summaryrefslogtreecommitdiffstats
path: root/Modules/linuxaudiodev.c
blob: fa2e441f6812e335c823e6e403bbb10aad14be19 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
/* Hey Emacs, this is -*-C-*- 
 ******************************************************************************
 * linuxaudiodev.c -- Linux audio device for python.
 * 
 * Author          : Peter Bosch
 * Created On      : Thu Mar  2 21:10:33 2000
 * Status          : Unknown, Use with caution!
 * 
 * Unless other notices are present in any part of this file
 * explicitly claiming copyrights for other people and/or 
 * organizations, the contents of this file is fully copyright 
 * (C) 2000 Peter Bosch, all rights reserved.
 ******************************************************************************
 */

#include "Python.h"
#include "structmember.h"

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#else
#define O_RDONLY 00
#define O_WRONLY 01
#endif


#include <sys/ioctl.h>
#if defined(linux)
#include <linux/soundcard.h>

typedef unsigned long uint32_t;

#elif defined(__FreeBSD__)
#include <machine/soundcard.h>

#ifndef SNDCTL_DSP_CHANNELS
#define SNDCTL_DSP_CHANNELS SOUND_PCM_WRITE_CHANNELS
#endif

#endif

typedef struct {
    PyObject_HEAD;
    int		x_fd;		/* The open file */
    int         x_mode;           /* file mode */
    int		x_icount;	/* Input count */
    int		x_ocount;	/* Output count */
    uint32_t	x_afmts;	/* Audio formats supported by hardware*/
} lad_t;

/* XXX several format defined in soundcard.h are not supported,
   including _NE (native endian) options and S32 options
*/

static struct {
    int		a_bps;
    uint32_t	a_fmt;
    char       *a_name;
} audio_types[] = {
    {  8, 	AFMT_MU_LAW, "logarithmic mu-law 8-bit audio" },
    {  8, 	AFMT_A_LAW,  "logarithmic A-law 8-bit audio" },
    {  8,	AFMT_U8,     "linear unsigned 8-bit audio" },
    {  8, 	AFMT_S8,     "linear signed 8-bit audio" },
    { 16, 	AFMT_U16_BE, "linear unsigned 16-bit big-endian audio" },
    { 16, 	AFMT_U16_LE, "linear unsigned 16-bit little-endian audio" },
    { 16, 	AFMT_S16_BE, "linear signed 16-bit big-endian audio" },
    { 16, 	AFMT_S16_LE, "linear signed 16-bit little-endian audio" },
    { 16, 	AFMT_S16_NE, "linear signed 16-bit native-endian audio" },
};

static int n_audio_types = sizeof(audio_types) / sizeof(audio_types[0]);

staticforward PyTypeObject Ladtype;

static PyObject *LinuxAudioError;

static lad_t *
newladobject(PyObject *arg)
{
    lad_t *xp;
    int fd, afmts, imode;
    char *mode;
    char *basedev;

    /* Check arg for r/w/rw */
    if (!PyArg_ParseTuple(arg, "s:open", &mode)) return NULL;
    if (strcmp(mode, "r") == 0)
        imode = O_RDONLY;
    else if (strcmp(mode, "w") == 0)
        imode = O_WRONLY;
    else {
        PyErr_SetString(LinuxAudioError, "mode should be 'r' or 'w'");
        return NULL;
    }

    /* Open the correct device.  The base device name comes from the
     * AUDIODEV environment variable first, then /dev/dsp.  The
     * control device tacks "ctl" onto the base device name.
     * 
     * Note that the only difference between /dev/audio and /dev/dsp
     * is that the former uses logarithmic mu-law encoding and the
     * latter uses 8-bit unsigned encoding.
     */

    basedev = getenv("AUDIODEV");
    if (!basedev)
        basedev = "/dev/dsp";

    if ((fd = open(basedev, imode)) == -1) {
        PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
        return NULL;
    }
    if (imode == O_WRONLY && ioctl(fd, SNDCTL_DSP_NONBLOCK, NULL) == -1) {
        PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
        return NULL;
    }
    if (ioctl(fd, SNDCTL_DSP_GETFMTS, &afmts) == -1) {
        PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
        return NULL;
    }
    /* Create and initialize the object */
    if ((xp = PyObject_New(lad_t, &Ladtype)) == NULL) {
        close(fd);
        return NULL;
    }
    xp->x_fd = fd;
    xp->x_mode = imode;
    xp->x_icount = xp->x_ocount = 0;
    xp->x_afmts  = afmts;
    return xp;
}

static void
lad_dealloc(lad_t *xp)
{
    /* if already closed, don't reclose it */
    if (xp->x_fd != -1)
	close(xp->x_fd);
    PyObject_Del(xp);
}

static PyObject *
lad_read(lad_t *self, PyObject *args)
{
    int size, count;
    char *cp;
    PyObject *rv;
	
    if (!PyArg_ParseTuple(args, "i:read", &size))
        return NULL;
    rv = PyString_FromStringAndSize(NULL, size);
    if (rv == NULL)
        return NULL;
    cp = PyString_AS_STRING(rv);
    if ((count = read(self->x_fd, cp, size)) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        Py_DECREF(rv);
        return NULL;
    }
    self->x_icount += count;
    if (_PyString_Resize(&rv, count) == -1)
	return NULL;
    return rv;
}

static PyObject *
lad_write(lad_t *self, PyObject *args)
{
    char *cp;
    int rv, size;
    fd_set write_set_fds;
    struct timeval tv;
    int select_retval;
    
    if (!PyArg_ParseTuple(args, "s#:write", &cp, &size)) 
	return NULL;

    /* use select to wait for audio device to be available */
    FD_ZERO(&write_set_fds);
    FD_SET(self->x_fd, &write_set_fds);
    tv.tv_sec = 4; /* timeout values */
    tv.tv_usec = 0; 

    while (size > 0) {
      select_retval = select(self->x_fd+1, NULL, &write_set_fds, NULL, &tv);
      tv.tv_sec = 1; tv.tv_usec = 0; /* willing to wait this long next time*/
      if (select_retval) {
        if ((rv = write(self->x_fd, cp, size)) == -1) {
	  if (errno != EAGAIN) {
	    PyErr_SetFromErrno(LinuxAudioError);
	    return NULL;
	  } else {
	    errno = 0; /* EAGAIN: buffer is full, try again */
	  }
        } else {
	  self->x_ocount += rv;
	  size -= rv;
	  cp += rv;
	}
      } else {
	/* printf("Not able to write to linux audio device within %ld seconds\n", tv.tv_sec); */
	PyErr_SetFromErrno(LinuxAudioError);
	return NULL;
      }
    }
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
lad_close(lad_t *self, PyObject *args)
{
    if (!PyArg_ParseTuple(args, ":close"))
	return NULL;

    if (self->x_fd >= 0) {
        close(self->x_fd);
        self->x_fd = -1;
    }
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
lad_fileno(lad_t *self, PyObject *args)
{
    if (!PyArg_ParseTuple(args, ":fileno")) 
	return NULL;
    return PyInt_FromLong(self->x_fd);
}

static PyObject *
lad_setparameters(lad_t *self, PyObject *args)
{
    int rate, ssize, nchannels, n, fmt, emulate=0;

    if (!PyArg_ParseTuple(args, "iiii|i:setparameters",
                          &rate, &ssize, &nchannels, &fmt, &emulate))
        return NULL;
  
    if (rate < 0) {
	PyErr_Format(PyExc_ValueError, "expected rate >= 0, not %d",
		     rate); 
	return NULL;
    }
    if (ssize < 0) {
	PyErr_Format(PyExc_ValueError, "expected sample size >= 0, not %d",
		     ssize);
	return NULL;
    }
    if (nchannels != 1 && nchannels != 2) {
	PyErr_Format(PyExc_ValueError, "nchannels must be 1 or 2, not %d",
		     nchannels);
	return NULL;
    }

    for (n = 0; n < n_audio_types; n++)
        if (fmt == audio_types[n].a_fmt)
            break;
    if (n == n_audio_types) {
	PyErr_Format(PyExc_ValueError, "unknown audio encoding: %d", fmt);
	return NULL;
    }
    if (audio_types[n].a_bps != ssize) {
	PyErr_Format(PyExc_ValueError, 
		     "for %s, expected sample size %d, not %d",
		     audio_types[n].a_name, audio_types[n].a_bps, ssize);
	return NULL;
    }

    if (emulate == 0) {
	if ((self->x_afmts & audio_types[n].a_fmt) == 0) {
	    PyErr_Format(PyExc_ValueError, 
			 "%s format not supported by device",
			 audio_types[n].a_name);
	    return NULL;
	}
    }
    if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT, 
	      &audio_types[n].a_fmt) == -1) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, &nchannels) == -1) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    if (ioctl(self->x_fd, SNDCTL_DSP_SPEED, &rate) == -1) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }

    Py_INCREF(Py_None);
    return Py_None;
}

static int
_ssize(lad_t *self, int *nchannels, int *ssize)
{
    int fmt;

    fmt = 0;
    if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT, &fmt) < 0) 
        return -errno;

    switch (fmt) {
    case AFMT_MU_LAW:
    case AFMT_A_LAW:
    case AFMT_U8:
    case AFMT_S8:
        *ssize = sizeof(char);
        break;
    case AFMT_S16_LE:
    case AFMT_S16_BE:
    case AFMT_U16_LE:
    case AFMT_U16_BE:
        *ssize = sizeof(short);
        break;
    case AFMT_MPEG:
    case AFMT_IMA_ADPCM:
    default:
        return -EOPNOTSUPP;
    }
    *nchannels = 0;
    if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, nchannels) < 0)
        return -errno;
    return 0;
}


/* bufsize returns the size of the hardware audio buffer in number 
   of samples */
static PyObject *
lad_bufsize(lad_t *self, PyObject *args)
{
    audio_buf_info ai;
    int nchannels, ssize;

    if (!PyArg_ParseTuple(args, ":bufsize")) return NULL;

    if (_ssize(self, &nchannels, &ssize) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    return PyInt_FromLong((ai.fragstotal * ai.fragsize) / (nchannels * ssize));
}

/* obufcount returns the number of samples that are available in the 
   hardware for playing */
static PyObject *
lad_obufcount(lad_t *self, PyObject *args)
{
    audio_buf_info ai;
    int nchannels, ssize;

    if (!PyArg_ParseTuple(args, ":obufcount"))
        return NULL;

    if (_ssize(self, &nchannels, &ssize) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    return PyInt_FromLong((ai.fragstotal * ai.fragsize - ai.bytes) / 
                          (ssize * nchannels));
}

/* obufcount returns the number of samples that can be played without
   blocking */
static PyObject *
lad_obuffree(lad_t *self, PyObject *args)
{
    audio_buf_info ai;
    int nchannels, ssize;

    if (!PyArg_ParseTuple(args, ":obuffree"))
        return NULL;

    if (_ssize(self, &nchannels, &ssize) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    return PyInt_FromLong(ai.bytes / (ssize * nchannels));
}

/* Flush the device */
static PyObject *
lad_flush(lad_t *self, PyObject *args)
{
    if (!PyArg_ParseTuple(args, ":flush")) return NULL;

    if (ioctl(self->x_fd, SNDCTL_DSP_SYNC, NULL) == -1) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
lad_getptr(lad_t *self, PyObject *args)
{
    count_info info;
    int req;

    if (!PyArg_ParseTuple(args, ":getptr"))
	return NULL;
    
    if (self->x_mode == O_RDONLY)
	req = SNDCTL_DSP_GETIPTR;
    else
	req = SNDCTL_DSP_GETOPTR;
    if (ioctl(self->x_fd, req, &info) == -1) {
        PyErr_SetFromErrno(LinuxAudioError);
        return NULL;
    }
    return Py_BuildValue("iii", info.bytes, info.blocks, info.ptr);
}

static PyMethodDef lad_methods[] = {
    { "read",		(PyCFunction)lad_read, METH_VARARGS },
    { "write",		(PyCFunction)lad_write, METH_VARARGS },
    { "setparameters",	(PyCFunction)lad_setparameters, METH_VARARGS },
    { "bufsize",	(PyCFunction)lad_bufsize, METH_VARARGS },
    { "obufcount",	(PyCFunction)lad_obufcount, METH_VARARGS },
    { "obuffree",	(PyCFunction)lad_obuffree, METH_VARARGS },
    { "flush",		(PyCFunction)lad_flush, METH_VARARGS },
    { "close",		(PyCFunction)lad_close, METH_VARARGS },
    { "fileno",     	(PyCFunction)lad_fileno, METH_VARARGS },
    { "getptr",         (PyCFunction)lad_getptr, METH_VARARGS },
    { NULL,		NULL}		/* sentinel */
};

static PyObject *
lad_getattr(lad_t *xp, char *name)
{
    return Py_FindMethod(lad_methods, (PyObject *)xp, name);
}

static PyTypeObject Ladtype = {
    PyObject_HEAD_INIT(&PyType_Type)
    0,				/*ob_size*/
    "linuxaudiodev.linux_audio_device", /*tp_name*/
    sizeof(lad_t),		/*tp_size*/
    0,				/*tp_itemsize*/
    /* methods */
    (destructor)lad_dealloc,	/*tp_dealloc*/
    0,				/*tp_print*/
    (getattrfunc)lad_getattr,	/*tp_getattr*/
    0,				/*tp_setattr*/
    0,				/*tp_compare*/
    0,				/*tp_repr*/
};

static PyObject *
ladopen(PyObject *self, PyObject *args)
{
    return (PyObject *)newladobject(args);
}

static PyMethodDef linuxaudiodev_methods[] = {
    { "open", ladopen, METH_VARARGS },
    { 0, 0 },
};

void
initlinuxaudiodev(void)
{
    PyObject *m;
  
    m = Py_InitModule("linuxaudiodev", linuxaudiodev_methods);

    LinuxAudioError = PyErr_NewException("linuxaudiodev.error", NULL, NULL);
    if (LinuxAudioError)
	PyModule_AddObject(m, "error", LinuxAudioError);

    if (PyModule_AddIntConstant(m, "AFMT_MU_LAW", (long)AFMT_MU_LAW) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_A_LAW", (long)AFMT_A_LAW) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_U8", (long)AFMT_U8) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_S8", (long)AFMT_S8) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_U16_BE", (long)AFMT_U16_BE) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_U16_LE", (long)AFMT_U16_LE) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_S16_BE", (long)AFMT_S16_BE) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_S16_LE", (long)AFMT_S16_LE) == -1)
	return;
    if (PyModule_AddIntConstant(m, "AFMT_S16_NE", (long)AFMT_S16_NE) == -1)
	return;

    return;
}