/*- * Copyright (c) 2007, 2008 Edward Tomasz Napierała * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * ALTHOUGH THIS SOFTWARE IS MADE OF WIN AND SCIENCE, IT IS PROVIDED BY THE * AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL * THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ /** * \file * * Public interface declaration for libsmf, Standard MIDI File format library. */ /** * * \page libsmf libsmf - general usage instructions * * An smf_t structure represents a "song". Every valid smf contains one or more tracks. * Tracks contain zero or more events. Libsmf doesn't care about actual MIDI data, as long * as it is valid from the MIDI specification point of view - it may be realtime message, * SysEx, whatever. * * The only field in smf_t, smf_track_t, smf_event_t and smf_tempo_t structures your * code may modify is event->midi_buffer and event->midi_buffer_length. Do not modify * other fields, _ever_. You may read them, though. Do not declare static instances * of these types, i.e. never do something like this: "smf_t smf;". Always use * "smf_t *smf = smf_new();". The same applies to smf_track_t and smf_event_t. * * Say you want to load a Standard MIDI File (.mid) file and play it back somehow. * This is (roughly) how you do this: * * \code * smf_t *smf; * smf_event_t *event; * * smf = smf_load(file_name); * if (smf == NULL) { * Whoops, something went wrong. * return; * } * * while ((event = smf_get_next_event(smf)) != NULL) { * if (smf_event_is_metadata(event)) * continue; * * wait until event->time_seconds. * feed_to_midi_output(event->midi_buffer, event->midi_buffer_length); * } * * smf_delete(smf); * * \endcode * * Saving works like this: * * \code * * smf_t *smf; * smf_track_t *track; * smf_event_t *event; * * smf = smf_new(); * if (smf == NULL) { * Whoops. * return; * } * * for (int i = 1; i <= number of tracks; i++) { * track = smf_track_new(); * if (track == NULL) { * Whoops. * return; * } * * smf_add_track(smf, track); * * for (int j = 1; j <= number of events you want to put into this track; j++) { * event = smf_event_new_from_pointer(your MIDI message, message length); * if (event == NULL) { * Whoops. * return; * } * * smf_track_add_event_seconds(track, event, seconds since start of the song); * } * } * * ret = smf_save(smf, file_name); * if (ret) { * Whoops, saving failed for some reason. * return; * } * * smf_delete(smf); * * \endcode * * There are two basic ways of getting MIDI data out of smf - sequential or by track/event number. * You may mix them if you need to. First one is used in the example above - seek to the point * from which you want the playback to start (using smf_seek_to_seconds(), smf_seek_to_pulses() * or smf_seek_to_event()) and then do smf_get_next_event() in loop, until it returns NULL. * Calling smf_load() causes the smf to be rewound to the start of the song. * * Getting events by number works like this: * * \code * * smf_track_t *track = smf_get_track_by_number(smf, track_number); * smf_event_t *event = smf_track_get_event_by_number(track, event_number); * * \endcode * * To create new event, use smf_event_new(), smf_event_new_from_pointer() or * smf_event_new_from_bytes(). First one creates an empty event - you need to manually allocate * (using malloc(3)) buffer for MIDI data, write MIDI data into it, put the address of that * buffer into event->midi_buffer, and the length of MIDI data into event->midi_buffer_length. * Note that deleting the event (using smf_event_delete()) will free the buffer. * * Second form does most of this for you: it takes an address of the buffer containing MIDI data, * allocates storage and copies MIDI data into it. * * Third form is useful for manually creating short events, up to three bytes in length, for * example Note On or Note Off events. It simply takes three bytes and creates MIDI event * containing them. If you need to create MIDI message that takes only two bytes, pass -1 as * the third byte. For one byte message (System Realtime), pass -1 as second and third byte. * * To free an event, use smf_event_delete(). * * To add event to the track, use smf_track_add_event_delta_pulses(), smf_track_add_event_pulses(), * or smf_track_add_event_seconds(). The difference between them is in the way you specify the * time of the event - with the first one, you specify it as an interval, in pulses, from the * previous event in this track; with the second one, you specify it as pulses from the start * of the song, and with the last one, you specify it as seconds from the start of the song. * Obviously, the first version can only append events at the end of the track. * * To remove an event from the track it's attached to, use smf_event_remove_from_track(). * You may want to free the event (using smf_event_delete()) afterwards. * * To create new track, use smf_track_new(). To add track to the smf, use smf_add_track(). * To remove track from its smf, use smf_track_remove_from_smf(). To free the track structure, * use smf_track_delete(). * * Note that libsmf keeps things consistent. If you free (using smf_track_delete()) a track * that is attached to an smf and contains events, libsmf will detach the events, free them, * detach the track, free it etc. * * Tracks and events are numbered consecutively, starting from one. If you remove a track * or event, the rest of tracks/events will get renumbered. To get the number of a given * event in its track, use event->event_number. To get the number of track in its smf, use * track->track_number. To get the number of events in the track, use track->number_of_events. * To get the number of tracks in the smf, use smf->number_of_tracks. * * In SMF File Format, each track has to end with End Of Track metaevent. If you load SMF file * using smf_load(), that will be the case. If you want to create or edit an SMF, you don't * need to worry about EOT events; libsmf automatically takes care of them for you. If you * try to save an SMF with tracks that do not end with EOTs, smf_save() will append them. * If you try to add event that happens after EOT metaevent, libsmf will remove the EOT. * If you want to add EOT manually, you can, of course, using smf_track_add_eot_seconds() * or smf_track_add_eot_pulses(). * * Each event carries three time values - event->time_seconds, which is seconds since * the start of the song, event->time_pulses, which is PPQN clocks since the start of * the song, and event->delta_pulses, which is PPQN clocks since the previous event * in that track. These values are invalid if the event is not attached to the track. * If event is attached, all three values are valid. Time of the event is specified when * adding the event (using smf_track_add_event_seconds(), smf_track_add_event_pulses() or * smf_track_add_event_delta_pulses()); the remaining two values are computed from that. * * Tempo related stuff happens automatically - when you add a metaevent that is Tempo PropertyChange or * Time Signature, libsmf adds that event to the tempo map. If you remove Tempo PropertyChange event * that is in the middle of the song, the rest of the events will have their event->time_seconds * recomputed from event->time_pulses before smf_event_remove_from_track() function returns. * Adding Tempo PropertyChange in the middle of the song works in a similar way. * * MIDI data (event->midi_buffer) is always kept in normalized form - it always begins with * status byte (no running status), there are no System Realtime events embedded in them etc. * Events like SysExes are in "on the wire" form, without embedded length that is used in SMF * file format. Obviously libsmf "normalizes" MIDI data during loading and "denormalizes" (adding * length to SysExes, escaping System Common and System Realtime messages etc) during writing. * * Note that you always have to first add the track to smf, and then add events to the track. * Doing it the other way around will trip asserts. Also, try to add events at the end of the * track and remove them from the end of the track, that's much more efficient. * * All the libsmf functions have prefix "smf_". First argument for routines whose names start * with "smf_event_" is "smf_event_t *", for routines whose names start with "smf_track_" - * "smf_track_t *", and for plain "smf_" - "smf_t *". The only exception are smf_whatever_new * routines. Library does not use any global variables and is thread-safe, as long as you * don't try to work on the same SMF (smf_t and its descendant tracks and events) from several * threads at once without protecting it with mutex. Library depends on glib and nothing else. * License is BSD, two clause, which basically means you can use it freely in your software, * both Open Source (including GPL) and closed source. * */ #ifndef SMF_H #define SMF_H #ifdef __cplusplus extern "C" { #endif #include #include #include #if defined(__GNUC__) && __GNUC__ >= 4 #define WARN_UNUSED_RESULT __attribute__ ((warn_unused_result)) #else #define WARN_UNUSED_RESULT #endif /** Represents a "song", that is, collection of one or more tracks. */ struct smf_struct { int format; /** These fields are extracted from "division" field of MThd header. * Valid is _either_ ppqn or frames_per_second/resolution. */ uint16_t ppqn; int frames_per_second; int resolution; int number_of_tracks; /** These are private fields using only by loading and saving routines. */ FILE *stream; void *file_buffer; size_t file_buffer_length; size_t next_chunk_offset; int expected_number_of_tracks; /** Private, used by smf.c. */ GPtrArray *tracks_array; double last_seek_position; /** Private, used by smf_tempo.c. */ /** Array of pointers to smf_tempo_struct. */ GPtrArray *tempo_array; }; typedef struct smf_struct smf_t; /** Describes a single tempo or time signature change. */ struct smf_tempo_struct { size_t time_pulses; double time_seconds; int microseconds_per_quarter_note; int numerator; int denominator; int clocks_per_click; int notes_per_note; }; typedef struct smf_tempo_struct smf_tempo_t; /** Represents a single track. */ struct smf_track_struct { smf_t *smf; int track_number; size_t number_of_events; /* this will be set from the SMF file if present, during loading */ char* name; char* instrument; /** These are private fields using only by loading and saving routines. */ void *file_buffer; size_t file_buffer_length; int last_status; /* Used for "running status". */ /** Private, used by smf.c. */ /** Offset into buffer, used in parse_next_event(). */ size_t next_event_offset; size_t next_event_number; /** Absolute time of next event on events_queue. */ size_t time_of_next_event; GPtrArray *events_array; }; typedef struct smf_track_struct smf_track_t; /** Represents a single MIDI event or metaevent. */ struct smf_event_struct { /** Pointer to the track, or NULL if event is not attached. */ smf_track_t *track; /** Number of this event in the track. Events are numbered consecutively, starting from 1. */ size_t event_number; /** Note that the time fields are invalid, if event is not attached to a track. */ /** Time, in pulses, since the previous event on this track. */ int32_t delta_time_pulses; /** Time, in pulses, since the start of the song. */ size_t time_pulses; /** Time, in seconds, since the start of the song. */ double time_seconds; /** Tracks are numbered consecutively, starting from 1. */ int track_number; /** Pointer to the buffer containing MIDI message. This is freed by smf_event_delete. */ uint8_t *midi_buffer; /** Length of the MIDI message in the buffer, in bytes. */ size_t midi_buffer_length; }; typedef struct smf_event_struct smf_event_t; /* Routines for manipulating smf_t. */ smf_t *smf_new(void) WARN_UNUSED_RESULT; void smf_delete(smf_t *smf); int smf_set_format(smf_t *smf, int format) WARN_UNUSED_RESULT; int smf_set_ppqn(smf_t *smf, uint16_t ppqn) WARN_UNUSED_RESULT; char *smf_decode(const smf_t *smf) WARN_UNUSED_RESULT; smf_track_t *smf_get_track_by_number(const smf_t *smf, int track_number) WARN_UNUSED_RESULT; smf_event_t *smf_peek_next_event(smf_t *smf) WARN_UNUSED_RESULT; smf_event_t *smf_get_next_event(smf_t *smf) WARN_UNUSED_RESULT; void smf_skip_next_event(smf_t *smf); void smf_rewind(smf_t *smf); int smf_seek_to_seconds(smf_t *smf, double seconds) WARN_UNUSED_RESULT; int smf_seek_to_pulses(smf_t *smf, size_t pulses) WARN_UNUSED_RESULT; int smf_seek_to_event(smf_t *smf, const smf_event_t *event) WARN_UNUSED_RESULT; size_t smf_get_length_pulses(const smf_t *smf) WARN_UNUSED_RESULT; double smf_get_length_seconds(const smf_t *smf) WARN_UNUSED_RESULT; int smf_event_is_last(const smf_event_t *event) WARN_UNUSED_RESULT; void smf_add_track(smf_t *smf, smf_track_t *track); void smf_track_remove_from_smf(smf_track_t *track); /* Routines for manipulating smf_track_t. */ smf_track_t *smf_track_new(void) WARN_UNUSED_RESULT; void smf_track_delete(smf_track_t *track); smf_event_t *smf_track_get_next_event(smf_track_t *track) WARN_UNUSED_RESULT; smf_event_t *smf_track_get_event_by_number(const smf_track_t *track, size_t num) WARN_UNUSED_RESULT; smf_event_t *smf_track_get_last_event(const smf_track_t *track) WARN_UNUSED_RESULT; void smf_track_add_event_delta_pulses(smf_track_t *track, smf_event_t *event, uint32_t delta); void smf_track_add_event_pulses(smf_track_t *track, smf_event_t *event, size_t pulses); void smf_track_add_event_seconds(smf_track_t *track, smf_event_t *event, double seconds); int smf_track_add_eot_delta_pulses(smf_track_t *track, uint32_t delta) WARN_UNUSED_RESULT; int smf_track_add_eot_pulses(smf_track_t *track, size_t pulses) WARN_UNUSED_RESULT; int smf_track_add_eot_seconds(smf_track_t *track, double seconds) WARN_UNUSED_RESULT; void smf_event_remove_from_track(smf_event_t *event); /* Routines for manipulating smf_event_t. */ smf_event_t *smf_event_new(void) WARN_UNUSED_RESULT; smf_event_t *smf_event_new_from_pointer(const void *midi_data, size_t len) WARN_UNUSED_RESULT; smf_event_t *smf_event_new_from_bytes(int byte1, int byte2, int byte3) WARN_UNUSED_RESULT; smf_event_t *smf_event_new_textual(int type, const char *text); void smf_event_delete(smf_event_t *event); int smf_event_is_valid(const smf_event_t *event) WARN_UNUSED_RESULT; int smf_event_is_metadata(const smf_event_t *event) WARN_UNUSED_RESULT; int smf_event_is_system_realtime(const smf_event_t *event) WARN_UNUSED_RESULT; int smf_event_is_system_common(const smf_event_t *event) WARN_UNUSED_RESULT; int smf_event_is_sysex(const smf_event_t *event) WARN_UNUSED_RESULT; int smf_event_is_eot(const smf_event_t *event) WARN_UNUSED_RESULT; int smf_event_is_textual(const smf_event_t *event) WARN_UNUSED_RESULT; char *smf_event_decode(const smf_event_t *event) WARN_UNUSED_RESULT; char *smf_event_extract_text(const smf_event_t *event) WARN_UNUSED_RESULT; /* Routines for dealing with Variable Length Quantities (VLQ's). Slightly odd names reflect original static names within libsmf */ int smf_format_vlq (unsigned char *buf, int length, unsigned long value); int smf_extract_vlq(const unsigned char *buf, const size_t buffer_length, uint32_t *value, uint32_t *len); /* Routines for loading SMF files. */ smf_t *smf_load(FILE *) WARN_UNUSED_RESULT; smf_t *smf_load_from_memory(void *buffer, const size_t buffer_length) WARN_UNUSED_RESULT; /* Routine for writing SMF files. */ int smf_save(smf_t *smf, FILE *file) WARN_UNUSED_RESULT; /* Routines for manipulating smf_tempo_t. */ smf_tempo_t *smf_get_tempo_by_pulses(const smf_t *smf, size_t pulses) WARN_UNUSED_RESULT; smf_tempo_t *smf_get_tempo_by_seconds(const smf_t *smf, double seconds) WARN_UNUSED_RESULT; int smf_get_tempo_count (const smf_t *smf) WARN_UNUSED_RESULT; smf_tempo_t *smf_get_tempo_by_number(const smf_t *smf, size_t number) WARN_UNUSED_RESULT; smf_tempo_t *smf_get_last_tempo(const smf_t *smf) WARN_UNUSED_RESULT; const char *smf_get_version(void) WARN_UNUSED_RESULT; #ifdef __cplusplus } #endif #endif /* SMF_H */