Using lossless data compression for audio?

Posted: Wed Apr 02, 2008 7:56 am

Codemonkey wrote:

Audible silence (as in you hear nothing) or actual zero samples?

That is one of the problems with nulling tests. You will not get a total null even with the same file. What you will get is audible silence at a reasonable spl level.

Posted: Wed Apr 02, 2008 7:57 am

Well...you should if it's the same exact file.

However, I've not seen this be the case with lossless compression versus uncompressed.

Posted: Wed Apr 02, 2008 8:10 am

Codemonkey wrote:

Audible silence (as in you hear nothing) or actual zero samples?

That is one of the problems with nulling tests. You will not get a total null even with the same file. What you will get is audible silence at a reasonable spl level.

Posted: Wed Apr 02, 2008 8:17 am

Codemonkey wrote:

Didn't know Traction was free (even to try). Might do it later, once I escape some lectures.

I was talking about winRAR, sorry. Tracktion has a demo version of course.

Posted: Wed Apr 02, 2008 8:21 am

J_Carlo wrote:

Codemonkey wrote:

Audible silence (as in you hear nothing) or actual zero samples?

That is one of the problems with nulling tests. You will not get a total null even with the same file. What you will get is audible silence at a reasonable spl level.

I get a total null when subtracting a wav file from a flac'ed version of the same. (According to Tracktion's own meters, Inspector XL and the SSL X-ISM bit meter.)

Any other result is a bug.

Posted: Wed Apr 02, 2008 8:24 am

Cucco wrote:

Well...you should if it's the same exact file.

However, I've not seen this be the case with lossless compression versus uncompressed.

Then there was something wrong, either with the test or with the compression. Lossless means you get back exactly the same numbers you put in, just like ZIP or RAR compression.

Posted: Fri Apr 11, 2008 11:47 am

I work this way with my guitarist who lives a bit out of my way.

First, I'll lay down comps of a song I'm working on then bounce the tracks to AAC 256 Kbps files and post them up via FTP for HTTP download. He downloads the files and imports them into his DAW and writes his parts. Then he bounces the pure guitar tracks back to AAC and I download them. When every thing begins to solidify I swap out the butter for cream and download Apple Lossless versions of the files. A quick swap in the DAW and the hi-res files have replaced the AACs. It's a lot like working with video and offline editing.

Very quick and a great way to work with remote musicians. Also saves hard drive space until you really need it.

Posted: Fri Apr 11, 2008 3:10 pm

I archive with Monkey.
There's a free filter available for Adobe Audition that lets me batch-compresses 32-bit float files.

Posted: Sat Apr 12, 2008 7:47 am

zemlin wrote:

I archive with Monkey.
There's a free filter available for Adobe Audition that lets me batch-compresses 32-bit float files.

Archiving is another great use of lossless compression. The format I use is a 2:1 compression which helps the files fit on archive grade dual layer DVDs. They're not cheap and using half as many is a nice bonus.

Of course, when archiving make sure your files are in a format you'll be able to read in 10+ years. Open source formats are the best bet.

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