DVD's and 24fps support

[voltz]

I want to look more into this due to the fact I like having my Blu-ray films in their native frame rate and what I understand is most DVD's are encoded for 30fps. I think I had a few discs that worked with one of my sony players before the thing broke, so I'm trying to figure out what I need to look for or if there are lists of 24fps DVD's out there.

[SillyG]

Originally Posted by voltz

I'm trying to figure out what I need to look for or if there are lists of 24fps DVD's out there.

There is no such thing as 24fps DVDs. DVD specs only support 25fps and 29.976fps. A very small number of players may be able to simulate 24fps for DVDs, but it is just that, a simulation.

DVD supports the following resolutions:

PAL: 25fps (50i)
720 × 576 pixels
704 × 576 pixels
352 × 576 pixels
352 × 288 pixels (also supported at MPEG-1 for VCD backwards compatibility)

NTSC: 29.976fps (60i)
720 × 480 pixels
704 × 480 pixels
352 × 480 pixels
352 × 240 pixels (also supported at MPEG-1 for VCD backwards compatibility)

Only Blu-rays support native 23.976fps and also 24fps. Blu-ray also supports 59.94fps and 50fps at 720p, but 720p is only rarely used.

[voltz]

Yeah that's what I know of the NTSC standard.

I've read a few discussions on some DVD's being pressed for 23.976fps before, but I wasn't too sure if I was willing to believe that. However interesting is the my now defunct player used to have both an automatic and 24fps (locked, not automatic) that was able to work with DVD's and it did bare a difference in smoothness. Now that I can't use that I can't go with any further testing until I manage to pick up another player that does keep the 24fps option open.

I'm wondering if anyone else is willing to chime in on this, cause I do think the frame rate is still possible... somehow.

[David M]

Originally Posted by voltz

I want to look more into this due to the fact I like having my Blu-ray films in their native frame rate and what I understand is most DVD's are encoded for 30fps. I think I had a few discs that worked with one of my sony players before the thing broke, so I'm trying to figure out what I need to look for or if there are lists of 24fps DVD's out there.

Almost all NTSC film releases are encoded with pulldown flags, which is the DVD specification's way of implementing 24fps. The format is still 60hz-centric but a modern player can choose to just ignore the repeat field flags to get 24p output.

There is no such thing as 24fps DVDs. DVD specs only support 25fps and 29.976fps. A very small number of players may be able to simulate 24fps for DVDs, but it is just that, a simulation.

The original purpose of the repeat field flags / pulldown in DVD was to improve compression efficiency. But it effectively means it's possible for a player to extract perfect 24p for DVDs encoded this way. It just wasn't (as far as I know) the original reason.

[Geoff D]

I still don't like how players do the 24p output from DVDs though David, it still seems a bit choppy on 4K players like the Panny and the OPPO whereas the reverse 3:2 pulldown on my Sony telly is excellente.

[voltz]

I think the Sony BDP series really knew what they were doing. Not sure about their 4k player though.

Too bad they're not exactly built to last and I sure as hell hate Sony's consumer help for products designed to fail after warranty.

[WaltWiz1901]

Originally Posted by SillyG

There is no such thing as 24fps DVDs. DVD specs only support 25fps and 29.976fps. A very small number of players may be able to simulate 24fps for DVDs, but it is just that, a simulation.

DVD supports the following resolutions:

PAL: 25fps (50i)
720 × 576 pixels
704 × 576 pixels
352 × 576 pixels
352 × 288 pixels (also supported at MPEG-1 for VCD backwards compatibility)

NTSC: 29.976fps (60i)
720 × 480 pixels
704 × 480 pixels
352 × 480 pixels
352 × 240 pixels (also supported at MPEG-1 for VCD backwards compatibility)

Only Blu-rays support native 23.976fps and also 24fps. Blu-ray also supports 59.94fps and 50fps at 720p, but 720p is only rarely used.

Not completely true.

As David pointed out, most NTSC DVDs use pulldown flags to store 23.976/24 frame-per-second material at that frame rate on disc. Most players will recognize these flags and play progressively-encoded material at 29.976/30 frames per second, but more recent players can bypass them and play said material at 24fps.

[oddbox83]

Originally Posted by Geoff D

I still don't like how players do the 24p output from DVDs though David, it still seems a bit choppy on 4K players like the Panny and the OPPO whereas the reverse 3:2 pulldown on my Sony telly is excellente.

My Oppo will do 24p automatically for DVDs encoded 24p with pulldown flags. At least as far as I'm aware.

The problematic setting is forcing 24p playback on titles hard-encoded as 60i. We've discussed this before and agreed it barely ever makes anything but a mangled mess.

[SpaceDandy]

Originally Posted by OKVnDa

Hi there. Could you please tell me which model of Sony player were you using? Looking for Blu-ray Players can handle reverse 3:2 pulldown correctly.

The Sony X700 and X800M2 definitely do not support it. They have an adaptive comb detection filter that occasionally fail and produce ugly artifacts on SD footage. It sometime switches between field blending to frame deinterlacing in the middle of a shot, absolutely disastrous in motion. Furthermore you can't disable it or force a mode.

If your player produce choppy motion on DVDs then most likely you are forcing 24p on hard-telecined content, or your player has one of these terrible comb detection filter that adaptively choose to deinterlace or blend.

[OKVnDa]

Originally Posted by SpaceDandy

The Sony X700 and X800M2 definitely do not support it. They have an adaptive comb detection filter that occasionally fail and produce ugly artifacts on SD footage. It sometime switches between field blending to frame deinterlacing in the middle of a shot, absolutely disastrous in motion. Furthermore you can't disable it or force a mode.

If your player produce choppy motion on DVDs then most likely you are forcing 24p on hard-telecined content, or your player has one of these terrible comb detection filter that adaptively choose to deinterlace or blend.

According to manuel X700's DVD 24hz output function seems to same as BDP models. So I'm just wondering which model would output hard telecine NTSC DVD at 24p correctly. My Panasonic UB45 doesn't support DVD 24p output at all.

[SpaceDandy]

None. Hard-telecines have no metadata in the stream to let the player know which field to remove, and which should be blended togethers. Software players also fail at this task. There is simply no solution unless you can figure out the pull-down pattern yourself, and specify it to the player.

[OKVnDa]

Originally Posted by voltz

I think the Sony BDP series really knew what they were doing. Not sure about their 4k player though.

Too bad they're not exactly built to last and I sure as hell hate Sony's consumer help for products designed to fail after warranty.

You mean Sony BDP series are reserving hard telecined content back to 24p?

[OKVnDa]

Originally Posted by SpaceDandy

None. Hard-telecines have no metadata in the stream to let the player know which field to remove, and which should be blended togethers. Software players also fail at this task. There is simply no solution unless you can figure out the pull-down pattern yourself, and specify it to the player.

I thought detecting 3:2 pulldown isn't that hard to do as players are doing 60hz deinterlacing anyway. But OPPO&Sony did some terrible job here I'd leave this for my LG OLED real cinema mode to handle. Thanks.

[SpaceDandy]

Pulldown patterns are all over the place and can change all the time within the same movie.

[SpaceBlackKnight]

Originally Posted by SpaceDandy

Pulldown patterns are all over the place and can change all the time within the same movie.

Theatrical features usually have the same pulldown pattern, but with stuff edited on tape/digital its all over the place. Some have things like overlays and texts done at frame rates like 30fps and 60i and these rarely pull down properly causing whiplash inducing strobing jitter.