View Full Version : AC3 Audio down from 6ch to 2 channel?

28th March 2009, 05:31
I am trying to convert VOB files from a DVD.

When I play a cutted VOB file, it shows this information in Media Player Classic. (audio info)

Audio: Dolby AC3 48000Hz 6ch 192Kbps [AC-3]

I use AutoGK to convert it to AVI format (with original Audio option). But during conversion, I get a file like this in my agk_tmp folder

"videocut T01 2_0ch 192Kbps DELAY -111ms.ac3"

And my final AVI file output displays this audio info:---

Audio: Dolby AC3 48000Hz stereo 192Kbps [Audio 1]

Seems like that 6channel audio has been transformed into 2 channel audio? I don't know what's happening here. I don't notice any difference in audio on my computer, but is there really any transformation from 6 channel to 2 channel? If yes, why, because AVI files can support 6 channel audio, why the transformation?

AutoGK displays "Audio Streatm 0 AC3" as soon as the file is loaded into it before conversion process.


28th March 2009, 12:51
6 channel AC3 at 192 would be almost unheard of, and probably wouldn't happen on a retail DVD, so maybe there's been a mistake. What's it say when opened in GSpot? In any event, AutoGK won't reencode 6 channel AC3 audio to 2 channel AC3, so I suspect the source audio is really 2 channel.

28th March 2009, 13:41
Most likely a display bug in MPC.

28th March 2009, 14:45
GSpot displays:---
0xbd[0x80]:48000Hz 192 kb/s tot , stereo (2/0)

So maybe, it's a bug in MPC? strange, never thought MPC can have such bugs.

28th March 2009, 15:23
So maybe, it's a bug in MPC? strange, never thought MPC can have such bugs.Yes, bug in MPC. MPC is a piece of software, and software will have bugs, sure. Assuming this is the latest build of whatever fork of MPC you are using, if I were you, I'd report this bug so that they can fix it. If this is an older build you are using, try a newer build. Maybe this was already reported and fixed.