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Re: MusicPlayer questions
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Re: MusicPlayer questions


  • Subject: Re: MusicPlayer questions
  • From: Lars Peters <email@hidden>
  • Date: Tue, 10 Dec 2002 22:21:13 +0100

I not sure I remember correctly, but I think after my mail took quite a while to reach the list (don't know why), I simply went for what I saw. I didn't need to actually change the tempo but didn't feel very good about assuming undocumented things (I never do).

Yes, you're right though, your answer is what I was looking for. Thanks!

Lars


Am Dienstag, 10.12.02 um 15:12 Uhr schrieb Patrick Beard:

On Thursday, November 7, 2002, at 07:10 PM, Bill Stewart wrote:

On Wednesday, November 6, 2002, at 11:54 AM, Lars Peters wrote:

Hello,

MusicPlayer.h states that MusicTimeStamp depends on the unit the track has. If so, how can I set the unit?

The unit currently is beats per minute

In case this didn't completely answer your question (it didn't for me), I'll add here that to set what the current BPM value should be during playback, you use MusicSequenceGetTempoTrack(), and then call MusicTrackNewExtendedTempoEvent() to specify at what beat the tempo should change to. In code:

OSStatus ChangeSequenceTempo(MusicSequence sequence, MusicTimeStamp when, Float64 beatsPerMinute)
{
OSStatus status;
MusicTrack tempoTrack;
status = MusicSequenceGetTempoTrack(sequence, &tempoTrack);
if (status == noErr)
status = MusicTrackNewExtendedTempoEvent(tempoTrack, when, beatsPerMinute);
return status;
}

Note that the time this will happen is a function of what the tempo was at the time this beat occurs, so it's probably a good idea to call this at time stamp 0 to establish an initial tempo. If this was already painfully clear to everybody, forgive me for being redundant.

- Patrick
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 >Re: MusicPlayer questions (From: email@hidden (Patrick Beard))

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