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| -rw-r--r-- | Modules/ossaudiodev.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/Modules/ossaudiodev.c b/Modules/ossaudiodev.c new file mode 100644 index 0000000..96f54af --- /dev/null +++ b/Modules/ossaudiodev.c @@ -0,0 +1,524 @@ +/* + * ossaudiodev -- Python interface to the OSS (Open Sound System) API. + * This is the standard audio API for Linux and some + * flavours of BSD [XXX which ones?]; it is also available + * for a wide range of commercial Unices. + * + * Originally written by Peter Bosch, March 2000, as linuxaudiodev. + * + * Renamed to ossaudiodev and rearranged/revised/hacked up + * by Greg Ward <gward@python.net>, November 2002. + * + * (c) 2000 Peter Bosch. All Rights Reserved. + * (c) 2002 Gregory P. Ward. All Rights Reserved. + * (c) 2002 Python Software Foundation. All Rights Reserved. + * + * XXX need a license statement + * + * $Id$ + */ + +#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]); + +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 *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; +} |