Framerate query.

SS5_Majin_Bebi · Post by **SS5_Majin_Bebi** » Wed May 14, 2003 12:38 am

I'm a little confused. Theres all these framerates hovering around out there (23.97, 24, 25, 29.97, 30) and I'm not sure which one is the "right" one to use. Seeing as I'm in Australia, the DVD's here are all R4, 25fps, Pal. When I rip them, thats what it displays anyway. So, as a result, I edit and export my music videos in 25fps. Out of curiosity, I checked out my collection of vids I've accrued over about a year, from here and other places. I found alot of 23's, and 29.97's, but I dont think I found a 25. Yet, I cant notice any difference between MY 25fps and others 23 / 29.97 fps. (I did originally edit some videos in 29.97 before I knew what I was doing, but theres still no difference)

So whats going on? Am I "ruining" my music videos by not doing all these framerate conversions or what? Personally I am quite happy to edit in 25fps, because then its consistent across all the programs I use. And remember, I'm in Australia, so PAL is the standard here.

klinky · Post by **klinky** » Wed May 14, 2003 1:33 am

24, 30 are whole number framerates of 23.976, 29.97. Technically when used alot of times they mean the same thing since it's easier to work with. However NTSC requires the frame rate to be %1 slower than the actual whole number so you get 23.976/29.97.

PAL is 25fps. I am not really that well versed in PAL(or NTSC for that matter), but alot of the time they just speed up the source by %4 to 25fps, or there are also telecining methods which, I hear, are a pain to de-interlace. If you're happy with PAL then I would just leave your videos the way they are and run a smart de-interlace on them for online distribution. Don't de-interlace them if you're going to make a PAL VCD/SVCD/DVD. I believe if you IVTC'd you could get it back to a regular 24fps rate. Not sure if it would be 23.976 though o.O Ack :p

If you do want to try IVTC, I believe you can force decomb in AVISynth to folow a PAL guide, which may help it. Or you could put AssumeFPS(24) then go through it frame-by-frame in virtualdub and see if you have any interlacing artifacts. If not you should be good to go.

As long as your videos look good, I would leave it be. Most AMVs are going to be viewed on a computer and I am guessing any Cons you send your video to are going to be in aussieland.

~klinky

Tab. · Post by **Tab.** » Wed May 14, 2003 2:38 pm

like klinky said, sometimes you get lucky and they just speed the 24fps footage up to 25fps, sometimes they telecine like 1 frame every 5. Try decomb's pal mode unless it already looks progressive. If it's already progressive go for assumefps(23.976), if not decomb will take it down to 23.976 for you. But again I've heard of crappy handling of stuff where its been converted to film then ntsc then pal and stuff and it gives you a load of crappy frames, so, I guess it depends.
And my knowledge of PAL cuts off there :/

Quu · Post by **Quu** » Wed May 14, 2003 5:41 pm

if you submit 25fps to any con I support yoru in luck... becasue all of my equipment is multi system aware... and i can ouput NTSC/PAL/SECAM or what ever is needed from any oroginal source....

so i can mix ant match PAL submissions with NTSC and still display them on the same screen

SS5_Majin_Bebi · Post by **SS5_Majin_Bebi** » Wed May 14, 2003 6:26 pm

thanks for the info, it helps, but all i really wanted to know is if there is any "right" framerate, or any that looks better. I have very precise eyesight, and I havnt noticed any differences between the framerates (not conversions mind you, i mean editing ALL in one as apposed to ALL in anohter, keeping it consistent, sticking with the rate of the source) Im content to keep editing in 25fps because it looks exactly the same. Although I may not know what I'm looking for, but....

Thanks anyway, and Quu, i'll keep that in mind if I ever look to mail some of my AMV's off to a Con.

jbone · Post by **jbone** » Wed May 14, 2003 9:48 pm

Quu wrote:if you submit 25fps to any con I support yoru in luck... becasue all of my equipment is multi system aware... and i can ouput NTSC/PAL/SECAM or what ever is needed from any oroginal source....

Duuuuuuuude! You can do SECAM?

koronoru · Post by **koronoru** » Thu May 15, 2003 11:23 am

SS5_Majin_Bebi wrote:thanks for the info, it helps, but all i really wanted to know is if there is any "right" framerate, or any that looks better.

All other things being equal, a higher frame rate is better. But all other things are *not* equal.

First of all, there's the frame rate the original was animated at - which is quite often 12 with occasional bursts of 24. They call it 24, but most of the time they're actually doubling up the frames, drawing 12 new frames per second of display; standard animation practice is to only anime 24 real frames in a second when there's a whole lot of motion and the 12 looks too jerky. If your frame rate is not an even multiple of the original, then you're going to see uneven motion, especially during slow pans. Movie film normally advances through the projector at 24 frames per second, although to make things even more confusing, the projector's shutter actually operates at twice that speed, flashing 48 frames per second. Anyway, based on using the original frame rate, you might think that the best frame rate would be 24, and that is quite often the case.

But television always runs at either 25 (PAL), or 29.970 (NTSC). In order to broadcast on television, the frame rate has to be converted, in a process called "telecine". There are several different ways that can be done, and they have different results. When you edit a video from television source, you're faced with the output of the telecine process. Of course, PAL telecine is totally different from NTSC telecine; both can be quite complicated.

So the question is, do you just keep the footage at the frame rate you got it in? That could be good because you're doing minimal processing... every stage of processing adds some distortion. On the other hand, the results of telecine are designed for display on television sets. Computers work differently (progressively instead of interlaced, but that's not the only difference!) and telecined footage often looks really bad on a computer. So you might want to attempt "inverse telecine" - undo the telecine process to get the footage back to the original 24 frames per second. Depending on the telecine that was applied, that can make a big improvement in the quality. But if you do it wrong, you'll just make things worse.

Finally, if you're submitting to a con, they may have fixed frame rate requirements in which case you have to meet the requirements one way or another.

The bottom line is that there isn't one "best" frame rate for all footage. Frame rate does make a big difference, but which one looks best depends on the footage. You must examine your particular footage, figure out what has been done to it, and then decide how you want to process it on a case-by-case basis.

JCD · Post by **JCD** » Thu May 15, 2003 11:52 am

SS5_Majin_Bebi wrote:thanks for the info, it helps, but all i really wanted to know is if there is any "right" framerate, or any that looks better.

There is no "right" framerate, there's only a original frame rate (24) like the others said.
The only difference when you're using another frame rate while editing (except visual quality) is how many frames you're able to synch.

In terms of quality... only in rare cases a pal movie has been telecided from 24 to 25 fps. Let me say that the most guys who convert to pal are stupid: If the original (master) footage they get is in 24 fps they just speed it up to 25. But if the master is in 29.97 ntsc (which is often the case with animes) they just delete frames out of it or -even worse- they overlay some frames to get 25. This makes the already interlaced and telecined footage look even more odd with up to 3 frames overlayed in one. The most Anime DVDs here look really crappy because of that.

So what I'm trying to say is that it really makes no difference if you're editing in 25 fps, it's even better because you're able to synch more frames per second as with 24.
The others explained to do inverse telecine on your source... but if the sources are like above it's very hard to do it. It may help in some cases, but will also cause the video to ruckle. Better find a good way to deinterlace it. (In every case of trying to do this your framerate still remains at 25)
If your source was just speeded up you can leave it as it is. It's already progressive then and you mustn't do anything of this deinterlacing / inverse telecining things.

Giton · Post by **Giton** » Thu May 15, 2003 5:41 pm

JCD's right!
If your source footage is already 25 fps, you should leave it this way.
Normally the video on the dvd is already progressive or it's interlaced, but beware: this is PAL interlacing and has nothing to do with IVTC!
You then just need a proper deinterlace filter as it is integrated in both VirtualDub or avisynth.
Since you live in Australia, I suppose your dvds are the same as the english releases, except for the region code, and therefore generally overblended.
Check this before you start editing. Overblending is really annoying once you notice it!
If it that way then try to get US-dvds or Japanese dvds next time.

And BTW: It's not possible to remove the overblendings in PAL source!

SS5_Majin_Bebi · Post by **SS5_Majin_Bebi** » Thu May 15, 2003 5:50 pm

okay, I'll look for this "overblending" as you call it, but what am I looking for? And yeh, I'm aware that PAL interlacing is different, and I use the interpolate setting for de-interlacing, because I don't know which field is out of synch, plus it works out better (in my experience anyway) to let the program detect and correct it itself.

But as long as 25fps is adequate thats all that concerns me right now. Seeing as I'm not a technical wizard at video editing (yet....) I'm gonna leave the higher level stuff alone for now, till I get a slightly better handle on things.