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Old 9th September 2014, 16:01   #21  |  Link
TheSkiller
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Originally Posted by johnmeyer View Post
The bigger issue is that the whole "flag" concept only applies to NTSC, AFIK. I don't think that the DVD standard has a concept of a flag when playing PAL video.
You are wrong. Pulldown can be used for PAL DVD output of 25i equally well. All players must support it. Soft-Pulldown isn't limited at all to NTSC output, it's just very rarely used.

There are 2 constraints which always apply:
  • The base frame rate needs to be lower than the output frame rate (which is either 29.97i or 25i, nothing else)
  • The base frame cannot be lower than 2/3 of the output frame rate

So you can soft-pulldown 16.666 progressive fps to 25 interlaced fps.

Last edited by TheSkiller; 9th September 2014 at 16:51.
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Old 9th September 2014, 16:25   #22  |  Link
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You are wrong. Pulldown can be used for PAL DVD output of 25i equally well. All players must support it. Soft-Pulldown isn't limited at all to NTSC output, it's just very rarely used ... So you can soft-pulldown 16.666 progressive fps to 25 interlaced fps.
I just went looking through the DVD specs, and I don't see anything like what you describe.

The information I found is consistent: the MPEG-2 soft pulldown flag for DVD authoring only has two values: 3:2 which adds fields to 24p material so it plays correctly on a 60i NTSC TV set; and 2:2 which adds fields to achieve a 4% speedup to go from 24p to 50i PAL.

I do not see anything, either in the spec, nor in any of my various MPEG-2 encoders, that permits any sort of arbitrary soft pulldown flag which would instruct the playback DVD device to add fields during playback to go from 16p or 18p to either 50i or 60i.

If you can point to something that supports this, I would love to know because this is what I do for a living, and it would be great if I could deliver DVDs that contain 16p or 18p material in native format, and then have the DVD player add the pulldown fields. I'd get massively better encodes, and I could fit a lot more material on a DVD.

Unfortunately, I've never seen this in any software I've ever used.
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Old 9th September 2014, 17:09   #23  |  Link
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Maybe you have better luck finding information about this if you're looking into the RFF flags rather than looking for pulldown in general, because that's essentially what's happening: the RFF flags tell a decoder to repeat fields. Those flags are set across the whole stream so that the desired output fps is reached (that's soft-pulldown at it's core). The decoder doesn't need to do anything different except repeating fields as instructed to output standard 25i or 29.97i. All MPEG2 decoders know the RFF flag, it's part of the MPEG spec. This exactly the way standard NTSC film telecine soft-pulldown works. It's not different at all.

Maybe search for threads related to "DGPulldown" here at doom9 for more information.


As to why professional MPEG2 encoders do not have any options for this other than regular NTSC film telecine pulldown... I don't know. Maybe because it's so rarely used by professionals where hard-pulldown (like 16p -> 25i) is most probably applied much earlier in the production chain because common professional storage formats such as DigiBeta do not allow raw 16 fps.


With every MPEG2 encoder to my knowledge you would have to encode a 16 fps source at 25 fps using AssumeFPS(25) and then afterwards use DGPulldown to apply the RFF flags and restore the original 16 fps playback speed.


Some things need to be considered:
  • The encoded GOPs must be no longer so that after soft-pulldown the longest GOPs are still <=15 frames for PAL and <=18 frames for NTSC. So if you're doing a pulldown of 16.666 fps to 25 fps the encoded GOPs must be limited to a maximum of
    15 / (25 / 16.666) = 10 frames for DVD compliance.

  • Bitrates are given in bits per second. Since we only temporarily speed up the video to 25 fps for encoding we need to calculate all bitrates with a factor of 25 / 16.666 = 1.5 if we're calculating using the real runtime of the video.

Last edited by TheSkiller; 9th September 2014 at 17:18.
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Old 9th September 2014, 17:48   #24  |  Link
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Hmmm ... I just read through a lot of that 25-page DGPulldown thread. As you say, it adds "pulldown" internally to the MPEG-2 file, rather than as a flag when the DVD is authored.

I decided to try it out, but could not find any MPEG-2 encoder in my kit that will encode a 16 fps 8mm film to 16 or 16.666 fps.

I'll keep looking for a few more minutes ...
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Old 9th September 2014, 18:06   #25  |  Link
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Originally Posted by johnmeyer View Post
I decided to try it out, but could not find any MPEG-2 encoder in my kit that will encode a 16 fps 8mm film to 16 or 16.666 fps.
Like I've said just assume the frame rate to 25 fps and encode it at 25 fps in any MPEG2 encoder.

When applying the RFF flags with DGPulldown you specify the real frame rate which restores the original playback speed.

Last edited by TheSkiller; 9th September 2014 at 18:08.
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Old 9th September 2014, 20:13   #26  |  Link
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I don't think this works very well for this frame rate.
You couldn't be more wrong. In fact, there is no better way to accomplish what the OP wants, and certainly not interpolation and reinterlacing as he said he plans on doing. In fact, if he applies a custom pulldown set for 16.667->25, he'll apply a 3:3 pulldown and rid himself of the jitter effects of a standard 3:2 pulldown in a standard NTSC DVD.

The others before me have explained it in detail, but for some more clarification:

No, you can't encode for 16.667fps. You encode for 25fps and after applying the pulldown, the length becomes correct. At the same time, adjust the bitrates in the MPEG encoder by a factor of 1.5:1 (25/16.667). For example, if the average bitrate is to be 4000, make it 6000. If the usual max bitrate is 9000, make it 13,5000. It'll all be fine in the end. I've done this many many times myself.

Don't use any Adobe products for authoring as they refuse some DVD-compliant streams. Otherwise I defy you to find any authoring program that won't author the result or player that won't play the result correctly.
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If you can point to something that supports this, I would love to know...
Virtually everything supports this as you're producing a 100% DVD complaint stream. It outputs interlaced 25fps as required. You can encode in CCE or HCEnc, among others, and author using Muxman, among others.
Quote:
...and it would be great if I could deliver DVDs that contain 16p or 18p material in native format
It has to be equal to or greater than 19.98fps for NTSC and 16.667fps for PAL. When working with NTSC silent films under 19.98fps, I interpolate up to 19.98fps and take it from there. Works great.
Quote:
I'd get massively better encodes, and I could fit a lot more material on a DVD.
Exactly. You're able to encode progressively at a much lower framerate than is usual for material at less than 23.976fps (NTSC). Hard telecine just eats up the bits.
Quote:
Unfortunately, I've never seen this in any software I've ever used.
DGPulldown.

Last edited by manono; 9th September 2014 at 20:16.
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Old 9th September 2014, 21:09   #27  |  Link
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OK, I now understand what DGPulldown does: it adds pulldown flags to the MPEG-2 encode itself rather than adding a pulldown flag during the DVD authoring stage. This provides a lot more flexibility for encoding native progressive footage from different frame rates (like 16 and 18 fps), as well as doing the 24p-->50i, and 25p-->60i conversions that were the original goal of the DGPulldown project.

Very clever, and I now fully understand why I didn't comprehend the initial claims that there were more pulldown flags than the two that are a hard-wired part of the DVD authoring process.

However ...

One problem in using this approach comes from the following restriction (quoted from the DGPulldown documentation):

"The input frame rate can be freely chosen, but it must be greater than or equal to 2/3 of the output frame rate,and less than or equal to the output frame rate."

Thus, you can take 16 fps material and use this technique to end up with 24 fps (this is exactly 3/2, or 2/3 depending on which way you look at it). However, you cannot go from 16 to 25 fps, and still maintain the correct playback speed. That ratio is greater than the 3/2 allowed, and DGPulldown simply gives you the 3/2 ratio, and nothing more (I just tried it, and that's what happens).

The OP can get pretty close (16.67 fps), however (edit: which is what Manono said earlier).

For me, in NTSC land, there is another, more subtle, issue. NTSC DVDs have to be either 23.976 with the pulldown flag set, or 29.97 interlaced. I don't believe that there is such a thing as a 23.976 DVD without pulldown.

However, the only way to put that on a DVD is with the pulldown flag set.

And that leads to this issue: when the DVD player puts its pulldown on top of the soft pulldown embedded in the MPEG-2 file, it will create a cadence that might not be optimal, and might be different from one player to the next.

To see if this is a major issue I'm going to burn a few test DVDs and see what they look like on my old CRT NTSC monitor.

If I had a progressive DVD player, I am pretty certain that these do permit the 23.976 progressive video to be played natively (they basically ignore the pulldown flag). So, if I had one of those, this scheme would work perfectly.

I definitely learned something today.

Last edited by johnmeyer; 9th September 2014 at 21:11. Reason: added: edit: which is what Manono said earlier
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Old 9th September 2014, 21:16   #28  |  Link
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Thus, you can take 16 fps material and use this technique to end up with 24 fps (this is exactly 3/2, or 2/3 depending on which way you look at it).
No, as 23.976fps isn't DVD-compliant. You apply pulldown to get it to interlaced 29.97fps. As I already explained, for NTSC the lowest framerate on which you can use DGPulldown is 19.98. Anything lower you have to first bring it up to 19.98fps.
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Old 9th September 2014, 23:16   #29  |  Link
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No, as 23.976fps isn't DVD-compliant. You apply pulldown to get it to interlaced 29.97fps. As I already explained, for NTSC the lowest framerate on which you can use DGPulldown is 19.98. Anything lower you have to first bring it up to 19.98fps.
Yup, I found out that the 23.976 video that results from DGPulldown is not compliant, even though 23.976 is obviously a legal, compliant format that I use all the time. I am not quite sure why that happens, but it does. Perhaps DGPulldown removes the DVD pulldown flag. That would definitely make it non-compliant.

Since starting with 19.98 rather than 16 is going to be quite noticeable, this technique will not work for my application. Even for 18 fps, that would be a 10% increase in speed.

For the OP, starting with 16.66 may be close enough, and therefore acceptable.

Thanks again for the explanations. DGPulldown is still a very cool hack -- another great contribution from "Guest."
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Old 9th September 2014, 23:18   #30  |  Link
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And that leads to this issue: when the DVD player puts its pulldown on top of the soft pulldown embedded in the MPEG-2 file, it will create a cadence that might not be optimal, and might be different from one player to the next.
There is only one instance of pulldown. A DVD-Player does not have any automatic 23.976 -> 29.97 pulldown. Without RFF pulldown flags insinde the stream you cannot even author a 23.976 stream because the only allowed output frame rates for DVD are 29.97 and 25.



Quote:
Originally Posted by johnmeyer View Post
If I had a progressive DVD player, I am pretty certain that these do permit the 23.976 progressive video to be played natively (they basically ignore the pulldown flag)
A progressive scan player has to obey the RFF flags as well. They usually have a cadence detection which removes the pulldown fields after decoding and outputs non-interlaced 60 Hz or applies deinterlacing when detected. This is necessary because a stream can in theory happily switch between soft- and hard-pulldown and real 60i (video camera) constantly (uncommon but possible). There's no way of outputting native (pulldown-less) 23.976 fps from a DVD (except on a PC).
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Old 10th September 2014, 00:23   #31  |  Link
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Since starting with 19.98 rather than 16 is going to be quite noticeable, this technique will not work for my application. Even for 18 fps, that would be a 10% increase in speed.
I never suggested speeding it up (only for Music Fan for whom a ~3% speedup won't be noticed). My suggestion is to interpolate to 19.98fps. Depending on the source, it may or may not work out quite well. The length remains the same; there's no speeding up of the video.

If you don't know the script for interpolating the needed frames, just ask.
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Old 10th September 2014, 00:35   #32  |  Link
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I never suggested speeding it up (only for Music Fan for whom a ~3% speedup won't be noticed). My suggestion is to interpolate to 19.98fps. Depending on the source, it may or may not work out quite well. The length remains the same; there's no speeding up of the video.

If you don't know the script for interpolating the needed frames, just ask.
I have dozens of scripts for interpolating, using MVTools, SVP, and Interframe, which is sort of a front end to these tools.

The problem I have with interpolating low frame rate material is that the temporal gaps between frames is so large that it is really difficult for the motion estimation to do a good job creating the intermediate frames. As a result, the lower the frame rate, the more obvious the artifacts. The inverse (or is it converse?) of this logic is that if you start with really high framerates, like 60p, you can estimate upwards and get some really amazing slow motions.

I do use interpolation during camera pans because the judder at 16 fps is something terrible to watch. So, my workflow at this point is to apply a "standard" pulldown to 16 fps or 18 fps to get 29.97, and render to an intermediate using a lossless codec. I then also render the same material using interpolation, usually using MVTools2, which for me seems to produce results I like.

I then edit these two similar 29.97 videos like I would a two-camera shoot, cutting between the pulldown version and the interpolated version as needed.

Panning usually interpolates almost perfectly, so I seldom have a problem with artifacts. However, since the difference in cadence between interpolated and pulldown versions is visually quite noticeable, I usually try to cut between them at scene changes, or when the camera gets bumped, or at some other discontinuity that "masks" the change.
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Old 10th September 2014, 09:48   #33  |  Link
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Thanks all of you, there are amazing informations here !
I'm very astonsihed by the fact that the bitrate can reach 13 Mbps and stay dvd compliant. I guess it means that for the player, the bitrate is detected after applying the pulldown that decreases framerate from 25 to 16.667 which spills the bitrate in a longer duration and thus decreases the bitrate for each second. If yes, it's strange because before applying the pulldown, the player has to decode mpeg-2 stream and at this moment, the bitrate reaches 13 Mbps. Or it doesn't work like that ?

There is something I don't understand about rff flags and encoding in 16.667 fps : at which framerate and speed will the video be sent by the player to the screen ?
Will the player triple the framerate (like I could do with Interframe) ? If yes, I guess there will no be interpolation but just a tripling of each frame, which will not be very fluid.
And does it mean the player decodes at 25 fps and then slow down to 16.667 fps ? I guess no because it would need to keep a lot of frames in memory and the player would be decoding the end of the movie when displaying the 2/3 of the movie, which is impossible. So I guess the player actually never reaches 25 fps in this case during the mpeg-2 decoding process.

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Originally Posted by TheSkiller View Post
The decoder doesn't need to do anything different except repeating fields as instructed to output standard 25i or 29.97i. All MPEG2 decoders know the RFF flag, it's part of the MPEG spec. This exactly the way standard NTSC film telecine soft-pulldown works. It's not different at all.
If there is a simple frame repeating, there will be a big judder. But this seems contradictory with another part of your message ;
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With every MPEG2 encoder to my knowledge you would have to encode a 16 fps source at 25 fps using AssumeFPS(25) and then afterwards use DGPulldown to apply the RFF flags and restore the original 16 fps playback speed.
In this case there is no frame repeating, it's just as if the player did an assumefps, which leads to a big duration changing compared to the encoded stream, unlike the soft pulldown used for 24p sources that have to be displayed at 29.97 fps ; it duplicates fields but does not change the total duration.
So I'm a little bit lost, what happens exactly with the solution you recommended me ?
If a kind of assumefps is done, what happens with the sound ?


About the way players handle 23.976 fps with 29.97 pulldown, I had asked years ago to Oppo how they did to allow 24p output for ntsc dvd (when encoded with soft pulldown) : they said the decoder didn't ignore the flag, but after converting in 29.97 fps, an IVTC was done to find again the original 23.976 frames.
This seems complex but is actually simpler for the decoder. They also said that the pulldown flag was technically ignorable, but it would need another decoding architecture, a second clock IIRC.
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Old 10th September 2014, 10:42   #34  |  Link
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If yes, it's strange because before applying the pulldown, the player has to decode mpeg-2 stream and at this moment, the bitrate reaches 13 Mbps.
It's only 13000 for 25fps. But by applying pulldown you're effectively slowing it back to 16.667fps. The bitrate declines by the same percentage.
Quote:
at which framerate and speed will the video be sent by the player to the screen ?
It'll play at 16.667fps. I mentioned 3:3 pulldown before. A PAL DVD player outputs 50 fields per second. To make 50 fields per second, each field of your 16.667fps DVD is played 3 times in succession - 3:3. Two are from each frame (they're the same) and the third is added by the pulldown you applied. A progressive scan player sending to a progressive display sends each frame three times and the TV set will show 50 frames per second.
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If there is a simple frame repeating, there will be a big judder.
Nope. Here the only jerkiness will be from the original 16.667fps. This particular kind of pulldown adds no judder at all. You're in PAL land and have never had to work with pulldown before the way we NTSC people live with 3:2 pulldown. Just try it out with a sample DVD to convince yourself.
Quote:
In this case there is no frame repeating, it's just as if the player did an assumefps, which leads to a big duration changing compared to the encoded stream, unlike the soft pulldown used for 24p sources that have to be displayed at 29.97 fps ; it duplicates fields but does not change the total duration.
For NTSC you encode at 23.976fps and add pulldown to output 29.97fps. The length doesn't change. Here you're encoding at 25fps and then slowing it with the pulldown later. This is very different from what happens with standard 3:2 pulldown. 23.976fps is a 'legal' framerate for encoding, 16.667fps isn't.
Quote:
If a kind of assumefps is done, what happens with the sound ?
If you add audio to fit a 16.667fps source, nothing happens to the audio - it stays in synch.

Last edited by manono; 10th September 2014 at 10:44.
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Old 10th September 2014, 11:32   #35  |  Link
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Thanks !

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It'll play at 16.667fps. I mentioned 3:3 pulldown before.
Ok, I forgot you wrote it. I knew that Dvd/Divx players could play divx files with strange framerates but I didn't know a dvd player could do 3:3 pulldown with compliant dvd.
Are you 100% certain it will play on all Pal dvd players ?

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A PAL DVD player outputs 50 fields per second. To make 50 fields per second, each field of your 16.667fps DVD is played 3 times in succession - 3:3. Two are from each frame (they're the same) and the third is added by the pulldown you applied. A progressive scan player sending to a progressive display sends each frame three times and the TV set will show 50 frames per second.
If I understand well, if sent in interlaced by the dvd player, the video won't be as fluid as if sent in 50p because the player does not triple each frame and interlace this 50p ?

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Nope. Here the only jerkiness will be from the original 16.667fps. This particular kind of pulldown adds no judder at all.
Right, I actually meant not fluid but this is not judder.
And you prefer this lack of fluidity than interpolation made with Interframe (or other filter) ?

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For NTSC you encode at 23.976fps and add pulldown to output 29.97fps. The length doesn't change. Here you're encoding at 25fps and then slowing it with the pulldown later. This is very different from what happens with standard 3:2 pulldown.
Yes, that's what I understood. Does it mean slowing down could also work for 23.976fps with the same kind of flag than for 16.667fps (but flagged in 29.97 instead of 25) ?
I guess no because dvd players are not supposed to allow 24p output, although some Blu-ray/dvd players can output ntsc movies in 24p but with a double conversion (as I explained above about Oppo).
But this gives me another idea : could your trick work to encode 23.976fps onto Pal dvd (to encode a 23.976fps movie in 720*576 instead of 720*480) with a 25p flag and a rff flag to slow down it to 23.976 ?
Mmmh, actually no, same problem than with ntsc dvd, a dvd player is not supposed to allow 24p output, whatever Pal or Ntsc, right ?
And if it was allowed, the flag wouldn't be needed.

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23.976fps is a 'legal' framerate for encoding, 16.667fps isn't.
Don't you mean common instead of legal ? Because if your trick works for 16.667fps, I guess this is not "illegal".

Last edited by Music Fan; 10th September 2014 at 11:36.
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Old 10th September 2014, 11:36   #36  |  Link
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It's field repeating, not frame repeating. For every single decoded frame, three fields are displayed, when you max out the pulldown like that. When displayed, every third frame is "interlaced" (Aa, Ab, Bb, CC, Cd, Dd, etc), but when you're watching on TV, that's as smooth as it's possible to get without blending or interpolating. If your player deinterlaces, you'll get even more extra fake smoothness; if it tries to IVTC, it'll almost certainly fail horribly, but most won't even attempt it with this pattern.

24 fps on 25 fps PAL is generally known as 2:2 pulldown, although it's really 2:2:...:3 (I forget exactly how many 2s). It repeats one field every 12 frames.

No matter how small or large the framerate, the video can still only be 9 Mbps, because DVD is only specified to read data off the disc at 9 Mbps. Framerate has absolutely nothing to do with bitrate, other than if you change the framerate without changing anything else, you change the bitrate. Pulldown changes both the framerate and the frame count, though.
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Old 10th September 2014, 11:52   #37  |  Link
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It's field repeating, not frame repeating. For every single decoded frame, three fields are displayed, when you max out the pulldown like that. When displayed, every third frame is "interlaced" (Aa, Ab, Bb, CC, Cd, Dd, etc), but when you're watching on TV, that's as smooth as it's possible to get without blending or interpolating.
When watching on CRT only, not on flat screens that de-interlace, right ?
But if one has a flat scren, the best idea is to send the video in 1080p to allow a frame tripling by the player.
Anyway I find this pattern doesn't look fluid : some fields are displayed 2 times and others 1 time.

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If your player deinterlaces, you'll get even more extra fake smoothness; if it tries to IVTC, it'll almost certainly fail horribly, but most won't even attempt it with this pattern.
If I understand what manono said, the player will do nor deinterlacing neither IVTC with 16.667fps videos ; if sent in progressive, each frame is tripled, and if sent in interlaced, there is a field repetition (1 or 2 times).

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Originally Posted by foxyshadis View Post
24 fps on 25 fps PAL is generally known as 2:2 pulldown, although it's really 2:2:...:3 (I forget exactly how many 2s). It repeats one field every 12 frames.
Ok but that's very rare, for PAL dvd, movies are usually encoded with the Pal speed-up technique.

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Originally Posted by foxyshadis View Post
No matter how small or large the framerate, the video can still only be 9 Mbps, because DVD is only specified to read data off the disc at 9 Mbps. Framerate has absolutely nothing to do with bitrate, other than if you change the framerate without changing anything else, you change the bitrate. Pulldown changes both the framerate and the frame count, though.
But manono said it worked with 13 Mbps
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Old 10th September 2014, 13:52   #38  |  Link
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Anyway I find this pattern doesn't look fluid : some fields are displayed 2 times and others 1 time.
With such low frame rates you will never notice slightly irregular patterns in the pulldown.
Edit: 16.666 fps is not irregular. As explained by foxyshadis every frame is spread across 3 fields. It doesn't get anymore regular than that.


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When watching on CRT only, not on flat screens that de-interlace, right ?
But if one has a flat scren, the best idea is to send the video in 1080p to allow a frame tripling by the player.
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Originally Posted by Music Fan View Post
If I understand what manono said, the player will do nor deinterlacing neither IVTC with 16.667fps videos ; if sent in progressive, each frame is tripled, and if sent in interlaced, there is a field repetition (1 or 2 times).
No matter the requested output format for the TV (interlaced or progressive) the player will honor the RFF flags and create 25i as instruced by the flags. For 1080p output this will then run through the player's deinterlacer to create 50p from 25i. That's how it works. Cadence detection, which would avoid deinterlacing, doesn't work with oddball frame rate like 16.666 fps. Cadence detection generally only works with NTSC 3:2 pulldown. Euro-Pulldown (2:2:....:3 as described by foxyshadis) will be deinterlaced as well.

So for progressive output formats the video runs through a player's deinterlacer which is not optimal but if you encoded the video with hard-pulldown instead this would be no different.



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Originally Posted by Music Fan View Post
But manono said it worked with 13 Mbps
It's Megabits per second at 25 fps. If you play the same stream at 16.666 fps the Bitrate per second declines by the same factor and thus stays within DVD spec.

Last edited by TheSkiller; 10th September 2014 at 14:40.
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Old 10th September 2014, 14:58   #39  |  Link
Music Fan
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I had understood it, that's what I said earlier. So there was no reason to say that the maximum bitrate is 9 Mbps, it's confusing in this particular case.

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Originally Posted by TheSkiller View Post
No matter the requested output format for the TV (interlaced or progressive) the player will honor the RFF flags and create 25i as instruced by the flags. For 1080p output this will then run through the player's deinterlacer to create 50p from 25i.
Ok, so this kind of encoding (for 16.667fps) is not very interesting for fluidity, the only utility is to have more bitrate by image.
Thus there will be judder added by the player actually, at least when output is interlaced. But even when output is progressive, I'm not sure the result can be similar to a simple frame tripling because of the intermediate 25i step.

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Originally Posted by TheSkiller View Post
Euro-Pulldown (2:2:....:3 as described by foxyshadis) will be deinterlaced as well.
What is the utility of this kind of Euro-Pulldown ? If one frame is duplicated each second to get 25 frames from 23.976 encoding, it will be much less fluid than Pal speed-up encoding. The only advantage is to keep original duration and thus keep original sound without acceleration (even if compensation can be done, but it's not always done).

Last edited by Music Fan; 10th September 2014 at 15:05.
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Old 10th September 2014, 15:07   #40  |  Link
TheSkiller
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Quote:
Originally Posted by Music Fan View Post
Ok, so this kind of encoding (for 16.667fps) is not very interesting for fluidity, the only utility is to have more bitrate by image.
There is no motion interpolation if that's what you mean (unless the TV by itself does it on top of the pulldown) but fluidity is perfect in regards to the source; in other words it's as fluid as raw 16.666 fps is.

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Originally Posted by Music Fan View Post
What is the utility of this kind of Euro-Pulldown ?
You already mentioned it, the audio does not need to be speed up. This technique can be used if the audio is of greater importance than the video quality, say a music video.

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Originally Posted by Music Fan View Post
If one frame is duplicated each second to get 25 frames from 23.976 encoding, it will be much less fluid than Pal speed-up encoding.
Not 1 frame per second is duplicated but 1 field twice per second. So there are 2 slight hiccups every second. But it's not nearly as bad as duplicating a frame once per second (that's pretty much unwatchable).

Last edited by TheSkiller; 10th September 2014 at 15:27.
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