VHS to DVD, resulting interlace issue on television

[Sawood]

Hi,

Unlike many new posters I have spent a fair while looking around the forum to see if my question has already been mentioned previously, I can't find any exact answers, it is touched upon in both of the following though..

https://forum.videohelp.com/topic348373.html

https://forum.videohelp.com/topic344231.html

I am trying to convert VHS tapes to DVD. I am using a Belkin Hi-speed USB DVD Creator for the video input, and am capturing using Ulead VideoStudio 6 as follows:

PAL (25 fps)
Field order A
MPEG files
24 Bits, 720 x 576, 25 fps
(DVD-PAL)
Video data rate: Variable (Max. 6000 kbps)
Audio data rate: 224 kbps
Layer 2, 48 kHz, Joint stereo

To my knowledge, this is perfect for DVD, and does not require any re-encoding etc. When playing the file on my PC the footage looks excellent, with no issues at all. GSpot says the footage is DVD compliant.

I take the MPEG-2 file and use NeroVision 7 to add a few chapter marks, and burn the disc at 2x speed onto a Verbatim DVD-R. Nero's SmartEncoding clearly detects the footage is already DVD-compliant, does not appear to re-encode it, and gets on with authoring and burning.

However, when playing the DVD back on my Sony television (not HD or flatpanel) with Sony DVD player there appears to be some kind of interlacing issue. Moving objects appear to flicker across the screen, making the footage hard to watch properly. Playback on my second television has the same problem.

Seeing as I captured with 'Field Order A' and told NeroVision that I want 'Interlacing, Upper Field First', I do not understand the problem; to my knowledge these are the correct settings for PAL video? I have tried choosing Field Order B in capture and Lower Field Order in Nero.. but the same flickering occurs.

Please advise as to what I am doing wrong.

Thanks,
Sawood

[jagabo]

The field order is being set incorrectly somewhere along the line.

Each frame of interlaced video contains two half-pictures, called fields. These pictures were taken at different times. The field order tells the DVD player which field to display first (you only see one field at a time on a TV). If the player is displaying with the wrong field order you get jerky motions.

Seeing as I captured with 'Field Order A' and told NeroVision that I want 'Interlacing, Upper Field First', I do not understand the problem; to my knowledge these are the correct settings for PAL video? I have tried choosing Field Order B in capture and Lower Field Order in Nero.

Try the opposite: capture field order A, tell NeroVision it's lower field first. Or vice versa.

[dadrab]

You could also try a different authoring application like GuiForDVDAuthor.

If you feed it DVD compliant MPEG2 video, I don't believe you have to choose TFF or BFF. It's been a while since I used it, so I can't remember definitely.

In any case, GFD or some of the other free authoring applications will do a better job than Nero.

I haven't found Nero to be real good an much of anything - but that's just me.

Proceed with Nero and keep your expectations low, or do something else... 8)

[jagabo]

Analog video has no frames. It is broadcast as a series of alternating top and bottom fields. With analog PAL video each field reprents (half) a picture taken a 1/50 of a second intervals.

The digital capture process weaves two fields together to form frames. It can start with a top field then add the next field (a bottom field) to create top-field-first frames, or start with a bottom field then add the next field (a top field) to create bottom field first frames.

Not all compression codecs maintain flags to indicate field order, and even with codecs that do maintain field order flags software sometimes gets it wrong, so sometimes you need to keep track of the field order yourself. Typically, a device will always capture with the same field order.

Some programs can convert field order and will have settings for both input and output field order. With this type of software if you tell it to output the opposite field order it will convert the field order by recombining fields or by shifting every frame up or down by one scan line.

DVD can be TFF, BFF or progressive frames. And in the case of NTSC it can be progressive frames with pulldown flags that explicitely tell the DVD player how to create the interlaced fields from the frames.

[pepegot1]

The quick, easy and effective way to convert VHS to DVD is to use a good DVD Recorder. Dump from the VCR to the DVD Recorder and you have compliant DVD. Use a stabilizer to remove Macrovision, if required. My DVD Recorder improves the VCR quality noticeably. You can then edit and reauthor using VideoRedo and TDA, if you desire. Results are very good. Why work hard?

[lordsmurf]

Ulead is backwards. "B" is top field.

[Sawood]

Many thanks for everyone's help, it is much appreciated, and I understand a lot better now.

As for lordsmurf's point, that would explain the problem entirely.

EDIT: I have now attempted to capture again, this time with 'Field Order B.' However, the mpeg created is a full 1GB bigger?! The only difference between the old and new files, according to GSpot, is the field order...

Attempting to author with NeroVision, it insists it cannot fit this 2hr15min footage onto a disc anymore, but it could with the footage in the opposite field order.
Attempting to author with GuiforDVDAuthor, it says 'Mux = No' and is unable to use the footage at all, where it could before.

Any ideas as to why this adjustment of field order has made such a difference?

Thank you,
Sawood