[uzziah]

just got to thinking about lossless compression and this question popped up. i don't honestly know how you could losslessly compress any music, and in my mind i see a stream of 0's and 1's squished together

how exactly can you compress a data stream without lossing data or spacing between data? how does flac or whatever actually make less space but with all the data? are we loosing the spacing between the numbers? i assume it's something completely different that i don't understand, but perhaps someone can help me out

 

[BradH]

http://en.wikipedia.org/wiki/Audio_data_compression

 

[Grahame]

Lossless compression is representing the same information, just using fewer bits.

To give you an idea, there is simple form of called Run Length encoding.

At its simplest form, rather than say

000000001111100011111111

RLE might say

0:8,1:5,0:3,1:8

Same info, less space.

Flac is just data compression for audio data. (it doesnt use RLE by the way)

More on data compression here

http://www.data-compression.com

So lossless compression just stores the original data in less space than the original raw data, and can uncompress to produce the same raw data.

This is orthogonal to jitter.

Can the same bits, clocked out of a memory buffer, into a DAC, produce jitter.

Possibly.

The buffer doesnt care where the bits came from, or what form they were stored in prior to arrivael in the buffer.

Its down to the accuracy of the clock out, not the bits. (Assumining the case the buffer never empties).

To recap - in short no.

 

[uzziah]

ah, i understand. thanks for the excellent response; appreciate it

 

[wakked1]

Simpler version would be: same reason you can compress a file into a zip archive.

 

[Svperstar]

It can be confusing reading about audio related math. There are people that have everything ripped in .wav and refuse to use FLAC/APE because they don't understand how it could "really" be lossless.

Go read a nice article on how a DAC works................thats fun