FPS on DVD?

General questions or discussion about HandBrake, Video and/or audio transcoding, trends etc.
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SicMX
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FPS on DVD?

Post by SicMX »

How can I see what FPS a DVD is playing with?

I usually trust MediaForks same fps as source, but when deinterlacing that doesn't work so well. The video usually stutters
rhester
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Post by rhester »

"Same as source" in MediaFork is misnamed - it always defaults to film (23.976fps).

Rodney
Leo
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Post by Leo »

When I deinterlace, the video is slightly jerky, but I assumed this was because I was ditching half the fields, so it was only being changed half as often. For progressive sources at 24, 25 or 30 fps I think they let there be a bit more motion blur so it doesn't look so bad.

Or is the stuttering you're getting much worse?

You could try comparing it to "discard" deinterlacing in VLC, although I'm not sure if they are the same (and can't check at the moment).
Leo
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Post by Leo »

um, so should I always be setting the framerate when I'm deinterlacing? Or does it use the correct framerate by default? (I'm using the command line.)
Leo
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Post by Leo »

btw: Are all NTSC DVDs 30 frames per second? Are all PAL ones 25 fps?
rhester
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Post by rhester »

You should always set the framerate, regardless of whether you are deinterlacing or not, if the native framerate of the source material is anything other than constant 23.976.

Rodney
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Post by baggss »

How would one know if it is other than 23.976 and what is the impact of manually setting it higher?
rhester
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Post by rhester »

The best way I've found is to test with mplayer following the guide here:

http://www.mplayerhq.hu/DOCS/HTML-singl ... cine-ident

It's a little complex, but the only way to be sure you have the right answer.

Encoding at the 'wrong' FPS will have one of two effects: If your FPS is higher than the source, you will include extra and unnecessary frames that will give the appearance of jittery motion and, more importantly, waste bitrate. If your FPS is lower than the source, you will drop frames and it will result in more prominent jerky motion.

For mixed-rate source, you're better off going with the higher rate of the two.

Rodney
Nonsanity
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Post by Nonsanity »

...I wish I had known this 200 DVDs ago. :(
loyalty_anchored
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Post by loyalty_anchored »

Nonsanity wrote:...I wish I had known this 200 DVDs ago. :(
boy do i feel your pain :(
baggss
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Post by baggss »

Nonsanity wrote:...I wish I had known this 200 DVDs ago. :(
I was thinking that, but then again I'm not sure it makes too much difference. Quality is very subjective and my videos still look good to me...
hawkman
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Post by hawkman »

rhester wrote:"Same as source" in MediaFork is misnamed - it always defaults to film (23.976fps).

Rodney
Only for NTSC, I presume? My PAL DVDs all encode at 25fps, which I can only assume is right/best.
rhester
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Post by rhester »

Assuming PAL films and videos are both 25fps, that would be correct.

Rodney
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Post by Confused Amused »

Having some trouble clearing this up so maybe someone can help me. Since the current default is "Same as source" aka 23.976 for Handbrake I guess I assumed I'd want to encode at that framerate. I popped up ffmpegx and mplayer, dropped in a lot of VOBs from various DVDs, some movies, some TV shows and both applications always showed 29.97 as the framerate for whatever I threw in there.

So is 29.97 the more common rate for DVDs or am I looking at something wrong? Should I be encoding all these DVDs at 29.97 or is there a disadvantage to this?

I read the posts on how film is 23.976 and video is 29.97 and someone along the way indicated movies=film and video=TV, but I don't know if there's any truth to that statement. My tests would say that's no accurate. I actually didn't get ANY of my movies or TV shows disc to show 23.976. I tested The Office, 24, and Aqua Teen Hunger Force and then for movies Blood Diamond, The Departed, and Stranger Than Fiction. I guess what I'm trying to ultimately find out is which framerate is more prevalent and what I should usually be expecting to see?

FYI, this is for NTSC discs.
jbrjake
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Post by jbrjake »

Confused Amused wrote:Having some trouble clearing this up so maybe someone can help me.
No, because you haven't even bothered reading the information provided in this thread before posting in it. There's no way to help someone who won't help himself.

If you'd read the link Rodney posted, your questions would have been answered:
The MEncoder docs wrote:All video intended to be displayed on an NTSC television set must be 60000/1001 fields per second. Made-for-TV movies and shows are often filmed directly at 60000/1001 fields per second, but the majority of cinema is filmed at 24 or 24000/1001 frames per second. When cinematic movie DVDs are mastered, the video is then converted for television using a process called telecine.

On a DVD, the video is never actually stored as 60000/1001 fields per second. For video that was originally 60000/1001, each pair of fields is combined to form a frame, resulting in 30000/1001 frames per second. Hardware DVD players then read a flag embedded in the video stream to determine whether the odd- or even-numbered lines should form the first field.

Usually, 24000/1001 frames per second content stays as it is when encoded for a DVD, and the DVD player must perform telecining on-the-fly. Sometimes, however, the video is telecined before being stored on the DVD; even though it was originally 24000/1001 frames per second, it becomes 60000/1001 fields per second. When it is stored on the DVD, pairs of fields are combined to form 30000/1001 frames per second.
Which is to say, you'll often see 29.97fps as the frame rate when it's really 23.976, because whatever is telling you it's 29.976 isn't taking telecine into account.
deckeda
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Post by deckeda »

Important info in this thread about a commonly-asked topic. Would like to see it stickied, or better yet, the relevant posts copied and added to sr55's FAQ sticky in Support?
Confused Amused
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Post by Confused Amused »

If you'd read the link Rodney posted, your questions would have been answered

Sure would have, but I did read it. Silly me for reading the section Rodney actually linked to and not everything that was above it...
Which is to say, you'll often see 29.97fps as the frame rate when it's really 23.976, because whatever is telling you it's 29.976 isn't taking telecine into account.

This helps, so thanks, but is there any software that will give the correct framerate though? I guess I don't understand the point of mentioning that MPlayer or ffmpegx can give you the framerate - but not the right one.

But getting back to the encoding, is it safe to say in general use 29.97 for TV shows and 23.976 for movies? I'd like to figure this out before I dive into converting all my discs.
Confused Amused
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Post by Confused Amused »

From what I've found from reading a few sources is that anything you watch on your TV is being displayed at 29.97 fps. A movie is stored on a DVD at 23.976 and then your DVD player telecines it on the fly to 29.97 for your TV. Do I have that right so far?

Found some more info in the "Optimum settings for AppleTV" thread of all places.
scottyr wrote:Given your answer I'll assume TV shows = Video and Movies = film.
nightstrm wrote:not necessarily... a lot of the newer shows are shot on film as well.
deckeda wrote:guess that means a DVD player adjusts the framerate for the comfort of the TV but that AppleTV or software players can't.
Deckeda's question was left unanswered, but that's what I was really trying to get at. Should we encode the film or video at it's native framerate and leave the software (Quicktime?) to play it back correctly? Will Quicktime do the telecining like a DVD player or does Quicktime show the movie at whatever framerate you encoded at? If Quicktime doesn't do it, should we just encode the movies at 29.97 or is it better to leave it at 23.976?
deckeda
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Post by deckeda »

Confused Amused wrote: ... is there any software that will give the correct framerate though?
I've never seen anyone mention an OS X app that will do this, if that's what you mean. When using an OS X binary of MPlayer and watching the Console (or log) output, it doesn't report frame rate or other clues mentioned in the MPlayer documentation. That info is available if using the command line version, as I understand it, or perhaps a binary you compile yourself, and even then you have to watch the log as it's being written to see when a frame rate is reported ...
Confused Amused wrote:I guess I don't understand the point of mentioning that MPlayer or ffmpegx can give you the framerate - but not the right one.
The definition of "source" is absolutely critical here. A common --- albeit natural, IMO --- misconception is for users to regard their immediate source (i.e., the DVD) as the "source" being referred to in the software. It is not.

Rather, "source" refers to the original content. As content gets transferred to DVD it may or may not remain at its original frame rate.

FFMpegX for example is only going to show you what it's given --- and even then only for the first part when just dropping a file onto it.

If you give FFMpegX a 23.976 source that got turned into 29.97 for the DVD, all it can see is the fact that it's now a 29.97 item. FFMpegX can't read the minds of the DVD authors, who knew the original source was something else ...

Your goal is to have the transcoding software set to match the original content, as it was created, not necessarily as it got transferred to DVD. The reason is because transcoding software must consider individual frames when converting --- it can't consider the whole scene on the fly like humans do when watching on a TV.

By setting MediaFork's or Handbrake's frame rate correctly, you're telling it to ignore the DVD and treat the content as it was originally made. In this way, each frame that MediaFork or Handbrake encodes has the same image the original content did.
Confused Amused wrote:But getting back to the encoding, is it safe to say in general use 29.97 for TV shows and 23.976 for movies? I'd like to figure this out before I dive into converting all my discs.
That's the default way of deciding, and yeah, maybe safest if you aren't going to find out for certain.
jbrjake
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Post by jbrjake »

Short answer: you want to encode with the original content's frame rate, which is not always the same as the fps stored on the DVD, and the only way to know is to test with something like MPlayer that can, when you use it properly (as you obviously did not) alert you to duped frames and fps changes.

Believe it or not, Confused Amused, we're here to help with HandBrake, not to edify you on the finer points of film to video transfers. Every second I have to spend holding your hand through this stuff is a second I don't spend polishing a script for cvk_b and Loyalty_Anchored, testing out Nyx's awesome new patch, testing out awk's .vob patch, speeding up 2-pass encodes with x264, writing user documentation, updating our contrib libraries, patching our copy of x264 to use an adaptive quantizer, or answering other people's questions.

I mean, I just pasted an explanation of how some movies are stored on DVD hard telecined, and you come back with this:
A movie is stored on a DVD at 23.976 and then your DVD player telecines it on the fly to 29.97 for your TV.
Did you read? Obviously not. I'll paste again. Maybe you'll read this time.
The MEncoder docs still wrote:All video intended to be displayed on an NTSC television set must be 60000/1001 fields per second. Made-for-TV movies and shows are often filmed directly at 60000/1001 fields per second, but the majority of cinema is filmed at 24 or 24000/1001 frames per second. When cinematic movie DVDs are mastered, the video is then converted for television using a process called telecine.

On a DVD, the video is never actually stored as 60000/1001 fields per second. For video that was originally 60000/1001, each pair of fields is combined to form a frame, resulting in 30000/1001 frames per second. Hardware DVD players then read a flag embedded in the video stream to determine whether the odd- or even-numbered lines should form the first field.

Usually, 24000/1001 frames per second content stays as it is when encoded for a DVD, and the DVD player must perform telecining on-the-fly. Sometimes, however, the video is telecined before being stored on the DVD; even though it was originally 24000/1001 frames per second, it becomes 60000/1001 fields per second. When it is stored on the DVD, pairs of fields are combined to form 30000/1001 frames per second.
Will Quicktime do the telecining like a DVD player or does Quicktime show the movie at whatever framerate you encoded at?
I believe QT will play it at the encoded framerate, but it will be displayed by MacOS at the same refresh rate as your monitor. So it's doing telecine of a sort, but not to 30fps. This really has nothing to do with HandBrake and is the sort of question you should direct to the QuickTime discussion groups on Apple's support site. Come back with a definite answer, I'd be interested to know it.

On preview: hopefully deckeda's answer will help you
Confused Amused
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Post by Confused Amused »

Believe it or not, Confused Amused, we're here to help with HandBrake, not to edify you on the finer points of film to video transfers. Every second I have to spend holding your hand through this stuff is a second I don't spend polishing a script for cvk_b and Loyalty_Anchored, testing out Nyx's awesome new patch, testing out awk's .vob patch, speeding up 2-pass encodes with x264, writing user documentation, updating our contrib libraries, patching our copy of x264 to use an adaptive quantizer, or answering other people's questions.
That's great Jake, so go ahead and get back to that list of things you have to attend to. If you're too busy don't bother replying and bickering about how I've wasted your time. You chose to read the post, you chose to reply. I could have just as easily waited on this thread for someone else to reply or maybe not ever get an answer, but the point is you took your time out of your own free will to respond to this so don't chide me for wasting your time. You clearly have a very condescending and "holier than thou" attitude about this project. I can understand why and I certainly believe you're a fantastic programmer and have a great understanding of all this. Thank you very much for all the time and effort you've put into this project because it certainly wouldn't be this great without you, but there's no reason to walk around with your nose upturned at everyone along the way. All I'm saying is that you may want to work on improving your "help" methodology. Everyone's got their own method of helping people. I guess mine usually includes something about friendly or even remotely understanding and polite, but obviously that's not a universal sentiment.

Believe it or not, I've read the material you've pointed me at. I've spent awhile Googling for some more help on the matter as well, but in the end, I haven't been able to get my head around all of it. You win. You're obviously know more about this stuff that I do, but I never claimed to have even the slightest idea. Sure, I've read a lot now and I'm getting a little idea about pieces here and there, but no, reading a bunch of documents in a few days isn't going to make me an expert on these processes.

I end up with 2 options here - spend hours reading more about some technology and process I'm not terribly interested in and possibly discover the answer myself OR I could pose a question and hopefully someone who is much more knowledgeable on the subject can provide a concise answer for me. I'm sure they have a laundry list of things to take care of as well, but hopefully they won't provide a list of all the things I've prevented them from doing by receiving help from them. Call it lazy, call it efficient, it doesn't matter. I mean geez, in the time I've spent replying to you I could have gotten some lunch, fixed a few printer issues over here, someone's roaming profile is corrupted, my nails need to be trimmed, I need to call my friend back, get a drink of water and oh, that backup issue still needs to be sorted out. Gimme a break.

Deckeda, thank you sir for answering the questions and getting me straightened out. It's much appreciated. Your post was extremely helpful.
cbud
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Post by cbud »

Confused Amused wrote:...I actually didn't get ANY of my movies or TV shows disc to show 23.976. I tested The Office, 24, and Aqua Teen Hunger Force and then for movies Blood Diamond, The Departed, and Stranger Than Fiction. I guess what I'm trying to ultimately find out is which framerate is more prevalent and what I should usually be expecting to see?

FYI, this is for NTSC discs.
I actually own most of those discs you speak of and just so happen to have a few sitting on a my hard drive (Office, Blood Diamond, Departed). I just dropped the third VOB file from each movie/episode into ffmpegX and it reported 23.976 fps for each. Not sure what VOBs you were dropping, but they were not from the main content of these discs.

I can only speak from experience and not hard fact.

But, a single VOB file can contain cells which have a frame rate of 29 and also contain cells that have a frame rate of 23. So, when you drop this VOB into ffmpegX (Mencoder) it will give you the fps of the first cell.

For example, the first VOB on a 'West Wing' DVD will report 29 fps, but if you drop the second VOB file from that set it will report 23 fps. This is because the title sequence is at 29 fps.

Another example, MGMs 'Straw Dogs', the lions roar (MGM logo) is at 29 fps, but the rest of the movie (except one scene in the middle) is at 23 fps.

ffmpegX does a good job of determining the fps for me. MPEG Streamclip can also report fps, but it to reads from the first cell, so you will need to open another VOB to double check.

Lastly, all 29 fps (in my experience) is interlaced. Watch your DVD on your computer before you encode and you can figure out the fps!
deckeda
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Post by deckeda »

Last night, when reading jbrjake's quote and summation about how the wrong frame rate is often reported by FFMpegX I didn't see where he reached his conclusion.

And then it hit me --- it would have been better if they'd written that (in that example) the DVD player performs NTSC frame rate conversion on-the-fly. Frame rate conversion is a consideration when telecining, but frame rate and the telecine process aren't the same thing.

A DVD player doesn't "telecine" unless you can literally stuff a film reel into the tray and have it create video at the rear jacks. By the same token, something originally shot on video, regardless of frame rate is never telecined anywhere in the chain because it was never film to begin with.

The MEncoder docs come closest to explaining this, but even they need some parsing because staring at software that demands us to make a specific fps decision necessarily turns us all into literalists, splitting the hairs of finer points until practical, reliable and applicable conclusions are distilled.
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