AC3 in Avisynth not properly decoded by FFDShow with DirectShowSource

[Reino]

Hello,

I encountered something weird.
When I import demuxed AC3-files, or VOB-files directly (either from a DVD or a camcorder) in Avisynth with DirectShowSource just like this: DirectShowSource("C:\test\test.ac3") or DirectShowSource("C:\test\test.vob"), the sound decoded by FFDShow (rev. 2079 clsid at the moment) has a pitch I think ± 5 times higher than normal!! When I use AC3Filter instead, the problem is gone.
I uploaded a sample here (www.degeelebosch.nl/reino/1-Subaru_shot1.ac3). Please tell me if you can reproduce it by just using DirectShowSource("C:\###\1-Subaru_shot1.ac3") in your avs-file with FFDShow.
I normally use FFDShow and I prefere to use FFDShow as well, so if many can reproduce this, can this problem be fixed, clsid? :rolleyes:

[tebasuna51]

Yep, seems ffdshow don't decode properly this stream.

Your sample is an ac3 2.0, 48 KHz, 384 Kb/s with 195 frames (6.24 seconds). Only this header value isn't habitual:
Version (bsid) : 4 (Subset of standard version)

Is decoded by ffdshow (2033, 2008-06-27) like 6 channel 2.08 seconds.

You can use NicAc3Source() than work fine.

[Reino]

Thanks tebasuna51,

I know, I've already tested NicAC3Source() and it works fine, but that required me to decode and make a D2V-file from the original VOB-file first. I'd like to use DirectShowSource(), or can you discourage me to because of some important disadvantages?

Like I said, I didn't encounter this problem when I used AC3Filter to decode (nor with NicAC3Source), so I really think it's FFDShow to blame here. (no problems with normal playback what so ever)

[tebasuna51]

I'd like to use DirectShowSource(), or can you discourage me to because of some important disadvantages?

With ffdshow you can't disable the DialNorm attenuation.
I have ffdshow ac3 decoder with adjust to play (different than transcode adjust) in Volume, DownMix and Dynamic Range Compression.

For transcode, preserving the best quality, I use NicAc3Source()

[Reino]

Actually I prefer the highest quality as well! Okay, I'll use NicAC3Source, thanks!