Making a DVD from progressive footage

[JIM E]

Hi Everyone,

I have some progressive video that I want to make into a DVD. I've searched all over these forums, but I haven't found a clear answer to this question. I want this DVD to be as universally playable as possible. In other words, I want it to be playable even on the old non-progressive DVD players, and non-progressive TV's. As I understand it, to properly play a DVD on that old equipment, it is pretty much a requirement that the DVD be interlaced otherwise it won't play properly. Is this correct? If so, how do I interlace my non-interlaced source material? I am using MainConcept MPEG2 encoder, and there is an option for "field order". Do I simply select something like "lower field first" and it will encode the footage interlaced? I'm hoping it is that simple but just wanted to double check if this is correct. Thanks for any insight into this.

[manono]

Is this correct?

No.

There's a distinction between how the footage is encoded and what the content itself is like. You haven't said if this is for PAL or for NTSC and, if for NTSC, if the source framerate is 23.976 or 29.97fps. These things make a difference.

PAL progressive sources are normally encoded as interlaced 25fps, although it's not a strict requirement (I don't believe), and then outputs 50 fields per second. NTSC progressive 29.97fps content is ordinarily encoded as interlaced and outputs 59.94 fields per second. NTSC progressive 23.976fps content is encoded as progressive with 3:2 pulldown applied to output 59.94 fields per second. Since the content is progressive, just leave the field order as TFF.

[JIM E]

Sorry, I should have included that info. The source material is NTSC, 720x480, 29.97 fps. So does that mean I should encode it as interlaced? If so, does it matter whether I pick top or bottom field first?

[manono]

I would (and have several times) encode it as progressive 29.97fps and TFF.

[aedipuss]

I would (and have several times) encode it as progressive 29.97fps and TFF.

since setting rff=1 is not an option on any consumer mpeg-2 encoder i know of it's probably best to go interlaced tff. and remember to keep the total bitrate of video/audio/other streams under 9.8mbps.

[SameSelf]

Seriously, why? Aren't all non-progressive DVD players in landfills already and the lasers nearly dead on the lingering dinosaurs? Interlacing is an artifact of the bandwidth limited analog days and should have never found its way into digital (ahh, who am I kidding? we are still in a bandwidth limited world, I want my 8Kp120!). If your progressive source is only 29.97p, interlacing it is not going to be nearly as smooth as you will have to double the frame rate. IOW, NTSC footage is really 720x240p59.94. So while half of the frame is missing, half of the temporal information is still present which your source material lacks. If you really need to interlace progressive footage, you should ideally be starting with a 59.94p source.

[Skiller]

First, you can use Zig-Zag scan when encoding entirely progressive video for DVD without risking compatibilty issues with any playback hardware ever made. Zig-Zag is the scan type used for progressive video in MPEG2; "Alternate" is for interlaced parts, although it can be used for both it is less efficient than Zig-Zag scan for progressive video.

That's the part that affects encoding efficiency (really, just that, the scan type).

Then there are the flags.
There are 3:

• TFF (True/False)
• Frametype Progressive (True/False)
• Progressive Sequence (True/False)

You can either flag or not flag the stream progressive. It does make sense to flag it as progressive because it tells the player if it should even bother deinterlacing or not and also how to upsample the 4:2:0 chroma. In case of a traditional player without progressive scan, it makes little difference in terms of deinterlacing due to a lack of it of course. It still should affect chroma upscaling – if the player cares that is. It also affects minor things like when you are pausing the video, whether the player would still the whole frame or just one field.


The TFF and Frametype Progressive flags do not affect compatibilty. Some people argue the last one, Progressive Sequence, is not DVD-compliant. However nobody ever found valid proof of this or reported a player that would not play a stream flagged as such, assuming the overall combination of the three flags was not illegal as documented in some parts of the MPEG2 specs (it says if Progressive Sequence=True, you must have TFF=false and Frametype Progressive=True, otherwise it's an illegal combination causing weird behaviours!).


Personally I have been using the "full" set of flags for many years and tested it on various players (old, new, cheap and expensive) and never had any trouble with it, despite the occasional claims it may not be compliant:

TFF=False, Frametype Progressive=True, Progressive Sequence=True

Aren't all non-progressive DVD players in landfills already and the lasers nearly dead on the lingering dinosaurs?

Nah, the ones from 2001-2006 were often very well built. I still have two non-progressive scan DVD players (both from 2003) and I actually use one of them as my standard DVD player because it's a great player.

Interlacing is an artifact of the bandwidth limited analog days and should have never found its way into digital

DVD was intended to store the analog data in a digital format, so naturally it was never meant to get rid of interlacing but rather support it like everything did before.
When DVD came out it was actually ahead of it's time, supporting true 25p, 24p with soft-pulldown and 30p as well as anamorphic widescreen.

[aedipuss]

you guys seem to miss that taking true 30p to 60i really changes nothing. the 30 frames per second are split into 60 fields of alternating lines. when it's "de-interlaced" to be shown on a digital tv the 2 fields of each frame are reassembled back into the original picture.

[Skiller]

In an ideal situation, yes, but no deinterlacer or comb detection is perfect. If the player or TV is expecting the video to be "anything" it will always trigger the deinterlacing here or there and therefore affecting picture quality as there is nothing to deinterlace.

The Frametype Progressive and Progressive Sequence flags actually completely turn off deinterlacing in a player. If, just for the fun of testing, you flag an interlaced video like this you will see combing everywhere.

[manono]

since setting rff=1 is not an option on any consumer mpeg-2 encoder i know of it's probably best to go interlaced tff.

Any video encoded as 29.97fps, progressive or interlaced, has the RFF flag turned off (set for 0 or 'false'), because there are no repeated fields. Not sure of your point there but it isn't a reason not to encode as progressive.

you guys seem to miss that taking true 30p to 60i really changes nothing...

If it's been encoded as interlaced the vast majority of progressive scan DVD players (the flag-reading players) will bob deinterlace it, whether the content is really interlaced or progressive. That's why I suggested earlier JIM E's content be encoded as progressive.

Only a cadence reading DVD player (only the very best, like Denons or Oppos) will 'notice' the fields are from the same point in time and keep the frames untouched to be output in pairs at 59.94 frames per second for a digital television. If for an old-fashioned CRT interlaced display, both kinds of players will have progressive scan turned off and will output at 59.94 fields per second, with each field having a match.

[Anonymous344]

Some people argue the last one, Progressive Sequence, is not DVD-compliant.

Yeah, my instinct is that it's not technically in spec, but I've never had a problem with it either and always use it for 25p. I'd also guess that encoding 29.97p is technically out of spec, but I've had no problems with that either. Like manono, I'd encode it as progressive.

[JIM E]

Thanks for all of your responses. I have to admit that the technical level of this discussion has gone far over my head. Haha. But to answer SameSelf's question about my intentions, I am making a video for my mom's birthday. She's has some very antique equipment in her house. She still uses an old tube TV, and I'm pretty sure her DVD player doesn't have progressive scan. I guess my thinking with my original question was this: I know that the "extras" on most DVDs are interlaced. And I think most documentaries are usually interlaced as well. And they play fine. So I thought I could just interlace my video to achieve the same thing. I guess I was just under the impression that all video had to be interlaced for this old equipment to be able to play it. Is that not true?

[davexnet]

I don't think it's necessary to interlace your video. Regular DVD players can handle it whether it has progressive scan or not.
Why don't you try it and see?

[manono]

Is this correct?

No.

Is that not true?

For the second time, no. Or, yes, it's not true.

[_Al_]

I mentioned that couple of times before, I used to make DVD's for lots of years with 720x480, 29.97 p content, playing on all possible players, TV's, CRT's.

Besides theory that is always out there, some great advises, like here in this thread, it always goes down how it is actually done with what software. I used HcEncoder for making mpeg2 DVD compatible streams and muxman for muxing DVD:
Using HcEncoder use defaults, or click "made DVD compliant" button first a then - check 4:3 or 16:9, interlace options use progressive and choose TFF. That TFF is flag that suppose to be tff of bff only so choose one, your content will be progressive anyway. Chroma downsampling (progressive or interlace) makes no difference because it applies only if HcEncoder downnsamples. If your content is less than one hour, or one hour 10 min or so check constant quantization, quant value 3 I think seams ok. It will encode 1pass only. Otherwise you'd encode 2pass and you'd need to set max and average bitrate

[JIM E]

Alright, I'm just going to try encoding it progressive as everyone suggests. Thanks for the help everyone.

[SameSelf]

Interlacing is an artifact of the bandwidth limited analog days and should have never found its way into digital

DVD was intended to store the analog data in a digital format

Are you sure about that? I thought DVD was created to succeed CDs as a larger capacity form of data storage? It was only after that, that DVD-Video came along. And analog or not, film is/was natively progressive. Fortunately, interlacing is quickly fading into history like silent films.

[Skiller]

No, when I said DVD, I was referring to the DVD-Video standard, sorry for being inaccurate. You're right that the data DVD was first and then came DVD-Video, of course.
The idea of DVD-Video was to store video signals adhering to either PAL or NTSC in a digital compressed format. Analog PAL and NTSC is a continous stream of fields. Frames (either progressive or interlaced) do not exist at that point. This means whether the picture content is progressive or not, for the analog signal and a CRT displaying it it really does not make a difference at all.

That's why I disagree with this

And analog or not, film is/was natively progressive.

Not when it's analog. It would be if we capture (digitize) such signal, but as long as it's analog it's just a stream of fields.




Film in it's native format does not adhere to any TV standard, so it was remarkable, for the time (1997), DVD-Video featured the storage of film in it's native format while still adhering to PAL or NTSC output, rather than simply supporting just the field based storage to output the overlaying TV standards (like all tape based formats).