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exodious0
11th August 2003, 21:30
I'm trying to capture a TV show with my BT848 Hauppauge WinTV card with framerate 25fps and resolution 768*576.
But the captured video is interlaced!!

Here's an example:
Picture (610KB): http://w1.865.telia.com/~u86517630/forum/bilder/interlaced.png
Video clip (6.4MB DivX5):http://w1.865.telia.com/~u86517630/forum/bilder/interlaced%20(divx5).avi


The 25fps capture should be progressive (and 50fps capture would have been interlaced). Am I right?
I have tried to capture in 50fps but I don't think the card supports that high framerate because every other frame is dropped so I'll end up with 25fps in the end anyway.

What should I do?

vmesquita
11th August 2003, 21:34
exodious0,

50 fps should be progressive, and 25 fps should be interlaced. Capture 25 fps, even if ou manage to capture 50 fps you would get 25 duplicated interlaced frames per second.

[]'s
VMesquita

exodious0
11th August 2003, 21:40
Aha...of course, I'm a little tired today ;)

Is there any way to get rid of the interlace "lines" without loosing any information then?
Or is it better to leave the video as it is?

jggimi
12th August 2003, 03:13
I looked at your sample. At first glance, it appears that this was shot with a handheld video camera, with every frame interlaced.

I first ran your sample video through this AviSynth filter:

SeparateFields()

to make sure the interlace artifacts were due to two fields per frame, and not in individual fields. That was the case, individual fields did not have the artifacts. I than ran the video through the Decomb filter set to see if frames were shifted:

Telecide(guide=2,post=false)

And that appears to be the case, as well. Setting post=true, which will deinterlace any frames that don't assemble properly, did not appear to make much difference in the output.

My guess: perhaps this handheld video was modern/digital, and recording progressive frames. Perhaps the video was later broadcast and/or captured by you with reversed field order.

I don't do PAL, but reversed field order is common with PAL DVDs, according to Hakko504's comments in this tutorial (http://www.doom9.org/ivtc-tut.htm).

exodious0
12th August 2003, 11:40
Thanks, jggimi! I'll try that.

I have one more question.
I will encode the captured clip with CCE and thus it has to have resolution 720*576.
What will give the best image quality:
1. Capture in 768*576 and then rezie to 720*576
or
2. Capture in 720*576

Is the broadcasted video stream in 768*576 or 720*576?

Kika
12th August 2003, 12:15
Broadcast PAL is 704x576, not 720x576!

Capture in 768x576 and Resize to 704x576 or capture in 704x576. But never use 720x576 - this Format is for digital Sources only.

Wilbert
12th August 2003, 13:44
Broadcast PAL is 704x576, not 720x576!
Broadcast PAL is neither one of them.


Capture in 768x576 and Resize to 704x576 or capture in 704x576. But never use 720x576 - this Format is for digital Sources only.
Sure you can use 720x576: If you capture card uses an internal scaler (thus you don't see 18 pixels overscan = not ITU compliant) you can resize directly to a 4:3 format. If there's 18 pixels overscan (= ITU compliant), crop that and resize to a 4:3 format.


I will encode the captured clip with CCE and thus it has to have resolution 720*576.
What will give the best image quality:
1. Capture in 768*576 and then rezie to 720*576
or
2. Capture in 720*576
In case your capture card adds 18 pixels overscan when capping at 720x576, I would use this resolution (cause no extra resizing/scaling is necessary). Otherwise 768x576 => resize to 720x576.

Kika
12th August 2003, 15:31
Broadcast PAL is neither one of them.

OK,OK, Broadcast PAL-D1 is like 702.XXX x576.... :rolleyes:


If you capture card uses an internal scaler (thus you don't see 18 pixels overscan = not ITU compliant)

Yeah, if the Card is doing it the right way (BT-Cards do not!), you can use 720x576, but why shall anyone do that? There's absolutly no reason for capturing from analogue Source with an other Resolution than 704x576.

Otherwise 768x576 => resize to 720x576.

No!
720x576 = 786x576
704x576 = 768x576

Any other kind of calculation is wrong.

Since the earlyest Days of this Board, Guys like TheWEF and other ALWAYS are using this Resultions, because they are Part of the Specs.

Wilbert
12th August 2003, 16:05
No!
720x576 = 786x576
704x576 = 768x576

Any other kind of calculation is wrong.
Yes, I typed to fast. That's what I meant. "Otherwise 768x576 => resize to 704x576."

Yeah, if the Card is doing it the right way (BT-Cards do not!), you can use 720x576, but why shall anyone do that?
ITU compliant, doesn't mean the right way. There are just two ways (ITU compliant or internal scaler) of doing that, and you have to know which one of the two you are dealing with. Sure if you are capping at 704x576 or 768x576 you don't need to know that. Btw, with NTSC that are two resolutions (720x480 and 704x480) which are not ITU compliant, in case your chip uses an internal scaler.

OK,OK, Broadcast PAL-D1 is like 702.XXX x576....:)
There is no such thing as "Broadcast PAL-D1". Accordingly to the ITU standard there should be about 702 active digital pixels, but we are talking about digital video now.

Kika
12th August 2003, 16:20
There is no such thing as "Broadcast PAL-D1". Accordingly to the ITU standard there should be about 702 active digital pixels, but we are talking about digital video now.

Hum, we are talking here about digital Video from analogue Sources. According to the ITU (to be exact: the CCIR), the max. horizontal Resolution is 702 (704) Pixels (active Pixels).

And on NTSC: Yeah, TRUE Broadcast NTSC has a completly different Resulution, something around 711x486... ;)

SeeMoreDigital
12th August 2003, 16:51
Yes, the whole issue regarding 'compliance' appears to be a complete cock up.

I mean, why the hell was Mpeg2 DVD ever ratified to follow on from Mpeg1 to give us a pixel frame size of 720x480 or 720x576.

Surely 854x480 and 1024x576 would have been better (at 24fps). And well within a stand alone players 'brain' to puke out to a TV!

And if the 16 pixel rule had been stuck to. Why is High-Def 1920x1080. And not 1936x1088?

exodious0
13th August 2003, 11:46
OK..so if 704*576 is max resolution for PAL....


Which one of these two options is best then?
1. Capture in 704*576 and then resize to DVD resolution 720*576
or
2. Capture in 768*576 and then resize to DVD resolution 720*576


It's one thing that the PAL signal is maximum 704 pixels per line, but T what resolution does my card sample the signal? If the card samples at 768 pixels per line, doesn't it have to be better to take the full resolution that the card has to offer and then resize with some good algorithm?

Kika
13th August 2003, 11:57
Which one of these two options is best then?

None of them! 704x576 IS a DVD-Resolution. It's Part of the DVD-Standard especially for analogue Sources (never noticed that PAL Half-D1 is 352x576 and NOT 360x576?).

What you can do is capturing with 704x576 and letterbox to 720x576.

Capture cards are working different. Some of them are doing the Scaling the right way, some of them don't. So, using 704x576 instead of 720x576 is always right, using 720x576 for capturing sometimes is wrong.

ppera2
13th August 2003, 15:33
I think that it's pretty nonsense talking about exact hor. res. by analog video. In praxis, any resolution between 640-768 is good for capture. If you want resulting of 640 it's better to capture in that, not to resize later. For lower output res like VCD is better to capture in double res and resize.

If you try BT Tweaker you will see that even by same output res you can have different pixel width - just try fine adjust of right border. It works by slightly changing clock of sampler chip.

Other thing - every card has different black border left and right - it's normal, because of nature of analogue signal. Sync pulse starts sampling in one hor. line, and it can't be 100% accurate and same in all cases.

cweb
19th August 2003, 15:53
I always use 720x576 for my PAL analog captures and everything is fine for me. I do crop afterwards before resizing.

Originally posted by Kika
OK,OK, Broadcast PAL-D1 is like 702.XXX x576.... :rolleyes:




Yeah, if the Card is doing it the right way (BT-Cards do not!), you can use 720x576, but why shall anyone do that? There's absolutly no reason for capturing from analogue Source with an other Resolution than 704x576.

cweb
19th August 2003, 15:57
You aren't giving a valid reason as to why it is wrong.

The results are fine so there is no 'wrong'.

You prefer to capture at a different size, that's all. Keep capturing
at that size, I'll keep capturing at 720x576.

There are even commercial software packages which make mention of
720x576 e.g.
http://www.quintic.com/software/coaching/


Originally posted by Kika

Capture cards are working different. Some of them are doing the Scaling the right way, some of them don't. So, using 704x576 instead of 720x576 is always right, using 720x576 for capturing sometimes is wrong.

Kika
19th August 2003, 16:56
Huh, there IS a valid Reason: The Specs!
OK, the difference between 720 and 704 isn't much, but there is on.
Standard for analogue TV is CCIR 601, and it say's it clearly: Resolution is 704x576 not 720x576. And a PAL-Line do have 52 us, not 53.33!
Like i wrote before:

It's Part of the DVD-Standard especially for analogue Sources (never noticed that PAL Half-D1 is 352x576 and NOT 360x576?).

And the other thing... You wrote:
There are even commercial software packages which make mention of

That's right, but they aren't right. Even Adobe Premiere does use wrong aspect ratios for DV-Video! If you don't belive that, do a test with an exact Circle (576x576). But it centered into a Pic of 768x576 and let Premiere render it to an DV-Video. After that, you circle is not longer a circle!

I said it before, the difference is very small, but why should i encode something at a bigger size then in original size?

Wilbert
19th August 2003, 17:05
Huh, there IS a valid Reason: The Specs!
That doesn't mean your capture card needs to be ITU compliant.

@Cweb,
Is your capture card ITU compliant, or does your image fill the whole 720x576 (horizontally)?

ppera2
20th August 2003, 22:29
Originally posted by Kika
Huh, there IS a valid Reason: The Specs!
OK, the difference between 720 and 704 isn't much, but there is on.
Standard for analogue TV is CCIR 601, and it say's it clearly: Resolution is 704x576 not 720x576. And a PAL-Line do have 52 us, not 53.33!...
I said it before, the difference is very small, but why should i encode something at a bigger size then in original size?

What you write can be useful in only few specific situations.
By capturing analogue source at big resolution, goal is not to get bigger size, but to get more accurate capture (oversampling).
People usually resizes after capture.

Other thing: are authors of Win DVD or Pinnacle PCTV Studio idiots?

Why they offer res 720x576 for capture?

Kika
21st August 2003, 10:17
are authors of Win DVD or Pinnacle PCTV Studio idiots?

Ask them, not me. My guess: Yes! Hey, even the Guys from Vidac (a small german Hardware-Producer with a good MPEG2-Capture Card) did'nt know the full Video-Standard. Maybe that's because you have to pay for the Specs.

OK, part of the Specs:
PAL CCIR 601: 704x576
PAL ITU-R: 720x576 with an Motion Area of 704x576 (the same like for DVDs)
To be exact: There is no Picture-Format in the Specs with an Area of 720x576 active Pixels!
So there are two ways to produce ITU-R-Compatible Videos:
1: 720x576 with black Bars at the left and right side.
2: 720x576 without Bars, but with 16 Pixels Overscan.

Way one is used for analogue Source (but you can also use 704x576). Some Cards like the Pinnacle Bungee are capturing this Way, some DV-Camcorders also if they are used as Capture-Devices.
Way two is used for other Sources like Scanned Films or DV. But the active Area is only 704x576.

CRT-based TVs are not able to Show 720x576, because for doing that, you need 53.33 us to display a Line, but PAL-Timing is only(!) at 52 us for each Line - and that's, compared to Pixel-Resolutions, 704x576.

By capturing analogue source at big resolution, goal is not to get bigger size, but to get more accurate capture

Um, that's also one of the Web-Legends. First, you have to capture the RIGHT resolution, even if you want to resize. Ask one of the programmers of a Resizing-Filter. It DOES matter which Resizing-Factors are used. 768x576 -> 704x576 gives you a different Picture than 768x576 -> 720x576 (from the encoders point of view).

But, do it as you wish, not a problem for me... :rolleyes:

ppera2
21st August 2003, 14:27
Kika:

I don't want to start here some big discussion, just to mention couple argument more, because you abviously didn't get the point:

Most of TV stations (ground) still playbacks movies from studio tapes. It's analogue and therefore no sense talking about some standards, about RIGHT resolution of capturing.
Practice is to cut edges and therefore you may be in right when say that can't display 720 pixels hor. But there is no something like 720 pixel hor. res. in analogue world. If I capture in bigger res, I will have it on TV too, of course less sharp.
I could write here many things more, but that's enough. If you don't see what is essencial difference between analogue and digital, nothing will help.
With BT Tweaker I can set that 720 res capture fill whole pic.
However, black bars left and right always change - depending from TV station, from current programm, and sometimes even during the movie.

Kika
21st August 2003, 16:16
@ppera2

But there is no something like 720 pixel hor. res. in analogue world.

Guess there is a missunderstanding. Yes, there are no Pixels in the analogue World. But if i talk about Pixels in this context, i talk about how Capture-Cards have to sample and scale the signal to get the right amount of Pixels with the correct PAR for the given DAR.
DVD and DV always do have a PAR of 1.092:1 - in both Formats (704x576 AND 720x576).

If you don't see what is essencial difference between analogue and digital, nothing will help.

I know this difference perfectly. It's exactly what i tried to explain.

With BT Tweaker I can set that 720 res capture fill whole pic.

Me too ;) The Pic will be stretched if you (or i) do that. The PAR will be 1.0667 after that, and that's not correct.
However, if you do a resizing to a TRUE 4:3-Format after capturing (maybe to 620x480), it does not matter. But if it is for DVD, it does matter.

However, black bars left and right always change - depending from TV station, from current programm

Yeah, that's true.

cweb
14th February 2004, 18:51
Originally posted by Wilbert
That doesn't mean your capture card needs to be ITU compliant.

@Cweb,
Is your capture card ITU compliant, or does your image fill the whole 720x576 (horizontally)?

Oops - I didn't answer this..


My card is a geforce4 - I wouldn't know about ITU compliance, sorry.
The image is a whole 720x576 of course, and then I resize using avisynth into other formats (XviD/KVCD usually).

The image does not appear stretched to me.

ronnylov
18th February 2004, 17:18
Originally posted by Kika

CRT-based TVs are not able to Show 720x576, because for doing that, you need 53.33 us to display a Line, but PAL-Timing is only(!) at 52 us for each Line - and that's, compared to Pixel-Resolutions, 704x576.


If 720 pixels corresponds to 53.33 us, shouldn't 52 us correspond to 702 pixels? What is the exact pixel aspect ratio of 720x576 and 704x576 DVD resolution? I have seen 59/54 but also the value 128/117.
Acording to this (http://www.iki.fi/znark/video/conversion/#conversion_table) it should be 128/117 (active pixel area is 702 pixels) but according to this (http://www.mir.com/DMG/aspect.html#reftable) it is 59/54 (corresponds to 703 pixels active area).

What does the CCIR specification actually say?

EDIT:
After some thinking I have concluded that the correct pixel aspect ratio is 128/117. The TV signal is sampled by 13.5 MHz. The PAL line frequency is 15625 Hz. So each line is sampled by 13500000/15625 samples which equals to 864 samples per line. But only 52 us of the 64 us line contains the active picture area. That corresponds to 52*864/64 pixels which is exactly 702 pixels. I used values from here (http://www.uwasa.fi/~f76998/video/modes/) in the calulation. Anyway the page I linked to explains everything.

Kika
18th February 2004, 17:31
shouldn't 52 us correspond to 702 pixels?

Haven't the correct size in mind, but it corrspondents to 702.??? Pixels, so 54/59 should be right. 704x576 is choosen because of the mod16-Rule for MPEG-Encoding.

mustardman
19th February 2004, 00:49
Good grief you guys. You argue about the "correct" aspect ratio, and you start talking about pixels in hundreds, or nanoseconds in a line (eg:52uS and 52.3333uS).

The difference is less than 1 or 2 percent. Are you really going to try and capture a perfect circle, and then measure it to make sure it is right? I don't think so.

Live with the error, somehow I don't think you'll notice. You can bet your life when the original is filmed (or taped) they didn't care if their line frequency was off by a few nanoseconds, or it gave an effective resolution of 719 pixels! Can you be really sure that your correction is not just making it worse?

ronnylov
19th February 2004, 10:50
According to specification of PAL on one of the sites I linked to each line duration is 64 us, but the active picture are actually 52 us plus minus 0.3 us so it can range from 51.7 us up to 52.3 us. With 720x576 resolution (13.5 MHz sampling frequency) this give a range of from 698 pixels and up to 706 pixels active area of the total 720 pixels per line.

Normally when capturing for DVD i capture 704x576 and crops to 672x544 and adds 16 pixels black borders on all sides to get 704x576 PAL DVD resolution (I replace border pixels with black). The aspect ratio is unchanged but the active picture area is smaller. The black borders are hidden by TV overscan and it makes it easier to compress for the encoder.

crusty
2nd March 2004, 19:51
Sorry guys...just adding my 0.0000000002 Cents

exodious0The 25fps capture should be progressive (and 50fps capture would have been interlaced). Am I right?
Most capture cards just convert the analog signal into a digital stream which then gets thrown into a file. Normal PAL is 25 fps interlaced.
Interlaced means there's two fields instead of one frame.
That means 2x25 fps = 50 fields per second. 50 fps couldn't have been interlaced without doubling each field. 50 fps interlaced amounts to 100 fields per second.
You can have a capture card that converts it into progressive, but those are expensive. Usually the deinterlacing is done in software.
(btw: hauppages aren't one of those expensive cards)

Framedropping occurs because your computer isn't fast enough to capture in 50 fps (remember, it has to do most of it's work in software, which is CPU limited). Get a faster cpu or a better capture card if you want to capture in 50 fps. But it's not worth it, as most computers can't play most 50 fps video , as playback is also very cpu intensive.

Is there any way to get rid of the interlace "lines" without loosing any information then?
Or is it better to leave the video as it is?
That depends on what you want to do with it. If you want VCD, DVD or SVCD there's no need to deinterlace. If you want to encode it to MPEG-4, Realvideo or Windows Media Video it's better to deinterlace, as progressive video has much better support all around.
Also, much interlaced captures came from originally progressive content...deinterlacing would be 'reconstructing the original' and is generally a good thing.

What will give the best image quality:
1. Capture in 768*576 and then rezie to 720*576
or
2. Capture in 720*576

First some caveats:
What are you capturing? Are you capturing from analog TV, digital TV or a VHS or Betamax recording?
VHS is crap, there's no need to use a resolution higher than VCD (VCD was designed to be a VHS equivalent). Betamax is much better.
Analog TV is next in line, Digital TV is best.
Analog TV has a LOT of chroma noise, try to use a denoiser, preferably during capture.
Also, option 1 does not give you more information than option 2. So best is to use option 2.

Is the broadcasted video stream in 768*576 or 720*576?
The video stream is 720 in length, but that's only half of the story.

Broadcast PAL is 704x576, not 720x576!
Capture in 768x576 and Resize to 704x576 or capture in 704x576. But never use 720x576 - this Format is for digital Sources only.

All MPEG video standards use standards taken over from the analog world. This was done mostly to prevent all previous analog equipment from becoming obsolete.
Analog standards prescribe 'extra' lines outside of the real picture to adjust for equipment inaccuracy in the analog world.
That goes for both horizontally and vertically!!
Ever noticed those few twitching lines of noise above some of those Simpsons or South Park captures hanging around? That's Teletext that's not properly cropped. And closed captioning for hearing impaired, or subtitles.
If people actually looked at this site, http://www.uwasa.fi/~f76998/video/modes/ you would have noticed that the actual height is 625 lines. So there are actually plenty of lines above and beneath the real picture as well. These are used sometimes to contain abovementioned 'extras'. Generally speaking however, the vertical resolution is more strictly adhered to than the horizontal resolution; most problems focus on horizontal resolution.
To sum it up, 720x625 is simply a frame in which the analog picture is stored. Because of it's analog nature, it isn't centered, but 'floats around' or 'hovers' inside that 720x625 frame.
NTSC uses an even stranger visible picture, about 710.85x486 out of 711x525.

How the TV actually portrays it is the TV's business, not that of the broadcasting TV station. So capturing in 720x576 from analog source ALWAYS requires both cropping and resizing if you want just the picture, and store it some standard-defined medium (like VCD or DVD).
(never mind pixel aspect ratios)

DVDs require the picture to be mod-16, dividable by 16, so they use 704 or 720 instead of what the real visible picture is, 702 for PAL or 710,85 for NTSC.
To further complicate things, DVD's are mastered by companies, almost universally from analog source.
These DVD implementations can be completely different from one DVD to the next. So if one DVD mastering company says, 'He we like 720x576 to have ALL the content', they just store the complete picture in it without any regard of space around it. Then 720x576 would be the picture.
But another company, a lazy one, can just say 'Nah, the TV knows what to do', they just store the picture like it was to be displayed on TV.
(in fact, there is a gradual spectrum from one extreme to the other)

So DVD's are stored in lots of different ways, and the DVD player is expected to make sense of it. DVD players are more intelligent than it appears, as they can handle both interlaced and progressive, both NTSC and PAl, and they can also (up to a point) handle these extremes.
It also depends on model and make of DVD's and in the case of TV broadcasts also of human intervention.
Needless to say, when an anolog source put on a DVD gets analogically broadcast by a TV station and then captured again by you, you lose a lot of the original in the process, not just by all the loss, but also by all the adjustments in aspect ratio. Trying to keep the last Aspect Ratio in line sounds a bit narrow-minded in this respect.

Say you have a DVD that has the picture stored in all 720x576 pixels. Then imagine a DVD player not correcting for this but just sending this 720x576 pixels unaltered to the TV. The TV can only display a part of this picture, as is defined in the standard.
The result is that some of the picture is outside the visible part of the screen, and you visibly loose some information during playback.
A good DVD player would have corrected for this, and resized the original 720x576 to within the visible region defined by the standard (in PAL case 704x516), and then send it to the TV, which would then show it correctly.
Of course during a broadcast a human technician can adjust this, but most commercial stations have kinda lazy technicians which happily let the subtitles run WAY out of sync for three hours, so don't count on them to adjust something like this. :)

Broadcast PAL is neither one of them.
So this is correct, the whole signal is supposed to be 720x625, but this is not the same as the picture. Broadcast PAL is the whole signal, and that is 720x625. Or tries to be; due to it;s analog nature it can waver around a bit.

Sure you can use 720x576: If you capture card uses an internal scaler (thus you don't see 18 pixels overscan = not ITU compliant) you can resize directly to a 4:3 format. If there's 18 pixels overscan (= ITU compliant), crop that and resize to a 4:3 format.
That's correct. I strongly suspect Hauppage not to be ITU compliant, but I have no knowledge of this. However you gain little in quality by
capturing in 720x576 and both the file and the CPU requirements will be bigger. It is also a big no-no if you want to encode directly to the end result, without any intermediate steps, because you risk capturing al the noise, teletext and other crap around the real picture. Especially when encoding to MPEG-2 or MPEG-4, which has to be mod-16.
And if your capturing process isn't ITU compliant, you end up upscaling a 702x516 picture to 720x576 which is both cpu intensive and results in (some) quality loss. Remember that dropped frames are a mess.
768x576 is overkill, you just end up resizing anyway. 768x576 is also out of MPEG specs.

Since the earlyest Days of this Board, Guys like TheWEF and other ALWAYS are using this Resultions, because they are Part of the Specs.
Well just because they're part of the Specs doesn't necessarily mean you have to. AFAIK, ANY resolution above 720 is outside MPEG specs. This goes for MPEG-1, MPEG-2 and MPEG-4. So capturing in this resolution to any MPEG format is strictly speaking out of spec.
My guess is, they've been using it to adjust for different pixel aspect ratios. Capturing in that resolution makes sense only if you want to encode to a standard that cannot adjust for pixel ratios. And like I mentioned before, apparently 'guys like TheWEF and others' assume that the broadcast picture has the correct aspect ratio, which doesn't necessarily has to be true.
Yes, there are no Pixels in the analogue World.
Sure there are pixels in the analog world, they're just not square. And they're not formed by bits but by signals, and they're less precise. But they are called Pixels.
And on NTSC: Yeah, TRUE Broadcast NTSC has a completly different Resulution, something around 711x486...
NTSC is generally crappier than PAL...this includes the broadcasting. Expect NTSC captures to waver more around the 'ideal' frame.
Which one of these two options is best then?
1. Capture in 704*576 and then resize to DVD resolution 720*576
or
2. Capture in 768*576 and then resize to DVD resolution 720*576
That depends purely on your resize filter. Some filters are better for resizing up and some are better for resizing down.
Don't know which does what of the top of my head....In praxis, any resolution between 640-768 is good for capture. If you want resulting of 640 it's better to capture in that, not to resize later. For lower output res like VCD is better to capture in double res and resize.
I can agree with that...Trying to capture an analog TV source in either 720x576 or 704x576 or 704x516 is hoping for a miracle...you won't get the original quality anyway, analog is simply too crappy for that. Stick with what works for you.
Huh, there IS a valid Reason: The Specs!
Well, to put it mild: The specs are supposed to be approximated. No one expects you to be precise, not even the industry itself.
Other thing: are authors of Win DVD or Pinnacle PCTV Studio idiots?
Many, MANY professionals get it wrong. Some people who have been working on this for 20 years have it wrong. That includes those guys.
It's because the specs are so wildy differently interpreted, estimated and approximated that everything works the way it works now.
If some major player in the media world would suddenly start playing it exactly by the rules they would be out of business due to incompatabilities very soon. :DFirst, you have to capture the RIGHT resolution, even if you want to resize. Ask one of the programmers of a Resizing-Filter. It DOES matter which Resizing-Factors are used. 768x576 -> 704x576 gives you a different Picture than 768x576 -> 720x576 (from the encoders point of view).
Well that's true, most filters and codecs need the resolution to be dividable by some value like 4, 8, 16, 32, whatever...
You can resize anything you like anyway you like it, just don't expect every filter or codec to cooperate. :)
Most of TV stations (ground) still playbacks movies from studio tapes. It's analogue and therefore no sense talking about some standards, about RIGHT resolution of capturing.
In my experience most stuff gets played from digital media nowadays. But I'm in Europe. Maybe it's different overseas. But analog or digital, it doesn't really matter, as you have to be very observant during the whole process to keep the correct aspect ratio. At least digital media give you the possibility to exactly figure out how wrong they are...with analog it's just visual interpretation.
If you don't see what is essencial difference between analogue and digital, nothing will help.
Lol. Urhm.. really. The industry doesn't mind, why should we?Can you be really sure that your correction is not just making it worse?
Good point.

Woops....a little more than just 0.00000002 Cents, but hey what the heck. :D

mustardman
3rd March 2004, 23:25
VHS is crap, there's no need to use a resolution higher than VCD (VCD was designed to be a VHS equivalent). Betamax is much better. VHS is not as bad as you might think. Having done tests of VHS vs. VCD (and SVCD), VHS wins every time - on a decent deck. VHS (being analog) gives you none of the (IMO very objectionable) digital artifacts. Sure, it does not have a very good resolution, but I would prefer a slightly blurrier picture (compared to SVCD) to one that is full of artifacts!

The VCD vertical resolution is also half of SVCD and VHS (AFAIK it does field duplication).

VCD may have been designed to be VHS equivilant - but as far as I'm concerned, it does not come close.

By the way - I really like your response! (though long). These people that talk about resizing by one pixel to get the aspect ratio right - geezz!

SeeMoreDigital
3rd March 2004, 23:48
Originally posted by mustardman
...VCD may have been designed to be VHS equivilant - but as far as I'm concerned, it does not come close.

By the way - I really like your response! (though long). These people that talk about resizing by one pixel to get the aspect ratio right - geezz! Like with all video encoding this remark is very subjective!

Some time ago I generated some high motion PAL VCD tests using different encoders, such as Ulead, TMPGenc, Pinnacle, Adobe, Nero etc. And the differences between them were quite surprising.

I'll have to dig out the encodes to find out which ones came out on top. But given that we have people like kwag over at KVCD.net (who's constantly tweaking and re-designing Mpeg1/VCD matrices), I think it's fair to say that VCD can look much better than VHS.

Cheers

Kika
4th March 2004, 09:57
I think it's fair to say that VCD can look much better than VHS

Not realy, only if you have a very crappy VHS.
VCD has only half the resolution of VHS and 1/2.7 of SVCD. So it CAN'T come even close to a good VHS-Recording.

SeeMoreDigital
4th March 2004, 14:01
Originally posted by Kika
Not realy, only if you have a very crappy VHS.
VCD has only half the resolution of VHS and 1/2.7 of SVCD. So it CAN'T come even close to a good VHS-Recording. Maybe using the phrase 'much better' was a little over zealous.

It all comes down to the source, more so in todays 16:9 world.

One thing that is for sure. When capturing 16:9 broadcasts, VHS does a better job than when using VCD's standard matrices.

Anyway, given the humble VCR's rapid drop in price. I think it's high time that everyone was 'forced' to go out and buy an S-VHS machine.

Bring back analog. Or should that be 'analogue'!

Cheers