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**Dr Mordrid** · 14 November 2002, 13:01

First of all understand that in NTSC land full frame is typically 704x480 (ATSC Table 3 D1) or 720x480 (CCIR D1/DVD/DV).

The reason for the difference is that a quarter sized frame for 720 wide video (360x240) is not MPEG legal because it's not evenly divisible by MPEG's 16 pixel wide macroblocks. This is important for VideoCD, which uses a quarter size frame.

A quarter size of 704 wide video (352x240) is evenly divisible by 16, and therefore MPEG comaptable, and so it was put into the ATSC standard.

As such;

704x480 = NTSC ATSC Table 3, aka "D1". Best used when there are highly detailed graphics, titles or effects.

352X480 = half/D1. Often used by cable companies to reduce the bitrate. Handy for projects without highly detailed graphics, titles or fancy effects. Also handy if your hard drive isn't fast enough for D1.

352x240 = quarter D1. Most often used for VideoCD.

There is another resolution in the mix that you may end up rendering to;

480x480 = 2/3 D1. Used for SuperVideoCD but also used for cable & satellite (DirecTV for one). Yes, it fits into a normal 4:3 video frame; 2/3 D1 is what they call anamorphic, which means horizontally "squeezed".

You should be capturing with a tool that can use the correct NTSC frame rate for TV beause 30 fps isn't it. That is for video intended for display on a computer monitor. TV requires a fractional frame rate: 29.970 fps.

avi_io is the tool of choice with your card as it will not only lock 29.970 fps solid (which PC-VCR cannot) but it is far less likely to drop frames and also actively tries to keep the audio and video in synchronization.

Dr. Mordrid

**morse** · 14 November 2002, 13:52

Originally posted by Dr Mordrid

352x240 = quarter D1. Most often used for VideoCD.

avi_io is the tool of choice with your card as it will not only lock 29.970 fps solid (which PC-VCR cannot) but it is far less likely to drop frames and also actively tries to keep the audio and video in synchronization.

Dr. Mordrid [/B]

So if I plan on making a mpeg-1 file or a VCD from a TV recording, ..then I should be recording at 352X240? Or is it better to record at the highest quality and come down from there?

What is avi_io and how do I use it with my G200 Marvel to record
TV broadcasts?

Thanks for the help!
m

**Dr Mordrid** · 14 November 2002, 14:15

When using analog cards I record for VCD at 352x480 because in NTSC broadcast video there are only 352 horizontal color samples but TWO fields (thus 480 lines).

In a full 704 wide frame there are only 352 color samples...each of which is spread across 2 horizontal pixels, so in capturing at 352 wide you don't lose any color data; all you lose is half the black & white data, which isn't as important unless you're adding effects. Capturing only 240 high instead of 480, however, cuts out a lot of vertical information a good MPEG encoder can use.

I encode the VCD file with TMPGEnc using one of its advanced delacers; "Double (field, daptation)" or "Even-Odd (field, adaptation)" work nicely. These delacers use both fields to interpolate a single new field, which looks a lot better than just dropping one of the fields to get down to 240 lines. They can be found in TMPGEnc's Advanced menu under Deinterlace/Method.

Most other MPEG encoders would just drop one of the original fields, losing all of its information.

Dr. Mordrid

**morse** · 14 November 2002, 17:24

Originally posted by Dr Mordrid

I encode the VCD file with TMPGEnc using one of its advanced delacers; "Double (field, daptation)" or "Even-Odd (field, adaptation)" work nicely. These delacers use both fields to interpolate a single new field, which looks a lot better than just dropping one of the fields to get down to 240 lines. They can be found in TMPGEnc's Advanced menu under Deinterlace/Method.

Most other MPEG encoders would just drop one of the original fields, losing all of its information.

Dr. Mordrid [/B]

I am using Ulead Studio Video 6 and I encode as VCD. I usually archive it as a mpg file and if I want a VCD I will burn the mpg file as one. Is this a mistake? Should I be using TMPGEnc instead.

For some reason I can't use the latest versions of TMPGnc. The last one that worked was 2.02.31.119. Once they went to the new interface video stopped working. It acts like it works, I have no error messages, but there is no video display.

**Dr Mordrid** · 14 November 2002, 17:31

You can encode with VideoStudio 6 but you don't get the extra quality TMPGEnc's delacers add. Still; they'll look pretty good if you make sure the 6.02 update is applied. This update has the latest MainConcept MPEG modules in it.

Dr. Mordrid

**morse** · 15 November 2002, 14:06

Originally posted by Dr Mordrid
You can encode with VideoStudio 6 but you don't get the extra quality TMPGEnc's delacers add. Still; they'll look pretty good if you make sure the 6.02 update is applied. This update has the latest MainConcept MPEG modules in it.

Dr. Mordrid

I am indeed using the latest VS6 6.02 patch. Thanks for all this info.

I will change my recording size to 352x480. Will this still make a difference if I use VS6 to encode?

I would give TMPGEnc's a try again but I use VS6 to edit and TMPGEnc no longer seems to support the Matrox avi codec. I have downloaded and am experimenting with AVI_IO. Unfortunately it doesn't support the Matrox TV tuner but it does allow me to select source channels individually.

I am considering purchasing AVI_IO. At least it has continuous updates where as Matrox hasn't had one for 2 plus years.You really think that using it will improve my final VCD result. Record with AVI_IO ....edit and encode with VS6?

thanks

m

**Dr Mordrid** · 15 November 2002, 16:27

It will cut down on dropped frames, do a better job of keeping the audio and video in synch, lock down a 29.970 fps frame rate and it does very nice segmented captures (multiple 2 gig captures without dropping frames between segments); none of which PCVCR does very well at all.

AVI_IO is used by beginners and pros alike for analog captures. That alone should say something about its utility.

Dr. Mordrid

**Brian Ellis** · 16 November 2002, 02:48

Personally, I recommend capturing with AVI_IO at the highest resolution you can (7xx x 480 or 576), editing, and then reducing to VCD MPEG format. Transitions and titles become far smoother.

For the anecdote, after doing a number of DVDs, I recently had a 50 minute project and I thought of doing it in VCD. It was captured at 720 x 576 from my DVCAM deck, edited and then converted to MPEG-1. The first time I viewed it on a TV at a normal viewing distance, it didn't look too bad, although the standard white-on-black copyright notice at the start was a little bit rough. The second time was when the person for whom it was intended came over to see it. They were seated at normal viewing distance, but I was much closer than normal to the 29" screen, perhaps 1.5 metres. I was literally horrified by the vertical jaggies, which I had hardly noticed before. I tried burning it as an SVCD, but the bitrate was too low to fit it on with anything like decent quality, so I eventually did a DVD at 8000 CBR and the quality was excellent, even though the disk was 1/3 empty. Lesson learnt

This is another reason to capture at max: you can change formats!

**Prospero** · 16 November 2002, 05:39

An example of a file can be found
here . Recorded at 704x480 in huffyuv via AVI_IO, lightly filtered and resized in VirtualDub, and then encoded in Tmpeg. File is 11megs and 15 seconds long. It's a clip from Trauma Life in the ER, that was shot at my hospital (no that guy is not me, I'm in it later). Source recording was digital cable to a G450eTV, and the footage was shot in DV.

**morse** · 17 November 2002, 14:12

Originally posted by Brian Ellis
Personally, I recommend capturing with AVI_IO at the highest resolution you can (7xx x 480 or 576), editing, and then reducing to VCD MPEG format. Transitions and titles become far smoother.

This is the question I posed when I started this thread. It seemed to me, that you wanted to start out with as much information in the file as possible before you edit it down. However, I have tried it both ways and I don't see much of a difference. What I have noticed is that after turning my Ulead VideoStudio 6 edited G200 TV recordings into a VCD, using both the Matrox Video tools or AVI_IO, they are not as sharp as if I had recorded them with a VCR. Why not?

thanks

**Dr Mordrid** · 17 November 2002, 14:29

As noted in my first reply:

352X480 = half/D1. Often used by cable companies to reduce the bitrate. Handy for projects without highly detailed graphics, titles or fancy effects.

Dr. Mordrid

**morse** · 17 November 2002, 15:21

I just created a VCD with my G200. I used AVI_IO to record a TV broadcast at 29.97 352x240 and standard stereo audio...and then selected Form =mpg highest quality. An hours recording resulted in 3 files totaling about 6 GB. When recording I was using less then 50 percent CPU time and had no dropped frames.

I then edited using latest version of Ulead VideoStudio 6 and then encoded to VCD. Finally I burned the VCD with EZCD Creator 5X Platinum.

When played in my DVD player, outputted to my TV, I can see block pixels when movement is occurring. Why? What am I doing wrong? How do I get regular VHS quality?

Is it just that this is as good as the G200 Marvel can do?

**KRSESQ** · 17 November 2002, 16:37

The standard VCD video/audio bitrate settings can be a little skewed, resulting in less than optimal results. Usually the video bitrate defaults to 1150 and the audio to @ 250-350. I set my VCD bitrates to 1372 video and 128 audio and encode using TMPGEnc and I don't get any blockies.

As long as the total bitrate for your VCD doesn't exceed 1500 or so, all should be good. Some use higher video bitrates but this is what plays best in my DVD player.

Kevin

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