Vegas timeline and 23.976 frames a sec questions.

For the first time I've tried editing in 23.976 in Vegas and days later when I went back to the project, it would show frames that I didn't put in it, and they would mainly be noticeable by cuts because I'd insert a scene that was right after a previous scene in the original source.



Everytime it was a previous frame in the timeline that showed up, not the one after or some other random frame, it was always the one just before the intended frame.

So what caused this? What causes this? I'm thinking it may be because I'm editing in 23.976 frames a second because I've never had this happen before.

Help's appreciated.

I'm using Vegas 6.0d(build 210)

I'm sure I've been using the same build for quite a while and I just now noticed problems but also the first time I've edited in 23.976 frames a second. Normally I edit in 24 fps or 29.970.

I was thinking it may have been a codec issue before because I have had recent codec issues. Also another issue I had was with exporting a video in vegas where frame 1781 is the same image in 1782 and everything after that in the export is off by a frame. I doubled check that the duplicate frame wasn't in the timeline and it wasn't, so it's kinda weird it showed up in the export. The audio was fine and everything before frame 1781 was fine as well when exported.

The source is the same frame rate as the project settings, 23.976 and I'm editing vobs directly using avisynth, dgindex and convincing the program to use it using vfapi. Also have been editing with vfapi for a year and it has always been working just fine.

Thanks for the help. I'll do some reading and see if I can fix this. The first few steps you mentioned I tried and didn't work. I'll go to DMN and look around and look through that thread you posted.

WOW, WOW, WOW, WOW!!!!!!!

I tried out the trial and it fixed EVERYTHING!! It must have been vegas then and not my codecs!

Thanks a bunch!! I will have to update!

OK, I thought it did. Now I'm noticing the next frame instead of the previous one right before a cut.

Take the pic above and reverse it, now the problem is happening before the cut, the last frame before the slice is suppose to be cut off and the correct frame is to the left of that frame.

I'm not sure how Vegas works, but does it tell you if your source is 23.98 or 23.976?

Originally Posted by Guiboche

I'm not sure how Vegas works, but does it tell you if your source is 23.98 or 23.976?

It looks to say it's 23.976

I fixed it. I don't know if I may have added this at some time to screw it up, but the thing that was causing it to be messed up was having AssumeFPS(23.976) in the script. Even when I take it away, when I put info() in the script, it still is 23.976 frames a second, though it comes up as 23.9760 frames a second(ok, know pointing out that 0 may be pointless, though I want to give the entire info that I can.)

Does this problem make sense? Anyone here of this happening before? I put AssumeFPS and set it at the same frame what the source originally is.. so why would there be a problem from adding this in the script? I'm so HAPPY I've figured this out.. somewhat. I want to know what I did to make it do that by adding the AssumeFPS(23.976).. in detail please.

Yes, this problem does make sense.

Because "23.976" as a framerate, is not calculated as such.

Framerate is based on a fraction. The fraction is a number that has been divided.

So, 29.97fps, isn't that, but: 30000/1001 = 29.97

Same with 23.976, but, there are 2 ways and 2 fractions commonly used:

2997/125 = 23.976
or
24000/1001 = 23.976

I can never truly get any clear answers as to why this framerate discrepancy exists, but regardless of which method the editor uses, your source MUST use the same method or you will have framerate rounding and audio sync issues (and yes, if it reads framerate as 23.9760, there could be problems).

Why thank you for clearing that up!

That gives me a better understanding, it doesn't make things super clear, but a lot clearer than they were before.

Onto another similar issue, Like BJ_M mentioned, some things may be wrong in 6.0 that were fixed in 7.0. I imported a veg project file that was created in 6.0 into vegas 7.0 and I noticed a frame that was off. I don't know what is up there..?? In vegas 6.0, in the timeline, frame 615 is using frame 126,200 in the original source and when I look at the same project in vegas 7.0, the timeline frame 615 is showing frame 126,201 instead of 126,200 for some reason. I think it may mean vegas 6.0 or 7.0 is screwed up with handling the original source or the veg file just doesn't work the same in both versions. They are both showing frames that is accurate to the original source footage(checked in vdub to make sure) in the vegas timelines, just the placement is different for some reason. Maybe it just means I must use one or the other editor because each one looks at .veg files differently. Not sure, though that would be one thing I'd like to figure out.

Also, do you know any link that explains deeper into this? Also should I not use AssumeFPS(23.976) when the original source is already set at that framerate? (like I said it was 23.976 to begin with and I'm not sure if I added the AssumeFPS to the script at some point and forgot about it which is the cause of the frames being off. I just want to avoid this ever happening again! )

I did check the new export with the original export and every frame is correct to the original. I mainly found out these frame were off because I exported this project long ago which I forgot to mention in the first post, so I insure you, all the frames have been fixed and the new export is exact to the original export.

Are you import AVS files into Vegas to edit with? Or are you saving out AVIs from an AVS script and importing that into Vegas?

In my experience with importing AVS files (at least in Premiere Pro) the framerate rules get lost in translation.

The editor expects an AVI header (where framerate info is stored). When that is not found from the AVS, it will round off the incoming framerate. In this case to: 23.98

That again would be wrong and case framesync upsets.

I can tell you that on the Adobe side, all their video applications use: 2997/1001
DGMPG and many conversion softwares use: 24000/1001.

You can edit the d2v file. Just open it up in notepad and you will see:

Stream_Type=1
MPEG_Type=2
iDCT_Algorithm=6
YUVRGB_Scale=1
Luminance_Filter=0,0
Clipping=0,0,0,0
Aspect_Ratio=16:9
Picture_Size=720x480
Field_Operation=1
Frame_Rate=23976 (24000/1001)
Location=0,0,0,C548

Change this line:
Frame_Rate=23976 (24000/1001)

To line:
Frame_Rate=23976 (2997/1001)

I believe you would also have to create a new AVI frame serve with vfapi.

Since I have found out about 2997/125, I have used it for ALL my editing, and have always had(including audio) perfect frame sync.

I currently force this setting into all my AVI headers....

Originally Posted by Guiboche

Are you import AVS files into Vegas to edit with? Or are you saving out AVIs from an AVS script and importing that into Vegas?

I'm editing vobs directly using avisynth, dgindex and convincing the program to use it using vfapi.

So I make a d2v, make an avs with it then convert the avs to a fake avi using vfapi




I'm using version 1.4.0 of dgindex and this is how that info shows up for me in notepad

Stream_Type=1
MPEG_Type=2
iDCT_Algorithm=3
YUVRGB_Scale=1
Luminance_Filter=0,0
Clipping=0,0,0,0
Aspect_Ratio=16:9
Picture_Size=720x480
Field_Operation=1
Frame_Rate=23976
Location=0,0,20,571

I don't see the (24000/1001) anywhere, am I suppose to add (2997/1001) next to 23976 anyway?

Oh and I don't mind editing 24fps so if I edit with AssumeFPS(24) in the script, am I less likely to run into issues? I just want to avoid editing a d2v in the future is all.

You can continue to edit with AssumeFPS(24) if you wish. It will never cause framesync problems.

Are you using audio as well?

In that case, you'd use:
AssumeFPS(24,true)

That will keep the audio in sync.

You can also try: AssumeFPS(2997,125,false), but again, I don't think that will translate to the editor.....

I must thank you a lot, since we are not in person that would be hard, but maybe a thank you is good enough.

I will be editing the video without audio in the video source but music audio will be added to the timeline because I make mvs, but i thought the true part isnt needed unless you're linking audio and video with a script. I'm not fully sure how it works. I'll look into it more but if you have any more info that would be great. Thanks

good info Guiboche.

not saying one is right and the other is wrong - but adobe rounds off their frame rate - while avid and vegas use the full fraction 23.97601...

Well the full fraction is 23.976024..... (never ending)

The only time Premiere Pro rounds off is when it sees that fraction (to 23.98. Definitely wrong)

I'm certain there is a definitive "Right" 23.976 framerate.

24000/1001 is a never ending fraction.

While 2997/125 is 23.976.

As well, 23.976 divides perfectly intro 59.94 (TV refresh rate).

( 2997 / 125 = 23.976 ) * 2.5 = 59.94

While with the other method:

( 24000 / 1001 = 23.976023976023976023976023976024) * 2.5 = 59.94005994005994005994005994006

Also:

( ( 2997 / 125 = 23.976 ) * 1.25 = 29.97 ) * 2 = 59.94

So, in all standard framerates, the math contains complete fractions that add up perfectly to 59.94.

After Effects also uses 2997/125 to calculate 23.976.

Is there someone here really technical that can elaborate? I've been trying to settle this framerate anomaly for a while....

Here's just a screenshot of the project windows:

Just an update, Premiere Pro 2.0 will import both 2997/125 and 24000/1001 without sync issues.