ossaudiodev -- Python interface to the OSS (Open Sound System) API.
This module is a replacement for linuxaudiodev, which will eventually be deprecated. Initial revision is rev 2.20 of linuxaudiodev.c, with a rewritten header comment.
This commit is contained in:
Greg Ward
parent
888e100356
commit
04613a9308
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@ -0,0 +1,524 @@
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/*
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* ossaudiodev -- Python interface to the OSS (Open Sound System) API.
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* This is the standard audio API for Linux and some
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* flavours of BSD [XXX which ones?]; it is also available
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* for a wide range of commercial Unices.
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*
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* Originally written by Peter Bosch, March 2000, as linuxaudiodev.
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*
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* Renamed to ossaudiodev and rearranged/revised/hacked up
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* by Greg Ward <gward@python.net>, November 2002.
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*
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* (c) 2000 Peter Bosch. All Rights Reserved.
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* (c) 2002 Gregory P. Ward. All Rights Reserved.
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* (c) 2002 Python Software Foundation. All Rights Reserved.
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*
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* XXX need a license statement
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*
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* $Id$
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*/
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#include "Python.h"
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#include "structmember.h"
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#ifdef HAVE_FCNTL_H
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#include <fcntl.h>
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#else
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#define O_RDONLY 00
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#define O_WRONLY 01
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#endif
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#include <sys/ioctl.h>
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#if defined(linux)
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#include <linux/soundcard.h>
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typedef unsigned long uint32_t;
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#elif defined(__FreeBSD__)
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#include <machine/soundcard.h>
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#ifndef SNDCTL_DSP_CHANNELS
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#define SNDCTL_DSP_CHANNELS SOUND_PCM_WRITE_CHANNELS
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#endif
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#endif
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typedef struct {
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PyObject_HEAD;
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int x_fd; /* The open file */
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int x_mode; /* file mode */
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int x_icount; /* Input count */
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int x_ocount; /* Output count */
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uint32_t x_afmts; /* Audio formats supported by hardware*/
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} lad_t;
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/* XXX several format defined in soundcard.h are not supported,
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including _NE (native endian) options and S32 options
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*/
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static struct {
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int a_bps;
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uint32_t a_fmt;
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char *a_name;
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} audio_types[] = {
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{ 8, AFMT_MU_LAW, "logarithmic mu-law 8-bit audio" },
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{ 8, AFMT_A_LAW, "logarithmic A-law 8-bit audio" },
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{ 8, AFMT_U8, "linear unsigned 8-bit audio" },
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{ 8, AFMT_S8, "linear signed 8-bit audio" },
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{ 16, AFMT_U16_BE, "linear unsigned 16-bit big-endian audio" },
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{ 16, AFMT_U16_LE, "linear unsigned 16-bit little-endian audio" },
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{ 16, AFMT_S16_BE, "linear signed 16-bit big-endian audio" },
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{ 16, AFMT_S16_LE, "linear signed 16-bit little-endian audio" },
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{ 16, AFMT_S16_NE, "linear signed 16-bit native-endian audio" },
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};
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static int n_audio_types = sizeof(audio_types) / sizeof(audio_types[0]);
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static PyTypeObject Ladtype;
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static PyObject *LinuxAudioError;
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static lad_t *
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newladobject(PyObject *arg)
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{
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lad_t *xp;
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int fd, afmts, imode;
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char *basedev = NULL;
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char *mode = NULL;
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/* Two ways to call linuxaudiodev.open():
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open(device, mode) (for consistency with builtin open())
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open(mode) (for backwards compatibility)
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because the *first* argument is optional, parsing args is
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a wee bit tricky. */
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if (!PyArg_ParseTuple(arg, "s|s:open", &basedev, &mode))
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return NULL;
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if (mode == NULL) { /* only one arg supplied */
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mode = basedev;
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basedev = NULL;
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}
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if (strcmp(mode, "r") == 0)
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imode = O_RDONLY;
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else if (strcmp(mode, "w") == 0)
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imode = O_WRONLY;
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else {
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PyErr_SetString(LinuxAudioError, "mode should be 'r' or 'w'");
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return NULL;
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}
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/* Open the correct device. The base device name comes from the
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* AUDIODEV environment variable first, then /dev/dsp. The
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* control device tacks "ctl" onto the base device name.
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*
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* Note that the only difference between /dev/audio and /dev/dsp
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* is that the former uses logarithmic mu-law encoding and the
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* latter uses 8-bit unsigned encoding.
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*/
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if (basedev == NULL) { /* called with one arg */
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basedev = getenv("AUDIODEV");
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if (basedev == NULL) /* $AUDIODEV not set */
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basedev = "/dev/dsp";
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}
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if ((fd = open(basedev, imode)) == -1) {
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PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
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return NULL;
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}
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if (imode == O_WRONLY && ioctl(fd, SNDCTL_DSP_NONBLOCK, NULL) == -1) {
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PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
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return NULL;
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}
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if (ioctl(fd, SNDCTL_DSP_GETFMTS, &afmts) == -1) {
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PyErr_SetFromErrnoWithFilename(LinuxAudioError, basedev);
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return NULL;
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}
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/* Create and initialize the object */
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if ((xp = PyObject_New(lad_t, &Ladtype)) == NULL) {
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close(fd);
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return NULL;
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}
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xp->x_fd = fd;
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xp->x_mode = imode;
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xp->x_icount = xp->x_ocount = 0;
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xp->x_afmts = afmts;
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return xp;
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}
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static void
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lad_dealloc(lad_t *xp)
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{
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/* if already closed, don't reclose it */
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if (xp->x_fd != -1)
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close(xp->x_fd);
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PyObject_Del(xp);
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}
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static PyObject *
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lad_read(lad_t *self, PyObject *args)
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{
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int size, count;
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char *cp;
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PyObject *rv;
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if (!PyArg_ParseTuple(args, "i:read", &size))
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return NULL;
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rv = PyString_FromStringAndSize(NULL, size);
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if (rv == NULL)
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return NULL;
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cp = PyString_AS_STRING(rv);
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if ((count = read(self->x_fd, cp, size)) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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Py_DECREF(rv);
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return NULL;
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}
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self->x_icount += count;
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_PyString_Resize(&rv, count);
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return rv;
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}
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static PyObject *
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lad_write(lad_t *self, PyObject *args)
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{
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char *cp;
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int rv, size;
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fd_set write_set_fds;
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struct timeval tv;
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int select_retval;
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if (!PyArg_ParseTuple(args, "s#:write", &cp, &size))
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return NULL;
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/* use select to wait for audio device to be available */
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FD_ZERO(&write_set_fds);
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FD_SET(self->x_fd, &write_set_fds);
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tv.tv_sec = 4; /* timeout values */
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tv.tv_usec = 0;
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while (size > 0) {
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select_retval = select(self->x_fd+1, NULL, &write_set_fds, NULL, &tv);
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tv.tv_sec = 1; tv.tv_usec = 0; /* willing to wait this long next time*/
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if (select_retval) {
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if ((rv = write(self->x_fd, cp, size)) == -1) {
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if (errno != EAGAIN) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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} else {
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errno = 0; /* EAGAIN: buffer is full, try again */
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}
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} else {
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self->x_ocount += rv;
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size -= rv;
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cp += rv;
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}
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} else {
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/* printf("Not able to write to linux audio device within %ld seconds\n", tv.tv_sec); */
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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}
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Py_INCREF(Py_None);
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return Py_None;
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}
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static PyObject *
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lad_close(lad_t *self, PyObject *args)
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{
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if (!PyArg_ParseTuple(args, ":close"))
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return NULL;
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if (self->x_fd >= 0) {
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close(self->x_fd);
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self->x_fd = -1;
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}
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Py_INCREF(Py_None);
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return Py_None;
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}
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static PyObject *
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lad_fileno(lad_t *self, PyObject *args)
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{
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if (!PyArg_ParseTuple(args, ":fileno"))
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return NULL;
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return PyInt_FromLong(self->x_fd);
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}
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static PyObject *
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lad_setparameters(lad_t *self, PyObject *args)
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{
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int rate, ssize, nchannels, n, fmt, emulate=0;
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if (!PyArg_ParseTuple(args, "iiii|i:setparameters",
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&rate, &ssize, &nchannels, &fmt, &emulate))
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return NULL;
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if (rate < 0) {
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PyErr_Format(PyExc_ValueError, "expected rate >= 0, not %d",
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rate);
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return NULL;
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}
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if (ssize < 0) {
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PyErr_Format(PyExc_ValueError, "expected sample size >= 0, not %d",
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ssize);
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return NULL;
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}
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if (nchannels != 1 && nchannels != 2) {
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PyErr_Format(PyExc_ValueError, "nchannels must be 1 or 2, not %d",
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nchannels);
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return NULL;
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}
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for (n = 0; n < n_audio_types; n++)
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if (fmt == audio_types[n].a_fmt)
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break;
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if (n == n_audio_types) {
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PyErr_Format(PyExc_ValueError, "unknown audio encoding: %d", fmt);
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return NULL;
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}
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if (audio_types[n].a_bps != ssize) {
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PyErr_Format(PyExc_ValueError,
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"for %s, expected sample size %d, not %d",
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audio_types[n].a_name, audio_types[n].a_bps, ssize);
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return NULL;
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}
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if (emulate == 0) {
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if ((self->x_afmts & audio_types[n].a_fmt) == 0) {
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PyErr_Format(PyExc_ValueError,
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"%s format not supported by device",
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audio_types[n].a_name);
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return NULL;
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}
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}
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if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT,
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&audio_types[n].a_fmt) == -1) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, &nchannels) == -1) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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if (ioctl(self->x_fd, SNDCTL_DSP_SPEED, &rate) == -1) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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Py_INCREF(Py_None);
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return Py_None;
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}
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static int
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_ssize(lad_t *self, int *nchannels, int *ssize)
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{
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int fmt;
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fmt = 0;
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if (ioctl(self->x_fd, SNDCTL_DSP_SETFMT, &fmt) < 0)
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return -errno;
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switch (fmt) {
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case AFMT_MU_LAW:
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case AFMT_A_LAW:
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case AFMT_U8:
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case AFMT_S8:
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*ssize = sizeof(char);
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break;
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case AFMT_S16_LE:
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case AFMT_S16_BE:
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case AFMT_U16_LE:
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case AFMT_U16_BE:
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*ssize = sizeof(short);
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break;
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case AFMT_MPEG:
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case AFMT_IMA_ADPCM:
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default:
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return -EOPNOTSUPP;
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}
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*nchannels = 0;
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if (ioctl(self->x_fd, SNDCTL_DSP_CHANNELS, nchannels) < 0)
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return -errno;
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return 0;
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}
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/* bufsize returns the size of the hardware audio buffer in number
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of samples */
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static PyObject *
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lad_bufsize(lad_t *self, PyObject *args)
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{
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audio_buf_info ai;
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int nchannels, ssize;
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if (!PyArg_ParseTuple(args, ":bufsize")) return NULL;
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if (_ssize(self, &nchannels, &ssize) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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return PyInt_FromLong((ai.fragstotal * ai.fragsize) / (nchannels * ssize));
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}
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/* obufcount returns the number of samples that are available in the
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hardware for playing */
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static PyObject *
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lad_obufcount(lad_t *self, PyObject *args)
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{
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audio_buf_info ai;
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int nchannels, ssize;
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if (!PyArg_ParseTuple(args, ":obufcount"))
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return NULL;
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if (_ssize(self, &nchannels, &ssize) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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return PyInt_FromLong((ai.fragstotal * ai.fragsize - ai.bytes) /
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(ssize * nchannels));
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}
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/* obufcount returns the number of samples that can be played without
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blocking */
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static PyObject *
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lad_obuffree(lad_t *self, PyObject *args)
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{
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audio_buf_info ai;
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int nchannels, ssize;
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if (!PyArg_ParseTuple(args, ":obuffree"))
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return NULL;
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if (_ssize(self, &nchannels, &ssize) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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if (ioctl(self->x_fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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return PyInt_FromLong(ai.bytes / (ssize * nchannels));
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}
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/* Flush the device */
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static PyObject *
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lad_flush(lad_t *self, PyObject *args)
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{
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if (!PyArg_ParseTuple(args, ":flush")) return NULL;
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if (ioctl(self->x_fd, SNDCTL_DSP_SYNC, NULL) == -1) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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Py_INCREF(Py_None);
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return Py_None;
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}
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static PyObject *
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lad_getptr(lad_t *self, PyObject *args)
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{
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count_info info;
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int req;
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if (!PyArg_ParseTuple(args, ":getptr"))
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return NULL;
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if (self->x_mode == O_RDONLY)
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req = SNDCTL_DSP_GETIPTR;
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else
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req = SNDCTL_DSP_GETOPTR;
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if (ioctl(self->x_fd, req, &info) == -1) {
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PyErr_SetFromErrno(LinuxAudioError);
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return NULL;
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}
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return Py_BuildValue("iii", info.bytes, info.blocks, info.ptr);
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}
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static PyMethodDef lad_methods[] = {
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{ "read", (PyCFunction)lad_read, METH_VARARGS },
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{ "write", (PyCFunction)lad_write, METH_VARARGS },
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{ "setparameters", (PyCFunction)lad_setparameters, METH_VARARGS },
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{ "bufsize", (PyCFunction)lad_bufsize, METH_VARARGS },
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{ "obufcount", (PyCFunction)lad_obufcount, METH_VARARGS },
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{ "obuffree", (PyCFunction)lad_obuffree, METH_VARARGS },
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{ "flush", (PyCFunction)lad_flush, METH_VARARGS },
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{ "close", (PyCFunction)lad_close, METH_VARARGS },
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{ "fileno", (PyCFunction)lad_fileno, METH_VARARGS },
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{ "getptr", (PyCFunction)lad_getptr, METH_VARARGS },
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{ NULL, NULL} /* sentinel */
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};
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static PyObject *
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lad_getattr(lad_t *xp, char *name)
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{
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return Py_FindMethod(lad_methods, (PyObject *)xp, name);
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}
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static PyTypeObject Ladtype = {
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||||
PyObject_HEAD_INIT(&PyType_Type)
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0, /*ob_size*/
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"linuxaudiodev.linux_audio_device", /*tp_name*/
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sizeof(lad_t), /*tp_size*/
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0, /*tp_itemsize*/
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/* methods */
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(destructor)lad_dealloc, /*tp_dealloc*/
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0, /*tp_print*/
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(getattrfunc)lad_getattr, /*tp_getattr*/
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0, /*tp_setattr*/
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0, /*tp_compare*/
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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;
|
||||
}
|
||||
Loading…
Reference in New Issue