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Topic: information theory?
Replies: 83   Last Post: Dec 22, 2011 5:14 AM

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Peter Webb

Posts: 122
Registered: 11/21/11
Re: information theory?
Posted: Dec 22, 2011 5:14 AM
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"Martin Brown" <|||newspam|||@nezumi.demon.co.uk> wrote in message
news:jcupqt$l1m$3@speranza.aioe.org...
> On 22/12/2011 08:08, Richard Outerbridge wrote:
>> In article
>> <bd7a5bf2-f8be-4dde-82bd-0b8b7d14655c@v31g2000prg.googlegroups.com>,
>> RichD<r_delaney2001@yahoo.com> wrote:
>>

>>> On Nov 4, Martin Brown<|||newspam...@nezumi.demon.co.uk> 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.

>>>>
>>>>> 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.

>>>>
>>>> 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.

>>>
>>> I suspect that's the case.
>>>

>>>> 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.
>>>>

>>>>> To get a smaller figure for music, you have to
>>>>> define what subsets of sounds are music. Lots of luck.

>>>
>>> Not so hard, if you analyze samples of what we label 'music'.
>>>

>>>> I think that may have been his intention although
>>>> I don't recall seeing the 40 bit/s number
>>>> 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.

>>>
>>> That appears to be the case.
>>>

>>>> 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.

>>>
>>> You fail to account for the essential concept
>>> of correlation.
>>>

>>>> Can anyone provide a citation to this alleged paper
>>>> on music bitrate?

>>>
>>>
>>> I found the reference in John Pierce's book.
>>> It's not attributed to Shannon. My boner.
>>> He claims a humans can absorb information,
>>> e.g. reading or music, at 40 bits/second.

>
> That sounds way too low. I can flash read this entire page in about second
> and there are a lot more than 40 bits of data in it. And the processing to
> do that much text recognition in real time would tax a super computer -
> that is why Captcha is used to test for humans!
>

>>> He also cites a paper where it's claimed that
>>> sheet music contains 2.5 bits entropy per note.

>
> Again sounds far too low even when you only allow for pitch, duration and
> amplitude (plus any changes in amplitude, incidentals, time signature or
> syncopation). Please can you post the citation?
>
> I would only believe this claim iff they can demonstrate a real musical
> score compressed to the equivalent of 2.5bits/note. That is the acid test.
> Hand waving arguments and gut feel do not hack it.
>

>>> This supports the MIDI model, as opposed to
>>> digitization of a recording. In that case,
>>> what is the bit rate? Though the question of
>>> chords arises, with much redundancy there.
>>>
>>> It also raises the possibility that recorded
>>> music might be adequately represented by a
>>> MIDI stream.

>>
>> IIRC, it's interesting to note that most modern media
>> compression codecs rely not so much upon what the raw
>> data can absolutely do without as they do upon what the
>> human ear or eye can be fooled by: they leave out what
>> you "cannot" hear or "cannot" see. Really, this is
>> nothing new: all screens of any sort are really just
>> optical illusions of one sort or another. The codecs
>> are just leveraging the limitations of the wiring of
>> the human brain.

>
> Absolutely. There is no point in transmitting detail that the ear cannot
> hear or the eye cannot see. But you do have to be a little bit careful.
> The UK's new DAB audio bitrate is insufficient to support quality live
> broadcast of classical music and is distinctly inferior to either FM or
> off satellite SD or HD digital audio. The problems with DAB are
> sufficiently bad that it is hampering uptake of new DAB radios.
>
> Regards,
> Martin Brown


And here in Australia. The standard allows for 128 kbps or 2 x 64 kbps, in
practice most DAB broadcasts are stereo compressed into a single 64 kbps
channel. This gives a quality less than the FM radio it is replacing. When
everything else is moving to high definition, I have no idea why the new
standard for digital sound broadcasts is such low definition. Very
shortsighted.





Date Subject Author
10/31/11
Read information theory?
Rich Delaney
11/1/11
Read Re: information theory?
Eric Jacobsen
11/1/11
Read Re: information theory?
Chris
11/1/11
Read Re: information theory?
Rich Delaney
11/1/11
Read Re: information theory?
jim
11/1/11
Read Re: information theory?
jim
11/1/11
Read Re: information theory?
Cindy
11/1/11
Read Re: information theory?
BJACOBY@teranews.com
11/2/11
Read Re: information theory?
jim
11/2/11
Read Re: information theory?
BJACOBY@teranews.com
11/2/11
Read Re: information theory?
jim
11/2/11
Read Re: information theory?
Cindy
11/2/11
Read Re: information theory?
jim
11/3/11
Read Re: information theory?
Cindy
11/1/11
Read Re: information theory?
BJACOBY@teranews.com
11/2/11
Read Re: information theory?
Les Cargill
11/3/11
Read Re: information theory?
Andrew Haley
11/3/11
Read Re: information theory?
gdewilde@gmail.com
11/2/11
Read Re: information theory?
Martin Brown
11/2/11
Read Re: information theory? (copyright question followup)
JohnF
11/2/11
Read Re: information theory? (copyright question followup)
Martin Brown
11/2/11
Read Re: information theory? (copyright question followup)
Martin Brown
11/2/11
Read Re: information theory? (copyright question followup)
Bernd Jendrissek
11/2/11
Read Re: information theory? (copyright question followup)
David Eather
11/2/11
Read Re: information theory? (copyright question followup)
Bill Unruh
11/24/11
Read Re: information theory? (copyright question followup)
J. Clarke
11/24/11
Read Re: information theory? (copyright question followup)
Martin Brown
11/25/11
Read Re: information theory? (copyright question followup)
Richard Outerbridge
11/25/11
Read Re: information theory? (copyright question followup)
Les Cargill
11/2/11
Read Re: information theory?
Rich Delaney
11/3/11
Read Re: information theory?
Martin Brown
11/2/11
Read Re: information theory?
Chris
11/2/11
Read Re: information theory?
robert bristow-johnson
11/2/11
Read Re: information theory?
Rich Delaney
11/2/11
Read Re: information theory?
VWWall
11/2/11
Read Re: information theory?
Richard Outerbridge
11/4/11
Read Re: information theory?
Frederick Williams
11/4/11
Read Re: information theory?
krw@att.bizzzzzzzzzzzz
11/4/11
Read Re: information theory?
jim
11/4/11
Read Re: information theory?
Jerry Avins
11/4/11
Read Re: information theory?
Greg Rose
11/5/11
Read Re: information theory?
Frederick Williams
11/5/11
Read Re: information theory?
Mike Terry
11/5/11
Read Re: information theory?
MrTallyman
11/5/11
Read Re: information theory?
R Kym Horsell
11/5/11
Read Re: information theory?
MrTallyman
11/5/11
Read Re: information theory?
unruh
11/5/11
Read Re: information theory?
krw@att.bizzzzzzzzzzzz
11/7/11
Read Re: information theory?
JW
11/7/11
Read Re: information theory?
krw@att.bizzzzzzzzzzzz
11/7/11
Read Re: information theory?
MrTallyman
11/7/11
Read Re: information theory?
krw@att.bizzzzzzzzzzzz
11/4/11
Read Re: information theory?
FigureItOut
11/6/11
Read Re: information theory?
jim
11/4/11
Read Re: information theory?
Rich Delaney
11/4/11
Read Re: information theory?
BJACOBY@teranews.com
11/4/11
Read Re: information theory?
Peter Webb
11/4/11
Read Re: information theory?
robertwessel2@yahoo.com
11/4/11
Read Re: information theory?
R Kym Horsell
11/4/11
Read Re: information theory?
Peter Webb
11/4/11
Read Re: information theory?
VWWall
11/4/11
Read Re: information theory?
jim
11/4/11
Read Re: information theory?
jim
11/4/11
Read Re: information theory?
Androcles
11/4/11
Read Re: information theory?
Martin Brown
11/4/11
Read Re: information theory?
Peter Webb
11/4/11
Read Re: information theory?
BJACOBY@teranews.com
11/4/11
Read Re: information theory?
Jerry Avins
12/21/11
Read Re: information theory?
Rich Delaney
12/21/11
Read Re: information theory?
Les Cargill
12/22/11
Read Re: information theory?
Richard Outerbridge
12/22/11
Read Re: information theory?
Martin Brown
12/22/11
Read Re: information theory?
Peter Webb
11/4/11
Read Re: information theory?
Androcles
11/4/11
Read Re: information theory?
Casper H.S. Dik
11/4/11
Read Re: information theory?
Bill Unruh
11/6/11
Read Re: information theory?
jim
11/7/11
Read Re: information theory?
jim
11/7/11
Read Re: information theory?
jim
11/8/11
Read Re: information theory?
jim
11/8/11
Read Re: information theory?
Michael A. Terrell
11/3/11
Read Re: information theory?
BJACOBY@teranews.com
11/3/11
Read Re: information theory?
Chris
11/3/11
Read Re: information theory?
Chris

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