diff options
Diffstat (limited to 'libs/evoral/libsmf/smf.h')
| -rw-r--r-- | libs/evoral/libsmf/smf.h | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/libs/evoral/libsmf/smf.h b/libs/evoral/libsmf/smf.h new file mode 100644 index 0000000000..82647779e8 --- /dev/null +++ b/libs/evoral/libsmf/smf.h @@ -0,0 +1,418 @@ +/*- + * Copyright (c) 2007, 2008 Edward Tomasz Napierała <trasz@FreeBSD.org> + * 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 <stdio.h> +#include <stdint.h> +#include <glib.h> + +#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 */ + |