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/***********************************************************************
*
* Global Include Files
*
***********************************************************************/
#include <string.h> /* 1995-07-11 shn */
#include <ctype.h>
#include <stdlib.h>
#include "common.h"
/***********************************************************************
*
* Global Variable Definitions
*
***********************************************************************/
char *mode_names[4] = { "stereo", "j-stereo", "dual-ch", "single-ch" };
char *version_names[2] = { "MPEG-2 LSF", "MPEG-1" };
/* 1: MPEG-1, 0: MPEG-2 LSF, 1995-07-11 shn */
double s_freq[2][4] = { {22.05, 24, 16, 0}, {44.1, 48, 32, 0} };
/* 1: MPEG-1, 0: MPEG-2 LSF, 1995-07-11 shn */
int bitrate[2][15] = {
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160},
{0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384}
};
double FAR multiple[64] = {
2.00000000000000, 1.58740105196820, 1.25992104989487,
1.00000000000000, 0.79370052598410, 0.62996052494744, 0.50000000000000,
0.39685026299205, 0.31498026247372, 0.25000000000000, 0.19842513149602,
0.15749013123686, 0.12500000000000, 0.09921256574801, 0.07874506561843,
0.06250000000000, 0.04960628287401, 0.03937253280921, 0.03125000000000,
0.02480314143700, 0.01968626640461, 0.01562500000000, 0.01240157071850,
0.00984313320230, 0.00781250000000, 0.00620078535925, 0.00492156660115,
0.00390625000000, 0.00310039267963, 0.00246078330058, 0.00195312500000,
0.00155019633981, 0.00123039165029, 0.00097656250000, 0.00077509816991,
0.00061519582514, 0.00048828125000, 0.00038754908495, 0.00030759791257,
0.00024414062500, 0.00019377454248, 0.00015379895629, 0.00012207031250,
0.00009688727124, 0.00007689947814, 0.00006103515625, 0.00004844363562,
0.00003844973907, 0.00003051757813, 0.00002422181781, 0.00001922486954,
0.00001525878906, 0.00001211090890, 0.00000961243477, 0.00000762939453,
0.00000605545445, 0.00000480621738, 0.00000381469727, 0.00000302772723,
0.00000240310869, 0.00000190734863, 0.00000151386361, 0.00000120155435,
1E-20
};
enum byte_order NativeByteOrder = order_unknown;
/***********************************************************************
*
* Global Function Definitions
*
***********************************************************************/
int
js_bound (int m_ext)
{
/* layer 2 only */
static int jsb_table[4] = { 4, 8, 12, 16 };
if (m_ext < 0 || m_ext > 3)
{
fprintf (stderr, "js_bound bad modext (%d)\n", m_ext);
exit (1);
}
return (jsb_table[m_ext]);
}
void
hdr_to_frps (frame_params * fr_ps)
/* interpret data in hdr str to fields in fr_ps */
{
layer *hdr = fr_ps->header; /* (or pass in as arg?) */
fr_ps->actual_mode = hdr->mode;
fr_ps->stereo = (hdr->mode == MPG_MD_MONO) ? 1 : 2;
fr_ps->sblimit = pick_table (fr_ps);
if (hdr->mode == MPG_MD_JOINT_STEREO)
fr_ps->jsbound = js_bound (hdr->mode_ext);
else
fr_ps->jsbound = fr_ps->sblimit;
/* alloc, tab_num set in pick_table */
}
int
BitrateIndex (int bRate, /* legal rates from 32 to 448 */
int version /* MPEG-1 or MPEG-2 LSF */ )
/* convert bitrate in kbps to index */
{
int index = 0;
int found = 0;
while (!found && index < 15)
{
if (bitrate[version][index] == bRate)
found = 1;
else
++index;
}
if (found)
return (index);
else
{
fprintf (stderr, "BitrateIndex: %d is not a legal bitrate\n", bRate);
return (-1); /* Error! */
}
}
int
SmpFrqIndex (long sRate, int *version)
/* convert samp frq in Hz to index */
/* legal rates 16000, 22050, 24000, 32000, 44100, 48000 */
{
if (sRate == 44100L)
{
*version = MPEG_AUDIO_ID;
return (0);
}
else if (sRate == 48000L)
{
*version = MPEG_AUDIO_ID;
return (1);
}
else if (sRate == 32000L)
{
*version = MPEG_AUDIO_ID;
return (2);
}
else if (sRate == 24000L)
{
*version = MPEG_PHASE2_LSF;
return (1);
}
else if (sRate == 22050L)
{
*version = MPEG_PHASE2_LSF;
return (0);
}
else if (sRate == 16000L)
{
*version = MPEG_PHASE2_LSF;
return (2);
}
else
{
fprintf (stderr, "SmpFrqIndex: %ld is not a legal sample rate\n",
sRate);
return (-1); /* Error! */
}
}
/********************************************************************
new_ext()
Puts a new extension name on a file name <filename>.
Removes the last extension name, if any.
1992-08-19, 1995-06-12 shn
***********************************************************************/
void
new_ext (char *filename, char *extname, char *newname)
{
int found, dotpos;
/* First, strip the extension */
dotpos = strlen (filename);
found = 0;
do
{
switch (filename[dotpos])
{
case '.':
found = 1;
break;
case '\\':
case '/':
case ':':
found = -1;
break;
default:
dotpos--;
if (dotpos < 0)
found = -1;
break;
}
}
while (found == 0);
if (found == -1)
strcpy (newname, filename);
if (found == 1)
{
strncpy (newname, filename, dotpos);
newname[dotpos] = '\0';
}
strcat (newname, extname);
}
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