m1abrams;279132 Wrote: > Yes but if you read it that passage he is talking about data sizes and > not the output analog audio. So I see nothing wrong with his > statement. He does not draw any direct conclusions based on data rate, > other than one is smaller.
Let's see: John Atkinson Wrote: > As a CD plays, the two channels of audio data (not including overhead) > are pulled off the disc at a rate of just over 1400 kilobits per > second. A typical MP3 plays at less than a tenth that rate, at 128kbps. > To achieve that massive reduction in data, the MP3 coder splits the > continuous musical waveform into discrete time chunks and, using > Transform analysis, examines the spectral content of each chunk. > Assumptions are made by the codec's designers, on the basis of > psychoacoustic theory, about what information can be safely discarded. > Quiet sounds with a similar spectrum to loud sounds in the same time > window are discarded, as are quiet sounds that are immediately followed > or preceded by loud sounds. And, as I wrote in the February 2008 "As We > See It," because the music must be broken into chunks for the codec to > do its work, transient information can get smeared across chunk > boundaries. He is arguing that MP3 is distorted and inferior, and part of his evidence is that the files are smaller. As I have demonstrated (and you agree), that is an invalid argument since two files of different size may have precisely the same audio quality, and two files of the same size may have different quality. Now, it's true that there is a connection between the smallest file size a given amount of information can ever be compressed into and the information content. But a better way to address that would be something like this: take a WAV file ripped from a CD and zip it, then compare that to a zipped 128 MP3 of the same track. -That- would give you a valid comparison, up to the limitations of the zip algorithm, and it will not give you the factor of 10 he mentions (it will give a factor that depends on the WAV file, for one thing). -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=44532 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
