source: python/trunk/Modules/linuxaudiodev.c@ 281

Last change on this file since 281 was 2, checked in by Yuri Dario, 15 years ago

Initial import for vendor code.
  • Property svn:eol-style set to native
File size: 13.6 KB
Line 
1/* Hey Emacs, this is -*-C-*-
2 ******************************************************************************
3 * linuxaudiodev.c -- Linux audio device for python.
4 *
5 * Author : Peter Bosch
6 * Created On : Thu Mar 2 21:10:33 2000
7 * Status : Unknown, Use with caution!
8 *
9 * Unless other notices are present in any part of this file
10 * explicitly claiming copyrights for other people and/or
11 * organizations, the contents of this file is fully copyright
12 * (C) 2000 Peter Bosch, all rights reserved.
13 ******************************************************************************
14 */
15
16#include "Python.h"
17#include "structmember.h"
18
19#ifdef HAVE_FCNTL_H
20#include <fcntl.h>
21#else
22#define O_RDONLY 00
23#define O_WRONLY 01
24#endif
25
26
27#include <sys/ioctl.h>
28#if defined(linux)
29#include <linux/soundcard.h>
30
31#ifndef HAVE_STDINT_H
32typedef unsigned long uint32_t;
33#endif
34
35#elif defined(__FreeBSD__)
36#include <machine/soundcard.h>
37
38#ifndef SNDCTL_DSP_CHANNELS
39#define SNDCTL_DSP_CHANNELS SOUND_PCM_WRITE_CHANNELS
40#endif
41
42#endif
43
44typedef struct {
45 PyObject_HEAD
46 int x_fd; /* The open file */
47 int x_mode; /* file mode */
48 int x_icount; /* Input count */
49 int x_ocount; /* Output count */
50 uint32_t x_afmts; /* Audio formats supported by hardware*/
51} lad_t;
52
53/* XXX several format defined in soundcard.h are not supported,
54 including _NE (native endian) options and S32 options
55*/
56
57static struct {
58 int a_bps;
59 uint32_t a_fmt;
60 char *a_name;
61} audio_types[] = {
62 { 8, AFMT_MU_LAW, "logarithmic mu-law 8-bit audio" },
63 { 8, AFMT_A_LAW, "logarithmic A-law 8-bit audio" },
64 { 8, AFMT_U8, "linear unsigned 8-bit audio" },
65 { 8, AFMT_S8, "linear signed 8-bit audio" },
66 { 16, AFMT_U16_BE, "linear unsigned 16-bit big-endian audio" },
67 { 16, AFMT_U16_LE, "linear unsigned 16-bit little-endian audio" },
68 { 16, AFMT_S16_BE, "linear signed 16-bit big-endian audio" },
69 { 16, AFMT_S16_LE, "linear signed 16-bit little-endian audio" },
70 { 16, AFMT_S16_NE, "linear signed 16-bit native-endian audio" },
71};
72
73static int n_audio_types = sizeof(audio_types) / sizeof(audio_types[0]);
74
75static PyTypeObject Ladtype;
76
77static PyObject *LinuxAudioError;
78
79static lad_t *
80newladobject(PyObject *arg)
81{
82 lad_t *xp;
83 int fd, afmts, imode;
84 char *basedev = NULL;
85 char *mode = NULL;
86
87 /* Two ways to call linuxaudiodev.open():
88 open(device, mode) (for consistency with builtin open())
89 open(mode) (for backwards compatibility)
90 because the *first* argument is optional, parsing args is
91 a wee bit tricky. */
92 if (!PyArg_ParseTuple(arg, "s|s:open", &basedev, &mode))
93 return NULL;
94 if (mode == NULL) { /* only one arg supplied */
95 mode = basedev;
96 basedev = NULL;
97 }
98
99 if (strcmp(mode, "r") == 0)
100 imode = O_RDONLY;
101 else if (strcmp(mode, "w") == 0)
102 imode = O_WRONLY;
103 else {
104 PyErr_SetString(LinuxAudioError, "mode should be 'r' or 'w'");
105 return NULL;
106 }
107
108 /* Open the correct device. The base device name comes from the
109 * AUDIODEV environment variable first, then /dev/dsp. The
110 * control device tacks "ctl" onto the base device name.
111 *
112 * Note that the only difference between /dev/audio and /dev/dsp
113 * is that the former uses logarithmic mu-law encoding and the
114 * latter uses 8-bit unsigned encoding.
115 */
116
117 if (basedev == NULL) { /* called with one arg */
118 basedev = getenv("AUDIODEV");
119 if (basedev == NULL) /* $AUDIODEV not set */
120 basedev = "/dev/dsp";
121 }
122
123 if ((fd = open(basedev, imode)) == -1) {
124 PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
125 return NULL;
126 }
127 if (imode == O_WRONLY && ioctl(fd, SNDCTL_DSP_NONBLOCK, NULL) == -1) {
128 PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
129 return NULL;
130 }
131 if (ioctl(fd, SNDCTL_DSP_GETFMTS, &afmts) == -1) {
132 PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
133 return NULL;
134 }
135 /* Create and initialize the object */
136 if ((xp = PyObject_New(lad_t, &Ladtype)) == NULL) {
137 close(fd);
138 return NULL;
139 }
140 xp->x_fd = fd;
141 xp->x_mode = imode;
142 xp->x_icount = xp->x_ocount = 0;
143 xp->x_afmts = afmts;
144 return xp;
145}
146
147static void
148lad_dealloc(lad_t *xp)
149{
150 /* if already closed, don't reclose it */
151 if (xp->x_fd != -1)
152 close(xp->x_fd);
153 PyObject_Del(xp);
154}
155
156static PyObject *
157lad_read(lad_t *self, PyObject *args)
158{
159 int size, count;
160 char *cp;
161 PyObject *rv;
162
163 if (!PyArg_ParseTuple(args, "i:read", &size))
164 return NULL;
165 rv = PyString_FromStringAndSize(NULL, size);
166 if (rv == NULL)
167 return NULL;
168 cp = PyString_AS_STRING(rv);
169 if ((count = read(self->x_fd, cp, size)) < 0) {
170 PyErr_SetFromErrno(LinuxAudioError);
171 Py_DECREF(rv);
172 return NULL;
173 }
174 self->x_icount += count;
175 _PyString_Resize(&rv, count);
176 return rv;
177}
178
179static PyObject *
180lad_write(lad_t *self, PyObject *args)
181{
182 char *cp;
183 int rv, size;
184 fd_set write_set_fds;
185 struct timeval tv;
186 int select_retval;
187
188 if (!PyArg_ParseTuple(args, "s#:write", &cp, &size))
189 return NULL;
190
191 /* use select to wait for audio device to be available */
192 FD_ZERO(&write_set_fds);
193 FD_SET(self->x_fd, &write_set_fds);
194 tv.tv_sec = 4; /* timeout values */
195 tv.tv_usec = 0;
196
197 while (size > 0) {
198 select_retval = select(self->x_fd+1, NULL, &write_set_fds, NULL, &tv);
199 tv.tv_sec = 1; tv.tv_usec = 0; /* willing to wait this long next time*/
200 if (select_retval) {
201 if ((rv = write(self->x_fd, cp, size)) == -1) {
202 if (errno != EAGAIN) {
203 PyErr_SetFromErrno(LinuxAudioError);
204 return NULL;
205 } else {
206 errno = 0; /* EAGAIN: buffer is full, try again */
207 }
208 } else {
209 self->x_ocount += rv;
210 size -= rv;
211 cp += rv;
212 }
213 } else {
214 /* printf("Not able to write to linux audio device within %ld seconds\n", tv.tv_sec); */
215 PyErr_SetFromErrno(LinuxAudioError);
216 return NULL;
217 }
218 }
219 Py_INCREF(Py_None);
220 return Py_None;
221}
222
223static PyObject *
224lad_close(lad_t *self, PyObject *unused)
225{
226 if (self->x_fd >= 0) {
227 close(self->x_fd);
228 self->x_fd = -1;
229 }
230 Py_RETURN_NONE;
231}
232
233static PyObject *
234lad_fileno(lad_t *self, PyObject *unused)
235{
236 return PyInt_FromLong(self->x_fd);
237}
238
239static PyObject *
240lad_setparameters(lad_t *self, PyObject *args)
241{
242 int rate, ssize, nchannels, n, fmt, emulate=0;
243
244 if (!PyArg_ParseTuple(args, "iiii|i:setparameters",
245 &rate, &ssize, &nchannels, &fmt, &emulate))
246 return NULL;
247
248 if (rate < 0) {
249 PyErr_Format(PyExc_ValueError, "expected rate >= 0, not %d",
250 rate);
251 return NULL;
252 }
253 if (ssize < 0) {
254 PyErr_Format(PyExc_ValueError, "expected sample size >= 0, not %d",
255 ssize);
256 return NULL;
257 }
258 if (nchannels != 1 && nchannels != 2) {
259 PyErr_Format(PyExc_ValueError, "nchannels must be 1 or 2, not %d",
260 nchannels);
261 return NULL;
262 }
263
264 for (n = 0; n < n_audio_types; n++)
265 if (fmt == audio_types[n].a_fmt)
266 break;
267 if (n == n_audio_types) {
268 PyErr_Format(PyExc_ValueError, "unknown audio encoding: %d", fmt);
269 return NULL;
270 }
271 if (audio_types[n].a_bps != ssize) {
272 PyErr_Format(PyExc_ValueError,
273 "for %s, expected sample size %d, not %d",
274 audio_types[n].a_name, audio_types[n].a_bps, ssize);
275 return NULL;
276 }
277
278 if (emulate == 0) {
279 if ((self->x_afmts & audio_types[n].a_fmt) == 0) {
280 PyErr_Format(PyExc_ValueError,
281 "%s format not supported by device",
282 audio_types[n].a_name);
283 return NULL;
284 }
285 }
286 if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT,
287 &audio_types[n].a_fmt) == -1) {
288 PyErr_SetFromErrno(LinuxAudioError);
289 return NULL;
290 }
291 if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, &nchannels) == -1) {
292 PyErr_SetFromErrno(LinuxAudioError);
293 return NULL;
294 }
295 if (ioctl(self->x_fd, SNDCTL_DSP_SPEED, &rate) == -1) {
296 PyErr_SetFromErrno(LinuxAudioError);
297 return NULL;
298 }
299
300 Py_INCREF(Py_None);
301 return Py_None;
302}
303
304static int
305_ssize(lad_t *self, int *nchannels, int *ssize)
306{
307 int fmt;
308
309 fmt = 0;
310 if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT, &fmt) < 0)
311 return -errno;
312
313 switch (fmt) {
314 case AFMT_MU_LAW:
315 case AFMT_A_LAW:
316 case AFMT_U8:
317 case AFMT_S8:
318 *ssize = sizeof(char);
319 break;
320 case AFMT_S16_LE:
321 case AFMT_S16_BE:
322 case AFMT_U16_LE:
323 case AFMT_U16_BE:
324 *ssize = sizeof(short);
325 break;
326 case AFMT_MPEG:
327 case AFMT_IMA_ADPCM:
328 default:
329 return -EOPNOTSUPP;
330 }
331 if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, nchannels) < 0)
332 return -errno;
333 return 0;
334}
335
336
337/* bufsize returns the size of the hardware audio buffer in number
338 of samples */
339static PyObject *
340lad_bufsize(lad_t *self, PyObject *unused)
341{
342 audio_buf_info ai;
343 int nchannels=0, ssize=0;
344
345 if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) {
346 PyErr_SetFromErrno(LinuxAudioError);
347 return NULL;
348 }
349 if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
350 PyErr_SetFromErrno(LinuxAudioError);
351 return NULL;
352 }
353 return PyInt_FromLong((ai.fragstotal * ai.fragsize) / (nchannels * ssize));
354}
355
356/* obufcount returns the number of samples that are available in the
357 hardware for playing */
358static PyObject *
359lad_obufcount(lad_t *self, PyObject *unused)
360{
361 audio_buf_info ai;
362 int nchannels=0, ssize=0;
363
364 if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) {
365 PyErr_SetFromErrno(LinuxAudioError);
366 return NULL;
367 }
368 if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
369 PyErr_SetFromErrno(LinuxAudioError);
370 return NULL;
371 }
372 return PyInt_FromLong((ai.fragstotal * ai.fragsize - ai.bytes) /
373 (ssize * nchannels));
374}
375
376/* obufcount returns the number of samples that can be played without
377 blocking */
378static PyObject *
379lad_obuffree(lad_t *self, PyObject *unused)
380{
381 audio_buf_info ai;
382 int nchannels=0, ssize=0;
383
384 if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) {
385 PyErr_SetFromErrno(LinuxAudioError);
386 return NULL;
387 }
388 if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
389 PyErr_SetFromErrno(LinuxAudioError);
390 return NULL;
391 }
392 return PyInt_FromLong(ai.bytes / (ssize * nchannels));
393}
394
395/* Flush the device */
396static PyObject *
397lad_flush(lad_t *self, PyObject *unused)
398{
399 if (ioctl(self->x_fd, SNDCTL_DSP_SYNC, NULL) == -1) {
400 PyErr_SetFromErrno(LinuxAudioError);
401 return NULL;
402 }
403 Py_RETURN_NONE;
404}
405
406static PyObject *
407lad_getptr(lad_t *self, PyObject *unused)
408{
409 count_info info;
410 int req;
411
412 if (self->x_mode == O_RDONLY)
413 req = SNDCTL_DSP_GETIPTR;
414 else
415 req = SNDCTL_DSP_GETOPTR;
416 if (ioctl(self->x_fd, req, &info) == -1) {
417 PyErr_SetFromErrno(LinuxAudioError);
418 return NULL;
419 }
420 return Py_BuildValue("iii", info.bytes, info.blocks, info.ptr);
421}
422
423static PyMethodDef lad_methods[] = {
424 { "read", (PyCFunction)lad_read, METH_VARARGS },
425 { "write", (PyCFunction)lad_write, METH_VARARGS },
426 { "setparameters", (PyCFunction)lad_setparameters, METH_VARARGS },
427 { "bufsize", (PyCFunction)lad_bufsize, METH_VARARGS },
428 { "obufcount", (PyCFunction)lad_obufcount, METH_NOARGS },
429 { "obuffree", (PyCFunction)lad_obuffree, METH_NOARGS },
430 { "flush", (PyCFunction)lad_flush, METH_NOARGS },
431 { "close", (PyCFunction)lad_close, METH_NOARGS },
432 { "fileno", (PyCFunction)lad_fileno, METH_NOARGS },
433 { "getptr", (PyCFunction)lad_getptr, METH_NOARGS },
434 { NULL, NULL} /* sentinel */
435};
436
437static PyObject *
438lad_getattr(lad_t *xp, char *name)
439{
440 return Py_FindMethod(lad_methods, (PyObject *)xp, name);
441}
442
443static PyTypeObject Ladtype = {
444 PyVarObject_HEAD_INIT(&PyType_Type, 0)
445 "linuxaudiodev.linux_audio_device", /*tp_name*/
446 sizeof(lad_t), /*tp_size*/
447 0, /*tp_itemsize*/
448 /* methods */
449 (destructor)lad_dealloc, /*tp_dealloc*/
450 0, /*tp_print*/
451 (getattrfunc)lad_getattr, /*tp_getattr*/
452 0, /*tp_setattr*/
453 0, /*tp_compare*/
454 0, /*tp_repr*/
455};
456
457static PyObject *
458ladopen(PyObject *self, PyObject *args)
459{
460 return (PyObject *)newladobject(args);
461}
462
463static PyMethodDef linuxaudiodev_methods[] = {
464 { "open", ladopen, METH_VARARGS },
465 { 0, 0 },
466};
467
468void
469initlinuxaudiodev(void)
470{
471 PyObject *m;
472
473 if (PyErr_WarnPy3k("the linuxaudiodev module has been removed in "
474 "Python 3.0; use the ossaudiodev module instead", 2) < 0)
475 return;
476
477 m = Py_InitModule("linuxaudiodev", linuxaudiodev_methods);
478 if (m == NULL)
479 return;
480
481 LinuxAudioError = PyErr_NewException("linuxaudiodev.error", NULL, NULL);
482 if (LinuxAudioError)
483 PyModule_AddObject(m, "error", LinuxAudioError);
484
485 if (PyModule_AddIntConstant(m, "AFMT_MU_LAW", (long)AFMT_MU_LAW) == -1)
486 return;
487 if (PyModule_AddIntConstant(m, "AFMT_A_LAW", (long)AFMT_A_LAW) == -1)
488 return;
489 if (PyModule_AddIntConstant(m, "AFMT_U8", (long)AFMT_U8) == -1)
490 return;
491 if (PyModule_AddIntConstant(m, "AFMT_S8", (long)AFMT_S8) == -1)
492 return;
493 if (PyModule_AddIntConstant(m, "AFMT_U16_BE", (long)AFMT_U16_BE) == -1)
494 return;
495 if (PyModule_AddIntConstant(m, "AFMT_U16_LE", (long)AFMT_U16_LE) == -1)
496 return;
497 if (PyModule_AddIntConstant(m, "AFMT_S16_BE", (long)AFMT_S16_BE) == -1)
498 return;
499 if (PyModule_AddIntConstant(m, "AFMT_S16_LE", (long)AFMT_S16_LE) == -1)
500 return;
501 if (PyModule_AddIntConstant(m, "AFMT_S16_NE", (long)AFMT_S16_NE) == -1)
502 return;
503
504 return;
505}
Note: See TracBrowser for help on using the repository browser.