1/2 screen YUY2 capture, can U tell the difference?

[acarr]

If I capture in 1/2 screen (352x576) using YUY2 and Huffyuv, 48k for audio. Can I author the clip to DVD the NORMAL way? (full screen) Will I be able to tell the difference with a standalone DVD player and TV?

Thanks

AC

[Dr Mordrid]

half-D1 is DVD legal and any player that doesn't support it isn't worth having. All you lose is horizontal grayscale resolution, which mainly affects detailed graphics or small titles. In 90% of the video you see you'll have a hard time seeing the difference until the titles come on...and who reads those?

There are only 352 color samples in broadcast video anyhow, each being spread across 2 horizontal pixels, so you're losing nothing in terms of color qualty.

If it'll make you feel better cable/satllite TV providers use half-D1 all the time to save bandwidth.

The following page will give you all the encoding info you'll need;

http://www.disctronics.co.uk/technology/dvdvideo/dvdvid_videnc.htm

Note that you can also encode NTSC DVD video at 24 fps. Many encoders have a setting for this it is advantageous in that by reducing the number of frames you can allocate more bits to each frame to up qualty. The DVD player itself does the up-sample for playback at TV frame rates.

Dr. Mordrid

[acarr]

Thanks for the link Dr. I'll have a go tomorrow.

After studying your machines spec. I was wondering if you've ever tried to capture/burn the video clip realtime onto a DVD-R or DVD-Ram?

AC

[Dr Mordrid]

I have and with decent results, but it doesn't give the quality I prefer.

Dr. Mordrid

[Flying dutchman]

@DocMordrid:
>There are only 352 color samples in broadcast video anyhow,
>each being spread across 2 horizontal pixels, so you're losing
>nothing in terms of color quality.

That's true only if the capturing is perfect - if the new sampling positions match the original positions rather than overlap across pixels.

I've heard it said often in this forum that capturing at more than half-D1 resolution is useless for archiving VHS material because it has a low resolution anyway. I doubt this very much. Capturing a low-resolution signal at the same low resolution is like applying a low-pass filter to an already low-pass filtered signal. A video capture card is a non-ideal digital low-pass filter. What makes this filter non-ideal is that there's no guarantee that the sampling positions exactly match the positions of the pixels in the CCD of the recording camera - blurring occurs because of pixel overlap. Therefore the filter cutoff is not infinitely steep. And if you cascade two identical low-pass filters the result is always a new and steeper low-pass filter with an even lower -3DB cutoff frequency.
So you'll lose detail and there's little you can do to prevent it.

My own experience is that a simple 2:1 bilinear or averaging resize from 704x576 to 352x576 makes much better copies of a VHS original than capturing at 352x576 straight away. S/N ratio is much better (noise gets averaged out) and aliasing/moiré are reduced. Some programs like VirtualDub allow you to apply the resizing filter while capturing, so one can have this advantage at no extra cost in terms of disk space.
Because of the better S/N ratio and the lesser moiré, an Mpeg encoder such as tMpeg will spend more bandwidth on signal and less bandwidth on noise. The improvement in output quality is dramatic.

[Kris1]

I concur.

Before a series of unfortunate events threw me off my normal routine a couple of weeks ago, I was experimenting with MSP7.0 quite intensivly, and D1 was one of the things I was toying around with a lot.

I too saw a substantial drop in quality if I went straight from a VHS source to a Half DVD capture format. Capturing in full res, and recoding back to Half DVD gave far better results. Of course, I can't measure the difference, but it was perfectly observable by my own "black box testing device" (aka, my wife) who pointed out "that footage looks like crap compared to the previous attempt !".

If however I captured straight into HalfDVD straight from a video source (like a Tuner), the result was perfectly acceptable and I could avoid the recompressing stage without too much quality suffering.

Take Care,
Kris
----------------

[acarr]

Interesting. I don't know its possible to resize it real time with VDub. I captured in 1/2 D1 because the speed and capacity of my HD. I'm using avi_io to capture, Vdub to edit and frame serve. I can't get any audio in Vdub while I was in capture mode, don't know why. I'll try to resolve the problem and do the capture in vdub from now on.

1 more question, how can I record 5.1 audio from my sky digibox? I use a scart to s-video and 2 phono lead, will that be a 5.1 signal or stereo only?

Thanks guys.

Andy

[Peter B]

accar, your 2 phono lead will be stereo (probably Dolby surround) only. You will need 6 phono leads, optical cable or coaxial output to capture 5.1 sound. Then you will require the same input into your computer.

[bitz4brainz]

Dr Mordrid

Coming from DV, using the hidden advanced settings in MF2 and DVDWS, is it possible to:
- IVTC the film source to 24 fps progressive for DVD?
- crop and resample a letterbox movie to become 16:9?
- get anywhere near the quality of TMPGenc 2-pass VBR?

I am still at wits end trying to get TMPGenc'd video authored into DVD without trashing it (stutters, seizing up...) I don't know what's wrong but I have tried so many different versions. Something happens when it is remuxed to VOBs. I don't want to blindly buy another authoring package, only to have it not work.

[Flying dutchman]

I can confirm that remuxing tMpeg-encoded DVD compliant files to VOB's using IFOEDIT results in stuttering also.

Remuxing it using Pinnacle Expression works without stuttering, but the time display is wrong by a factor two on both a hardware DVD player and WinDVD (a 36 minutes clip is displayed as having a duration of 18 minutes). Maybe I'm gonna try tMpeg's DVD authoring package just because I'm curious how compliant the result is.

[bitz4brainz]

Flying Dutchman

I have only been able to get a non-stuttering DVD with MF2 if the input is an 29.97 telecined mpg - or MF2 does the encoding (same way). Needless to say that the quality loss is significant. Basically VHS quality at 4Mbps. Very disappointing. I am at a loss for ideas.

I have also observed time problems. For me the time show on playback is 80% of the correct time, which makes sense if MF2 is miscalculating the frame rate (24 vs 30).

Pinnacle Expression simply hangs. I have to reset my XP computer.

[bitz4brainz]

Flying Dutchman

I just downloaded TMPGenc's authoring package and built a quickie DVD. As you might expect, it accepts the 24-frame, 16:9 formatted (TMPGenc'd) video, no problem, and plays back on my hard drive without ANY stutters (PowerDVD).

The film is beautiful again. Even at 4300 Mbps it looks every bit as good as the laserdisc original.

I guess I will have to pay for this proggie and learn how to use it. Not very much flexibility in the menus, but I can live with it. Very few templates, but some work better for me than MF2. Can change the background, fonts, thumbnail, and menu action but little else. Interesting and precise chapter editor; visually shows you each actual I frame on a time line (chapter points must be I frames), tells you when you are cutting on a P or B frame. Chapter thumbnails show up 16:9, which is good. Wish it would build a disc image file but I can live with that too.

I can't tell you how much of a relief it is to see Star Wars as it was meant to be seen. I hope I won't run into any more bugs. I wish I knew why MF2 wouldn't work, but c'est la vie. After a month of fighting this issue, I won't complain. If I could figure out how to change the audio from MP2 to AC3 (NTSC compliant), that would be good.

[bitz4brainz]

Postscript.

Since I also have Premiere and MainConcept, I do want to learn some day how to accomplish the same thing. But I've invested so much time learning TMPGenc, and I need to get these transfers done, so I guess I will learn MC another day.

[Flying dutchman]

I too have downloaded tmpeg's authoring proggie yesterday and indeed it multiplexes PAL clips without any stuttering and gets the time display right also. Also I was able to set chapter markers in the clip that work on my DVD player (I don't use a menu).

Still, as an authoring program it is much too limited and for a basic multiplexer it's much too expensive.

[Maggi]

Originally posted by Dr Mordrid
...

If it'll make you feel better cable/satllite TV providers use half-D1 all the time to save bandwidth.

...

Not true ... at least not over here in Europe.

Bandwidth saving standard is 2/3 D1, ie. 480x576, but there are quite a few stations that broadcast full D1 (720x576) 24/7.