source: trunk/essentials/dev-lang/python/Modules/linuxaudiodev.c@ 3506

Last change on this file since 3506 was 3225, checked in by bird, 19 years ago

Python 2.5
File size: 13.4 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
31typedef unsigned long uint32_t;
32
33#elif defined(__FreeBSD__)
34#include <machine/soundcard.h>
35
36#ifndef SNDCTL_DSP_CHANNELS
37#define SNDCTL_DSP_CHANNELS SOUND_PCM_WRITE_CHANNELS
38#endif
39
40#endif
41
42typedef struct {
43 PyObject_HEAD
44 int x_fd; /* The open file */
45 int x_mode; /* file mode */
46 int x_icount; /* Input count */
47 int x_ocount; /* Output count */
48 uint32_t x_afmts; /* Audio formats supported by hardware*/
49} lad_t;
50
51/* XXX several format defined in soundcard.h are not supported,
52 including _NE (native endian) options and S32 options
53*/
54
55static struct {
56 int a_bps;
57 uint32_t a_fmt;
58 char *a_name;
59} audio_types[] = {
60 { 8, AFMT_MU_LAW, "logarithmic mu-law 8-bit audio" },
61 { 8, AFMT_A_LAW, "logarithmic A-law 8-bit audio" },
62 { 8, AFMT_U8, "linear unsigned 8-bit audio" },
63 { 8, AFMT_S8, "linear signed 8-bit audio" },
64 { 16, AFMT_U16_BE, "linear unsigned 16-bit big-endian audio" },
65 { 16, AFMT_U16_LE, "linear unsigned 16-bit little-endian audio" },
66 { 16, AFMT_S16_BE, "linear signed 16-bit big-endian audio" },
67 { 16, AFMT_S16_LE, "linear signed 16-bit little-endian audio" },
68 { 16, AFMT_S16_NE, "linear signed 16-bit native-endian audio" },
69};
70
71static int n_audio_types = sizeof(audio_types) / sizeof(audio_types[0]);
72
73static PyTypeObject Ladtype;
74
75static PyObject *LinuxAudioError;
76
77static lad_t *
78newladobject(PyObject *arg)
79{
80 lad_t *xp;
81 int fd, afmts, imode;
82 char *basedev = NULL;
83 char *mode = NULL;
84
85 /* Two ways to call linuxaudiodev.open():
86 open(device, mode) (for consistency with builtin open())
87 open(mode) (for backwards compatibility)
88 because the *first* argument is optional, parsing args is
89 a wee bit tricky. */
90 if (!PyArg_ParseTuple(arg, "s|s:open", &basedev, &mode))
91 return NULL;
92 if (mode == NULL) { /* only one arg supplied */
93 mode = basedev;
94 basedev = NULL;
95 }
96
97 if (strcmp(mode, "r") == 0)
98 imode = O_RDONLY;
99 else if (strcmp(mode, "w") == 0)
100 imode = O_WRONLY;
101 else {
102 PyErr_SetString(LinuxAudioError, "mode should be 'r' or 'w'");
103 return NULL;
104 }
105
106 /* Open the correct device. The base device name comes from the
107 * AUDIODEV environment variable first, then /dev/dsp. The
108 * control device tacks "ctl" onto the base device name.
109 *
110 * Note that the only difference between /dev/audio and /dev/dsp
111 * is that the former uses logarithmic mu-law encoding and the
112 * latter uses 8-bit unsigned encoding.
113 */
114
115 if (basedev == NULL) { /* called with one arg */
116 basedev = getenv("AUDIODEV");
117 if (basedev == NULL) /* $AUDIODEV not set */
118 basedev = "/dev/dsp";
119 }
120
121 if ((fd = open(basedev, imode)) == -1) {
122 PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
123 return NULL;
124 }
125 if (imode == O_WRONLY && ioctl(fd, SNDCTL_DSP_NONBLOCK, NULL) == -1) {
126 PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
127 return NULL;
128 }
129 if (ioctl(fd, SNDCTL_DSP_GETFMTS, &afmts) == -1) {
130 PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
131 return NULL;
132 }
133 /* Create and initialize the object */
134 if ((xp = PyObject_New(lad_t, &Ladtype)) == NULL) {
135 close(fd);
136 return NULL;
137 }
138 xp->x_fd = fd;
139 xp->x_mode = imode;
140 xp->x_icount = xp->x_ocount = 0;
141 xp->x_afmts = afmts;
142 return xp;
143}
144
145static void
146lad_dealloc(lad_t *xp)
147{
148 /* if already closed, don't reclose it */
149 if (xp->x_fd != -1)
150 close(xp->x_fd);
151 PyObject_Del(xp);
152}
153
154static PyObject *
155lad_read(lad_t *self, PyObject *args)
156{
157 int size, count;
158 char *cp;
159 PyObject *rv;
160
161 if (!PyArg_ParseTuple(args, "i:read", &size))
162 return NULL;
163 rv = PyString_FromStringAndSize(NULL, size);
164 if (rv == NULL)
165 return NULL;
166 cp = PyString_AS_STRING(rv);
167 if ((count = read(self->x_fd, cp, size)) < 0) {
168 PyErr_SetFromErrno(LinuxAudioError);
169 Py_DECREF(rv);
170 return NULL;
171 }
172 self->x_icount += count;
173 _PyString_Resize(&rv, count);
174 return rv;
175}
176
177static PyObject *
178lad_write(lad_t *self, PyObject *args)
179{
180 char *cp;
181 int rv, size;
182 fd_set write_set_fds;
183 struct timeval tv;
184 int select_retval;
185
186 if (!PyArg_ParseTuple(args, "s#:write", &cp, &size))
187 return NULL;
188
189 /* use select to wait for audio device to be available */
190 FD_ZERO(&write_set_fds);
191 FD_SET(self->x_fd, &write_set_fds);
192 tv.tv_sec = 4; /* timeout values */
193 tv.tv_usec = 0;
194
195 while (size > 0) {
196 select_retval = select(self->x_fd+1, NULL, &write_set_fds, NULL, &tv);
197 tv.tv_sec = 1; tv.tv_usec = 0; /* willing to wait this long next time*/
198 if (select_retval) {
199 if ((rv = write(self->x_fd, cp, size)) == -1) {
200 if (errno != EAGAIN) {
201 PyErr_SetFromErrno(LinuxAudioError);
202 return NULL;
203 } else {
204 errno = 0; /* EAGAIN: buffer is full, try again */
205 }
206 } else {
207 self->x_ocount += rv;
208 size -= rv;
209 cp += rv;
210 }
211 } else {
212 /* printf("Not able to write to linux audio device within %ld seconds\n", tv.tv_sec); */
213 PyErr_SetFromErrno(LinuxAudioError);
214 return NULL;
215 }
216 }
217 Py_INCREF(Py_None);
218 return Py_None;
219}
220
221static PyObject *
222lad_close(lad_t *self, PyObject *unused)
223{
224 if (self->x_fd >= 0) {
225 close(self->x_fd);
226 self->x_fd = -1;
227 }
228 Py_RETURN_NONE;
229}
230
231static PyObject *
232lad_fileno(lad_t *self, PyObject *unused)
233{
234 return PyInt_FromLong(self->x_fd);
235}
236
237static PyObject *
238lad_setparameters(lad_t *self, PyObject *args)
239{
240 int rate, ssize, nchannels, n, fmt, emulate=0;
241
242 if (!PyArg_ParseTuple(args, "iiii|i:setparameters",
243 &rate, &ssize, &nchannels, &fmt, &emulate))
244 return NULL;
245
246 if (rate < 0) {
247 PyErr_Format(PyExc_ValueError, "expected rate >= 0, not %d",
248 rate);
249 return NULL;
250 }
251 if (ssize < 0) {
252 PyErr_Format(PyExc_ValueError, "expected sample size >= 0, not %d",
253 ssize);
254 return NULL;
255 }
256 if (nchannels != 1 && nchannels != 2) {
257 PyErr_Format(PyExc_ValueError, "nchannels must be 1 or 2, not %d",
258 nchannels);
259 return NULL;
260 }
261
262 for (n = 0; n < n_audio_types; n++)
263 if (fmt == audio_types[n].a_fmt)
264 break;
265 if (n == n_audio_types) {
266 PyErr_Format(PyExc_ValueError, "unknown audio encoding: %d", fmt);
267 return NULL;
268 }
269 if (audio_types[n].a_bps != ssize) {
270 PyErr_Format(PyExc_ValueError,
271 "for %s, expected sample size %d, not %d",
272 audio_types[n].a_name, audio_types[n].a_bps, ssize);
273 return NULL;
274 }
275
276 if (emulate == 0) {
277 if ((self->x_afmts & audio_types[n].a_fmt) == 0) {
278 PyErr_Format(PyExc_ValueError,
279 "%s format not supported by device",
280 audio_types[n].a_name);
281 return NULL;
282 }
283 }
284 if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT,
285 &audio_types[n].a_fmt) == -1) {
286 PyErr_SetFromErrno(LinuxAudioError);
287 return NULL;
288 }
289 if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, &nchannels) == -1) {
290 PyErr_SetFromErrno(LinuxAudioError);
291 return NULL;
292 }
293 if (ioctl(self->x_fd, SNDCTL_DSP_SPEED, &rate) == -1) {
294 PyErr_SetFromErrno(LinuxAudioError);
295 return NULL;
296 }
297
298 Py_INCREF(Py_None);
299 return Py_None;
300}
301
302static int
303_ssize(lad_t *self, int *nchannels, int *ssize)
304{
305 int fmt;
306
307 fmt = 0;
308 if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT, &fmt) < 0)
309 return -errno;
310
311 switch (fmt) {
312 case AFMT_MU_LAW:
313 case AFMT_A_LAW:
314 case AFMT_U8:
315 case AFMT_S8:
316 *ssize = sizeof(char);
317 break;
318 case AFMT_S16_LE:
319 case AFMT_S16_BE:
320 case AFMT_U16_LE:
321 case AFMT_U16_BE:
322 *ssize = sizeof(short);
323 break;
324 case AFMT_MPEG:
325 case AFMT_IMA_ADPCM:
326 default:
327 return -EOPNOTSUPP;
328 }
329 if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, nchannels) < 0)
330 return -errno;
331 return 0;
332}
333
334
335/* bufsize returns the size of the hardware audio buffer in number
336 of samples */
337static PyObject *
338lad_bufsize(lad_t *self, PyObject *unused)
339{
340 audio_buf_info ai;
341 int nchannels=0, ssize=0;
342
343 if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) {
344 PyErr_SetFromErrno(LinuxAudioError);
345 return NULL;
346 }
347 if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
348 PyErr_SetFromErrno(LinuxAudioError);
349 return NULL;
350 }
351 return PyInt_FromLong((ai.fragstotal * ai.fragsize) / (nchannels * ssize));
352}
353
354/* obufcount returns the number of samples that are available in the
355 hardware for playing */
356static PyObject *
357lad_obufcount(lad_t *self, PyObject *unused)
358{
359 audio_buf_info ai;
360 int nchannels=0, ssize=0;
361
362 if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) {
363 PyErr_SetFromErrno(LinuxAudioError);
364 return NULL;
365 }
366 if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
367 PyErr_SetFromErrno(LinuxAudioError);
368 return NULL;
369 }
370 return PyInt_FromLong((ai.fragstotal * ai.fragsize - ai.bytes) /
371 (ssize * nchannels));
372}
373
374/* obufcount returns the number of samples that can be played without
375 blocking */
376static PyObject *
377lad_obuffree(lad_t *self, PyObject *unused)
378{
379 audio_buf_info ai;
380 int nchannels=0, ssize=0;
381
382 if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) {
383 PyErr_SetFromErrno(LinuxAudioError);
384 return NULL;
385 }
386 if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
387 PyErr_SetFromErrno(LinuxAudioError);
388 return NULL;
389 }
390 return PyInt_FromLong(ai.bytes / (ssize * nchannels));
391}
392
393/* Flush the device */
394static PyObject *
395lad_flush(lad_t *self, PyObject *unused)
396{
397 if (ioctl(self->x_fd, SNDCTL_DSP_SYNC, NULL) == -1) {
398 PyErr_SetFromErrno(LinuxAudioError);
399 return NULL;
400 }
401 Py_RETURN_NONE;
402}
403
404static PyObject *
405lad_getptr(lad_t *self, PyObject *unused)
406{
407 count_info info;
408 int req;
409
410 if (self->x_mode == O_RDONLY)
411 req = SNDCTL_DSP_GETIPTR;
412 else
413 req = SNDCTL_DSP_GETOPTR;
414 if (ioctl(self->x_fd, req, &info) == -1) {
415 PyErr_SetFromErrno(LinuxAudioError);
416 return NULL;
417 }
418 return Py_BuildValue("iii", info.bytes, info.blocks, info.ptr);
419}
420
421static PyMethodDef lad_methods[] = {
422 { "read", (PyCFunction)lad_read, METH_VARARGS },
423 { "write", (PyCFunction)lad_write, METH_VARARGS },
424 { "setparameters", (PyCFunction)lad_setparameters, METH_VARARGS },
425 { "bufsize", (PyCFunction)lad_bufsize, METH_VARARGS },
426 { "obufcount", (PyCFunction)lad_obufcount, METH_NOARGS },
427 { "obuffree", (PyCFunction)lad_obuffree, METH_NOARGS },
428 { "flush", (PyCFunction)lad_flush, METH_NOARGS },
429 { "close", (PyCFunction)lad_close, METH_NOARGS },
430 { "fileno", (PyCFunction)lad_fileno, METH_NOARGS },
431 { "getptr", (PyCFunction)lad_getptr, METH_NOARGS },
432 { NULL, NULL} /* sentinel */
433};
434
435static PyObject *
436lad_getattr(lad_t *xp, char *name)
437{
438 return Py_FindMethod(lad_methods, (PyObject *)xp, name);
439}
440
441static PyTypeObject Ladtype = {
442 PyObject_HEAD_INIT(&PyType_Type)
443 0, /*ob_size*/
444 "linuxaudiodev.linux_audio_device", /*tp_name*/
445 sizeof(lad_t), /*tp_size*/
446 0, /*tp_itemsize*/
447 /* methods */
448 (destructor)lad_dealloc, /*tp_dealloc*/
449 0, /*tp_print*/
450 (getattrfunc)lad_getattr, /*tp_getattr*/
451 0, /*tp_setattr*/
452 0, /*tp_compare*/
453 0, /*tp_repr*/
454};
455
456static PyObject *
457ladopen(PyObject *self, PyObject *args)
458{
459 return (PyObject *)newladobject(args);
460}
461
462static PyMethodDef linuxaudiodev_methods[] = {
463 { "open", ladopen, METH_VARARGS },
464 { 0, 0 },
465};
466
467void
468initlinuxaudiodev(void)
469{
470 PyObject *m;
471
472 m = Py_InitModule("linuxaudiodev", linuxaudiodev_methods);
473 if (m == NULL)
474 return;
475
476 LinuxAudioError = PyErr_NewException("linuxaudiodev.error", NULL, NULL);
477 if (LinuxAudioError)
478 PyModule_AddObject(m, "error", LinuxAudioError);
479
480 if (PyModule_AddIntConstant(m, "AFMT_MU_LAW", (long)AFMT_MU_LAW) == -1)
481 return;
482 if (PyModule_AddIntConstant(m, "AFMT_A_LAW", (long)AFMT_A_LAW) == -1)
483 return;
484 if (PyModule_AddIntConstant(m, "AFMT_U8", (long)AFMT_U8) == -1)
485 return;
486 if (PyModule_AddIntConstant(m, "AFMT_S8", (long)AFMT_S8) == -1)
487 return;
488 if (PyModule_AddIntConstant(m, "AFMT_U16_BE", (long)AFMT_U16_BE) == -1)
489 return;
490 if (PyModule_AddIntConstant(m, "AFMT_U16_LE", (long)AFMT_U16_LE) == -1)
491 return;
492 if (PyModule_AddIntConstant(m, "AFMT_S16_BE", (long)AFMT_S16_BE) == -1)
493 return;
494 if (PyModule_AddIntConstant(m, "AFMT_S16_LE", (long)AFMT_S16_LE) == -1)
495 return;
496 if (PyModule_AddIntConstant(m, "AFMT_S16_NE", (long)AFMT_S16_NE) == -1)
497 return;
498
499 return;
500}
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