Changing fps

[jh443]

Is there any way to change a vid's fps? Say I have one that's 25 fps and I want to make it 30 fps. (Or, as you might guess from reading my other post... I have a vid with 30.112 fps that I want to make 30 fps).

[redwudz]

Sure, just re-encode it with a different fps. You will have some quality loss, though. How much depends on the original quality and the bitrate you set for a re-encode. A slightly higher bitrate than the original usually helps. But it also makes the filesize larger.

With AVI type files, you could try VirtualDub.

[jagabo]

If it's AVI you can use AviFRate to simply change the frame rate in the AVI header. Audio will become unsyncronized though.

In VirtualDub you can use Video -> Frame Rate. In the top section you can change the assumed source frame rate (you still get all the frames, just at a different rate). In the middle section the rate will change by duplicating or removing frames.

In AviSynth you can use AssumeFPS() to change the assumed rate. ChangeFPS() to duplicate or decimate frames. ConvertFPS() to get temporally blended frames. SmoothFPS() to get temporally predicted frames.

[jh443]

Geez, I must be blind... I've overlooked VDub's Frame Rate option at least a 100 times in just the past week.

AviSynth... is that, really? I've downloaded it and looked it over - but there's no EXE. Well, none other than the Uninstall.exe

I have over 2 meg of HTML files in the DOCs directory, half a dozen AVS files that Windows doesn't know how to open in the Examples directory, 3 files in the plugins directory... but nothing resembling a README.DOC in the main
directory.

Yes, there are docs... too many. How about a Cliff notes version of it?

[redwudz]

AviSynth is a bit difficult to get started with, but very quick and powerful. I use a simple script similar to this to open Real Media files with VirtualDub then edit or convert them to a different format: DirectShowSource("C:\LOTR.RM", fps=29.97, convertfps=true) That short script and Real Alternative Player for the RM codec is all that's needed. This will also work with WMV and many other formats that VD can't normally open without plugins.

You can write the scripts in Notepad, change the extension to .avs and Virtualdub will load them, just like a file.

Just that convinced me AviSynth is worth learning. (I hate the RM/RMVB format and this helps convert them to something more useable)

BTW, there are plenty of guides for the AviSynth on their site: http://avisynth.org/mediawiki/Main_Page

[jh443]

Thank you for the info and the place to start looking.

At this point, I don't even know what to do with the AVS files. I'm sure I have to save them somewhere special - and I'm guessing I have to copy the files from the AVISynth\plugins directory to the VirtualDub plugins directory... but that's just a guess at this point. I'll start reading the link you provided.

===

Hmmm... I just did the "First Script" page and created a script containing the single line it said to do:

AviSource("c:\folder\myclip.avi"),

(Yes, the folder and file do exist now )

I saved the one line script to MYCLIP.AVS and attempted to open it with WMP. I got a dialog box saying file type AVS isn't recognized by WMP, followed (after telling it to try anyway) by "Windows Media Player cannot play the file. The Player might not support the file type or might not support the codec that was used to compress the file."

I had no better luck when trying to open it with VLC.

The AVI plays fine in both players

The one line "Version" script doesn't work either.

??????????????????????

[jagabo]

Did you go through the AviSynth installation? It doesn't sound like you did.



Download from here:

http://downloads.sourceforge.net/avisynth2/AviSynth_080912.exe?modtime=1221214982&big_mirror=0

You will get an EXE file. Run it. The default installation options should be fine.

Once you run the installation all the files should be in the right place. You don't need to copy anything anywhere. AviSynth works invisibly in the background. There is no EXE to run, no window to see, etc. Try your Version script and verify it works.

[jh443]

I found out what the problem was: I used every default value in the installation program The installer chose not to make the file associations - and I trusted it. This meant that when I attempted to manually open the AVS with WMP, it was opening it with WMP11 - instead of WMP 6.4.

The "tipoff" that everything really WAS working as it should was when I opened TEST.AVS with VirtualDub - and got the 10 second copyright notice I was expecting. That's when I reran the installer and told it to make the file associations that it had previously chosen not to do.

Thank you for all your help.

[jagabo]

I have no problems playing AVS scripts with WMP 11.

[jh443]

I've done some playing around... and have found that I often CAN use WMP11. But, the very first script mentioned in the docs is the following single line script:

Version

This is the very first one I tried - with WMP11, and it crashed and burned. I have found that the following one line script will play in WMP11:

BlankClip(length=250, width=640, height=480, fps=25)

So I'm guessing it's hit or miss - with misses happening rarely... but, of course, it's the first thing I came across when starting out from square one.

[jagabo]

I've done some playing around... and have found that I often CAN use WMP11. But, the very first script mentioned in the docs is the following single line script:

Version

You're right! A script with just Version() won't play in WMP 11. It's not clear exactly what the problem is. Adding AddBorders(2,0,0,0) or Crop(2,0,-0,-0) made it work. Even just adding some comment lines. Strange.

[poisondeathray]

Weird.

A script with just Version() (without borders or cropping) plays on my WMP11, perhaps it's the avisynth "version" - I'm using 2.57

[jh443]

I'm using 2.5.7 too. Try it without the ()

(I'm WinXP SP2, if that matters)

edit: Nvm - even with the () it doesn't work on mine.

[jagabo]

I tried both with and without the (). I have version 2.58 of AviSynth. WinXP Pro SP3.