TMpeg field order (PAL) definition changed again

[Flying dutchman]

I just noticed, much to my dismay, that the field order definition in tMpeg has changed again (V. 2.5X). At least for PAL. I KNOW that my Marvel captures bottom-field-first but I have to encode them top-field-first with tMpeg to come out right! It used to be different!

[Dr Mordrid]

They put in automatic field detection, which means it sets up for the field of the source. As such when you feed it a bottom it sets up to export a bottom even if DVD etc. expect upper.

They should have left it alone....

Dr. Mordrid

[Flying dutchman]

Yes Doc, but they really changed the definition. I set it up manually as "B" (just like I always did, literally hundreds of times) and suddenly I get interlacing problems. If I set it up as "A" it comes out correct.

Could it be that PAL and NTSC interpret the filed order differently?

[colinbr]

<i>At least for PAL. I KNOW that my Marvel captures bottom-field-first</i>

This sounds strange. I thought that the field order was UPPER field first for PAL (for F1 dominant), while NTSC is lower field first. Replies on the Matrox forums also seem to state this. I think that this is also the order when making SVCDs. So it seems strange that the card is capturing lower field first.

Perhaps if TMPGEnc has just implemented automatic field detection then it is performing some "clever" pairing of fields across adjacent frames? Just a thought....

Colin

[Indiana]

Anyone know what's up with the tmpeg homepage? It's not been accessible here for quite some time. Or have they changed the address?

Where can I d/l the latest version?

[Tempest]

If http://www.tmpgenc.net does not work for you (it does for me), try my upped files:

TMPGEnc 2.53
VFAPI Plug-In

[Indiana]

Thanks! (I was still trying the .com site...)

[Flying dutchman]

@colinbr:

A "standard" field order, either for PAL or NTSC, is just wishful thinking. I am absolutely sure that the Marvel captures bottom field first in PAL mode; it's easy to verify on a frame-by-frame basis if you record a tv show.

I've observed that rental video tapes come in both flavours (top- and bottom field first). In PAL countries, film movies are videotaped at 25 fps without need for telecine. Since film is a non-interlaced medium, the captured video should come out "progressive" if it was digitized "bottom-field-first" or with heavy interlacing artefacts if it was digitized "top-field-first".
I have observed both variants. Some videotapes come out progressive right away, in some others I have to apply the PAL deinterlacing filter first. I guess it all depends on the equipment used for digitizing.

I have the impression that the "top field first" flag in Mpeg-2 files (such as used for Svcd, DVD) has the opposite meaning in PAL and NTSC. I must set it to "yes" though I know that in reality it isn't true...

[Fred H]

I wonder if all this have some connections with an error in my W2K VT 2.04 (leaked) and/or in Win XP with VT 2.04 hacked/patched?
The errors in both systems are that when I capture/play a HW MJPEG file (PAL), than the PD (5.39) resets automatically to NTSC and I’m forced to manually reset to PAL, which is not so easy in XP.
It happens mostly when I switch from PICVideo codec to Matrox HW MJPEG.
Is it an issue because the "wrong" field order?

Fred H

[colinbr]

<i>A "standard" field order, either for PAL or NTSC, is just wishful thinking.</i>

There seem to be a set of standards for whether F1 or F2 fields are placed as upper or lower for 625 and 525 line systems, but the field dominance (whether F1 or F2 is chonologically first in a frame) seems to be just a "recommendation". As you say, in the real world it seem to be a bit of a free-for-all!

<i>I am absolutely sure that the Marvel captures bottom field first in PAL mode; it's easy to verify on a frame-by-frame basis if you record a tv show. </i>

Is that recorded through the Video In connector (sorry I can't remember if the Marvel has a built-in TV tuner)?

I just checked my G450eTV by examining some captured PAL (from a camcorder) in Virtual Dub and it seems to be upper frame first. Perhaps Matrox changed the captured field order when they produced the 450eTV, or maybe its just down to different versions of the drivers. Incidentally, there was a posting a few months ago on the Matrox forum which said that TV captured from the built-in TV tuner using the Matrox PC-VCR was "OK" , but captured with VirtualDub had the field sequence altered.

It would be interesting to know what the captured field order is for NTSC material for the Marvel and G450eTV.

<i>I've observed that [PAL] rental video tapes come in both flavours (top- and bottom field first. The captured video should come out "progressive" if it was digitized "bottom-field-first" or with heavy interlacing artefacts if it was digitized "top-field-first".
I have observed both variants.</i>

Yes, I see what you mean. I suppose for my capture card the situation would be reversed - i.e. it would come out OK if the film had been digitised "top-field-first" and with interlacing artefacts if it had been digitised "bottom-field-first".

FWIW, I found some interesting pages which explain field order and interlacing in more depth than I could find elsewhere, and certainly filled in some gaps in my understanding. I'll post the URL in a new thread for greater visibility.