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