Reply by Richard Dobson March 26, 20072007-03-26
Jerry Avins wrote:

>> I want to know about the data compression of audio. >> >> i need some links regarding this. >> >> which algorithm is good example for audio compression? > > > MP3 is widely used for music and general sounds. Other methods are more > efficient for voice, especially voice telephony. See > http://www.howstuffworks.com/mp3.htm >
Not forgetting free/open-source alternatives: [Ogg]Vorbis for lossy compression and FLAC for lossless compression: http://www.xiph.org To discuss compression thoroughly, it is important to understand and document the difference between lossy and lossless forms (and between them and plain binary data compression a la gzip, etc). As usual, "Google is your friend". Richard Dobson
Reply by salaria March 26, 20072007-03-26
>Sir, > >I am udhay. I am a student and i am working on Audio compression for >my exam. > >I want to know how does the compression take place in audio??
I think you have already got the answer for this question
>I have doubt in human earing capacity.The maximun hearing capacity of >a human is 20-20khz.
Yes, a human can hear between 20 to 20K hertz. But the response is not the same for all frequencies. It follows some standard curves(i think it is an inverted U or a U, not sure.)
>if a take a sample wave file,its coming around 40khz.
The sample wave file you are taking might have a sampling frequency of 44.1 Khz(which is around 40Khz), which is a standard sampling rate. I dont know what you meant by 'its'.
>what it mean? can anyone help me to clear this doubt..
It means that the audio in the wav file has been sampled at 44.1 Khz..
>udhay
aps
>
Reply by Jerry Avins March 26, 20072007-03-26
Udhay wrote:

> Thanks for your reply. > > I want to know about the data compression of audio. > > i need some links regarding this. > > which algorithm is good example for audio compression?
MP3 is widely used for music and general sounds. Other methods are more efficient for voice, especially voice telephony. See http://www.howstuffworks.com/mp3.htm Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by Udhay March 26, 20072007-03-26
On Mar 25, 9:35 pm, "robert bristow-johnson"
<r...@audioimagination.com> wrote:
> On Mar 26, 12:25 am, "Udhay" <udhyakum...@gmail.com> wrote: > > > Sir, > > some of the ladies that follow this newsgroup might be offended by the > assumption. (but then again, i dunno specifically who they are.) > > > I am udhay. I am a student and i am working on Audio compression for > > my exam. > > > I want to know how does the compression take place in audio?? > > > I have doubt in human earing capacity.The maximun hearing capacity of > > a human is 20-20khz. > > > if a take a sample wave file,its coming around 40khz. > > > what it mean? can anyone help me to clear this doubt.. > > particular to the field of audio signal processing, there can be at > least two different meanings to the term "compression". usually it > means level compression and you could buy devices that do that for 5 > decades or more. the other meaning. more recent, is data > compression. it could also mean "time compression" a.k.a. "time > scaling" for when the scaling factor is less than one, but i doubt > that is what you're inquiring about. can you tell if it's about level > compression of audio signals or data compression of audio? > > r bpj
Sir Thanks for your reply. I want to know about the data compression of audio. i need some links regarding this. which algorithm is good example for audio compression? udhay
Reply by robert bristow-johnson March 26, 20072007-03-26
On Mar 26, 12:25 am, "Udhay" <udhyakum...@gmail.com> wrote:
> Sir,
some of the ladies that follow this newsgroup might be offended by the assumption. (but then again, i dunno specifically who they are.)
> I am udhay. I am a student and i am working on Audio compression for > my exam. > > I want to know how does the compression take place in audio?? > > I have doubt in human earing capacity.The maximun hearing capacity of > a human is 20-20khz. > > if a take a sample wave file,its coming around 40khz. > > what it mean? can anyone help me to clear this doubt..
particular to the field of audio signal processing, there can be at least two different meanings to the term "compression". usually it means level compression and you could buy devices that do that for 5 decades or more. the other meaning. more recent, is data compression. it could also mean "time compression" a.k.a. "time scaling" for when the scaling factor is less than one, but i doubt that is what you're inquiring about. can you tell if it's about level compression of audio signals or data compression of audio? r bpj
Reply by Udhay March 26, 20072007-03-26
Sir,

I am udhay. I am a student and i am working on Audio compression for
my exam.

I want to know how does the compression take place in audio??

I have doubt in human earing capacity.The maximun hearing capacity of
a human is 20-20khz.

if a take a sample wave file,its coming around 40khz.

what it mean? can anyone help me to clear this doubt..

udhay