2 midi.c -- implement Python midi parser module
4 source file of the GNU LilyPond music typesetter
6 (c) 2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
7 Jan Nieuwenhuizen <janneke@gnu.org>
15 s = open ("s.midi").read ()
24 #if HAVE_PYTHON2_PYTHON_H
25 #include <python2/Python.h>
26 #elif HAVE_PYTHON2_2_PYTHON_H
27 #include <python2.2/Python.h>
28 #elif HAVE_PYTHON2_1_PYTHON_H
29 #include <python2.1/Python.h>
30 #elif HAVE_PYTHON2_0_PYTHON_H
31 #include <python2.0/Python.h>
32 #elif HAVE_PYTHON1_5_PYTHON_H
33 #include <python1.5/Python.h>
34 #elif HAVE_PYTHON_PYTHON_H
36 #include <python/Python.h>
47 #define debug_print(f, args...) fprintf (stderr, "%s:%d: track: %p :" f, __FUNCTION__, __LINE__, *track, ##args)
49 #define debug_print(f, args...)
52 static PyObject *Midi_error;
53 static PyObject *Midi_warning;
58 PyErr_SetString (Midi_error, s);
63 midi_warning (char *s)
65 PyErr_SetString (Midi_warning, s);
70 typedef struct message {
75 message_t channelVoiceMessages[] = {
78 0xA0, "POLYPHONIC_KEY_PRESSURE",
79 0xB0, "CONTROLLER_CHANGE",
80 0xC0, "PROGRAM_CHANGE",
81 0xD0, "CHANNEL_KEY_PRESSURE",
86 message_t channelModeMessages[] = {
87 0x78, "ALL_SOUND_OFF",
88 0x79, "RESET_ALL_CONTROLLERS",
89 0x7A, "LOCAL_CONTROL",
90 0x7B, "ALL_NOTES_OFF",
91 0x7C, "OMNI_MODE_OFF",
98 message_t metaEvents[] = {
99 0x00, "SEQUENCE_NUMBER",
101 0x02, "COPYRIGHT_NOTICE",
102 0x03, "SEQUENCE_TRACK_NAME",
103 0x04, "INSTRUMENT_NAME",
107 0x20, "MIDI_CHANNEL_PREFIX",
109 0x2F, "END_OF_TRACK",
111 0x54, "SMTPE_OFFSET",
112 0x58, "TIME_SIGNATURE",
113 0x59, "KEY_SIGNATURE",
114 0x7F, "SEQUENCER_SPECIFIC_META_EVENT",
120 add_constants (PyObject *dict)
122 message_t * p[] = {metaEvents, channelModeMessages, channelVoiceMessages ,0};
124 for ( j =0; p[j]; j++)
125 for ( i = 0; p[j][i].description; i++)
126 PyDict_SetItemString (dict, p[j][i].description, Py_BuildValue ("i", p[j][i].msg));
130 get_number (unsigned char ** str, unsigned char * end_str, int length)
132 /* # MIDI uses big-endian for everything */
136 for (; i < length; i++)
137 sum = (sum << 8) + (unsigned char) (*str)[i];
140 debug_print ("%d:\n", sum);
145 get_variable_length_number (unsigned char **str, unsigned char * end_str)
149 while (*str < end_str)
151 unsigned char x = **str;
153 sum = (sum << 7) + (x & 0x7F);
157 debug_print ("%d:\n", sum);
162 read_one_byte (unsigned char **track, unsigned char *end,
165 PyObject *pyev = Py_BuildValue ("(i)", x);
166 debug_print ("%x:%s", x, "event\n");
172 read_two_bytes (unsigned char **track, unsigned char *end,
175 PyObject *pyev = Py_BuildValue ("(ii)", x, (*track)[0]);
177 debug_print ("%x:%s", x, "event\n");
182 read_three_bytes (unsigned char **track, unsigned char *end,
185 PyObject *pyev = Py_BuildValue ("(iii)", x, (*track)[0],
189 debug_print ("%x:%s", x, "event\n");
194 read_string (unsigned char **track, unsigned char *end)
196 unsigned long length = get_variable_length_number (track, end);
197 if (length > end - *track)
198 length = end - *track;
201 return Py_BuildValue ("s#", ((*track) -length), length);
204 typedef PyObject* (*Read_midi_event)
205 (unsigned char **track, unsigned char *end,
210 read_f0_byte (unsigned char **track, unsigned char *end,
214 debug_print ("%x:%s", x, "event\n");
217 unsigned char z = (*track)[0 ];
219 debug_print ("%x:%s", z, "f0-event\n");
221 return Py_BuildValue ("(iiO)", x, z, read_string (track, end));
224 return Py_BuildValue ("(iO)", x, read_string (track, end));
227 Read_midi_event read_midi_event [16] =
235 read_one_byte, // 60 data entry.
236 read_two_bytes, // 70 all notes off
237 read_three_bytes, // 80 note off
238 read_three_bytes, // 90 note on
239 read_three_bytes, // a0 poly aftertouch
240 read_three_bytes, // b0 control
241 read_two_bytes, // c0 prog change
242 read_two_bytes, // d0 ch aftertouch
243 read_three_bytes, // e0 pitchwheel range
249 read_event (unsigned char **track, unsigned char *end, PyObject *time,
250 unsigned char *running_status)
252 int rsb_skip = ((**track & 0x80)) ? 1 :0;
254 unsigned char x = (rsb_skip) ? (*track)[0]: *running_status;
256 PyObject * bare_event = 0;
257 debug_print ("%x:%s", x, "event\n");
261 // printf ("%x %x %d next %x\n", x, (*track)[0], rsb_skip, (*track)[1]);
262 bare_event = (*read_midi_event[x >> 4]) (track, end, x);
264 return Py_BuildValue ("(OO)", time, bare_event);
270 midi_parse_track (unsigned char **track, unsigned char *track_end)
272 unsigned int time = 0;
273 unsigned char running_status;
274 unsigned long track_len, track_size;
275 PyObject *pytrack = 0;
277 debug_print ("%s", "\n");
279 track_size = track_end - *track;
281 debug_print ("%s", "\n");
282 if (strcmp (*track, "MTrk"))
283 return midi_error (__FUNCTION__ ": MTrk expected");
287 track_len = get_number (track, *track + 4, 4);
290 debug_print ("track_len: %u\n", track_len);
291 debug_print ("track_size: %u\n", track_size);
292 debug_print ("track begin: %p\n", track);
293 debug_print ("track end: %p\n", track + track_len);
295 if (track_len > track_size)
296 return midi_error (__FUNCTION__ ": track size corrupt");
298 pytrack = PyList_New (0);
300 track_end = *track + track_len;
303 PyObject *pytime = PyInt_FromLong (0L);
304 while (*track < track_end)
306 long dt = get_variable_length_number(track, track_end);
311 pytime = PyInt_FromLong (time);
313 pyev = read_event (track, track_end, pytime,
316 PyList_Append (pytrack, pyev);
326 pymidi_parse_track (PyObject *self, PyObject *args)
328 unsigned char *track, *track_end;
329 unsigned long track_size, track_len;
331 PyObject * sobj = PyTuple_GetItem (args, 0);
333 debug_print ("%s", "\n");
334 if (!PyArg_ParseTuple (args, "s#", &track, &track_size))
338 return midi_error (__FUNCTION__ ": negative track size");
340 track_end = track + track_size;
342 return midi_parse_track (&track, track_end);
346 midi_parse (unsigned char **midi,unsigned char *midi_end)
348 PyObject *pymidi = 0;
349 unsigned long header_len;
350 unsigned format, tracks;
354 debug_print ("%s", "\n");
357 header_len = get_number (midi, *midi + 4, 4);
361 return midi_error (__FUNCTION__ ": header too short");
363 format = get_number (midi, *midi + 2, 2);
364 tracks = get_number (midi, *midi + 2, 2);
367 return midi_error (__FUNCTION__ ": too many tracks");
369 division = get_number (midi, *midi + 2, 2) * 4;
373 /* return midi_error ("can't handle non-metrical time"); */
375 *midi += header_len - 6;
377 pymidi = PyList_New (0);
380 for (i = 0; i < tracks; i++)
381 PyList_Append (pymidi, midi_parse_track (midi, midi_end));
383 pymidi = Py_BuildValue ("(OO)", Py_BuildValue ("(ii)", format, division),
389 pymidi_parse (PyObject *self, PyObject *args)
391 unsigned char *midi, *midi_end;
392 unsigned long midi_size, midi_len;
394 PyObject *sobj = PyTuple_GetItem (args, 0);
396 debug_print ("%s", "\n");
397 if (!PyArg_ParseTuple (args, "s#", &midi, &midi_size))
400 if (strcmp (midi, "MThd"))
401 return midi_error (__FUNCTION__ ": MThd expected");
405 midi_end = midi + midi_size;
407 return midi_parse (&midi, midi_end);
411 static PyMethodDef MidiMethods[] =
413 {"parse", pymidi_parse, 1},
414 {"parse_track", pymidi_parse_track, 1},
415 {0, 0} /* Sentinel */
421 m = Py_InitModule ("midi", MidiMethods);
422 d = PyModule_GetDict (m);
424 Midi_error = PyString_FromString ("midi.error");
425 PyDict_SetItemString (d, "error", Midi_error);
427 Midi_warning = PyString_FromString ("midi.warning");
428 PyDict_SetItemString (d, "warning", Midi_warning);