems that this also causes the color to move downward as you re-record the video again and again. And editors get frustrated with the 8 field color pattern that makes it difficult to cut a PAL video on any desired frame.

I for one won't be sad to see these old formats disappear.

Xesdeeni