Creates a sample stream to render real-time MIDI events.

    DWORD channels,
    DWORD flags,
    DWORD freq


channelsThe number of MIDI channels... 1 (min) - 128 (max). The number of channels can subsequently be changed via the BASS_ATTRIB_MIDI_CHANS attribute.
flagsA combination of these flags.
BASS_SAMPLE_8BITSUse 8-bit resolution. If neither this or the BASS_SAMPLE_FLOAT flags are specified, then the stream is 16-bit.
BASS_SAMPLE_FLOATUse 32-bit floating-point sample data. See Floating-point channels for info.
BASS_SAMPLE_MONODecode/play the MIDI in mono. This flag is automatically applied if BASS_DEVICE_MONO was specified when calling BASS_Init.
BASS_SAMPLE_3DEnable 3D functionality. The stream must be mono, so BASS_SAMPLE_MONO is automatically applied. The SPEAKER flags cannot be used together with this flag.
BASS_STREAM_AUTOFREEAutomatically free the stream when playback ends.
BASS_STREAM_DECODEDecode/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.
BASS_SPEAKER_xxxSpeaker assignment flags. The BASS_SAMPLE_MONO flag is automatically applied when using a mono speaker assignment flag.
BASS_MIDI_ASYNCProcess events asynchronously in BASS_MIDI_StreamEvent and BASS_MIDI_StreamEvents calls. This flag can be toggled at any time using BASS_ChannelFlags.
BASS_MIDI_NODRUMPARAMDo not apply default per-drum reverb and chorus levels and instead set them all to full. The default is to set different levels for different types of drum, eg. lower levels on kick drums. The levels can subsequently be changed via the MIDI_EVENT_DRUM_REVERB and MIDI_EVENT_DRUM_CHORUS events. This flag can be toggled at any time using BASS_ChannelFlags, but will only take effect upon a program change or system reset.
BASS_MIDI_NOFXDisable reverb and chorus processing, saving some CPU time. This flag can be toggled at any time using BASS_ChannelFlags.
BASS_MIDI_NOSYSRESETIgnore system reset events (MIDI_EVENT_SYSTEM) when the system mode is unchanged. This flag can be toggled at any time using BASS_ChannelFlags.
BASS_MIDI_NOTEOFF1Only release the oldest instance upon a note off event (MIDI_EVENT_NOTE with velocity=0) when there are overlapping instances of the note. Otherwise all instances are released. This flag can be toggled at any time using BASS_ChannelFlags.
freqSample rate to render/play the MIDI stream 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_INITBASS_Init has not been successfully called.
BASS_ERROR_ILLPARAMchannels is not valid.
BASS_ERROR_FORMATThe sample format is not supported.
BASS_ERROR_SPEAKERThe specified SPEAKER flags are invalid.
BASS_ERROR_MEMThere is insufficient memory.
BASS_ERROR_NO3DCould not initialize 3D support.
BASS_ERROR_UNKNOWNSome other mystery problem!


This function creates a stream solely for real-time MIDI events. As it is not based on any file, the stream has no predetermined length and is never-ending. Seeking is not possible, but it is possible to reset everything, including playback buffer, by calling BASS_ChannelPlay (restart = TRUE) or BASS_ChannelSetPosition (pos = 0).

MIDI events are applied using the BASS_MIDI_StreamEvent and BASS_MIDI_StreamEvents functions. Byte and/or tick-based timing may be used. The stream will default to 120 ticks per beat, but that can be changed via the BASS_ATTRIB_MIDI_PPQN attribute. There may be some delay in the effect of the events being heard, due to buffering. This latency can be reduced via the BASS_ATTRIB_BUFFER attribute.

Channel 10 (if it exists) defaults to percussion/drums and the rest melodic. That can be changed using BASS_MIDI_StreamEvent and the MIDI_EVENT_DRUMS event. The number of channels can be changed via the BASS_ATTRIB_MIDI_CHANS attribute.

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. By default, linear interpolation will be used in playing the samples from the soundfonts. Sinc interpolation is also available via the BASS_ATTRIB_MIDI_SRC attribute, which increases the sound quality but also uses more CPU.

To play a predefined event sequence, BASS_MIDI_StreamCreateEvents can be used instead. To play a MIDI file, use BASS_MIDI_StreamCreateFile.

See also


BASS_ChannelGetInfo, BASS_ChannelPlay, BASS_ChannelSetAttribute, BASS_ChannelSetDSP, BASS_ChannelSetFX, BASS_ChannelSetLink, BASS_StreamFree