HD & SD Edit, What field order?

[HallmarkProductions]

We are currently producing a programme which is a mix of HDV, XDCAM HD and SD DVCAM. The HD material is 50i, 1440 x 1080. The intended destination is SD DVD.

The HDV timeline in Avid Liquid has been created with top field priority (as per HDV), but, the DVCAM clips are placed on the timeline with bottom field priority by default. I presume we should change the field order of the SD clips to match the timeline properties?

When we have finished the edit we want to export the footage into DVD Studio. previously we have exported the files from AL7 as AVI, SD, bottom field first. Thus the whole field priority is now reversed, which I believe to be correct. What effect does reversing the field order actually have?

Can anyone confirm that this is the best way to go?

When we open DVD studio, "Preferences", - "Encoding" - we have set to Field order "bottom", Mode "2 pass variable" Bit rate min 4 and max 7, Motion Estimation "Best"
Does that sound right?

[pkbristol]

I was under the impression that anything destined for tv/dvd/sd was upper field first.
Anything i've ever put on the timeline,(vegas) ,dv,hdv,mxf, whatever, i always render as upper field first when the destination is for dvd/tv, doesn't matter if it's crt or lcd, it's what gives me the best results.

Paul.

[HallmarkProductions]

DVD should be bottom field first, surely?

[pkbristol]

Try it, look at the result.
I've rendered and burnt 3 dvd's, one upper, one lower, one none (progressive),with footage that was originally progressive and upper field, played them on different tv's, lcd and crt, the upper looks lovely, the other 2 look awful.
That's just my experience.
I've since found out that anything destined for tv (crt and lcd) should be upper field, anything destined for a pc monitor or web should be progressive.
I now always render to upper field for dvd's, always get stunning results.
Paul.

[PaulD]

Hi
DVD authoring software like DVD Studio Pro *knows* what it has to output to make a correct DVD - an upper-field MPEG-2 if its PAL.

What DVD SP/Compressor doesn't necessarily know is what source files you are feeding into the transcoding process.
You can feed either in, as long as you tell it (correctly), and you will get a correctly interlaced DVD burn.

Analogue PAL, and digital 720x576 except DV is upper field.
DV is lower field (except on some anomalous older Matrox systems).

With Final Cut Pro 5.1 and 6 a Shift-field filter will automatically be added to any footage that isn't correct for you sequence settings.
So in an HDV timeline any DV clips dragged in will have their field setting swapped to upper.

[Alan Craven]

.....

Analogue PAL, and digital 720x576 except DV is upper field.
DV is lower field (except on some anomalous older Matrox systems)......

I am not so sure about "older" Matrox systems. The RTX100 is certainly Upper Field, and as far as I know, so is the current RTX2 series. Matrox continue to insist that they, alone , are correct in this.

I have just started to mix down-converted HDV with SD on a Matrox RTX100 system, and have discovered that I have to set Procoder 3 to produce a Lower Field first avi, or I get the characteristic wrong field order image problems.

[David L Lewis]

Can confirm that using Premiere Pro CS3 and encore with a Matrox RTX2 card you get awful results if you use Lower Field.

[HallmarkProductions]

Hi

What DVD SP/Compressor doesn't necessarily know is what source files you are feeding into the transcoding process.
You can feed either in, as long as you tell it (correctly), and you will get a correctly interlaced DVD burn.

.

Morning Paul, How do you tell DVD SP/Compressor what the source file is, so it can do a correctly interlaced DVD burn ?

Just out of interest I have output straight from the timeline in Liquid to a DVD and it seems much better ??? Still doing more tests......

[Alan Roberts]

All HD is upper field first. 480 SD is upper first, 576 SD is lower first.

If in doubt, record something with fast motion, and using a short shutter. the correct field order is that which produces the best motion. beware that any decent flat panel will not care about field order (strictly speaking, it doesn't care about the position of the fields) if it has a devent de-interlacer. I have test signals to check this.

[pkbristol]

[QUOTE=Alan Roberts;328287] 576 SD is lower first.QUOTE]


As in 720x576 ?
If i render dvd's in anything other than upper field first i get horrible results, on all tv's, from 5 year old crt's to new sony 40inch lcd's.
Doesn't matter if i film in interlaced (50i) or progressive (50p).

Paul.

[Bob Aldis]

I got the impression that SD was Lower and it is what I have always used and I see that HDV is upper. I didn't know that 480 was upper. If old stuff is downloaded through a DV camcorder is it safe to say it will be Lower?

[Alan Roberts]

Paul, what I've given is the correct position for the DV and HD recording formats. As I understand it, DV at 576-line is lower first, but is actually transposed on both coding and decoding, such that it appears to be the wrong way round.

There are contradictions in the hardware and software, and that's why I said, and repeat, make tests with motion sequences, and use whichever setting produces the best results.

[Imagine Video]

There are contradictions in the hardware and software, and that's why I said, and repeat, make tests with motion sequences, and use whichever setting produces the best results

I could not agree more - there seems to be a general towards DV lower field first and HDV upper field first encoding BUT NOT ALWAYS as sometimes the rule produces odd results, Between various software and haedware encoders/ edit setups.

I have used Upper field first on all HDV projects so far with 100% success SO FAR;-)