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Which program to decode ac3 files on a mac? Pulling my hair out!
Hi there. First time posting on these forums. Hope I’ve posted in the right section. Obviously I can’t post in a more program specific section as I don’t know what program I need!
Basically I have an ac3 file ripped and demuxed from a dvd and that is all I’ve got to work with. Original audio and video are gone!
I demuxed the ac3 with Mpeg Streamclip. However it seems the fates are conspiring against me, because I’ve researched for 2 days straight and can’t find a working solution to decode the ac3 into it’s constituent 6 discrete channels.
mac3dec was my first instinct, but it would seem it doesn’t work under Snow Leopard.
Second solution I found was QuickTime Pro, however encoding with that brings up the error qtKitErrorCatchAll (-1309)
I’m at my wits end. There don’t seem to be any other programs for mac for doing this.
Any help is greatly appreciated.
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15 Replies
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Ripped DVD will not give you 6 tracks of audio. You have 2, left and right. If you want to edit the Audio/Video from the DVD then rip to quicktime video and AIF audio files.
Do you still have the DVD? to rip from?Or do you only have the ac3 file and you need to convert it?
Chris Tompkins
Video Atlanta LLC -
The dvd was burnt with 5.1 surround sound, and the ac3 IS 6 track. On a PC I’d be putting it through Hypercube transcoder to seperate the 6 discrete tracks into 6 mono wav files (have done so before), however I’m on a mac nowadays.
I don’t know where you’re coming from saying that DVDs only have stereo sound – why would people have surround systems if that were the case? :-p
And as I said, I’ve ripped 6 discrete tracks from dvds with 5.1 surround sound before. But only on windows. -
Mpegstreamclip will do the job very easy and it’s free
just export audio or demux
hope tthat helps 🙂
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I’ve already done the demuxing with mpeg streamclip…..what I need to do is seperate the resulting ac3 into 6 mono channels (the ones that make it up)
i.e. l, r, lfe, c…etc
For doing that, there used to be a program called mac3dec which would decode the ac3 into its seperate streams and save each stream as an individual aiff. However this program no longer works in snow leopard.
And as I said earlier, Quicktime has the capability but comes up with the error qtKitErrorCatchAll (-1309)
Hope I’ve been a bit clearer this time. The file has been demuxed from the VOB, so all 6 channels are intact within it.
Hope someone can help. 🙁
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I’ve never ripped more than 2 audio tracks w/Mpeg StreamClip before.
Sorry.Chris Tompkins
Video Atlanta LLC -
Ok I think people have their wires crossed here. Mpeg Streamclip can only output stereo audio or demux the VOB file to an ac3 and m2v.
The ac3 is unchanged. VOB is just a wrapper for those 2 files.
What I want to know is what programs can deal with splitting the ac3 file into 6 channels.
Mpeg streamclip has nothing to do with any of this…It’s already done its job in demuxing the file in the first place. I have already demuxed. I want to DECODE the ac3.
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You have an option on mpegstreamclip to select the audio channels by stereo pairs and then import them to your audio application (logic, dp7) and create a master surround and bounce back as independent mono
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Hi I’m in Mpeg Streamclip now and can’t find that option?
Also only 4 of the channels would be in stereo pairs. The centre channel and the low frequency effects channel are always single unlinked channels.
This is getting quite frustrating now, as they’re obviously able to be seperated (I can do it in a second in windows). The only program anyone ever talks about that’s able to do this is mac3dec, and it doesn’t work. It’s also a feature in quicktime pro……but that won’t work either.
Someone please help 🙁
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Hi Rhodri,
The ProApps are great for creating DVD’s, not so much for reverse-engineering them. You can import an AC3 file directly to FCP, so what I’d do in a pinch is to take the AC3 to FCP, create a sequence with a single mono output and drag the individual sound channels to it to export each as a mono AIFF or WAV. A 2-pop would ensure sync when recombining them, though there is no reason for sync to be affected at all.
Alternatively, you can open the AC3 in QTPro, go to its Properties (cmd-J), select the Sound Track and go to the Audio Settings tab. There, you can access the setting of the audio track, which include the output assignment. Any channel directed to “unused” will be muted, while any channel directed to “Center” will be mono. You can set all channels to “unused” and toggle them to “center” one by one to be exported as a mono audio file through QT’s Export dialog.
Not particularly elegant processes by any means, but they’ll get you there.
JC Boulay
Technical Director
Audio Z
Montreal, Canada
http://www.audioz.com -
Thankyou for your helpful and informative post. It is something i’d considered doing, though only as a last resort – basically importing the ac3 into fcp, unlinking all the channels then exporting them individually as aiffs. Is that what you’re saying?
Though I have no idea what Pop-2 is :p
I’ll certainly look into the Quicktime method though! 😀
I had hoped for a program that’d automate it all. Had you heard of mac3dec, by any chance? I was hoping someone here would know of an alternative that works under snow leopard 🙂
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