I'm not trying to start a flame war but it's simple to test if a compression algorithm is lossless or lossy. This has been done for lossless compression algorithms and the data is always intact and without any loss. Use the codec to compress and decompress a file a few thousand or hundred thousand times then do a bit compare.
Audio isn't the only file types that must be compressed without any loss in data. Text, graphics, and even video have to be compressed from time to time for storage and they have to be decompressed. Now, if you use a lossy compression algorithm like MP3, you will probably hear a difference. However, MP4 is lossless, and the only difference is perception. Think about it. If the compression formats of ZIP or GZIP or RAR were lossy, they would never be used because you would destroy the data. Lossy compression formats are used because the compression is only expected to be used once, or the compression has to be higher than what is available in a lossy codec, or it has to be done for legacy support on an older device that does not support a lossless codec. You may be willing to accept some loss in video or audio, but a text document will have inaccuracies, or an executable file usually will not work if some data is lost. If you want a very good read on lossy/lossless audio compression and possible reasons why there is a perceived difference between live recordings, vinyl, cds, and 'mp3s', then go on over to: http://www.firstpr.com.au/audiocomp/lossless/ Something to always consider with anything that is not an analog recording (not vinyl or a wax cylinder) is that you've already digitized and in a way compressed the audio once you've recorded it. Of course, if a recording is done properly then that loss will be only once and you will never be able to detect a difference. -William -----Original Message----- From: Bill Gross <[email protected]> To: 'The Horn List' <[email protected]> Sent: Tue, Aug 31, 2010 8:19 pm Subject: Re: [Hornlist] survey: digital download vs CD release Ain't gonna touch it, wouldn't be prudent. _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
