BASS_MIDI_StreamCreateEvents

Creates a sample stream from a sequence of MIDI events.

HSTREAM BASS_MIDI_StreamCreateEvents(
    BASS_MIDI_EVENT *events,
    DWORD ppqn,
    DWORD flags,
    DWORD freq
);

Parameters

events

Pointer to an array containing the event sequence to play.

ppqn

The Pulses Per Quarter Note, or ticks per beat.

flags

Any combination of these flags.

BASS_SAMPLE_8BITS	Use 8-bit resolution. If neither this or the BASS_SAMPLE_FLOAT flags are specified, then the sample data will be 16-bit.
BASS_SAMPLE_FLOAT	Use 32-bit floating-point sample data. See Floating-point channels for more info.
BASS_SAMPLE_MONO	Decode/play the MIDI in mono (uses less CPU than stereo). This flag is automatically applied if BASS_DEVICE_MONO was specified when calling BASS_Init.
BASS_SAMPLE_SOFTWARE	Force the stream to not use hardware mixing.
BASS_SAMPLE_3D	Enable 3D functionality. This requires that the BASS_DEVICE_3D flag was specified when calling BASS_Init. 3D channels must also be mono, so BASS_SAMPLE_MONO is automatically applied. The SPEAKER flags cannot be used together with this flag.
BASS_SAMPLE_FX	Enable the old implementation of DirectX 8 effects. See the DX8 effect implementations section for details. Use BASS_ChannelSetFX to add effects to the stream.
BASS_STREAM_AUTOFREE	Automatically free the stream when playback ends.
BASS_STREAM_DECODE	Decode/render the sample data, without playing it. Use BASS_ChannelGetData to retrieve decoded sample data. The BASS_SAMPLE_3D, BASS_STREAM_AUTOFREE and SPEAKER flags cannot be used together with this flag. The BASS_SAMPLE_SOFTWARE and BASS_SAMPLE_FX flags are also ignored.
BASS_SPEAKER_xxx	Speaker assignment flags. The BASS_SAMPLE_MONO flag is automatically applied when using a mono speaker assignment flag.
BASS_MIDI_NOFX	Disable reverb and chorus processing, saving some CPU time. This flag can be toggled at any time using BASS_ChannelFlags
BASS_MIDI_SINCINTER	Use sinc interpolated sample mixing. This increases the sound quality, but also requires more CPU. Otherwise linear interpolation is used. .

freq

Sample rate to render/play the MIDI at... 0 = the rate specified in the BASS_Init call, 1 = the device's current output rate (or the BASS_Init rate if that is not available).

Return value

If successful, the new stream's handle is returned, else 0 is returned. Use BASS_ErrorGetCode to get the error code.

Error codes

BASS_ERROR_INIT	BASS_Init has not been successfully called.
BASS_ERROR_NOTAVAIL	Only decoding channels (BASS_STREAM_DECODE) are allowed when using the "no sound" device. The BASS_STREAM_AUTOFREE flag is also unavailable to decoding channels.
BASS_ERROR_ILLPARAM	ppqn cannot be 0.
BASS_ERROR_POSITION	The events must be in chronological order (within each track).
BASS_ERROR_FORMAT	The sample format is not supported by the device/drivers. If the stream is more than stereo or the BASS_SAMPLE_FLOAT flag is used, it could be that they are not supported.
BASS_ERROR_SPEAKER	The specified SPEAKER flags are invalid. The device/drivers do not support them or 3D functionality is enabled.
BASS_ERROR_MEM	There is insufficient memory.
BASS_ERROR_NO3D	Could not initialize 3D support.
BASS_ERROR_UNKNOWN	Some other mystery problem!

Remarks

This function creates a 16 channel MIDI stream to play a predefined sequence of MIDI events. Any of the standard MIDI events listed in the BASS_MIDI_StreamEvent section can be used, but the MIDI_EVENT_MIXLEVEL, MIDI_EVENT_TRANSPOSE, and MIDI_EVENT_SYSTEMEX events are not available and will be ignored. The sequence should end with a MIDI_EVENT_END event. Multiple tracks are possible via the MIDI_EVENT_END_TRACK event, which signals the end of a track; the next event will be in a new track.

The event sequence is copied, so the events array does not need to persist beyond the function call.

Soundfonts provide the sounds that are used to render a MIDI stream. A default soundfont configuration is applied initially to the new MIDI stream, which can subsequently be overridden using BASS_MIDI_StreamSetFonts.

Platform-specific

Away from Windows, all mixing is done in software (by BASS), so the BASS_SAMPLE_SOFTWARE flag is unnecessary. The BASS_SAMPLE_FX flag is also ignored. On Android and iOS, sinc interpolation requires a NEON-supporting CPU; the BASS_MIDI_SINCINTER flag will otherwise be ignored.

Example

Play a middle C note (key 60) on a violin every 2 seconds.

BASS_MIDI_EVENT events[]={
    {MIDI_EVENT_TEMPO, 500000, 0, 0}, // set the tempo to 0.5 seconds per quarter note
    {MIDI_EVENT_PROGRAM, 40, 0, 0}, // select the violin preset
    {MIDI_EVENT_NOTE, MAKEWORD(60, 100), 0, 0}, // press the key
    {MIDI_EVENT_NOTE, 60, 0, 200}, // release the key after 200 ticks
    {MIDI_EVENT_END, 0, 0, 400} // end after 400 ticks
};
HSTREAM stream=BASS_MIDI_StreamCreateEvents(events, 100, BASS_SAMPLE_LOOP, 0); // create a looping stream from the events
BASS_ChannelPlay(stream, 0); // start playing it