"Martin Brown" <|||email@example.com> wrote in message news:I9Psq.13644$Mg.firstname.lastname@example.org... > On 04/11/2011 09:33, Peter Webb wrote: >> >> >> >> He estimated music contains 40 bits/second entropy. >> How close is MP3 to that? >> >> ___________________________________ >> I doubt surprised Shannon said that, and if he did its somewhere between >> meaningless and wrong. >> > > If Shannon did make the statement attributed to him above (and I seriously > doubt it) - I would like to see references. > >> CD quality mp3s are roughly equivalent to 178 kbps, over 4,000 times his >> estimate. But then you can encode a lot of sounds that most people would >> not consider music. And it stereo, so you can halve it if Shannon was >> talking about mono. >> >> And how do you define music, except as sound? And random sound waveforms > > > Have you never seen sheet music? That is what Shannon was estimating - the > bitrate for describing music in the abstract. There are a finite number of > notes, durations and amplitudes in a classical composition. >
Far more plausible.
If you don't consider singing to be music.
> I suspect 40 bits/sec is still far too tight, but a midi stream using a > high end reconstruction codec represents a pretty good example of what is > possible by way of compression for *music* as opposed to voice or a random > noise stream. >
I wonder what Jimi Hendrix playing Star Spangled Banner would sound like as a midi stream?
>> cannot be compressed on average at all. To get a smaller figure for >> music, you have to define what subsets of sounds are music. Lots of luck. > > I think that may have been his intention although I don't actually recall > seeing the 40 bit/s number originally attributed to him above. > > As I said if he did anything I think he was estimating the information > content of music in the already concise form of an orchestral score.
= midi. A very plausible explanation, but one which requires a very limitted definition of music.
>> >> The real number probably lies somewhere between 178 kbps and 40 bps. The >> actual number is the base 2 logarithm of the number of different 1 >> second sound bites that the ear can distuingish and would consider as >> music. I doubt even Shannon would have known the answer to that equation. > > Maybe he didn't consider all the alternative atonal and continuous > frequency synthesisers of arbitrary waveforms that are possible now - or > perhaps it was a subtle dig at Stockhausen and Schoenberg as not music. >
Yeah, I was going to use a synthesiser as an example of an instrument that couldn't be compressed, but then I realised that Shannon didn't have to worry about digital synthesisers in his day.
> Be interesting if the reference to this paper can be found to see how he > allocated those 40 bits/s.... > > I reckon at a bare minimum about 7 to the note, 8 to amplitude, 6 > duration, 5 to the instrument - and it is already obvious that you cannot > encode more than a single note per second at this bitrate. > > Can anyone provide a citation to this alleged paper on music bitrate? > > -- > Regards, > Martin Brown