Avisynth through ffdshow uses wrong FPS Info from .avi Files

[thomaz909]

i have posted this in ffdshow forum:
http://forum.doom9.org/showpost.php?...ostcount=15282

since its also avisynth releated does anybody have an idea to stopping avisynth using "original framerate" instead of "frame rate" value from the .avi media info ?

[Sparktank]

The issue is already being addressed in the designated thread with reliable feedback.

You seem to not fully understand the possible issues with the codecs and containers involved.
SeeMoreDigital seems to have accurately addressed this matter.

The source does seem to have issues of its own, as SMD suggested.

[johnmeyer]

Two easy choices (pick one or the other):

1. Use AVISource to read the video into your AVISynth script. When I do this with your video, I get the "Frame Rate" of 30.00 fps.

AVISource("E:\Documents\Dnload\UNPACK\30fps.avi")

2. Add an "AssumeFPS(30)" statement immediately after you load the video in the AVISynth script. This will force your script to treat the video as though it were 30 fps instead of 23.976, regardless of how it is read. No frames will be dropped, added, or duplicated.

AssumeFPS(23.976)

I just tried it on your video, and it works.

[Sparktank]

Interestingly, that only works when a script (.avs) is created.

I thought OP was trying to apply a fix with FFDShow's Avisynth filter when playing the AVI.
Using AssumeFPS (any value) in FFDShow's filter, does nothing. With any setting.

But applying it in a script with AVISource fixes the playback.

I also notice there's a copyright for idtv (Internet TV), which makes me think this was a stream capture with some crude software and its settings.

[johnmeyer]

Since the OP cross-posted (in two other threads), I don't have time to read all posts. His question in this post is:

does anybody have an idea to stopping avisynth using "original framerate" instead of "frame rate"

and I answered that question.

[hello_hello]

Originally Posted by Sparktank

SeeMoreDigital seems to have accurately addressed this matter.

I'm not sure he got it right, unless I read a different post. What appears to have happened is thomaz909 opened an AVI with VirtualDub, changed the frame rate, then when he checked the new AVI with MediaInfo it showed the "original frame rate" of 23.976, which is probably the frame rate written to the video stream, and "frame rate" which is probably the frame rate written to the container.

I don't quite understand what thomaz909 meant when he said (in a different thread) "in ffdshow an avisynth script uses the "original frame rate" value instead of the "frame rate" value". I'm not quite clear how he's opening the video, whether it be via a script that ffdshow is decoding, or if he's put the frame rate conversion stuff in ffdshow's Avisynth filter to use it that way.

Originally Posted by Sparktank

Interestingly, that only works when a script (.avs) is created.

I thought OP was trying to apply a fix with FFDShow's Avisynth filter when playing the AVI.
Using AssumeFPS (any value) in FFDShow's filter, does nothing. With any setting.

But applying it in a script with AVISource fixes the playback.

If you're correct and he's is putting frame rate conversion stuff in ffdshow's Avisynth filter, then the result for me seems to be the same as it is for you. Nothing frame related works that way. Not AssumeFPS and not ChangeFPS. So I don't think it's a case of "avisynth still thinks that its 23.976" as thomaz909 said because nothing works in respect to changing the frame rate that way.

thomaz909, also said "with .mkv all runs fine", but I'd like to know how he's determining that, because I don't think it's correct. If he's checking the output frame rate with MPC-HC it's not always telling the truth.

When I open an AVI with MPC-HC and the LAV splitter (in my case it was a 25fps AVI remuxed as 30fps), ffdshow's on-screen display said 30fps while MPC-HC's File/Properties menu showed 25fps. When I disabled the MPC-HC AVI source filter to stop is using the LAV splitter, MPC-HC's File/Properties menu showed 30fps. Either way though, the video was still displaying at 30fps, easily confirmed by the lack of audio sync.
When muxing the AVI as an MKV, MPC-HC's File/Properties menu showed 30fps whether I used the LAV splitter or Haali, so for some reason MPC-HC is reporting the wrong frame rate when the AVI is opened directly even though it's playing the video at the correct (new) frame rate.

Maybe if thomaz909 describes exactly what he's working with and what he's trying to achieve someone might be able to suggest a better method, or one that'll actually work.

[hello_hello]

A related question I thought I'd ask as I wondered about it while playing around.

I've rarely used ffdshow's Avisynth filter so I've never known. It has a check-box to add ffdshow video source. With it unchecked, Avisynth offers an error, so I was wondering, under what circumstances would you not want that option checked? Obviously there must be one or there'd not be an ability to do so.

Thanks.

[Sparktank]

With FFDShow's Avisynth_filter, yes, I use the "ffdshow video source" as it gives errors without it.
I've not really tried it but invoking Avisource directly into FFDShow/AVSF.

I tried with ignore_pulldown and with apply_pulldown.
Not tried with smooth_timestamps.

But, that's if OP is even using FFDShow/AVSF or importing custom, written .avs script.

I've remuxed the AVI to MKV and played it in MPC-HC (LAV->FFDshow) and it still plays with increased motion, like it's on super High Frame Rate (23@30).