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#include "main.h"
#include "cddb.h"
#include <strsafe.h>
/*
* cddb_sum
* Convert an integer to its text string representation, and
* compute its checksum. Used by cddb_discid to derive the
* disc ID.
*
* Args:
* n - The integer value.
*
* Return:
* The integer checksum.
*/
int cddb_sum(int n)
{
char buf[12],
*p;
int ret = 0;
/* For backward compatibility this algorithm must not change */
StringCchPrintfA(buf, 12, "%lu", n);
for (p = buf; *p != '\0'; p++)
ret += (*p - '0');
return (ret);
}
/*
* cddb_discid
* Compute a magic disc ID based on the number of tracks,
* the length of each track, and a checksum of the string
* that represents the offset of each track.
*
* Return:
* The integer disc ID.
*/
unsigned long cddb_discid(unsigned char nTracks, unsigned int* pnMin, unsigned int* pnSec)
{
int i,
t = 0,
n = 0;
/* For backward compatibility this algorithm must not change */
for (i = 0; i < (int) nTracks; i++)
{
n += cddb_sum((pnMin[i] * 60) + pnSec[i]);
t += ((pnMin[i + 1] * 60) + pnSec[i + 1]) - ((pnMin[i] * 60) + pnSec[i]);
}
return ((n % 0xff) << 24 | t << 8 | nTracks);
}
// Functions used to generate the CDDB id
void CDGetEndFrame(MCIDEVICEID wDeviceID,
DINFO* psDI,
unsigned int nOffset,
unsigned int* pnFrame,
unsigned int* pnMin,
unsigned int* pnSec)
{
MCI_STATUS_PARMS sMCIStatus;
sMCIStatus.dwItem = MCI_STATUS_LENGTH;
MCISendCommand(wDeviceID, MCI_STATUS, MCI_STATUS_ITEM | MCI_WAIT,
(DWORD_PTR)(LPVOID) &sMCIStatus);
#ifdef _WIN64
*pnFrame = (unsigned int)((double)sMCIStatus.dwReturn * (75.0 / 1000.0));
#else
{
int nFrame;
static double tmp = 75.0 / 1000.0;
unsigned long a = sMCIStatus.dwReturn;
__asm
{
fld qword ptr tmp
fild dword ptr a
fmul
fistp dword ptr nFrame
}
*pnFrame = nFrame;
}
#endif
pnFrame[0] += 1 + nOffset; // Due to bug in MCI according to CDDB docs!
psDI->nDiscLength = (pnFrame[0] / 75);
*pnMin = pnFrame[0] / 75 / 60;
*pnSec = (pnFrame[0] / 75) % 60;
}
void CDGetAbsoluteTrackPos(MCIDEVICEID wDeviceID,
unsigned int nTrack,
unsigned int* pnFrame,
unsigned int* pnMin,
unsigned int* pnSec)
{
MCI_STATUS_PARMS sMCIStatus;
sMCIStatus.dwItem = MCI_STATUS_POSITION;
sMCIStatus.dwTrack = nTrack;
MCISendCommand(wDeviceID, MCI_STATUS, MCI_STATUS_ITEM | MCI_TRACK | MCI_WAIT,
(DWORD_PTR)(LPVOID) &sMCIStatus);
#ifdef _WIN64
*pnFrame = (int)((double)sMCIStatus.dwReturn * (75.0 / 1000.0));
#else
{
static double tmp = 75.0 / 1000.0;
unsigned long a = sMCIStatus.dwReturn;
__asm
{
fld qword ptr tmp
fild dword ptr a
fmul
fistp dword ptr a
}
*pnFrame = a;
}
#endif
*pnMin = *pnFrame / 75 / 60;
*pnSec = (*pnFrame / 75) % 60;
}
int GetDiscID(MCIDEVICEID wDeviceID, DINFO* psDI)
{
MCI_SET_PARMS sMCISet;
unsigned int nLoop;
unsigned int nMCITracks = CDGetTracks(wDeviceID);
unsigned int* pnMin = NULL;
unsigned int* pnSec = NULL;
if (nMCITracks > 65535) return 1;
if (nMCITracks > 128) nMCITracks = 128;
psDI->ntracks = nMCITracks;
pnMin = (unsigned int*)GlobalAlloc(GPTR, (nMCITracks + 1) * 2 * sizeof(unsigned int));
if (!pnMin) return 1;
pnSec = pnMin + (nMCITracks + 1);
sMCISet.dwTimeFormat = MCI_FORMAT_MILLISECONDS;
MCISendCommand(wDeviceID, MCI_SET, MCI_SET_TIME_FORMAT, (DWORD_PTR)(LPVOID) &sMCISet);
for (nLoop = 0 ; nLoop < nMCITracks; nLoop ++)
CDGetAbsoluteTrackPos(wDeviceID, nLoop + 1, &psDI->pnFrames[nLoop], &pnMin[nLoop], &pnSec[nLoop]);
CDGetEndFrame(wDeviceID, psDI, psDI->pnFrames[0], &psDI->pnFrames[nLoop], &pnMin[nLoop], &pnSec[nLoop]);
psDI->CDDBID = cddb_discid((unsigned char)nMCITracks, pnMin, pnSec);
sMCISet.dwTimeFormat = MCI_FORMAT_TMSF;
MCISendCommand(wDeviceID, MCI_SET, MCI_SET_TIME_FORMAT, (DWORD_PTR)(LPVOID) &sMCISet);
if (pnMin)
{
GlobalFree(pnMin);
}
return 0;
}
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