winamp/Src/Plugins/Input/in_mp3/DXHEAD.C

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2024-09-24 08:54:57 -04:00
/*---- DXhead.c --------------------------------------------
decoder MPEG Layer III
handle Xing header
mod 12/7/98 add vbr scale
Copyright 1998 Xing Technology Corp.
-----------------------------------------------------------*/
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <float.h>
#include <math.h>
#include "dxhead.h"
/*-------------------------------------------------------------*/
int SeekPoint(unsigned char TOC[100], int file_bytes, float percent)
{
// interpolate in TOC to get file seek point in bytes
int a, seekpoint;
float fa, fb, fx;
if (percent < 0.0f)
percent = 0.0f;
if (percent > 100.0f)
percent = 100.0f;
a = (int)percent;
if (a > 99) a = 99;
fa = TOC[a];
if (a < 99)
{
fb = TOC[a + 1];
}
else
{
fb = 256.0f;
}
fx = fa + (fb - fa) * (percent - a);
seekpoint = (int) ((1.0f / 256.0f) * fx * file_bytes);
return seekpoint;
}
/*-------------------------------------------------------------*/