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Use milliseconds rather than microseconds, to avoid integer overflow.

Subversion-branch: /branches/opl-branch
Subversion-revision: 1648

--- a/src/i_oplmusic.c

+++ b/src/i_oplmusic.c

@@ -108,7 +108,7 @@

     // Tempo control variables

     unsigned int ticks_per_beat;

-    unsigned int us_per_beat;

+    unsigned int ms_per_beat;

 } opl_track_data_t;

 typedef struct opl_voice_s opl_voice_t;

@@ -823,19 +823,19 @@

 static void ScheduleTrack(opl_track_data_t *track)

 {

     unsigned int nticks;

-    unsigned int us;

+    unsigned int ms;

     static int total = 0;

-    // Get the number of microseconds until the next event.

+    // Get the number of milliseconds until the next event.

     nticks = MIDI_GetDeltaTime(track->iter);

-    us = (nticks * track->us_per_beat) / track->ticks_per_beat;

-    total += us;

+    ms = (nticks * track->ms_per_beat) / track->ticks_per_beat;

+    total += ms;

     // Set a timer to be invoked when the next event is

     // ready to play.

-    OPL_SetCallback(us / 1000, TrackTimerCallback, track);

+    OPL_SetCallback(ms, TrackTimerCallback, track);

 }

 // Initialise a channel.

@@ -862,7 +862,7 @@

     // Default is 120 bpm.

     // TODO: this is wrong

-    track->us_per_beat = 500 * 1000 * 260;

+    track->ms_per_beat = 500 * 260;

     for (i=0; i<MIDI_CHANNELS_PER_TRACK; ++i)

     {