ffdshow reports incorrect frame rate when playing back mp4

[madoka]

A XviD video encoded at 23.976 fps and muxed into mp4 using mp4box, when played back, ffdshow shows the frame rate as 25 fps. To my untrained eye, the video doesn't seem to be played back faster, so is this just a glitch?

I'm using MPC and Haali Media Splitter.

[stephanV]

if you check the video renderer in MPC (in filters menu) what does it say?

[Doom9]

also, did you specify the framerate when muxing? by default mp4box uses 25 fps

[madoka]

if you check the video renderer in MPC (in filters menu) what does it say?
I don't think it reports the frame rate of the movie, just the playback frame rate.

also, did you specify the framerate when muxing? by default mp4box uses 25 fps
No, because mp4box recognized the video's frame rate correctly (as 23.98 fps, which I figured is due rounding), so I assume it'd be carried over.

I re-muxed the video this time specifying the frame rate explicitly:
mp4box -add video.avi#video -fps 23.976 output.mp4But there's no effect: ffdshow still reports the movie FPS as 25.000. Moreover, when I extract the video from the mp4, the resulting AVI has the correct frame rate. This leads me to believe that the issue is probably with ffdshow or Haali Media Splitter.

[DeeGee]

I just tested this and seems like the problem is on Haali Media Splitter. Nero Digital Splitter reported the framerates to ffdshow correctly, but after i unregistered it and gave mp4 handling to Haali, ffdshow always said that the fps is 25. But ffdshow still played the files at their correct fps.

[stephanV]

I don't think it reports the frame rate of the movie, just the playback frame rate.

Yes, so if playback rate = 23.976 ffdshow is wrong, if playback rate = 25 fps ffdshow is right!

but it seems something else is the issue.

[DeeGee]

Haali Media Splitter (http://koti.mbnet.fi/deegee/sekalaisia/haali.png)
Nero Digital Splitter (http://koti.mbnet.fi/deegee/sekalaisia/nero.png)

[Haali]

My splitter doesn't report any framerate as it is not needed for playback and is not stored in mp4 container.

[bond]

the framerate is indirectly stored in the .mp4 container

you can calculate it with the timescale and another value i forgot now, maybe haali doesnt pass that info to ffdshow and therefore it simply doesnt calculate it and therefore always displays 25fps?

[DeeGee]

While I took those screencaptures I noticed that while using haali as splitter ffdshow/mplayer didn't pause very fast... it took something like 1-2 seconds to pause. You don't notice this on longer clips but the test clip was short pov-ray rendering at 60 frames/s. Using Nero as splitter it paused instantaneously.
http://koti.mbnet.fi/deegee/sekalaisia/collide_fast.mp4

[Haali]

Unfortunately I couldn't reproduce that. I'm using ffdshow and MPC, and pause works instantly.

[DeeGee]

Seems like the problem was Media Player Classic and the WMR 9 (rendeless) output. Fixed when changed to default.