I have a project shot at 1080p 29.97 and this is my first attempt to export it for Blu-ray. When I select the H.264 Blu-ray Format in Export Settings, there is no Preset matching the source format. It looks like the best options are:
1. 1080i 29.97 - Would I lose resolution this way? Is 29.97i actually 59.94 fields/sec with even fields on one pass and odd fields on the next (which would be parts of the same frame because it was shot progressive) or am I only going to get 540 lines of resolution?
2. 1080p 23.976 - How bad would artifacting be if I change the frame rate? Would Twixtor do this perfectly or at least much better than Premiere?
3. 720p 59.94 - This would preserve the original frames (doubling them) but I would have less than half the resolution.
I notice the MPEG2 Blu-ray also does not have a format that matches the source but if I select Match Source Attributes (High Quality) the Summary lists the Output as 1920x1080, 29.97 fps, but doesn't indicate whether it's progressive or interlaced. I just checked Wikipedia and it appears 1080p 29.97 is not a valid Blu-ray format. So is the MPEG2 converting to interlaced without expliciting telling me in the Summary Output? Is H.264 going to look better than MPEG2 (that would be my guess)?
Bottom line, what is the best option for highest quality output given the source material I'm using?
I think your best setting would be 1080i 29.97. This preset (in theory) should create a 1080PsF (progressive segmented frame) file that, when sent to a display, would combine both fields back together to create a full 1080p image.
That just confirms Encore doesn't support 1080p 29.97 for Blu-ray either.
It isn't just Encore, the Blu-ray standard itself does not support 30p. Export out as 30i and it should work. It won't look as nice as real 30i or 24p, but it'll work.
My recommendation is to avoid 30p when shooting, as it isn't a defined standard anywhere. Stick to 30i, 60p or 24p and you're good for any deliverable.
Ann, I'm afraid you may be right. I thought maybe there was a definitive "this looks best".
Qengineering, that makes sense although it sounds like all playback equipment may not properly support PsF. I had heard the term before but didn't really understand it (still not sure I totally understand it). Thanks for the link.
Jim, that's what I meant in my original post when I said, "it appears 1080p 29.97 is not a valid Blu-ray format", i.e. it's not part of the Blu-ray standard. If I had known this earlier, I would have shot it at 24p. But the BD is an afterthought anyway so I can learn these things. Fortunately, the client just wanted a DVD.
The (BD) playback equipment does not detect PsF format, PsF is essentially progressive images in an interlaced envelope. Both fields represent the same moment in time, each at half resolution. When the display presents the image, both fields are shown simultaneously (unless you displaying on an old CRT) recreating the full resolution 1080p frame.
It should be noted that all modern flat screen displays, when fed an interlaced signal, will display both fields simultaneously. This is true for both PsF, and true interlaced video, when playing at normal speed. It is for this very reason, I would argue that 1080PsF is superior to 1080i when shown on any modern display.
Basically, that's correct. CRTs can display one field at a time and "interlace" two of them sequentially to create one frame. Flat screens are not designed to display (half resolution, interlaced) fields sequentially, so they just slap them together (when played at normal speed) to create the frame.
Modern displays do that because interlacing is an outdated technology, would be terribly difficult with LCD/plasma and progressive images are much sharper. Modern displays accept interlaced video for backwards compatibility and because certain TV networks chose to stay interlaced.
Interlacing allowed/allows the same number of scan lines (think pixels) but uses half the bandwidth of the equivalent size progressive for any given refresh rate (60Hz). In the old days, interlacing was simply more efficient and used less expensive circuitry.
Yes, I understand why interlacing was used in the old days (I think in addition to the bandwidth, the 60Hz refresh also helped with phosphor decay times). What I don't understand is why a modern display can't do that too because, without it, content from networks that are interlaced looks really bad. Do (LCD) broadcast monitors display interlaced content properly?
Modern displays would have to literally separate out every other horizontal row of pixels and feed them a separate image at a different time (field 2 delayed from field 1). This would require additional (expensive) circuitry, and display panels with considerably more complex control.
There's little incentive for manufacturers to create such a specialized, expensive item just to properly display "old technolgy" signals.
No, modern high-end broadcast monitors do not properly display interlacing, which is why production facilities that must produce interlaced files need to should have at least one CRT to confirm and diagnose correct field dominance. It's also why I see so many commercials with reversed (jittery) field dominance.
When the display presents the image, both fields are shown simultaneously
That's not true, even for flat panels. Each field will be 'deinterlaced' by the TV and shown sequentially. Since both fields are from the same image, you essentially see each frame twice, which accounts for the somewhat unnaturalness of 30p. It's not quit as smooth as 30i, and not quite as filmic as 24p. It's a no-mans-land best avoided altogether (in my view).
I didn't realize 30p wasn't part of the DVD spec either. Premiere has no problem exporting my video to MPEG2-DVD format in 30p and the DVD plays just fine.
I guess I need to haul out my old (SD) CRT monitor to check for proper interlacing. I really don't want to spend money on a HD CRT. Are there adapters available that will allow me to convert HD content to SD and still see the interlacing in the HD properly?
There is a way to get 1080p 29.97 though.
The 3rd party x264pro h.264 exporter encodes the video as 1080p 29.97 and sets a flag to say that it's interlaced even though it's not (it's progressive).
The result is all the quality of a progressive encode and it makes it blu-ray legal.
"30p is just the ugly stepchild no one wants."
This sort of broad, misinformed opinion is baseless and misguided. The real world (my eyes) tells me 30p looks great on DVD and Blu-ray.
Don't just take my word for it. I suggest the OP test it for themselves.
Your are correct, Serge. If your subject matter requires lots of pans, 50i will look smoother than 25p, just like 30p will look smoother than 24p. But you are speaking of subjective "looks". That's quite different from "best avoided altogether" (for reasons that still don't hold water). 30p is a reasonable compromise between 60i and 24p, gives me just the "look" I want (for the kind of material I shoot), and looks stunning (to me) on a computer monitor and TV screen (no matter how it is delivered).
serge kouper wrote:
I've done a lot of experiments recently and "My eyes tell me" that 25P @50Hz doesn't look smooth during the pans, but 50i does.
You shouldn't have to do lots of experiments to see that 50i is much smoother than 25p, it's a dramatic difference. The motion with 50i looks like live video with no judder and 25p looks more like film.
Yes. Actually I was experimenting something else I shouldn't have mentioned that. For me it's 50i all the way. I always wondered why it's so important for some to shoot at 30p/25p or even 24p. For me, the smoother, the better. I like to see the film at a real life speed, I'm not fan of a constant shutter effect.