WMV -> AVI with VirtualDub-MPEG2 (Bugreport)

[LoRd_MuldeR]

I just found a problem in VirtualDub-MPEG2:

I tried to convert a WMV file to AVI, since VDub-MPEG2 now can read those files. The file was opened, but audio and video run asynchron! In the original A/V was 100% synchron.

I managed to fix the problem with the "change [framerate] so audio and video durations match" setting plus adding some audio delay.

Still great work, but is there a way to fix A/V asynchronity?


Didn't know where to post bug-reports for VDub-MPEG2 :confused:

[meilin]

You should post bug report to virtualdub forum
forums.virtualdub.org
And the author fcchandler said this
"You're going to run into problems if the WMV uses B-frames, or its audio is VBR. But I guess you'll see what I mean soon... "

[LoRd_MuldeR]

okay. thanks for info.

[fccHandler]

One of the problems with converting ASF/WMV to AVI is the fact that ASF files don't have a fixed frame rate. All audio and video samples are simply time stamped, and it's entirely possible for the local frame rate to vary considerably at different points in the stream. I don't know how prevalent this is, but it's certainly allowed by the format.

Right now VirtualDub-MPEG2 just guesses the average framerate:
(last_timestamp - first_timestamp) / number_of_frames

I don't have a better solution yet, but it is something I'm thinking about. The support for VBR WMA9 needs some work too. It seems to play OK if you start from the beginning, but randomly seeking on the timeline throws off the sync.

[LoRd_MuldeR]

Would be great if you find a way :cool:

Until then, we need to find a workarround...

[movmasty]

FCC, please, i need vdub-mpeg2 1.5.10 build 18303, where to find it?

[LoRd_MuldeR]

One of the problems with converting ASF/WMV to AVI is the fact that ASF files don't have a fixed frame rate. All audio and video samples are simply time stamped, and it's entirely possible for the local frame rate to vary considerably at different points in the stream. I don't know how prevalent this is, but it's certainly allowed by the format.

Right now VirtualDub-MPEG2 just guesses the average framerate:
(last_timestamp - first_timestamp) / number_of_frames

I don't have a better solution yet, but it is something I'm thinking about. The support for VBR WMA9 needs some work too. It seems to play OK if you start from the beginning, but randomly seeking on the timeline throws off the sync.

Did you make any progress yet?

There's that tool called "ASF Tools" which seems to convert WMV/ASF to AVI with very good A/V sync. So there must be a way to do this...

[fccHandler]

FCC, please, i need vdub-mpeg2 1.5.10 build 18303, where to find it?
http://fcchandler.home.comcast.net/Previous/VirtualDub-MPEG2.zip

Did you make any progress yet?
Sorry, I don't have any free time. Maybe after the holidays.

[movmasty]

http://fcchandler.home.comcast.net/Previous/VirtualDub-MPEG2.zip


ahhhh MANY THANKS! As i feell that vdub 1.6x is still buggy