Interlace progressive video?

[Jeff Harper]

I just had a customer who cannot play her DVDs, and I strongly suspect it is because the DVD is progressive. Most of my customers have no trouble, but sometimes the parents cannot use their older players.

I'm wondering if I should interlace my footage for DVD?

It is common knowledge that Vegas doesn't deinterlace well. I've never interlaced progressive footage before, seems counterintuitive, but I want my DVDs to work for my customers also.

What happens when Vegas is used to convert 720p video to 480i, are the results as bad as when the reverse is done?

[Steve Game]

Jeff,

Whenever I render progressive video, (25p mostly) Vegas forces it into 25psf. Any player should recognise the flags and play this in the correct cadence, i.e. 25p. If you downconvert from 720p (I assume 60p) to 480i it should resample so would benefit from a low-pass prefilter to reduce aliasing.

Steve

[Jeff Harper]

Thanks Steve. Vegas is not doing that with my footage. Rendered footage is progressive. for 29.97 frame rate there is no such option, that only applies to 24 and 24p I believe. Vegas does that to your footage because it's 24 fps, not because it's progressive, at least that is my guess.

[David Jimerson]

It's far more likely that it won't play because of the incompatibility between the player and home-burned media (which doesn't happen often, but it happens). If it's a format DVD Architect will author a DVD with, then any player can play it. It's probably the physical disc itself which is the problem.

[Peter Manojlovic]

Originally Posted by Jeff Harper

I just had a customer who cannot play her DVDs, and I strongly suspect it is because the DVD is progressive. Most of my customers have no trouble, but sometimes the parents cannot use their older players.

Nope.
Don't bother going down the path of re encoding..

Let us know which DVD media, and method you're burning.

[Steve Game]

Originally Posted by Jeff Harper

Thanks Steve. Vegas is not doing that with my footage. Rendered footage is progressive. for 29.97 frame rate there is no such option, that only applies to 24 and 24p I believe. Vegas does that to your footage because it's 24 fps, not because it's progressive, at least that is my guess.

Jeff,

My footage is 25p (from a Canon 550D) so I have the option of keeping it as a progressive stream or creating a psf stream by asking Vegas to make it 576i/25 (you might call it 50i). In my experience, Vegas, (both Platinum Studio 10 and Pro 10) recognises the frame sequence as progressive and packages odd and even lines into separate fields. On playback, these fields are displayed simultaneously, therefore recreating a true progressive cadence.
The disc will also play as an interlaced stream showing image movement only every other field, so an aged DVD player will treat it as interlaced but the visual image will look like progressive. Just as we in 50Hz land have been used to feature films on TV for 60 years, (shot as 24 frames per second and run 4% fast at 25fps) and seen on ordinary sets as 25 non-interlaced frames.

I see no reason why you couldn't ask Vegas to render to 59.94i which will produce a psf stream. Vegas will interlace the full frame video on the timeline merely by sending the odd and even lines to their respective fields.

Steve

[David Jimerson]

No reason to do that.

[Jeff Harper]

I'm using Ridata DVD +R DL, best printable DL discs I can find. Yuden doesn't make them that I can find.

I burned multiple extra copies, and the ones I kept play fine for me. They've worked fine for everyone else since I started using them a month ago, except for one customer, and that problem resolved itself. Upon reflection, I'm sure my customer's player is very old and cheap.

[Steve Game]

Originally Posted by Jeff Harper

I'm using Ridata DVD +R DL, best printable DL discs I can find. Upon reflection, I'm sure my customer's player is very old and cheap. Yuden doesn't make them that I can find.

I burned multiple extra copies, and the ones I kept play fine for me. They've worked fine for everyone else since I started using them a month ago, except for one customer, and that problem resolved itself.

In the UK, its the cheaper players that are more tolerant of disc brands, even more so 10 years ago. The only player that I ever had problems with was the old Pioneer DV525, a very good one in its day costing over 250GBP. The cheap Chinese players, then less than 100GBP, would play anything thrown at them. This is maybe connected with the fact that they often used cheap DVD-ROM mechanisms instead of dedicated consumer devices made to the formal DVD consortium spec..

I think Jeff's initial suspicion is more likely. Early players tended to play interlaced discs only. The trend for progressive came when the distributors started releasing 24p movies. My old Pioneer DV565A was the first that was OK with them.

Steve

Steve

[Randall Leong]

In addition, there is a possibility that some early DVD players cannot read burned discs at all - they support only factory-replicated ("pressed") discs.

[David Jimerson]

There's a difference between progressive-scan players -- players which can output a progressive signal -- and DVD players which will play progressive DVDs. You do not need a progressive-scan player to play a progressive DVD.

Any DVD player should, in theory, be able to play any in-region DVD, whether it's progressive or interlaced. My oldest player from 1998 is still kicking and it plays any DVD -- interlaced, progressive, anything.

Commercial movie DVDs started being released as 24p very, very early, before there were any progressive-scan players available. There were no problems. There are instructions in progressive video files on a DVD which tell a DVD player how to output the signal as interlaced.

There may be a few very, very cheap players which have some sort of problem, but that's because it's a very, very cheap player, not because players in general can't handle progressive footage. They can. And it's not because it's an "early" player; it's because it's a *cheap* player.

[Aaron Courtney]

Originally Posted by David Jimerson

There are instructions in progressive video files on a DVD which tell a DVD player how to output the signal as interlaced.

Actually, it's the other way around. The stream is stored as fields with binary flags such as PROGRESSIVE_FRAME, PICTURE_STRUCTURE, REPEAT_FIRST_FIELD, and TOP_FIELD_FIRST that tell the playback device the proper way to playback the fields.

[David Jimerson]

On a theoretical level, yes. You might call it "48i" with flags, but it's functionally exactly the same as 24p, and would be treated as such by an NLE or video player. You can test this with 24p VOB files.

What it's not is 60i interlaced, from which 24p frames are extracted, which is the important point.

[David Jasany]

Weren't older desktop players more likely to be compatible with DVD-R rather than +R media? I always burn DVD-R disks and never had compatibility issues.

[Randall Leong]

Originally Posted by David Jasany

Weren't older desktop players more likely to be compatible with DVD-R rather than +R media? I always burn DVD-R disks and never had compatibility issues.

Actually, many older players have trouble reading disks that has a booktype set to a value other than 0. Unfortunately, DVD-R already has a pre-embedded booktype that's not 0 - and that booktype cannot be changed at all during a burn! As such, those older players are incompatible with DVD-R.

DVD+R, however, can have its booktype set to 0 (DVD-ROM) instead of its default of DVD+R - but only on a burner that supports DVD+R bitsetting. Some burners do not support bitsetting on single-layer DVD+R media while some others automatically set the booktype for DVD+R to 0 whether you like it or not.