WildMidi_InitVIO

Section: WildMidi Programmer's Manual (3)
Updated: 18 May 2018
Page Index
 

NAME

WildMidi_InitVIO - Initialize the library with file I/O callbacks

 

LIBRARY

libWildMidi

 

SYNOPSIS

#include <wildmidi_lib.h>

WildMidi_InitVIO (struct _WM_VIO *callbacks, const char *config_file, uint16_t rate, uint16_t options)

 

DESCRIPTION

Initializes libWildMidi in preparation for playback, and sets the function pointers for file I/O as provided by the caller. This function only needs to be called once by the program using libWildMidi.

callbacks
Pointer to a file IO callbacks structure. The _WM_VIO structure is like the following:
struct _WM_VIO {
 /* This function should allocate a buffer which has the size
  * of the requested file plus one (size+1), fill the buffer
  * with the file content, and the second parameter with the
  * size of the file. */
    void * (* allocate_file)(const char *, uint32_t *);

 /* This function should free the memory of the given buffer */
    void   (* free_file)    (void *);
};

config-file
The file that contains the instrument configuration for the library.

rate
The sound rate you want the the audio data output at. Rates accepted by libWildMidi are 11025 - 65000.

options
The initial options to set for the library. see below.

WM_MO_LOG_VOLUME
By default the library uses linear volume levels typically used in computer MIDI players. These can differ somewhat to volume levels found on some midi hardware which may use a volume curve based on decibels. This option sets the volume levels to what you'd expect on such devices.

WM_MO_ENHANCED_RESAMPLING
By default libWildMidi uses linear interpolation for the resampling of the sound samples. Setting this option enables the library to use a resampling method that attempts to fill in the gaps giving richer sound.

WM_MO_REVERB
libWildMidi has an 8 reflection reverb engine. Use this option to give more depth to the output.

WM_MO_WHOLETEMPO
Ignores the fractional or decimal part of a tempo setting. If you are having timing issues try WM_MO_ROUNDTEMPO before trying this option. This option added due to some software not supporting fractional tempos allowable in the MIDI specification.

WM_MO_ROUNDTEMPO
Rounds the fractional or decimal part of a tempo setting. Try this option is you are having timing issues, if this fails then try WM_MO_WHOLETEMPO. This option added due to some software not supporting fractional tempos allowable in the MIDI specification.

 

SEE ALSO

WildMidi_GetVersion(3), WildMidi_MasterVolume(3), WildMidi_Open(3), WildMidi_OpenBuffer(3), WildMidi_SetOption(3), WildMidi_GetOutput(3), WildMidi_GetMidiOutput(3), WildMidi_GetInfo(3), WildMidi_FastSeek(3), WildMidi_Close(3), WildMidi_Shutdown(3), wildmidi.cfg(5)

 

AUTHOR

Chris Ison <chrisisonwildcode@gmail.com> Bret Curtis <psi29a@gmail.com>

 

COPYRIGHT

Copyright (C) WildMidi Developers 2001-2016

This file is part of WildMIDI.

WildMIDI is free software: you can redistribute and/or modify the player under the terms of the GNU General Public License and you can redistribute and/or modify the library under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the licenses, or(at your option) any later version.

WildMIDI is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License and the GNU Lesser General Public License for more details.

You should have received a copy of the GNU General Public License and the GNU Lesser General Public License along with WildMIDI. If not, see <http://www.gnu.org/licenses/>.

This manpage is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.


 

Index

NAME
LIBRARY
SYNOPSIS
DESCRIPTION
SEE ALSO
AUTHOR
COPYRIGHT