Handbrake Lowering FPS issue (29.970 to 23.976) - Should I be concerned?

[kingaddi]

My source DVD (NTSC) is 29.970 fps. I am using Handbrake video setting [Framerate: Same as source]. But my output ends up being 23.976 fps.

Should I be concerned, is this normal practice?

[poisondeathray]

If it's a film source (e.g. a hollywood movie), it's probably normal

Read up on telecine, inverse telecine and , 3-2 pulldown if you want more information

[kingaddi]

If it's a film source (e.g. a hollywood movie), it's probably normal

Read up on telecine, inverse telecine and , 3-2 pulldown if you want more information

Film source is a movie.

[poisondeathray]

By "film source" I mean shot on celluloid or digital equivalent

Most movies are 24p (or 23.976p) . They are "stored" in DVD format as 29.97fps or 59.94i in a process called telecine or 2-3 pulldown. You have to inverse telecine (IVTC) or remove pulldown to get the original 24p back. Read up on those keywords if you want more info

[kingaddi]

By "film source" I mean shot on celluloid or digital equivalent

Most movies are 24p (or 23.976p) . They are "stored" in DVD format as 29.97fps or 59.94i in a process called telecine or 2-3 pulldown. You have to inverse telecine (IVTC) or remove pulldown to get the original 24p back. Read up on those keywords if you want more info

So technically, Handbrake is doing this process which is why it is returning back to 24p?

[kingaddi]

By "film source" I mean shot on celluloid or digital equivalent

Most movies are 24p (or 23.976p) . They are "stored" in DVD format as 29.97fps or 59.94i in a process called telecine or 2-3 pulldown. You have to inverse telecine (IVTC) or remove pulldown to get the original 24p back. Read up on those keywords if you want more info

Thanks for this info. Will be doing some homework.

[poisondeathray]

I'm guessing that's what it's doing. I really don't use handbrake and you never mentioned what settings you used. I think it has something called "detelecine"

A regular movie NTSC DVD needs to be IVTCed for you to get the original progressive frames back

[kingaddi]

I'm guessing that's what it's doing. I really don't use handbrake and you never mentioned what settings you used. I think it has something called "detelecine"

A regular movie NTSC DVD needs to be IVTCed for you to get the original progressive frames back

What program do you use?

[poisondeathray]

What program do you use?

Currently I use avisynth + x264.exe (command line)

Before that, I used MeGUI as a GUI when learning about avisynth and x264 .

[FulciLives]

Just make sure when using HandBrake that you always select CONSTANT FRAMERATE and I say this because it always seems to default to VARIABLE FRAMERATE which (in my opinion) should never be used.

[kingaddi]

Just make sure when using HandBrake that you always select CONSTANT FRAMERATE and I say this because it always seems to default to VARIABLE FRAMERATE which (in my opinion) should never be used.

I have been using Constant Framerate. I read another post explaining that it is better for video editing purposes. Although with Variable you might be able to get a better compression/quality.

[hello_hello]

How do you know the DVD is 29.970 and not 23.976? I'm in Pal-Land, but aren't 23.976 NTSC DVDs quite common?

[FulciLives]

HandBrake usually gets it right but if it does make it 23.976fps when it should not be then you can tell because motion will not be smooth. So once you have it all set up have it do a sample encode before doing the whole thing. It can do that up to 120 seconds. I do that all the time to make sure it looks the way I want.

[manono]

How do you know the DVD is 29.970 and not 23.976? I'm in Pal-Land, but aren't 23.976 NTSC DVDs quite common?

All NTSC DVDs output 29.97fps. While they may be encoded as progressive 23.976fps (and usually are, if from a film source), pulldown is applied so that they still output 29.97fps.

[hello_hello]

How do you know the DVD is 29.970 and not 23.976? I'm in Pal-Land, but aren't 23.976 NTSC DVDs quite common?

All NTSC DVDs output 29.97fps. While they may be encoded as progressive 23.976fps (and usually are, if from a film source), pulldown is applied so that they still output 29.97fps.

Is the actual stuff on the disc 23.976 fps though? I assume you mean the player applies the pulldown on playback rather than it being encoded that way?

Not that I'm saying 29.970 DVDs don't exist of course, I'm just wondering how kingaddi concluded the disc is definitely 29.970. Or at least the bits of it he's trying to encode.

[manono]

Is the actual stuff on the disc 23.976 fps though?

Yes, the video stored on the DVD is 23.976fps (much of the time).

I assume you mean the player applies the pulldown on playback rather than it being encoded that way?

That's right. The TFF and RFF flags are added to the video stream and they tell the player how and in what order to add in the repeated fields at playback time. There are plenty of films on NTSC DVD where the telecine is encoded into the video. It'll make an interlaced 29.97fps video. But 'good' DVDs will encode just progressive 23.976fps.

Not that I'm saying 29.970 DVDs don't exist of course

There are more than you might imagine. I work with them virtually every day of my life. All kinds of cheapo DVD companies both in the US and abroad encode hard telecine or field-blend their films. However, strictly speaking, all NTSC DVDs are 29.97fps. That's how they play, even if they're not encoded that way, and that's why most of those information utilities say they're 29.97fps. Because they are. GSpot explains it very well. It says 59.94 fields per second, 29.97 frames per second, and 23.976 pics per second. When it's hard telecined it'll say 29.97 pics per second

[hello_hello]

There are more than you might imagine. I work with them virtually every day of my life. All kinds of cheapo DVD companies both in the US and abroad encode hard telecine or field-blend their films.

I'm in PAL-Land and I've still seen my share. In fact I'm encoding one as we speak. The "Apollo 13" 2 disc anniversary edition. It confused me for a bit because I assumed it was PAL as the DVD is on loan from a friend (I'm backing it up for her, of course), and I couldn't understand why MeGUI wanted to IVTC it.... until the penny finally dropped.

I still don't quite understand this "Force Film" thing though. For example MeGUI is set to auto force film at 95% by default. I had trouble with one particular DVD a while back where there were obvious sections requiring de-interlacing and which prompted me to disable that option, but I guess you could tell me (sorry to the OP for sidetracking the thread a tad)..... actually I've got a few questions if you feel like imparting some knowledge......

Why "force film" at all? I assume doing so at around 95% is fairly normal, but to my way of thinking it's like saying "well as long as 95% of it is done correctly, don't worry about the rest". Am I missing something?

I think I discovered while trying to encode one particular "problem" 29.970 fps DVD, that when MeGUI applies "force film" it does so by altering the d2v file. I eventually only managed to work it out by running the same DVD through AutoGK (which just never seems to get it wrong) and using the d2v file it created to replace the one MeGUI created. Once I did, I could use MeGUI to analyse the video and it'd then realise it was a hybrid after-all, and the IVTC/de-interlacing I'd been manually adding to the script finally made a difference.

Is applying "force film" by altering the d2v file a normal thing for an encoder GUI to do? I asked in the MeGUI thread over at doom9 but as Zathor lives in PAL land he doesn't really understand the NTSC world any more than I do, so he couldn't help me.

I've still (after all this time) not really got my head around the possible combinations of film/telecine/NTSC and how they should be handled correctly. When video is a combination of film and telecine it seems obvious you'd convert it all to film, but film/NTSC combinations.... how are they converted to a single frame rate?

Cheers.

[poisondeathray]

Why "force film" at all? I assume doing so at around 95% is fairly normal, but to my way of thinking it's like saying "well as long as 95% of it is done correctly, don't worry about the rest". Am I missing something?

Some people don't force film unless it's >99%. The benefit of force film is it's faster (IVTC through TIVTC or IVTC through other means is slower) . If it's lower it means there are sections that aren't exactly 3:2:3:2:3:2 , ie. there are cadence breaks

When video is a combination of film and telecine it seems obvious you'd convert it all to film, but film/NTSC combinations.... how are they converted to a single frame rate?

Your best option (IMO) is to encode VFR. This way 23.976 film sections run at proper 23.976, and 29.97p sections run at proper 29.97p. Hybrid content is common in some sci fi genre DVD's like Star Trek series, where the CGI sequences were 29.97 . If you dont use VFR, then some section will be jerky

[hello_hello]

Your best option (IMO) is to encode VFR. This way 23.976 film sections run at proper 23.976, and 29.97p sections run at proper 29.97p. Hybrid content is common in some sci fi genre DVD's like Star Trek series, where the CGI sequences were 29.97 . If you dont use VFR, then some section will be jerky

Ahhhhh..... that's what I wanted to know..... it's either two frame rates or jerky bits..... no magic fix.

I guess as an AVISynth user, or as a user of encoder GUIs which use AVISynth to do the work, I'd be going with the "jerky bits" method. Not that it's really an issue for me. PAL is either progressive or interlaced and I don't really encode NTSC DVDs all that regularly, but I have run the same NTSC DVD through MeGUI and AutoGK before and the resulting encodes have had different frame rates, so I thought it might be an idea to understand this NTSC thing a little better. Generally AutoGK seems to get it right so if in doubt I go with what it decides, but I can't keep asking AutoGK what it'd do forever.....

Thanks for the info.

[manono]

Why "force film" at all? I assume doing so at around 95% is fairly normal, but to my way of thinking it's like saying "well as long as 95% of it is done correctly, don't worry about the rest". Am I missing something?

As pdr said, it's faster. It also saves the IVTC from making mistakes or deinterlacing something that doesn't need deinterlacing. I won't Force Film anything unless it's 100% film. That 95% figure comes from the remaining 5% being black frames, or some static stuff somewhere in the DVD some of the time. But I've been burned too many times even with a 99% figure. Criterion, for example, is notorious for having a few interlaced frames at chapter breaks. You're watching a film and all of a sudden there's a couple of interlaced frames. TIVTC has a setting that treats soft telecine as Force Film, and only IVTCs those few remaining percent of hard telecine when the Film percentage is high.

Ahhhhh..... that's what I wanted to know..... it's either two frame rates or jerky bits..... no magic fix.

Only if it's really a hybrid. You get hybrids sometimes with anime, where parts of an opening song might be real 29.97fps, either interlaced or progressive, and the rest is film. You also get it sometimes in documentaries that may be a mix of video and film. But if it's a movie and a mix of hard and soft telecine, there is a magic fix and no need for a VFR encode.

[hello_hello]

Thanks for the info!