cpython/Modules/linuxaudiodev.c

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/* Hey Emacs, this is -*-C-*-
******************************************************************************
* linuxaudiodev.c -- Linux audio device for python.
*
* Author : Peter Bosch
* Created On : Thu Mar 2 21:10:33 2000
* Last Modified By: Peter Bosch
* Last Modified On: Fri Mar 24 11:27:00 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_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <sys/ioctl.h>
#include <linux/soundcard.h>
typedef unsigned long uint32_t;
typedef struct {
PyObject_HEAD;
int x_fd; /* The open file */
int x_icount; /* Input count */
int x_ocount; /* Output count */
uint32_t x_afmts; /* Supported audio formats */
} lad_t;
static struct {
int a_bps;
uint32_t a_fmt;
} audio_types[] = {
{ 8, AFMT_MU_LAW },
{ 8, AFMT_U8 },
{ 8, AFMT_S8 },
{ 16, AFMT_U16_BE },
{ 16, AFMT_U16_LE },
{ 16, AFMT_S16_BE },
{ 16, AFMT_S16_LE },
};
staticforward PyTypeObject Ladtype;
static PyObject *LinuxAudioError;
static lad_t *
newladobject(PyObject *arg)
{
lad_t *xp;
int fd, afmts, imode;
char *mode;
char *basedev;
char *ctldev;
char *opendev;
/* Check arg for r/w/rw */
if (!PyArg_ParseTuple(arg, "s", &mode)) return NULL;
if (strcmp(mode, "r") == 0)
imode = 0;
else if (strcmp(mode, "w") == 0)
imode = 1;
else {
PyErr_SetString(LinuxAudioError, "Mode should be one of 'r', or 'w'");
return NULL;
}
/* Open the correct device. The base device name comes from the
* AUDIODEV environment variable first, then /dev/audio. The
* control device tacks "ctl" onto the base device name.
*/
basedev = getenv("AUDIODEV");
if (!basedev)
basedev = "/dev/dsp";
if ((fd = open(basedev, imode)) < 0) {
PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
return NULL;
}
if (imode) {
if (ioctl(fd, SNDCTL_DSP_NONBLOCK, NULL) < 0) {
PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
return NULL;
}
}
if (ioctl(fd, SNDCTL_DSP_GETFMTS, &afmts) < 0) {
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_icount = xp->x_ocount = 0;
xp->x_afmts = afmts;
return xp;
}
static void
lad_dealloc(lad_t *xp)
{
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", &size)) return NULL;
rv = PyString_FromStringAndSize(NULL, size);
if (rv == NULL) return NULL;
if (!(cp = PyString_AsString(rv))) {
Py_DECREF(rv);
return NULL;
}
if ((count = read(self->x_fd, cp, size)) < 0) {
PyErr_SetFromErrno(LinuxAudioError);
Py_DECREF(rv);
return NULL;
}
self->x_icount += count;
return rv;
}
static PyObject *
lad_write(lad_t *self, PyObject *args)
{
char *cp;
int rv, size;
if (!PyArg_ParseTuple(args, "s#", &cp, &size)) return NULL;
while (size > 0) {
if ((rv = write(self->x_fd, cp, size)) < 0) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
self->x_ocount += rv;
size -= rv;
cp += rv;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyObject *
lad_close(lad_t *self, PyObject *args)
{
if (!PyArg_ParseTuple(args, "")) 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, "")) return NULL;
return PyInt_FromLong(self->x_fd);
}
static PyObject *
lad_setparameters(lad_t *self, PyObject *args)
{
int rate, ssize, nchannels, stereo, n, fmt;
if (!PyArg_ParseTuple(args, "iiii", &rate, &ssize, &nchannels, &fmt))
return NULL;
if (rate < 0 || ssize < 0 || (nchannels != 1 && nchannels != 2)) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
if (ioctl(self->x_fd, SOUND_PCM_WRITE_RATE, &rate) < 0) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
if (ioctl(self->x_fd, SNDCTL_DSP_SAMPLESIZE, &ssize) < 0) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
stereo = (nchannels == 1)? 0: (nchannels == 2)? 1: -1;
if (ioctl(self->x_fd, SNDCTL_DSP_STEREO, &stereo) < 0) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
for (n = 0; n != sizeof(audio_types) / sizeof(audio_types[0]); n++)
if (fmt == audio_types[n].a_fmt)
break;
if (n == sizeof(audio_types) / sizeof(audio_types[0]) ||
audio_types[n].a_bps != ssize ||
(self->x_afmts & audio_types[n].a_fmt) == 0) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT, &audio_types[n].a_fmt) < 0) {
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, "")) 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, "")) 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, "")) 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, "")) return NULL;
if (ioctl(self->x_fd, SNDCTL_DSP_SYNC, NULL) < 0) {
PyErr_SetFromErrno(LinuxAudioError);
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef lad_methods[] = {
{ "read", (PyCFunction)lad_read, 1 },
{ "write", (PyCFunction)lad_write, 1 },
{ "setparameters", (PyCFunction)lad_setparameters, 1 },
{ "bufsize", (PyCFunction)lad_bufsize, 1 },
{ "obufcount", (PyCFunction)lad_obufcount, 1 },
{ "obuffree", (PyCFunction)lad_obuffree, 1 },
{ "flush", (PyCFunction)lad_flush, 1 },
{ "close", (PyCFunction)lad_close, 1 },
{ "fileno", (PyCFunction)lad_fileno, 1 },
{ 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*/
"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, 1 },
{ 0, 0 },
};
static int
ins(PyObject *d, char *symbol, long value)
{
PyObject* v = PyInt_FromLong(value);
if (!v || PyDict_SetItemString(d, symbol, v) < 0)
return -1; /* triggers fatal error */
Py_DECREF(v);
return 0;
}
void
initlinuxaudiodev()
{
PyObject *m, *d, *x;
m = Py_InitModule("linuxaudiodev", linuxaudiodev_methods);
d = PyModule_GetDict(m);
LinuxAudioError = PyErr_NewException("linuxaudiodev.error", NULL, NULL);
if (LinuxAudioError)
PyDict_SetItemString(d, "error", LinuxAudioError);
x = PyInt_FromLong((long) AFMT_MU_LAW);
if (x == NULL || PyDict_SetItemString(d, "AFMT_MU_LAW", x) < 0)
goto error;
Py_DECREF(x);
x = PyInt_FromLong((long) AFMT_U8);
if (x == NULL || PyDict_SetItemString(d, "AFMT_U8", x) < 0)
goto error;
Py_DECREF(x);
x = PyInt_FromLong((long) AFMT_S8);
if (x == NULL || PyDict_SetItemString(d, "AFMT_S8", x) < 0)
goto error;
Py_DECREF(x);
x = PyInt_FromLong((long) AFMT_U16_BE);
if (x == NULL || PyDict_SetItemString(d, "AFMT_U16_BE", x) < 0)
goto error;
Py_DECREF(x);
x = PyInt_FromLong((long) AFMT_U16_LE);
if (x == NULL || PyDict_SetItemString(d, "AFMT_U16_LE", x) < 0)
goto error;
Py_DECREF(x);
x = PyInt_FromLong((long) AFMT_S16_BE);
if (x == NULL || PyDict_SetItemString(d, "AFMT_S16_BE", x) < 0)
goto error;
Py_DECREF(x);
x = PyInt_FromLong((long) AFMT_S16_LE);
if (x == NULL || PyDict_SetItemString(d, "AFMT_S16_LE", x) < 0)
goto error;
Py_DECREF(x);
/* Check for errors */
if (PyErr_Occurred()) {
error:
Py_FatalError("can't initialize module linuxaudiodev");
}
}