Stop right now if this is old news, but…

Needing to convert some eight hours of CDR audio to play back on DVD under some home-made slideshows, and wanting to get it all onto 1 DVD, I knew AC3 was the only way to go.

I also knew from previously having converted some 25 hours of CDR audio to AC3 over an unbroken 13 hours of computer time, that there had to be a better way.

I believe I’ve found one.

First, convert the disc-length CDR audio of 44.1MHZ to DVD standard 48MHZ, which I do with Amadeus audio software. If there are multiple discs involved, join them as one large file (bearing in mind Amadeus bails out at 2GBs).

Then, swift intake of breath, save the result as a .wav file.

This is necessary, because, in the next step…

Open the free DVD authoring program MovieGate (my version, 2.0.1), and load a small .m2v file into the Video ‘box’ for the authoring job ahead. Doesn’t matter what it is because you are going to toss what MovieGate makes of it away at job’s end anyway.

Make sure that MovieGate’s preferences are set to encode to AC3 output and to the bitrate of choice, 224, in my case.

Also make sure that in the Preferences you select, under MISC, “Keep Elementary Streams”. I ‘save’ these to the Desktop for convenience.

Now, for the audio content of this MovieGate authoring job, select your .wav file. In my case, the first file was 2hrs 53mins long drawing on 3CDRs’ content.

OK, with minimal video input, MovieGate will always ‘tell’ you the resulting files are only going to be as long as the video, that the result will only last (in my case, three minutes, the length of the m2v file I used for visual coverage) but ignore that.

Add the loaded files as MovieGate requires to its ‘work window’, and then hit “Start”.

MovieGate will then author a set of DVD-ready files for you in the standard AUDIO_TS and VIDEO_TS folders - and also, because you checked “Keep Elementary Streams”, not trash its ‘building blocks’ for making those standard files.

And it will do it blooming fast. 25 minutes to encode 2hrs and 53mins in my case, round it out to 30 minutes for three hours of source sound as a rule of thumb, or 1/6th source time equals encoding time. Left A-Pack in the dust, I can tell you!

On your Desktop, find the AC3 file you have just had encoded amongst the elementary streams, usually called Track_1.AC3 by MovieGate, and toss out everything else.

There you have your AC3 audio file ready to author your mega-audio content DVD. Or the first of however many you need to get on the DVD – even the 25 hours of music set with slideshows I made was well shy of ‘full-length’, around 2.33GBs.

So, why convert the aiff file to wav? Because if you don’t, MovieGate will, as it authors a DVD’s audio ‘internally’ from wav encoding only. And MovieGate is slo-o-ow doing this, so slow none of the above is worth doing if you choose to use aiff files. Amadeus saved a near-on 3 hours long aiff file to wav in three to four minutes; MovieGate had only converted 45% of the aiff file to wav in half an hour while I was exploring the ins and outs of this technique.

That’s it. You may never want to get a very large amount of audio onto one single-sided DVDR, you may consider AC3 the work of the devil, but if you ever do want a speedy and high-quality method of encoding audio to two channel stereo AC3, now you know how.

Regards, Michael McGennan