View Single Post
Old 06-26-2014, 07:14 AM   #18
AmmoniumNitrate
Banned
 
Join Date: Jul 2013
Posts: 493
Default

Quote:
Originally Posted by alanofoz View Post
... 24 bit data will contain any of 8388608 positive integer values and the same number of negative values.
You're saying that in 24-bit PCM, half the possible values represent positive amplitudes, and the other half represent negative amplitudes; and that would leave you no value for representing 0. That's not the way PCM really works, as real PCM allows you to represent 0.

Quote:
Originally Posted by alanofoz View Post
The file... started with some low values, the first being 0.0051855091 (rounded) as indicated by Adobe Audition, and confirmed by my own calculations from the data shown in my hex editor.
i.e. 3BA9EB34 = 00111011 10101001 11101011 00110100 which converted to decimal is 0.00518550910055637359619140625.

Problem is, a 24 bit interface cannot possibly supply this value - it's not one of the integer values available. In the 24 bit range of 8388608 positive integer values, this is between the two possible values of 43499 and 43500, and closest to 43499.
How exactly are you translating between 24 bit PCM "integers" and 32 bit FP? What formula are you using for this translation?

Quote:
Originally Posted by alanofoz View Post
Boring mathematical background: ... (But you know all this of course).
No, I don't know all that, and I'm wondering where you got that idea.

Last edited by AmmoniumNitrate; 06-26-2014 at 01:11 PM.
AmmoniumNitrate is offline