ref: e6b4528626528c2bf11f760bfc660375195e6055
dir: /sys/src/cmd/python/Modules/linuxaudiodev.c/
/* 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> #ifndef HAVE_STDINT_H typedef unsigned long uint32_t; #endif #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]); static PyTypeObject Ladtype; static PyObject *LinuxAudioError; static lad_t * newladobject(PyObject *arg) { lad_t *xp; int fd, afmts, imode; char *basedev = NULL; char *mode = NULL; /* Two ways to call linuxaudiodev.open(): open(device, mode) (for consistency with builtin open()) open(mode) (for backwards compatibility) because the *first* argument is optional, parsing args is a wee bit tricky. */ if (!PyArg_ParseTuple(arg, "s|s:open", &basedev, &mode)) return NULL; if (mode == NULL) { /* only one arg supplied */ mode = basedev; basedev = 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. */ if (basedev == NULL) { /* called with one arg */ basedev = getenv("AUDIODEV"); if (basedev == NULL) /* $AUDIODEV not set */ 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; _PyString_Resize(&rv, count); 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 *unused) { if (self->x_fd >= 0) { close(self->x_fd); self->x_fd = -1; } Py_RETURN_NONE; } static PyObject * lad_fileno(lad_t *self, PyObject *unused) { 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; } 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 *unused) { audio_buf_info ai; int nchannels=0, ssize=0; if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) { 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 *unused) { audio_buf_info ai; int nchannels=0, ssize=0; if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) { 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 *unused) { audio_buf_info ai; int nchannels=0, ssize=0; if (_ssize(self, &nchannels, &ssize) < 0 || !ssize || !nchannels) { 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 *unused) { if (ioctl(self->x_fd, SNDCTL_DSP_SYNC, NULL) == -1) { PyErr_SetFromErrno(LinuxAudioError); return NULL; } Py_RETURN_NONE; } static PyObject * lad_getptr(lad_t *self, PyObject *unused) { count_info info; int req; 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_NOARGS }, { "obuffree", (PyCFunction)lad_obuffree, METH_NOARGS }, { "flush", (PyCFunction)lad_flush, METH_NOARGS }, { "close", (PyCFunction)lad_close, METH_NOARGS }, { "fileno", (PyCFunction)lad_fileno, METH_NOARGS }, { "getptr", (PyCFunction)lad_getptr, METH_NOARGS }, { 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); if (m == NULL) return; 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; }