-/*
- midi.c -- implement Python midi parser module
-
- source file of the GNU LilyPond music typesetter
-
- (c) 2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
- Jan Nieuwenhuizen <janneke@gnu.org>
-
-*/
-
-/*
-
-python2
-import midi
-s = open ("s.midi").read ()
-midi.parse_track (s)
-midi.parse (s)
-
-*/
-
-#include "config.h"
-
-/* urg */
-#if HAVE_PYTHON2_PYTHON_H
-#include <python2/Python.h>
-#elif HAVE_PYTHON2_1_PYTHON_H
-#include <python2.1/Python.h>
-#elif HAVE_PYTHON2_0_PYTHON_H
-#include <python2.0/Python.h>
-#elif HAVE_PYTHON1_5_PYTHON_H
-#include <python1.5/Python.h>
-#elif HAVE_PYTHON_PYTHON_H
-#define assert(x)
-#include <python/Python.h>
-#elif HAVE_PYTHON_H
-#define assert(x)
-#include <Python.h>
-#else
-#error Need Python.h
-#endif
-
-#if 0
-int x = 0;
-int *track = &x;
-#define debug_print(f, args...) fprintf (stderr, "%s:%d: track: %p :" f, __FUNCTION__, __LINE__, *track, ##args)
-#else
-#define debug_print(f, args...)
-#endif
-
-static PyObject *Midi_error;
-static PyObject *Midi_warning;
-
-static PyObject *
-midi_error (char *s)
-{
- PyErr_SetString (Midi_error, s);
- return 0;
-}
-
-static PyObject *
-midi_warning (char *s)
-{
- PyErr_SetString (Midi_warning, s);
- return 0;
-}
-
-
-typedef struct message {
- unsigned char msg;
- char * description;
-} message_t;
-
-message_t channelVoiceMessages[] = {
- 0x80, "NOTE_OFF",
- 0x90, "NOTE_ON",
- 0xA0, "POLYPHONIC_KEY_PRESSURE",
- 0xB0, "CONTROLLER_CHANGE",
- 0xC0, "PROGRAM_CHANGE",
- 0xD0, "CHANNEL_KEY_PRESSURE",
- 0xE0, "PITCH_BEND",
- 0,0
-};
-
-message_t channelModeMessages[] = {
- 0x78, "ALL_SOUND_OFF",
- 0x79, "RESET_ALL_CONTROLLERS",
- 0x7A, "LOCAL_CONTROL",
- 0x7B, "ALL_NOTES_OFF",
- 0x7C, "OMNI_MODE_OFF",
- 0x7D, "OMNI_MODE_ON",
- 0x7E, "MONO_MODE_ON",
- 0x7F, "POLY_MODE_ON",
- 0,0
-};
-
-message_t metaEvents[] = {
- 0x00, "SEQUENCE_NUMBER",
- 0x01, "TEXT_EVENT",
- 0x02, "COPYRIGHT_NOTICE",
- 0x03, "SEQUENCE_TRACK_NAME",
- 0x04, "INSTRUMENT_NAME",
- 0x05, "LYRIC",
- 0x06, "MARKER",
- 0x07, "CUE_POINT",
- 0x20, "MIDI_CHANNEL_PREFIX",
- 0x21, "MIDI_PORT",
- 0x2F, "END_OF_TRACK",
- 0x51, "SET_TEMPO",
- 0x54, "SMTPE_OFFSET",
- 0x58, "TIME_SIGNATURE",
- 0x59, "KEY_SIGNATURE",
- 0x7F, "SEQUENCER_SPECIFIC_META_EVENT",
- 0xFF, "META_EVENT",
- 0,0
-};
-
-void
-add_constants (PyObject *dict)
-{
- message_t * p[] = {metaEvents, channelModeMessages, channelVoiceMessages ,0};
- int i,j;
- for ( j =0; p[j]; j++)
- for ( i = 0; p[j][i].description; i++)
- PyDict_SetItemString (dict, p[j][i].description, Py_BuildValue ("i", p[j][i].msg));
-}
-
-unsigned long int
-get_number (unsigned char ** str, unsigned char * end_str, int length)
-{
- /* # MIDI uses big-endian for everything */
- long sum = 0;
- int i = 0;
-
- for (; i < length; i++)
- sum = (sum << 8) + (unsigned char) (*str)[i];
-
- *str += length;
- debug_print ("%d:\n", sum);
- return sum;
-}
-
-unsigned long int
-get_variable_length_number (unsigned char **str, unsigned char * end_str)
-{
- long sum = 0;
- int i = 0;
- while (*str < end_str)
- {
- unsigned char x = **str;
- (*str) ++;
- sum = (sum << 7) + (x & 0x7F);
- if (!(x & 0x80))
- break;
- }
- debug_print ("%d:\n", sum);
- return sum;
-}
-
-PyObject *
-read_one_byte (unsigned char **track, unsigned char *end,
- unsigned char x)
-{
- PyObject *pyev = Py_BuildValue ("(i)", x);
- debug_print ("%x:%s", x, "event\n");
-
- return pyev;
-}
-
-PyObject *
-read_two_bytes (unsigned char **track, unsigned char *end,
- unsigned char x)
-{
- PyObject *pyev = Py_BuildValue ("(ii)", x, (*track)[0]);
- *track += 1;
- debug_print ("%x:%s", x, "event\n");
- return pyev;
-}
-
-PyObject *
-read_three_bytes (unsigned char **track, unsigned char *end,
- unsigned char x)
-{
- PyObject *pyev = Py_BuildValue ("(iii)", x, (*track)[0],
- (*track)[1]);
-
- *track += 2;
- debug_print ("%x:%s", x, "event\n");
- return pyev;
-}
-
-PyObject *
-read_string (unsigned char **track, unsigned char *end)
-{
- unsigned long length = get_variable_length_number (track, end);
- if (length > end - *track)
- length = end - *track;
-
- *track += length;
- return Py_BuildValue ("s#", ((*track) -length), length);
-}
-
-typedef PyObject* (*Read_midi_event)
- (unsigned char **track, unsigned char *end,
- unsigned char x);
-
-
-static PyObject *
-read_f0_byte (unsigned char **track, unsigned char *end,
- unsigned char x)
-
-{
- debug_print ("%x:%s", x, "event\n");
- if (x == 0xff)
- {
- unsigned char z = (*track)[0 ];
- *track += 1;
- debug_print ("%x:%s", z, "f0-event\n");
-
- return Py_BuildValue ("(iiO)", x, z, read_string (track, end));
- }
-
- return Py_BuildValue ("(iO)", x, read_string (track, end));
-}
-
-Read_midi_event read_midi_event [16] =
-{
- read_one_byte, // 0
- read_one_byte, // 10
- read_one_byte, // 20
- read_one_byte, // 30
- read_one_byte, // 40
- read_one_byte, // 50
- read_one_byte, // 60 data entry.
- read_two_bytes, // 70 all notes off
- read_three_bytes, // 80 note off
- read_three_bytes, // 90 note on
- read_three_bytes, // a0 poly aftertouch
- read_three_bytes, // b0 control
- read_two_bytes, // c0 prog change
- read_two_bytes, // d0 ch aftertouch
- read_three_bytes, // e0 pitchwheel range
- read_f0_byte, // f0
-};
-
-
-static PyObject *
-read_event (unsigned char **track, unsigned char *end, PyObject *time,
- unsigned char *running_status)
-{
- int rsb_skip = ((**track & 0x80)) ? 1 :0;
-
- unsigned char x = (rsb_skip) ? (*track)[0]: *running_status;
-
- PyObject * bare_event = 0;
- debug_print ("%x:%s", x, "event\n");
- *running_status = x;
- *track += rsb_skip;
-
- // printf ("%x %x %d next %x\n", x, (*track)[0], rsb_skip, (*track)[1]);
- bare_event = (*read_midi_event[x >> 4]) (track, end, x);
- if (bare_event)
- return Py_BuildValue ("(OO)", time, bare_event);
- else
- return NULL;
-}
-
-static PyObject *
-midi_parse_track (unsigned char **track, unsigned char *track_end)
-{
- unsigned int time = 0;
- unsigned char running_status;
- unsigned long track_len, track_size;
- PyObject *pytrack = 0;
-
- debug_print ("%s", "\n");
-
- track_size = track_end - *track;
-
- debug_print ("%s", "\n");
- if (strcmp (*track, "MTrk"))
- return midi_error (__FUNCTION__ ": MTrk expected");
-
- *track += 4;
-
- track_len = get_number (track, *track + 4, 4);
-
-
- debug_print ("track_len: %u\n", track_len);
- debug_print ("track_size: %u\n", track_size);
- debug_print ("track begin: %p\n", track);
- debug_print ("track end: %p\n", track + track_len);
-
- if (track_len > track_size)
- return midi_error (__FUNCTION__ ": track size corrupt");
-
- pytrack = PyList_New (0);
-
- track_end = *track + track_len;
-
- {
- PyObject *pytime = PyInt_FromLong (0L);
- while (*track < track_end)
- {
- long dt = get_variable_length_number(track, track_end);
- PyObject *pyev = 0;
-
- time += dt;
- if (dt)
- pytime = PyInt_FromLong (time);
-
- pyev = read_event (track, track_end, pytime,
- &running_status);
- if (pyev)
- PyList_Append (pytrack, pyev);
- }
- }
-
- *track = track_end;
- return pytrack;
-}
-
-
-static PyObject *
-pymidi_parse_track (PyObject *self, PyObject *args)
-{
- unsigned char *track, *track_end;
- unsigned long track_size, track_len;
-
- PyObject * sobj = PyTuple_GetItem (args, 0);
-
- debug_print ("%s", "\n");
- if (!PyArg_ParseTuple (args, "s#", &track, &track_size))
- return 0;
-
- if (track_size < 0)
- return midi_error (__FUNCTION__ ": negative track size");
-
- track_end = track + track_size;
-
- return midi_parse_track (&track, track_end);
-}
-
-static PyObject *
-midi_parse (unsigned char **midi,unsigned char *midi_end)
-{
- PyObject *pymidi = 0;
- unsigned long header_len;
- unsigned format, tracks;
- int division;
- int i;
-
- debug_print ("%s", "\n");
-
- /* Header */
- header_len = get_number (midi, *midi + 4, 4);
-
-
- if (header_len < 6)
- return midi_error (__FUNCTION__ ": header too short");
-
- format = get_number (midi, *midi + 2, 2);
- tracks = get_number (midi, *midi + 2, 2);
-
- if (tracks > 32)
- return midi_error (__FUNCTION__ ": too many tracks");
-
- division = get_number (midi, *midi + 2, 2) * 4;
-
-
- if (division < 0)
- /* return midi_error ("can't handle non-metrical time"); */
- ;
- *midi += header_len - 6;
-
- pymidi = PyList_New (0);
-
- /* Tracks */
- for (i = 0; i < tracks; i++)
- PyList_Append (pymidi, midi_parse_track (midi, midi_end));
-
- pymidi = Py_BuildValue ("(OO)", Py_BuildValue ("(ii)", format, division),
- pymidi);
- return pymidi;
-}
-
-static PyObject *
-pymidi_parse (PyObject *self, PyObject *args)
-{
- unsigned char *midi, *midi_end;
- unsigned long midi_size, midi_len;
-
- PyObject *sobj = PyTuple_GetItem (args, 0);
-
- debug_print ("%s", "\n");
- if (!PyArg_ParseTuple (args, "s#", &midi, &midi_size))
- return 0;
-
- if (strcmp (midi, "MThd"))
- return midi_error (__FUNCTION__ ": MThd expected");
-
- midi += 4;
-
- midi_end = midi + midi_size;
-
- return midi_parse (&midi, midi_end);
-}
-
-
-static PyMethodDef MidiMethods[] =
-{
- {"parse", pymidi_parse, 1},
- {"parse_track", pymidi_parse_track, 1},
- {0, 0} /* Sentinel */
-};
-
-initmidi ()
-{
- PyObject *m, *d;
- m = Py_InitModule ("midi", MidiMethods);
- d = PyModule_GetDict (m);
-
- Midi_error = PyString_FromString ("midi.error");
- PyDict_SetItemString (d, "error", Midi_error);
- add_constants (d);
- Midi_warning = PyString_FromString ("midi.warning");
- PyDict_SetItemString (d, "warning", Midi_warning);
-}
projects / lilypond.git / blobdiff