Interlaced and Progressive videos on same Bluray disc?

[VideoFanatic]

I'm trying to make a compliant Bluray. My videos are both 29.97 FPS (4:3). One video is 720 x 480i and the other is 720 x 480p.

Are you allowed to have Interlaced and Progressive videos on the same Bluray disc?

[poisondeathray]

You can use different specs when they are on different titles, but not all authoring software will allow you to do this

It doesn't matter for your case anyways, because primary stream SD blu-ray only accepts interlaced 720x480i 59.94 fields/s

So progressive 720x480p29.97 SD must either be flagged as interlaced, or encoded as interlaced

[jman98]

Yes, it is most certainly allowed to mix interlaced and progressive titles on the same disc. Many movie BDs with extensive supplements do this very thing where the movie is in 1080p and the supplements are in 480i.

I am positive that I have actually seen 480p used in a commercial BluRay for supplemental material, but it would take some time to find the exact disc again. So that statement has no proof. I know that we've been told that 480 footage must be interlaced or flagged that way, but I'm not 100% convinced that this is really and truly a requirement. None of us have ever seen the actual specs.

Some consumer grade authoring programs may accept 480p at 39.97 fps or maybe even 24 fps, but I'm not sure that such is strictly legal. Again, we've been TOLD that it's not, but we haven't actually seen the official spec sheets.

[poisondeathray]

SD blu-ray primary streams must be interlaced. 100% sure. Native progressive is not allowed. It's in the official specs, and shon3i confirmed this (one of the guys that has access to the offical specs) . The rules on secondary streams are more relaxed

[jman98]

What does "primary stream" and "secondary stream" mean? Again, I could always be wrong in my supposition. I can tell you that if I did correctly remember seeing 480p that it was supplemental material, but I don't know if that means "secondary stream" or not.

[poisondeathray]

Primary stream is the main title stream. Secondary streams are for things like PiP

This chart is actually copied from the offical specs
http://forum.doom9.org/showthread.php?t=154533

[mazinz]

A bit confused a little with this thread since I do not do much of anything with actual bluray authoring.
So going by the specs (from the link Poisondeathray posted) lets say something that was dvd format in 720x480 at 23.97 with 29.97 applied from pulldown and progressive would not be allowed or just not allowed as the main video stream? So if one were to convert such a stream for blu, it would have to be interlaced again or would a flag work for that?

The other part that I do not understand is what tells a bluray just what the primary stream is? Technically couldn't you make a short 2 second dummy stream so you can then do want you want considering the secondary streams are more flexible?

[poisondeathray]

Note, that chart is for AVC blu-ray

A 23.976p 3:2 soft pulldown DVD source will be MPEG2 will output an 59.94 fields/s signal and already be compliant . Encoding from scratch 480p23.976 with AVC requires pulldown flags, and an interlaced flag . (I think VideoFanatic is filtering and encoding some wrestling vids). I'm not certain about a 29.97p MPEG2 DVD source, but the AVC version requires it to be encoded as interlaced, or an interlaced flag be present

Also , many authoring tools are "lax" and allow semi-compliant things to pass through that won't pass a true BD verifier, and that many BD players can play non compliant streams anyway.

It's authored as a primary stream (it's done in the authoring software) , so I don't think you can "cheat" it like that. Non compliant streams will be rejected

You can PM shon3i at doom9 if you want definitive answers, he's one of the guys with the actual spec book .

[Brad]

The other part that I do not understand is what tells a bluray just what the primary stream is? Technically couldn't you make a short 2 second dummy stream so you can then do want you want considering the secondary streams are more flexible?

As mentioned, secondary streams were added to Blu-ray for picture-in-picture functionality. They can be stretched to fullscreen, though, so I suppose you could encode a black video matching the length of your secondary encode and tell the authoring software to cover it up throughout playback if you want a hacky solution.