mirror of
https://github.com/vgmstream/vgmstream.git
synced 2024-11-13 18:20:50 +01:00
remove unused quanize() left over from the G.721 encoder
git-svn-id: https://vgmstream.svn.sourceforge.net/svnroot/vgmstream@33 51a99a44-fe44-0410-b1ba-c3e57ba2b86b
This commit is contained in:
parent
6fabc99db8
commit
fc231c7a35
@ -174,59 +174,6 @@ step_size(
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
|
||||||
* quantize()
|
|
||||||
*
|
|
||||||
* Given a raw sample, 'd', of the difference signal and a
|
|
||||||
* quantization step size scale factor, 'y', this routine returns the
|
|
||||||
* ADPCM codeword to which that sample gets quantized. The step
|
|
||||||
* size scale factor division operation is done in the log base 2 domain
|
|
||||||
* as a subtraction.
|
|
||||||
*/
|
|
||||||
int
|
|
||||||
quantize(
|
|
||||||
int d, /* Raw difference signal sample */
|
|
||||||
int y, /* Step size multiplier */
|
|
||||||
short *table, /* quantization table */
|
|
||||||
int size) /* table size of short integers */
|
|
||||||
{
|
|
||||||
short dqm; /* Magnitude of 'd' */
|
|
||||||
short exp; /* Integer part of base 2 log of 'd' */
|
|
||||||
short mant; /* Fractional part of base 2 log */
|
|
||||||
short dl; /* Log of magnitude of 'd' */
|
|
||||||
short dln; /* Step size scale factor normalized log */
|
|
||||||
int i;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* LOG
|
|
||||||
*
|
|
||||||
* Compute base 2 log of 'd', and store in 'dl'.
|
|
||||||
*/
|
|
||||||
dqm = abs(d);
|
|
||||||
exp = quan(dqm >> 1, power2, 15);
|
|
||||||
mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */
|
|
||||||
dl = (exp << 7) + mant;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* SUBTB
|
|
||||||
*
|
|
||||||
* "Divide" by step size multiplier.
|
|
||||||
*/
|
|
||||||
dln = dl - (y >> 2);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* QUAN
|
|
||||||
*
|
|
||||||
* Obtain codword i for 'd'.
|
|
||||||
*/
|
|
||||||
i = quan(dln, table, size);
|
|
||||||
if (d < 0) /* take 1's complement of i */
|
|
||||||
return ((size << 1) + 1 - i);
|
|
||||||
else if (i == 0) /* take 1's complement of 0 */
|
|
||||||
return ((size << 1) + 1); /* new in 1988 */
|
|
||||||
else
|
|
||||||
return (i);
|
|
||||||
}
|
|
||||||
/*
|
/*
|
||||||
* reconstruct()
|
* reconstruct()
|
||||||
*
|
*
|
||||||
|
Loading…
Reference in New Issue
Block a user