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-   -   Recording Video: useful resolution beyond 384x576/480 ? (http://www.digitalfaq.com/archives/capture/13309-recording-video-resolution.html)

Prodater64 02-11-2005 08:09 PM

Recording Video: useful resolution beyond 384x576/480 ?
 
Quote:

Now, it is a perfect opportunity to clarify a myth here: There is no way to grabb from any analogue source (including TV broadcasts) and with the use of "S-Video in" to get a usefull resolution beyond 384 X 576/480.
The reason for this, is that in analogue technology, there are no horizontal lines like the digital world, but horizontal DOTS. 720 dots in a raw, creates what we call a line. With the analogue transmissions, if a dot is missing in the raw, there gonna be no replacement, just a null dot, a nothing. The lenght of the raw, gonna be always the same with or not some dots. For example:

A line with all the dots: .................................................. .........
A line with some dots missing : ... ............. ............. ..................... ...

In theory all types of connections/cables are capable to carry a picture of CCIR-601 resolution from a source to a screen, but there gonna be loses in the dot raw line like those in the example. Those loses are more for composite, less for S-Video and even less for Component and RGB. It is not easy to expain it further in a simply post, maybe a future article
With S-Video, those loses are about 1/5 of the video in theory. In practice and mainstream cables/connectors, is more, about 2/5 or the original info.
So you end up with 384 horizontal usefull dots X 576/480 vertical lines. And becase in digital world only the usefull info counts, any grabb with the use of S-Video beyond 384 X 576/480 is a fake!
If you want source on higher resolutions, you can experiment with DV, DVB transmissions (when you grabb direct the stream with the use of special hardware), DVD - Video (ripping) and source which came from Component adaptors or RGB ones. The full Euroconnector cable (known more as SCART) includes sometimes the RGB info, but a Full SCART to SCART cable required , with high quality parts and those cables costs a lot!. Also, the difference ain't easy noticable on a TV, but is very noticable from the encoders!
Overall, don't expect higher resolutions beyond 384 X 576/480 with the use of S-Video! It is practicly impossible to have them! And because 384 X 576/480 ain't a supported resolution in any optical media, go straight for 352 X 576/480. And guess what, that is the resolution of CVD!
http://www.videohelp.com/forum/userguides/98177.php

kwag 02-11-2005 08:55 PM

Hi Prodater64,

You shouldn't take some of the (noob) stuff posted on that site very seriously :)
That quoted text is full of crap :!:
Read (and digest!) the truth here: http://www.uwasa.fi/~f76998/video/conversion/

-kwag

Prodater64 02-12-2005 07:25 AM

Hi and thanks:
I had read that time ago.
Now I just want to know:
1 - I need to buy a capture device to capture VHS material now and DV material in the future. I'm thinking in Pinnacle DV-AV v9. There is any other capture board better that this for digital and analogic material.
2 - Can I capture with high resolution with this hardware, related to analog material (and related with digital one)?

Shibblet 02-17-2005 01:10 AM

ProDater,
I have the Pinnacle AV/DV v9. It rocks for captures. And you can capture in 720x480, Via composite or S-Video inputs. It also has a firewire connector on board for digital captures as well.

Prodater64 02-17-2005 03:01 AM

What is the better resolution to capture from a VHS tape?

incredible 02-17-2005 04:45 AM

As the article above says it, ... there are no effective pixels in broadcastings but lines. But the articel points out facts too generally!
Anyhow .... everything depends on the quality of the broadcastings and so YOU HAVE TO TRY BY YOURSELF and compare ;-)

When capturing from VHS 704x576 is to much imho, so 352x576 is enough in most cases. I always do capture tv-broadcastings at 704x576 and I figured out that its worth. A 704x576 resolution for me is the best DVD conform target capture resolution where the quality will be kept at best.

If you have NOW the choice, then go and get a SAA7134 philips based capture card like the Terratec Cinergy 400 its mega cheap and you can choose any codec by yourself like HuffYUV or PicVideo mjpeg. DV imho is not a good capture stream format choice as ends up in 4:2:0 Colorspace and even here in a BIG target size on your HD.

Dialhot 02-17-2005 05:38 AM

Quote:

Originally Posted by incredible
DV imho is not a good capture stream format choice as ends up in 4:2:0 Colorspace and even here in a BIG target size on your HD.

But it's probably the best choice if you plan to convert it KVCD aftwerwards. Or HuffYUV, but not mjpeg.

incredible 02-17-2005 06:24 AM

Its a choice but defenitely not probably the best ...

The Hall of Fame ...

1. RGB24 (but as TV cards do work in YUV this would mean upsampling = Nonsense)
2. HuffYUV (lossless 4:2:2)
3. Mjpeg at very good quality/Bitrate (4:2:2) like Q=19 or about 4-6 MB/sec
4. Lossless 4:2:0 like the Alparysoft Codec
5. DV (4:2:0)
6. mpeg2 (4:2:0) - at VBR using a fixed quantizer and a HQ DCT Matrix
7. 3ivx (4:2:0) - dto.
8. Xvid or Divx (4:2:0) - dto.


The real logic is to get a most perfect stream on the HD, means as much as Colorinformations (like 4:2:2) as available, as much resolution as it makes sense and as much details as available ... out of the broadcasting/providing via TVcable or (s)VHS VCR.

Beside that I do like Hardware where you dont have to stuck on a give format/codec which is hard-wared given by the device.

Dialhot 02-17-2005 06:54 AM

Quote:

Originally Posted by incredible
The real logic is to get a most perfect stream on the HD, means as much as Colorinformations (like 4:2:2)

I didn't think HuffYUV was 4:2:2, so this become the best option I think. But a general question : do you think is necessary to keep 4:2:2 when the goal is to go to MPEG2 (4:2:0) ?

incredible 02-17-2005 07:09 AM

As said a CaptureCard inputs the signal into a YUV 4:2:2 Format.
Even if you choose RGB32/24 then a colorspace conversion would be the result and the Cspace converters on those cards are probably not the best.
Also if you have a 4:2:2 Stream on your HD you have a full frequency of colors "in stock" then you can choose what you want, means filtering in YUY2 in Avisynth and then providing a kept 4:2:2 to CCE for instance.

Prodater64 02-24-2005 01:44 PM

Quote:

Originally Posted by incredible
Its a choice but defenitely not probably the best ...

The Hall of Fame ...

1. RGB24 (but as TV cards do work in YUV this would mean upsampling = Nonsense)
2. HuffYUV (lossless 4:2:2)
3. Mjpeg at very good quality/Bitrate (4:2:2) like Q=19 or about 4-6 MB/sec
4. Lossless 4:2:0 like the Alparysoft Codec
5. DV (4:2:0)
6. mpeg2 (4:2:0) - at VBR using a fixed quantizer and a HQ DCT Matrix
7. 3ivx (4:2:0) - dto.
8. Xvid or Divx (4:2:0) - dto.


The real logic is to get a most perfect stream on the HD, means as much as Colorinformations (like 4:2:2) as available, as much resolution as it makes sense and as much details as available ... out of the broadcasting/providing via TVcable or (s)VHS VCR.

Beside that I do like Hardware where you dont have to stuck on a give format/codec which is hard-wared given by the device.

I buyed a Pinnacle AV-DV that I think it supports DV, MJPEG and MPEG.
Then, does my choice must to be MJPEG?

incredible 02-24-2005 02:10 PM

Post a tech specs product link so I can give you my option.

Prodater64 02-24-2005 03:57 PM

Quote:

Originally Posted by incredible
Post a tech specs product link so I can give you my option.

http://www.pinnaclesys.com/docloader_n.asp?templ=10&doclink=/WebVideo/studioavdvdeluxeversion9/English(UK)/doc/avdv_deluxe_features_specs_2.html&Product_ID=1883& Langue_ID=2&loc=spec&division_id=

the viking 03-09-2005 07:16 AM

Inc. wrote:
Quote:

....go and get a SAA7134 philips based capture card like the Terratec Cinergy 400 its mega cheap and you can choose any codec by yourself like HuffYUV or PicVideo mjpeg.
I looked at this card today,and on the dealers website its says digital
videoformat MPEG1(160x120) and MPEG2(720x576).


So the question,does this card supports both MPEG and MJPEG,or
have I missed some basics somewhere? :D

They sell the card here in Norway for about 80$

-----------------------
viking

Boulder 03-09-2005 10:37 AM

Based on Terratec's site, the card does support AVI and MPEG capturing. I don't know if it captures to MPEG in hardware though. However, if you can capture to AVI, you're better off doing so anyway :wink:

zerotype 03-13-2005 07:48 PM

I just skimmed through thsi and didnt see any one teling you the res to cap form vhs.
It is 640x480. I'll give you the link if you want, but that is the best to cap at.

Dialhot 03-13-2005 09:18 PM

I don't think so ! If you can cap at a standard resolution (something in ...x480 or ...x576) you will avoid further A/R distortion and/or resize.

I don't see really the point to cap at a PAR 1:1 when you target a (S)VCD/DVD. Can you give your link ?

Boulder 03-14-2005 02:47 AM

Whatever the source is, capture at n x 480 (NTSC) or n x 576 (PAL). n depends on your card and the drivers, but the general rule is to capture at maximum capture area. On my BT878 card with Hauppauge's drivers, it's 696x576. Over that and the card starts scaling upwards.

VHS has a horizontal resolution somewhere between 352 and 480 pixels. That is, encoding at 352x480/576 is usually enough and you won't be able to see any difference. If SVCD resolution was supported in DVD specs, that would be the best to use.

The point in capturing at max resolution and encoding at 720 or 704 pixels horizontal resolution is that the standalone doesn't need to scale the video by a large factor. In theory that will keep the video slightly sharper.

When you choose the capturing resolution, you have to keep in mind that the card will sample at a high resolution and then scale down to the desired resolution. That's why it's best to use the maximum active capture area when capturing.

See this thread for more information regarding the maximum capture area of different chips and drivers : http://forum.doom9.org/showthread.ph...pture+AND+area

rab 04-21-2005 02:01 PM

So which connections are best for capturing from a VCR?
Scart to S-Video or Scart to Composite?
I'm thinking of getting the Hauppauge PVR-350 and it has both S-Video and Composite.

Boulder 04-21-2005 02:11 PM

If your VCR has S-video out (which I doubt), use it. I use antenna out->antenna in.


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