common/JackMidiUtil.h

   1 /*
   2 Copyright (C) 2010 Devin Anderson
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU Lesser General Public License as published by
   6 the Free Software Foundation; either version 2.1 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU Lesser General Public License for more details.
  13
  14 You should have received a copy of the GNU Lesser General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17
  18 */
  19
  20 #ifndef __JackMidiUtil__
  21 #define __JackMidiUtil__
  22
  23 #include "JackMidiPort.h"
  24
  25 namespace Jack {
  26
  27     /**
  28      * Use this function to optimize MIDI output by omitting unnecessary status
  29      * bytes.  This can't be used with all MIDI APIs, so before using this
  30      * function, make sure that your MIDI API doesn't require complete MIDI
  31      * messages to be sent.
  32      *
  33      * To start using this function, call this method with pointers to the
  34      * `size` and `buffer` arguments of the MIDI message you want to send, and
  35      * set the `running_status` argument to '0'.  For each subsequent MIDI
  36      * message, call this method with pointers to its `size` and `buffer`
  37      * arguments, and set the `running_status` argument to the return value of
  38      * the previous call to this function.
  39      *
  40      * Note: This function will alter the `size` and `buffer` of your MIDI
  41      * message for each message that can be optimized.
  42      */
  43
  44     SERVER_EXPORT jack_midi_data_t
  45     ApplyRunningStatus(size_t *size, jack_midi_data_t **buffer,
  46                        jack_midi_data_t running_status=0);
  47
  48     /**
  49      * A wrapper function for the above `ApplyRunningStatus` function.
  50      */
  51
  52     SERVER_EXPORT jack_midi_data_t
  53     ApplyRunningStatus(jack_midi_event_t *event,
  54                        jack_midi_data_t running_status);
  55
  56     /**
  57      * Gets the estimated current time in frames.  This function has the same
  58      * functionality as the JACK client API function `jack_frame_time`.
  59      */
  60
  61     SERVER_EXPORT jack_nframes_t
  62     GetCurrentFrame();
  63
  64     /**
  65      * Gets the estimated frame that will be occurring at the given time.  This
  66      * function has the same functionality as the JACK client API function
  67      * `jack_time_to_frames`.
  68      */
  69
  70     SERVER_EXPORT jack_nframes_t
  71     GetFramesFromTime(jack_time_t time);
  72
  73     /**
  74      * Gets the precise time at the start of the current process cycle.  This
  75      * function has the same functionality as the JACK client API function
  76      * `jack_last_frame_time`.
  77      */
  78
  79     SERVER_EXPORT jack_nframes_t
  80     GetLastFrame();
  81
  82     /**
  83      * Returns the expected message length for the status byte.  Returns 0 if
  84      * the status byte is a system exclusive status byte, or -1 if the status
  85      * byte is invalid.
  86      */
  87
  88     SERVER_EXPORT int
  89     GetMessageLength(jack_midi_data_t status_byte);
  90
  91     /**
  92      * Gets the estimated time at which the given frame will occur.  This
  93      * function has the same functionality as the JACK client API function
  94      * `jack_frames_to_time`.
  95      */
  96
  97     SERVER_EXPORT jack_time_t
  98     GetTimeFromFrames(jack_nframes_t frames);
  99
 100 };
 101
 102 #endif