/* 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 = {

    PyVarObject_HEAD_INIT(&PyType_Type, 0)

    "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;

    if (PyErr_WarnPy3k("the linuxaudiodev module has been removed in "

                    "Python 3.0; use the ossaudiodev module instead", 2) < 0)

        return;

    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;

}