MQA -Master Quality Authenticated – is a music encoding method that allows to combine high definition audio content with relatively small file sizes and downward compatibility. Without a decoder, the quality is around CD (Red Book, 16 bit/22Khz) but a decoder will make the “Hi-Def” available – sort of. Here’s what you need to know ..
Streaming is getting more and more into the business view of the recording companies. But the sound quality is still limited – for two reasons: Available network bandwidth (high quality requires much bigger files) and the recording companies are somewhat afraid of loosing high value / high definition content to pirates (or normal people). So – when MQA came around, it seems to solve the puzzle: Relatively low bandwidth requirements in combination with a proprietary protocol.
If you ask the makers what is so special about MQA, they will say something about “folding” the audio, or “audio origami” . But MQA is a lossy format that compresses certain frequencies into the lower frequency bands of regular audio files. The decoder upsamples the audio into 24 bits using the “meta” data from the original file. No magic here. The only thing “proprietary” about that is the method of dithering. But they are making a big fuss out of it. There are no open source codecs and decoded audio streams can’t be taken from any digital output (no optical or usb).
Thankfully – it didn’t take very long for a fellow audio engineer to figure out how to enjoy “MQA” legally but without limiting proprietary voodoo. And it’s actually very simple. It’s called “minimum phase resampling” and there’s a little open source tool out there that does it very quickly. It’s the “Swiss Army Knife” of sound conversion and it’s called sox. If you want into the details .. click here.
If you just want to try it out, no problem. Grab an MQA encoded file from www.2l.no/hires and apply “sox” magic.
sox -S filein.flac fileout.flac rate -v -s -M 352800
Now – that wasn’t too hard now, was it?
Is that an exact reproduction of the MQA audio? No. It is not. Some ultrasonic-information is being squelched. However, a lot of studio engineers on Gearslutz, including grammy award winning Brian Lucey, have stated that MQA is not the master. It changes the depth and width. It also adds distortion. It’s also destructive. So we’re not losing too much valuable information.
However – the “sox” solution is so close to the “real thing”, that the open source community is integrating it into most players – from mpd to ffmpeg. That’s a real good development.
The sum it all up : MQA doesn’t solve any problem for us – the consumers. Engineers say it’s lossy, it’s destructive, it is proprietary and puts severe limitation on its users. The SOX minimum phase re-sampling gives us an alternative should we stumble upon MQA encoded files.
Though – I doubt it will seriously catch on. We here at Rollofone are most certainly not going to use it.