Changing fps from 60 to 30.

[DangeR!]

Hi,
I have fraps footage that I put together in Virtualdub and saved as an .avi file (non compressed). Basically so its just one file. Its about 30GB in total and is shot at 640x512 @ 60fps, 20 mins long.

based on this thread http://forum.doom9.org/showthread.php?t=125079 (great work btw)

Now I am encoding it into x264 using a batch file I created (attached) with switches. Could some of the more experienced look over it and see if its ok. It encodes the file down to 300MB and the quality is excellent, took 3 hours for one pass (first), but it doesn't seem to change the fps from 60 to 30fps. I am assuming it will reduce the file size further if its @ 30fps so I need to convert it. Is the --fps switch broken or am I missing something?

This is my very first time doing this sort of thing. Ripping from DVD's is easy, point and click lol. But doing this from scratch with avi files etc requires me to get some advice.

@ECHO OFF
ECHO.     ------------------------------
ECHO.         Setting Variables.
ECHO.     ------------------------------
SET bitrate=2000
SET threads=2
SET fps=30.00
SET input=frapScript.avs
SET output=output.mp4
ECHO.     ------------------------------
ECHO.         Encode First Pass
ECHO.     ------------------------------
x264.exe --fps %fps% --trellis 2 --me umh --bime --merange 64 --no-fast-pskip --partitions all --8x8dct --pass 1 --bitrate %bitrate%  --subme 7 --bframes 16 --b-pyramid --ref 5 --b-rdo --aq-strength 0.5 --mixed-refs --direct auto --weightb --progress --deblock 1:-1 --threads %threads% -o %output% %input%
ECHO.     ----------------------------------
ECHO.         Encode Second Pass
ECHO.     ----------------------------------
x264.exe --fps %fps% --trellis 2 --me umh --bime --merange 64 --no-fast-pskip --partitions all --8x8dct --pass 2 --bitrate %bitrate%  --subme 7 --bframes 16 --b-pyramid --ref 5 --b-rdo --aq-strength 0.5 --mixed-refs --direct auto --weightb --progress --deblock 1:-1 --threads %threads% -o %output% %input%
ECHO.     ------------------------------
ECHO.         Finished Encoding
ECHO.     ------------------------------
PAUSE
CLS
EXIT

Thanks,
D.

EDIT: once I have done 2 passes, what software can i use to put music and title screens in. Will I have to encode it again? won't it loose quality.

[AVmaniac]

hi .. what about using avisynth internal conversion of fps ?

convertfps(30) ... but the value choosen can be max. 2/3
of source fps.
so if you want to perhaps go convert to 25fps you can combine
multiple convertfps
convertfps(30).convertfps(25)

see also avisynth docs ConvertFPS().

About audio:
try ...

video = yourvideosource
audio = wavsource("your.wav") 
#or directshowsource("your.something.soundfile")

audiodub(video,audio)

convertfps(30)

... you can extract a *.wav file using virtualdub and loading your *.avs .

[akupenguin]

Multiple calls to convertfps? That's just asking for trouble. The convertfps doc even says so.

[DangeR!]

Hi,
thanks for the replys.

this is whats in my .avs file

DirectShowSource("video.avi")
ConvertToYV12()

so just add convertfps(30) to the end of it?

didn't realise .avs files could do that (don't really know what they do tbh lol.)

This is a good site for x264 commands, witch I have followed http://aflux.deltaanime.net/Zero1/MP4/x264.html

Also, does my x264 settings look ok + will 30fps reduce the file size by half, if any?

[LoRd_MuldeR]

Originally Posted by DangeR!

didn't realise .avs files could do that (don't really know what they do tbh lol.)

Avisynth is one of the most powerful softwares for video editing.
With Avisynth scripts you can do almost everything (some additional Plugins might be necessary though)

You might like to read this:
http://avisynth.org/YourFirstScript

[DangeR!]

Thanks LoRd_MuldeR, I'll have a read of that soon.

I have a problem. x264 cannot open my avs file, any ideas why?

my error:
avis [error]: unsupported input format (DIB )
x264 [error]: could not open input file 'frapScript.avs'

[DangeR!]

VLC doesn't play my original .avi file now :/. WMP and virtualDub do though, very strange.

[Blue_MiSfit]

It might be a lot faster if you re-encode to HuffYUV, or a similar universal lossless codec. It will save space and time.

~Misfit

[DangeR!]

how do i solve my error?

is HuffYUV as good quality as x264?

[LoRd_MuldeR]

Originally Posted by DangeR!

how do i solve my error?

is HuffYUV as good quality as x264?

HuffYUV is lossless, x264 usually is not (except you use CQ=0)

But don't expect HuffYUV to achieve a decent compression-ratio, it's more intended for real-time capturing and intermediate storage!

[Shinjite]

Originally Posted by DangeR!

Hi,
thanks for the replys.

this is whats in my .avs file

DirectShowSource("video.avi")
ConvertToYV12()

so just add convertfps(30) to the end of it?

didn't realise .avs files could do that (don't really know what they do tbh lol.)

This is a good site for x264 commands, witch I have followed http://aflux.deltaanime.net/Zero1/MP4/x264.html

Also, does my x264 settings look ok + will 30fps reduce the file size by half, if any?

to reduce the size of the output clip is depends on the target bitrate you want in the x264 settings.

[DangeR!]

Originally Posted by LoRd_MuldeR

HuffYUV is lossless, x264 usually is not (except you use CQ=0)

But don't expect HuffYUV to achieve a decent compression-ratio, it's more intended for real-time capturing and intermediate storage!

do you mean use virtualdub to record my game play using HuffYUV (using VD as a fraps substitute)?

I take it no one knows why this error has come up when the file used to encode fine before.

I also thought that reducing the fps would also reduce the overall size of the footage when encoded. less frames less size.

[DangeR!]

I figured out my error, or at least why it wouldn't open properly. its the command ConvertFPS(30). I took this out and it started to encode as it should.

If reducing the fps isn't going to reduce the file size, then there is no need to change it. I'm fine with 2000 bitrate, though I may experiment with it to get the file size down a bit.

[ballofsnow]

Why not just use selecteven()? By using ConvertFPS(30) you're removing half the frames, same as selecting every other frame.

edit- whoops, nevermind. Confused this with changefps. You may be looking to use changefps instead!

[DangeR!]

ok read a bit more.

Because the source file is at 60 fps and I have to do 2/3 of that, the convertfps will have to be 40fps.

[DangeR!]

Originally Posted by ballofsnow

Why not just use selecteven()? By using ConvertFPS(30) you're removing half the frames, same as selecting every other frame.

I'm new to this (1 day lol) and reading allot of info on the subject... haven't come across that command yet, thanks for the heads up. I will look into it.

[DangeR!]

The encoded footage wont play on WMP or QuickTime, but it plays in VCL. How can I make it more compatable? is it to do with --merange should I use 64 or 32, as I hear 32 allows it to be played in quicktime/ipod.

sorry for all the questions and thanks for the help so far.

[ballofsnow]

You may have missed my edit above. You should look into both selecteven(), and ChangeFPS(30). Changefps will delete or duplicate frames to meet the desired framerate. In your case it'd delete half of them, which I'm pretty sure is what you want.

To make it Quicktime 7 compatible, in MeGUI you'd select main profile, and make sure that bpyramid is off. Not sure what the exact command line would be though.

[DangeR!]

what about windows media player... thanks for reply

[LoRd_MuldeR]

Originally Posted by DangeR!

I also thought that reducing the fps would also reduce the overall size of the footage when encoded. less frames less size.

When compressing video, you usually select the target bitrate (when not using Constant Quantizer mode)
Bitrate is selected as "Kilobits per Second" and not "Bits per Frame" or something
This means the resulting Filesize will be the same, no matter which Framerate the video has!
Of course if the video has a lower Framerate, then you can usually encode at a lower Bitrate and still get a decent quality.
So reducing the Framerate will not make your file any smaller, as long as you don't adjust the Bitrate too!