A question for people from PAL/SECAM-istan

[Katie Boundary]

Out of all of the DVD/Blu-Ray content you've seen that was originally 30 progressive frames per second, but has been converted to 25 frames per second...

1) How much of it was converted by frame-blending?

2) How much of it was converted by decimating every 6th frame?

3) How much of it was converted by decimating every 6th field and rearranging the field order? example: separatefields().Selectevery(12,0,1,2,5,4,7,6,9,10,11).weave()

4) How much of it belongs in the category of "I don't know what they did but now sh** is all f***ed up"?

[wonkey_monkey]

Out of all of the DVD/Blu-Ray content you've seen that was originally 30 progressive frames per second

Don't know about anyone else, but for me that's "none." What material would that generally be, that starts out at 30fps (rare) and subsequently gets a converted release in PAL-land (even rarer)?

Do you have a point to make? If so, please just make it instead of trying to be all clever and mysterious and leading people up to an answer that most of us probably won't care about once we find out what it is.

And if you're just asking, for some reason: why? What would any answers - which would be anecdotal at best - tell you?

[johnmeyer]

I've had collectors send me all sorts of American TV show material that was converted to PAL and then found its way back to the USA. However, everything I've seen had clearly been modified by someone who didn't know what they were doing, and was almost certainly not directly ripped from the PAL DVD.

It has always been my understanding that most (almost all) PAL DVD players are capable of playing NTSC DVDs. Present-day TVs, of course, can play any frame rate. As a result, I see no reason why North American TV shows would ever have to be converted to PAL frame rate in the first place. Therefore I agree with davidhorman: I think we are talking about an almost-mythical, very rare creature.

Perhaps the OP would care to provide an example of a PAL DVD that has been converted from 60i or 30p to 50i or 25p? I'm not saying that such things don't exist, but I am saying that I expect that they are really rare, especially at this point in time, for the reason I just stated.

[manolito]

The commercial PAL DVDs I own are only US films, i.e. shot on optical film. They are not TV shows or sports broadcasts which were shot on digital cameras.

And all of these DVDs do not originate from an NTSC DVD master. They originate from the 24fps film transfers, and they were converted to PAL by speeding up the video and audio from 24fps to 25fps (mostly without audio pitch correction).

A peculiarity of most of these DVDs is that they are flagged as interlaced (probably encoded with interlaced settings) even if the content is progressive. One popular explanation is that the mastering folks had no idea what they were doing, so they played it safe and set up the hardware encoders to interlaced without analyzing the sources.


Cheers
manolito

[Groucho2004]

A peculiarity of most of these DVDs is that they are flagged as interlaced (probably encoded with interlaced settings) even if the content is progressive. One popular explanation is that the mastering folks had no idea what they were doing, so they played it safe and set up the hardware encoders to interlaced without analyzing the sources.
I'm pretty sure it's in the PAL DVD-Video specs for the video stream to be 25 FPS/interlaced (or at least flagged as interlaced).

[Sharc]

A peculiarity of most of these DVDs is that they are flagged as interlaced (probably encoded with interlaced settings) even if the content is progressive. One popular explanation is that the mastering folks had no idea what they were doing ...
DVDs must be flagged or encoded as interlaced to be DVD standards compliant, even though the video may be progressive (which is typical for films). If you should have some DVDs in your collection which are NOT flagged interlaced, then I'd say the mastering folks had probably no idea what they were doing ;)

[manolito]

DVDs must be flagged or encoded as interlaced to be DVD standards compliant, even though the video may be progressive (which is typical for films).

This is a bold statement, I totally disagree, and you need to backup your claim with some hard facts... :angry:

The official DVD specs have never been published, so there is some dark area here. But I have been doing this shit for ages, and DVDs encoded and flagged as progressive are totally compliant to the dvd specs...


Cheers
manolito

[Sharc]

The official DVD specs have never been published, ...... and DVDs encoded and flagged as progressive are totally compliant to the dvd specs...
Official .... never published .... totally compliant to the (official, unpublished) specs.
Confused, but I stand corrected.
Mind you backing up your experience with (few) commercial progressive DVD titles as I have not met such DVDs before. Always learning ..... Thanks.

[manolito]

I only have a very small collection of commercial PAL DVDs, and all of them are flagged as interlaced even when the content is progressive. But this does not mean that the DVD specs request it.

Just informational, from DVD Demystified by Jim Taylor:

Technically,DVD-Video can only be stored in interlaced format. Signals from standard video cameras are already in interlaced format.
Film, which is inherently progressive, is encoded into MPEG-2 as paired fields.
Even though the encoding is field-based, the frame-based nature of the source can be preserved.

In MPEG-2 encoding, the decision between progressive and interlaced format can be made all
the way down at the macroblock level.The DVD-Video specification limits MPEG-2 video to nonprogressive
sequences, which can include both progressive and interlaced frames.
Progressive frames are still encoded for display as two fields, but they are identified as progressive.
Interlaced frames can further include both progressive and interlaced macroblocks. Since progressive
macroblocks are more efficient (using one motion vector instead of two), even interlaced source
is often encoded with more than 50 percent progressive macroblocks. However, each frame is represented
as two fields of 720 x 240 pixels each for NTSC or 720 x 288 pixels each for PAL/SECAM.

All DVD authoring applications I am familiar with (even the very picky MuxMan software) allow authoring progressive PAL DVDs. And I never came across a software or hardware player which could not handle them...


Cheers
manolito

[hello_hello]

i assumed, rightly or wrongly, Katie was mainly referring to DVD content that for NTSC would have been a combination of film and interlaced or progressive, such as mixtures of film and CGI.

In the past PAL countries would have been subjected to lots of NTSC via free to air TV. Daytime soap operas for example. Weren't they traditionally video?
I know there's been some "best of" soap opera compilations released on DVD where I am but I've no idea if they're PAL or NTSC DVDs. How is analogue NTSC converted to PAL? I assume it's a completely different process than converting digital NTSC would be.

[wonkey_monkey]

i assumed, rightly or wrongly, Katie was mainly referring to DVD content that for NTSC would have been a combination of film and interlaced or progressive, such as mixtures of film and CGI.

Katie clearly said, without ambiguity, "30 progressive frames per second."

So going on past experience, she probably did mean something completely different.

On the subject of interlaced/progressive, aren't the 24fps streams you find on NTSC-land discs marked as progressive with repeat flags?

In the past PAL countries would have been subjected to lots of NTSC via free to air TV. Daytime soap operas for example. Weren't they traditionally video?

We tended not to get those really cheap ones.

[hello_hello]

Katie clearly said, without ambiguity, "30 progressive frames per second."

Good point. My brain must have translated the Katie question into something that'd apply in the real world, only I didn't realise at the time. Although would CGI generally be progressive or interlaced?

So going on past experience, she probably did mean something completely different.

Another good point.

[Sharc]

On the subject of interlaced/progressive, aren't the 24fps streams you find on NTSC-land discs marked as progressive with repeat flags?

Good point. I am from PAL, but as I understand the flagging for NTSC:

Soft pulldown:
Picture_Structure = Frame
Progressive_Frame = True
RFF = True/False/True/False.... (alternating)
TFF = True/False/False/True ..... (pattern)

Hard telecine:
Picture_Structure = Frame
Progressive_Frame = False
RFF = False
TFF = True

I don't know if or how these DVDs are classified in their .ifo's though

[Sharc]

At the risk of being off topic but out of curiosity I inspected the .vob header of progressive mpeg2 material, authored with the "picky" MuxMan, and I got:
- Picture Coding Extension: Progressive Frame = 1 (true)
- Sequence_Extensions: Progressive Sequence = 0 (false). Possibly required by the DVD spec (?) because the progressive picture is always stored as 2 fields on the DVD (from same instant of time)
- Stream Info as delivered by a Stream Analyzer: Interlaced: Yes (probably reading the Progressive Sequence flag)

Difference is at playback only. With Progressive Frame = True the 2 fields on the DVD can be woven (matched) without deinterlacing. With Progressive Frame = False the frame (=2 fields on the DVD) is getting deinterlaced (single rate) or bobbed (double rate) for a progressive monitor.

[burfadel]

Almost all 30 fps stuff I've seen is 29.97 fps, and if it is 30 fps it has been sped up from 29.97. The 29.97 of course being 23.976 material (24 fps slowed down) that has been telecined. Since almost all the source material is 23.976, the DVD's are simply sped up and encoded to the higher PAL resolution. Almost no DVD has gone back to the originals and done a proper transfer, they are just digital encodes of the old crappy broadcast transfers. The PAL versions of some NTSC shows may not look as good not because of PAL (which acutally looks better), but because the material is transferred from NTSC transfers. It's the horrible mess they made when they brought out DVD's because it was quick, cheap, and easy. The same happened with 1080P blurays originally, they were just upsized transfers from DVD's. Luckily most of those DVD's were more recent than the film --> NTSC broadcast --> DVD affected material. Want to know the quality difference between modern good transfers and the old NTSC transfers? Look at the recent HQ versions of Friends, Seinfeld etc. They didn't have to do much magic with them (althoug they likely did some tweaking), almost all of the goodness is because you haven't got a quality limiting transfer in the process.

Most PAL DVD's are just sped up NTSC transfers, but that doesn't really matter. If you think some shows you watch a just a tad bit slow in the interest department, the 4 percent speedup might be just what you need to make the show enjoyable :D.

[SeeMoreDigital]

Do you have a point to make? If so, please just make it instead of trying to be all clever and mysterious and leading people up to an answer that most of us probably won't care about once we find out what it is.
It's a real shame this forum doesn't offer a 'thumbs up' button ;)

[qyot27]

i assumed, rightly or wrongly, Katie was mainly referring to DVD content that for NTSC would have been a combination of film and interlaced or progressive, such as mixtures of film and CGI.

In the past PAL countries would have been subjected to lots of NTSC via free to air TV. Daytime soap operas for example. Weren't they traditionally video?
I know there's been some "best of" soap opera compilations released on DVD where I am but I've no idea if they're PAL or NTSC DVDs. How is analogue NTSC converted to PAL? I assume it's a completely different process than converting digital NTSC would be.
Based on previous posting history, anime is a strong contender too. Unlike American daytime shows or sitcoms, which would have been consistently 29.97 (or rather, 59.94i), anime is very often a mixture of telecined film and interlaced video content, and even American releases have screwed up the transfer before*, or in many cases it was a combination of bad transfers and the import company having lower-grade copies of whatever series it is to use as masters.

*despite Japan being an NTSC country too, but Japanese releases usually contain only 2 episodes per disc and spread the series out over 6-12 discs, whereas most North American anime DVD releases would shove 4-5 episodes on a disc so they could get away with 3-8 discs.

This was more common for old releases, and the reputation of PAL discs at the time was an "abandon hope all ye who enter here" situation. North American releases from the last 10 years or so are either using much better source copies, have people who know how to properly handle the authoring, a combination of both, or just use 23.976 progressive with pulldown flags. I have no idea what the PAL situation looks like now. But go back to before 2007 or thereabouts, and the older the series is, the more authoring problems it's going to be likely to have, unless there was an explicit remastered edition. If the PAL releases were using the same lower-grade master copies or - *shudder* - re-authoring from the released North American copies, it's going to get really ugly really fast.

[Ghitulescu]

Anime is a special case and personally I do not care about.

However, when compiling a DVD for PAListan (there is no SECAMistan in DVD), rarely a technician spends time thinking too much on how to process the video he had it from the US (or other studios). Usually he runs the film through a hardware encoder on which there are only a few knobs to switch and a few options are controlled by the software. Internally these HW are like blackboxes to him, he's not required to know how they function (some of them do however) like a car driver is not required to know how the EGR, ESP or even direct injection works. Important is that the final result will look ok on the control monitor.

[Katie Boundary]

Out of all of the DVD/Blu-Ray content you've seen that was originally 30 progressive frames per second, but has been converted to 25 frames per second...

They originate from the 24fps film transfers, and they were converted to PAL by speeding up the video and audio from 24fps to 25fps

Since almost all the source material is 23.976, the DVD's are simply sped up

When I mentioned 30 fps -> 25 fps conversion, it's because I was interested in 30 -> 25 fps conversion, not 24->25 fps conversion.

Babylon 5, for example, includes 30 fps content and has been released in Region 2.

[smok3]

Babylon 5, for example, includes 30 fps content and has been released in Region 2.

And that is on bluray/dvd? Any other example? Is 'Hobbit Blu-ray release' shot at 48fps being released as 50 fields in PAListan? How would that work in NTSCilian?

[Ghitulescu]

Babylon 5, for example, includes 30 fps content and has been released in Region 2.
Japan is IIRC in Region 2 :)

[hello_hello]

Babylon 5, for example, includes 30 fps content and has been released in Region 2.

Is it progressive though? (as per your original question)

[johnmeyer]

Is it progressive though? (as per your original question)I have the same question. She has never been clear as to whether she is talking about true 30 fps progressive material; 30 fps interlaced; 29.97 progressive (rare); or 29.97 interlaced. If I were to guess, based simply on the volume of DVDs produced in 29.97 interlaced, that this would be what she is asking about. However, there is no way to tell unless we are told.

I guess this is an obvious statement but, the answers will be different depending on the actual question being asked.

[wonkey_monkey]

However, there is no way to tell unless we are told.

In Katie's case, that's still no way to tell unless she uploads a sample.

She did say 30fps progressive in the opening post, though, and whether that's right or wrong, you will probably get berated for daring to doubt.

[Katie Boundary]

And that is on bluray/dvd?

Yes.

Any other example?

http://forum.doom9.org/showthread.php?t=173445

I have the same question. She has never been clear as to whether she is talking about true 30 fps progressive material; 30 fps interlaced; 29.97 progressive (rare); or 29.97 interlaced.

I'm talking about anything that was shot or animated as whole progressive frames, each of which is intended to be seen for approximately 1/30th of a second upon playback, give or take a tenth of a percent.

You know, the same definition of "30 progressive frames per second" that everyone in the entire world uses.

[johnmeyer]

I'm talking about anything that was shot or animated as whole progressive frames, each of which is intended to be seen for approximately 1/30th of a second upon playback, give or take a tenth of a percent.

You know, the same definition of "30 progressive frames per second" that everyone in the entire world uses.Actually, that is most definitely NOT the definition everyone uses. In fact, it is just the opposite (more below).

Also, there IS a big different between 30.00 fps and 30.00 (1000/1001) = 29.97 fps. You cannot take a cavalier attitude that it is just a matter of "give or take a tenth of a percent." To put it succinctly: the difference matters. If you use the wrong setting, bad things will happen. Guaranteed.

To take my point one step further, 30 fps is actually quite rare, especially for commercial content. NTSC SD video started out at 30.0 fps in the 1940s, but when the color standard was introduced in 1954, the timing had to be altered to accommodate the color timing, while still being compatible with the small installed base of B&W TV sets. From that point forward ALL NTSC video was 29.97. 30 fps no longer existed. Many people continued to use the shorthand "30 fps," but in fact all North American and Japanese video was 29.97.

This weird frame rate was carried over to North American digital HD specifications. Here is one of a million documents which describes the situation (this one from Final Cut Pro's documentation):

Final Cut Pro - Choosing a Frame Rate (https://documentation.apple.com/en/finalcutpro/usermanual/index.html#chapter=D%26section=4%26tasks=true)

It is only one page long. I recommend that you click on it and read it. It has the authority of Apple behind it.

The key "pull quote" from this document can be found under the entry for 30 fps:Some high definition cameras can record at 30 fps, as opposed to 29.97 fps. Before color was added to NTSC video signals, the frame rate was truly 30 fps. However, this format is almost never used today.So, true 30 fps progressive is seldom used, which is the complete opposite of what you are saying. Hopefully this correction will be helpful to you.

[Katie Boundary]

It's very rare for someone to tell me almost nothing but stuff that I already learned from READFAG ten years ago AND be wrong in the same post, but hot damn, you found a way to do it.

Aside from you, there is literally nobody on the planet who is referring specifically to 30.000000000000000 frames per second when they say "30 frames per second". The term is invariably used as shorthand for both 30 and 29.97 frames per second because actual 30.0000000000000000000000000 fps content effectively does not exist, just as "29.97 frames per second" is invariably used as shorthand for 29.97002997002997002997.... frames per second because actual 29.9700000000000000 fps content effectively does not exist. The only exception to this is when people are discussing the differences between 30.000000, 29.970000, and 29.97002997002997002997... frames per second, like we did in this thread that I started two and a half years ago (http://forum.doom9.org/showthread.php?t=171758).

So, true 30 fps progressive is seldom used, which is the complete opposite of what you are saying.

LOLWUT? Work on your reading comprehension.

[Ghitulescu]

It's very rare for someone to tell me almost nothing but stuff that I already learned from READFAG ten years ago AND be wrong in the same post, but hot damn, you found a way to do it.
Strange that you have to ask questions on which you have the answer for 10 years, now.