1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
Modules/ossaudiodev.c
/*
 * 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.
 * Mixer interface by Nicholas FitzRoy-Dale <wzdd@lardcave.net>, Dec 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>
#include <sys/soundcard.h>

#if defined(linux)

#ifndef HAVE_STDINT_H
typedef unsigned long uint32_t;
#endif

#elif defined(__FreeBSD__)

# ifndef SNDCTL_DSP_CHANNELS
#  define SNDCTL_DSP_CHANNELS SOUND_PCM_WRITE_CHANNELS
# endif

#endif

typedef struct {
    PyObject_HEAD
    char    *devicename;              /* name of the device file */
    int      fd;                      /* file descriptor */
    int      mode;                    /* file mode (O_RDONLY, etc.) */
    int      icount;                  /* input count */
    int      ocount;                  /* output count */
    uint32_t afmts;                   /* audio formats supported by hardware */
} oss_audio_t;

typedef struct {
    PyObject_HEAD
    int      fd;                      /* The open mixer device */
} oss_mixer_t;


static PyTypeObject OSSAudioType;
static PyTypeObject OSSMixerType;

static PyObject *OSSAudioError;


/* ----------------------------------------------------------------------
 * DSP object initialization/deallocation
 */

static oss_audio_t *
newossobject(PyObject *arg)
{
    oss_audio_t *self;
    int fd, afmts, imode;
    char *devicename = NULL;
    char *mode = NULL;

    /* Two ways to call 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", &devicename, &mode))
       return NULL;
    if (mode == NULL) {                 /* only one arg supplied */
       mode = devicename;
       devicename = NULL;
    }

    if (strcmp(mode, "r") == 0)
        imode = O_RDONLY;
    else if (strcmp(mode, "w") == 0)
        imode = O_WRONLY;
    else if (strcmp(mode, "rw") == 0)
        imode = O_RDWR;
    else {
        PyErr_SetString(OSSAudioError, "mode must be 'r', 'w', or 'rw'");
        return NULL;
    }

    /* Open the correct device: either the 'device' argument,
       or the AUDIODEV environment variable, or "/dev/dsp". */
    if (devicename == NULL) {              /* called with one arg */
       devicename = getenv("AUDIODEV");
       if (devicename == NULL)             /* $AUDIODEV not set */
          devicename = "/dev/dsp";
    }

    /* Open with O_NONBLOCK to avoid hanging on devices that only allow
       one open at a time.  This does *not* affect later I/O; OSS
       provides a special ioctl() for non-blocking read/write, which is
       exposed via oss_nonblock() below. */
    if ((fd = open(devicename, imode|O_NONBLOCK)) == -1) {
        PyErr_SetFromErrnoWithFilename(PyExc_IOError, devicename);
        return NULL;
    }

    /* And (try to) put it back in blocking mode so we get the
       expected write() semantics. */
    if (fcntl(fd, F_SETFL, 0) == -1) {
        close(fd);
        PyErr_SetFromErrnoWithFilename(PyExc_IOError, devicename);
        return NULL;
    }

    if (ioctl(fd, SNDCTL_DSP_GETFMTS, &afmts) == -1) {
        close(fd);
        PyErr_SetFromErrnoWithFilename(PyExc_IOError, devicename);
        return NULL;
    }
    /* Create and initialize the object */
    if ((self = PyObject_New(oss_audio_t, &OSSAudioType)) == NULL) {
        close(fd);
        return NULL;
    }
    self->devicename = devicename;
    self->fd = fd;
    self->mode = imode;
    self->icount = self->ocount = 0;
    self->afmts  = afmts;
    return self;
}

static void
oss_dealloc(oss_audio_t *self)
{
    /* if already closed, don't reclose it */
    if (self->fd != -1)
        close(self->fd);
    PyObject_Del(self);
}


/* ----------------------------------------------------------------------
 * Mixer object initialization/deallocation
 */

static oss_mixer_t *
newossmixerobject(PyObject *arg)
{
    char *devicename = NULL;
    int fd;
    oss_mixer_t *self;

    if (!PyArg_ParseTuple(arg, "|s", &devicename)) {
        return NULL;
    }

    if (devicename == NULL) {
        devicename = getenv("MIXERDEV");
        if (devicename == NULL)            /* MIXERDEV not set */
            devicename = "/dev/mixer";
    }

    if ((fd = open(devicename, O_RDWR)) == -1) {
        PyErr_SetFromErrnoWithFilename(PyExc_IOError, devicename);
        return NULL;
    }

    if ((self = PyObject_New(oss_mixer_t, &OSSMixerType)) == NULL) {
        close(fd);
        return NULL;
    }

    self->fd = fd;

    return self;
}

static void
oss_mixer_dealloc(oss_mixer_t *self)
{
    /* if already closed, don't reclose it */
    if (self->fd != -1)
        close(self->fd);
    PyObject_Del(self);
}


/* Methods to wrap the OSS ioctls.  The calling convention is pretty
   simple:
     nonblock()        -> ioctl(fd, SNDCTL_DSP_NONBLOCK)
     fmt = setfmt(fmt) -> ioctl(fd, SNDCTL_DSP_SETFMT, &fmt)
     etc.
*/


/* ----------------------------------------------------------------------
 * Helper functions
 */

/* _do_ioctl_1() is a private helper function used for the OSS ioctls --
   SNDCTL_DSP_{SETFMT,CHANNELS,SPEED} -- that are called from C
   like this:
     ioctl(fd, SNDCTL_DSP_cmd, &arg)

   where arg is the value to set, and on return the driver sets arg to
   the value that was actually set.  Mapping this to Python is obvious:
     arg = dsp.xxx(arg)
*/
static PyObject *
_do_ioctl_1(int fd, PyObject *args, char *fname, int cmd)
{
    char argfmt[33] = "i:";
    int arg;

    assert(strlen(fname) <= 30);
    strcat(argfmt, fname);
    if (!PyArg_ParseTuple(args, argfmt, &arg))
        return NULL;

    if (ioctl(fd, cmd, &arg) == -1)
        return PyErr_SetFromErrno(PyExc_IOError);
    return PyInt_FromLong(arg);
}


/* _do_ioctl_1_internal() is a wrapper for ioctls that take no inputs
   but return an output -- ie. we need to pass a pointer to a local C
   variable so the driver can write its output there, but from Python
   all we see is the return value.  For example,
   SOUND_MIXER_READ_DEVMASK returns a bitmask of available mixer
   devices, but does not use the value of the parameter passed-in in any
   way.
*/
static PyObject *
_do_ioctl_1_internal(int fd, PyObject *args, char *fname, int cmd)
{
    char argfmt[32] = ":";
    int arg = 0;

    assert(strlen(fname) <= 30);
    strcat(argfmt, fname);
    if (!PyArg_ParseTuple(args, argfmt, &arg))
        return NULL;

    if (ioctl(fd, cmd, &arg) == -1)
        return PyErr_SetFromErrno(PyExc_IOError);
    return PyInt_FromLong(arg);
}



/* _do_ioctl_0() is a private helper for the no-argument ioctls:
   SNDCTL_DSP_{SYNC,RESET,POST}. */
static PyObject *
_do_ioctl_0(int fd, PyObject *args, char *fname, int cmd)
{
    char argfmt[32] = ":";
    int rv;

    assert(strlen(fname) <= 30);
    strcat(argfmt, fname);
    if (!PyArg_ParseTuple(args, argfmt))
        return NULL;

    /* According to hannu@opensound.com, all three of the ioctls that
       use this function can block, so release the GIL.  This is
       especially important for SYNC, which can block for several
       seconds. */
    Py_BEGIN_ALLOW_THREADS
    rv = ioctl(fd, cmd, 0);
    Py_END_ALLOW_THREADS

    if (rv == -1)
        return PyErr_SetFromErrno(PyExc_IOError);
    Py_INCREF(Py_None);
    return Py_None;
}


/* ----------------------------------------------------------------------
 * Methods of DSP objects (OSSAudioType)
 */

static PyObject *
oss_nonblock(oss_audio_t *self, PyObject *unused)
{
    /* Hmmm: it doesn't appear to be possible to return to blocking
       mode once we're in non-blocking mode! */
    if (ioctl(self->fd, SNDCTL_DSP_NONBLOCK, NULL) == -1)
        return PyErr_SetFromErrno(PyExc_IOError);
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
oss_setfmt(oss_audio_t *self, PyObject *args)
{
    return _do_ioctl_1(self->fd, args, "setfmt", SNDCTL_DSP_SETFMT);
}

static PyObject *
oss_getfmts(oss_audio_t *self, PyObject *unused)
{
    int mask;
    if (ioctl(self->fd, SNDCTL_DSP_GETFMTS, &mask) == -1)
        return PyErr_SetFromErrno(PyExc_IOError);
    return PyInt_FromLong(mask);
}

static PyObject *
oss_channels(oss_audio_t *self, PyObject *args)
{
    return _do_ioctl_1(self->fd, args, "channels", SNDCTL_DSP_CHANNELS);
}

static PyObject *
oss_speed(oss_audio_t *self, PyObject *args)
{
    return _do_ioctl_1(self->fd, args, "speed", SNDCTL_DSP_SPEED);
}

static PyObject *
oss_sync(oss_audio_t *self, PyObject *args)
{
    return _do_ioctl_0(self->fd, args, "sync", SNDCTL_DSP_SYNC);
}

static PyObject *
oss_reset(oss_audio_t *self, PyObject *args)
{
    return _do_ioctl_0(self->fd, args, "reset", SNDCTL_DSP_RESET);
}

static PyObject *
oss_post(oss_audio_t *self, PyObject *args)
{
    return _do_ioctl_0(self->fd, args, "post", SNDCTL_DSP_POST);
}


/* Regular file methods: read(), write(), close(), etc. as well
   as one convenience method, writeall(). */

static PyObject *
oss_read(oss_audio_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);

    Py_BEGIN_ALLOW_THREADS
    count = read(self->fd, cp, size);
    Py_END_ALLOW_THREADS

    if (count < 0) {
        PyErr_SetFromErrno(PyExc_IOError);
        Py_DECREF(rv);
        return NULL;
    }
    self->icount += count;
    _PyString_Resize(&rv, count);
    return rv;
}

static PyObject *
oss_write(oss_audio_t *self, PyObject *args)
{
    char *cp;
    int rv, size;

    if (!PyArg_ParseTuple(args, "s#:write", &cp, &size)) {
        return NULL;
    }

    Py_BEGIN_ALLOW_THREADS
    rv = write(self->fd, cp, size);
    Py_END_ALLOW_THREADS

    if (rv == -1) {
        return PyErr_SetFromErrno(PyExc_IOError);
    } else {
        self->ocount += rv;
    }
    return PyInt_FromLong(rv);
}

static PyObject *
oss_writeall(oss_audio_t *self, PyObject *args)
{
    char *cp;
    int rv, size;
    fd_set write_set_fds;
    int select_rv;

    /* NB. writeall() is only useful in non-blocking mode: according to
       Guenter Geiger <geiger@xdv.org> on the linux-audio-dev list
       (http://eca.cx/lad/2002/11/0380.html), OSS guarantees that
       write() in blocking mode consumes the whole buffer.  In blocking
       mode, the behaviour of write() and writeall() from Python is
       indistinguishable. */

    if (!PyArg_ParseTuple(args, "s#:write", &cp, &size))
        return NULL;

    if (!_PyIsSelectable_fd(self->fd)) {
        PyErr_SetString(PyExc_ValueError,
                        "file descriptor out of range for select");
        return NULL;
    }
    /* use select to wait for audio device to be available */
    FD_ZERO(&write_set_fds);
    FD_SET(self->fd, &write_set_fds);

    while (size > 0) {
        Py_BEGIN_ALLOW_THREADS
        select_rv = select(self->fd+1, NULL, &write_set_fds, NULL, NULL);
        Py_END_ALLOW_THREADS
        assert(select_rv != 0);         /* no timeout, can't expire */
        if (select_rv == -1)
            return PyErr_SetFromErrno(PyExc_IOError);

        Py_BEGIN_ALLOW_THREADS
        rv = write(self->fd, cp, size);
        Py_END_ALLOW_THREADS
        if (rv == -1) {
            if (errno == EAGAIN) {      /* buffer is full, try again */
                errno = 0;
                continue;
            } else                      /* it's a real error */
                return PyErr_SetFromErrno(PyExc_IOError);
        } else {                        /* wrote rv bytes */
            self->ocount += rv;
            size -= rv;
            cp += rv;
        }
    }
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
oss_close(oss_audio_t *self, PyObject *unused)
{
    if (self->fd >= 0) {
        Py_BEGIN_ALLOW_THREADS
        close(self->fd);
        Py_END_ALLOW_THREADS
        self->fd = -1;
    }
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
oss_fileno(oss_audio_t *self, PyObject *unused)
{
    return PyInt_FromLong(self->fd);
}


/* Convenience methods: these generally wrap a couple of ioctls into one
   common task. */

static PyObject *
oss_setparameters(oss_audio_t *self, PyObject *args)
{
    int wanted_fmt, wanted_channels, wanted_rate, strict=0;
    int fmt, channels, rate;

    if (!PyArg_ParseTuple(args, "iii|i:setparameters",
                          &wanted_fmt, &wanted_channels, &wanted_rate,
                          &strict))
        return NULL;

    fmt = wanted_fmt;
    if (ioctl(self->fd, SNDCTL_DSP_SETFMT, &fmt) == -1) {
        return PyErr_SetFromErrno(PyExc_IOError);
    }
    if (strict && fmt != wanted_fmt) {
        return PyErr_Format
            (OSSAudioError,
             "unable to set requested format (wanted %d, got %d)",
             wanted_fmt, fmt);
    }

    channels = wanted_channels;
    if (ioctl(self->fd, SNDCTL_DSP_CHANNELS, &channels) == -1) {
        return PyErr_SetFromErrno(PyExc_IOError);
    }
    if (strict && channels != wanted_channels) {
        return PyErr_Format
            (OSSAudioError,
             "unable to set requested channels (wanted %d, got %d)",
             wanted_channels, channels);
    }

    rate = wanted_rate;
    if (ioctl(self->fd, SNDCTL_DSP_SPEED, &rate) == -1) {
        return PyErr_SetFromErrno(PyExc_IOError);
    }
    if (strict && rate != wanted_rate) {
        return PyErr_Format
            (OSSAudioError,
             "unable to set requested rate (wanted %d, got %d)",
             wanted_rate, rate);
    }

    /* Construct the return value: a (fmt, channels, rate) tuple that
       tells what the audio hardware was actually set to. */
    return Py_BuildValue("(iii)", fmt, channels, rate);
}

static int
_ssize(oss_audio_t *self, int *nchannels, int *ssize)
{
    int fmt;

    fmt = 0;
    if (ioctl(self->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 = 1;                     /* 8 bit formats: 1 byte */
        break;
    case AFMT_S16_LE:
    case AFMT_S16_BE:
    case AFMT_U16_LE:
    case AFMT_U16_BE:
        *ssize = 2;                     /* 16 bit formats: 2 byte */
        break;
    case AFMT_MPEG:
    case AFMT_IMA_ADPCM:
    default:
        return -EOPNOTSUPP;
    }
    if (ioctl(self->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 *
oss_bufsize(oss_audio_t *self, PyObject *unused)
{
    audio_buf_info ai;
    int nchannels=0, ssize=0;

    if (_ssize(self, &nchannels, &ssize) < 0 || !nchannels || !ssize) {
        PyErr_SetFromErrno(PyExc_IOError);
        return NULL;
    }
    if (ioctl(self->fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
        PyErr_SetFromErrno(PyExc_IOError);
        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 *
oss_obufcount(oss_audio_t *self, PyObject *unused)
{
    audio_buf_info ai;
    int nchannels=0, ssize=0;

    if (_ssize(self, &nchannels, &ssize) < 0 || !nchannels || !ssize) {
        PyErr_SetFromErrno(PyExc_IOError);
        return NULL;
    }
    if (ioctl(self->fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
        PyErr_SetFromErrno(PyExc_IOError);
        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 *
oss_obuffree(oss_audio_t *self, PyObject *unused)
{
    audio_buf_info ai;
    int nchannels=0, ssize=0;

    if (_ssize(self, &nchannels, &ssize) < 0 || !nchannels || !ssize) {
        PyErr_SetFromErrno(PyExc_IOError);
        return NULL;
    }
    if (ioctl(self->fd, SNDCTL_DSP_GETOSPACE, &ai) < 0) {
        PyErr_SetFromErrno(PyExc_IOError);
        return NULL;
    }
    return PyInt_FromLong(ai.bytes / (ssize * nchannels));
}

static PyObject *
oss_getptr(oss_audio_t *self, PyObject *unused)
{
    count_info info;
    int req;

    if (self->mode == O_RDONLY)
        req = SNDCTL_DSP_GETIPTR;
    else
        req = SNDCTL_DSP_GETOPTR;
    if (ioctl(self->fd, req, &info) == -1) {
        PyErr_SetFromErrno(PyExc_IOError);
        return NULL;
    }
    return Py_BuildValue("iii", info.bytes, info.blocks, info.ptr);
}


/* ----------------------------------------------------------------------
 * Methods of mixer objects (OSSMixerType)
 */

static PyObject *
oss_mixer_close(oss_mixer_t *self, PyObject *unused)
{
    if (self->fd >= 0) {
        close(self->fd);
        self->fd = -1;
    }
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
oss_mixer_fileno(oss_mixer_t *self, PyObject *unused)
{
    return PyInt_FromLong(self->fd);
}

/* Simple mixer interface methods */

static PyObject *
oss_mixer_controls(oss_mixer_t *self, PyObject *args)
{
    return _do_ioctl_1_internal(self->fd, args, "controls",
        SOUND_MIXER_READ_DEVMASK);
}

static PyObject *
oss_mixer_stereocontrols(oss_mixer_t *self, PyObject *args)
{
    return _do_ioctl_1_internal(self->fd, args, "stereocontrols",
        SOUND_MIXER_READ_STEREODEVS);
}

static PyObject *
oss_mixer_reccontrols(oss_mixer_t *self, PyObject *args)
{
    return _do_ioctl_1_internal(self->fd, args, "reccontrols",
        SOUND_MIXER_READ_RECMASK);
}

static PyObject *
oss_mixer_get(oss_mixer_t *self, PyObject *args)
{
    int channel, volume;

    /* Can't use _do_ioctl_1 because of encoded arg thingy. */
    if (!PyArg_ParseTuple(args, "i:get", &channel))
        return NULL;

    if (channel < 0 || channel > SOUND_MIXER_NRDEVICES) {
        PyErr_SetString(OSSAudioError, "Invalid mixer channel specified.");
        return NULL;
    }

    if (ioctl(self->fd, MIXER_READ(channel), &volume) == -1)
        return PyErr_SetFromErrno(PyExc_IOError);

    return Py_BuildValue("(ii)", volume & 0xff, (volume & 0xff00) >> 8);
}

static PyObject *
oss_mixer_set(oss_mixer_t *self, PyObject *args)
{
    int channel, volume, leftVol, rightVol;

    /* Can't use _do_ioctl_1 because of encoded arg thingy. */
    if (!PyArg_ParseTuple(args, "i(ii):set", &channel, &leftVol, &rightVol))
        return NULL;

    if (channel < 0 || channel > SOUND_MIXER_NRDEVICES) {
        PyErr_SetString(OSSAudioError, "Invalid mixer channel specified.");
        return NULL;
    }

    if (leftVol < 0 || rightVol < 0 || leftVol > 100 || rightVol > 100) {
        PyErr_SetString(OSSAudioError, "Volumes must be between 0 and 100.");
        return NULL;
    }

    volume = (rightVol << 8) | leftVol;

    if (ioctl(self->fd, MIXER_WRITE(channel), &volume) == -1)
        return PyErr_SetFromErrno(PyExc_IOError);

    return Py_BuildValue("(ii)", volume & 0xff, (volume & 0xff00) >> 8);
}

static PyObject *
oss_mixer_get_recsrc(oss_mixer_t *self, PyObject *args)
{
    return _do_ioctl_1_internal(self->fd, args, "get_recsrc",
        SOUND_MIXER_READ_RECSRC);
}

static PyObject *
oss_mixer_set_recsrc(oss_mixer_t *self, PyObject *args)
{
    return _do_ioctl_1(self->fd, args, "set_recsrc",
        SOUND_MIXER_WRITE_RECSRC);
}


/* ----------------------------------------------------------------------
 * Method tables and other bureaucracy
 */

static PyMethodDef oss_methods[] = {
    /* Regular file methods */
    { "read",           (PyCFunction)oss_read, METH_VARARGS },
    { "write",          (PyCFunction)oss_write, METH_VARARGS },
    { "writeall",       (PyCFunction)oss_writeall, METH_VARARGS },
    { "close",          (PyCFunction)oss_close, METH_NOARGS },
    { "fileno",         (PyCFunction)oss_fileno, METH_NOARGS },

    /* Simple ioctl wrappers */
    { "nonblock",       (PyCFunction)oss_nonblock, METH_NOARGS },
    { "setfmt",         (PyCFunction)oss_setfmt, METH_VARARGS },
    { "getfmts",        (PyCFunction)oss_getfmts, METH_NOARGS },
    { "channels",       (PyCFunction)oss_channels, METH_VARARGS },
    { "speed",          (PyCFunction)oss_speed, METH_VARARGS },
    { "sync",           (PyCFunction)oss_sync, METH_VARARGS },
    { "reset",          (PyCFunction)oss_reset, METH_VARARGS },
    { "post",           (PyCFunction)oss_post, METH_VARARGS },

    /* Convenience methods -- wrap a couple of ioctls together */
    { "setparameters",  (PyCFunction)oss_setparameters, METH_VARARGS },
    { "bufsize",        (PyCFunction)oss_bufsize, METH_NOARGS },
    { "obufcount",      (PyCFunction)oss_obufcount, METH_NOARGS },
    { "obuffree",       (PyCFunction)oss_obuffree, METH_NOARGS },
    { "getptr",         (PyCFunction)oss_getptr, METH_NOARGS },

    /* Aliases for backwards compatibility */
    { "flush",          (PyCFunction)oss_sync, METH_VARARGS },

    { NULL,             NULL}           /* sentinel */
};

static PyMethodDef oss_mixer_methods[] = {
    /* Regular file method - OSS mixers are ioctl-only interface */
    { "close",          (PyCFunction)oss_mixer_close, METH_NOARGS },
    { "fileno",         (PyCFunction)oss_mixer_fileno, METH_NOARGS },

    /* Simple ioctl wrappers */
    { "controls",       (PyCFunction)oss_mixer_controls, METH_VARARGS },
    { "stereocontrols", (PyCFunction)oss_mixer_stereocontrols, METH_VARARGS},
    { "reccontrols",    (PyCFunction)oss_mixer_reccontrols, METH_VARARGS},
    { "get",            (PyCFunction)oss_mixer_get, METH_VARARGS },
    { "set",            (PyCFunction)oss_mixer_set, METH_VARARGS },
    { "get_recsrc",     (PyCFunction)oss_mixer_get_recsrc, METH_VARARGS },
    { "set_recsrc",     (PyCFunction)oss_mixer_set_recsrc, METH_VARARGS },

    { NULL,             NULL}
};

static PyObject *
oss_getattr(oss_audio_t *self, char *name)
{
    PyObject * rval = NULL;
    if (strcmp(name, "closed") == 0) {
        rval = (self->fd == -1) ? Py_True : Py_False;
        Py_INCREF(rval);
    }
    else if (strcmp(name, "name") == 0) {
        rval = PyString_FromString(self->devicename);
    }
    else if (strcmp(name, "mode") == 0) {
        /* No need for a "default" in this switch: from newossobject(),
           self->mode can only be one of these three values. */
        switch(self->mode) {
            case O_RDONLY:
                rval = PyString_FromString("r");
                break;
            case O_RDWR:
                rval = PyString_FromString("rw");
                break;
            case O_WRONLY:
                rval = PyString_FromString("w");
                break;
        }
    }
    else {
        rval = Py_FindMethod(oss_methods, (PyObject *)self, name);
    }
    return rval;
}

static PyObject *
oss_mixer_getattr(oss_mixer_t *self, char *name)
{
    return Py_FindMethod(oss_mixer_methods, (PyObject *)self, name);
}

static PyTypeObject OSSAudioType = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "ossaudiodev.oss_audio_device", /*tp_name*/
    sizeof(oss_audio_t),        /*tp_size*/
    0,                          /*tp_itemsize*/
    /* methods */
    (destructor)oss_dealloc,    /*tp_dealloc*/
    0,                          /*tp_print*/
    (getattrfunc)oss_getattr,   /*tp_getattr*/
    0,                          /*tp_setattr*/
    0,                          /*tp_compare*/
    0,                          /*tp_repr*/
};

static PyTypeObject OSSMixerType = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "ossaudiodev.oss_mixer_device", /*tp_name*/
    sizeof(oss_mixer_t),            /*tp_size*/
    0,                              /*tp_itemsize*/
    /* methods */
    (destructor)oss_mixer_dealloc,  /*tp_dealloc*/
    0,                              /*tp_print*/
    (getattrfunc)oss_mixer_getattr, /*tp_getattr*/
    0,                              /*tp_setattr*/
    0,                              /*tp_compare*/
    0,                              /*tp_repr*/
};


static PyObject *
ossopen(PyObject *self, PyObject *args)
{
    return (PyObject *)newossobject(args);
}

static PyObject *
ossopenmixer(PyObject *self, PyObject *args)
{
    return (PyObject *)newossmixerobject(args);
}

static PyMethodDef ossaudiodev_methods[] = {
    { "open", ossopen, METH_VARARGS },
    { "openmixer", ossopenmixer, METH_VARARGS },
    { 0, 0 },
};


#define _EXPORT_INT(mod, name) \
  if (PyModule_AddIntConstant(mod, #name, (long) (name)) == -1) return;


static char *control_labels[] = SOUND_DEVICE_LABELS;
static char *control_names[] = SOUND_DEVICE_NAMES;


static int
build_namelists (PyObject *module)
{
    PyObject *labels;
    PyObject *names;
    PyObject *s;
    int num_controls;
    int i;

    num_controls = sizeof(control_labels) / sizeof(control_labels[0]);
    assert(num_controls == sizeof(control_names) / sizeof(control_names[0]));

    labels = PyList_New(num_controls);
    names = PyList_New(num_controls);
    if (labels == NULL || names == NULL)
        goto error2;
    for (i = 0; i < num_controls; i++) {
        s = PyString_FromString(control_labels[i]);
        if (s == NULL)
            goto error2;
        PyList_SET_ITEM(labels, i, s);

        s = PyString_FromString(control_names[i]);
        if (s == NULL)
            goto error2;
        PyList_SET_ITEM(names, i, s);
    }

    if (PyModule_AddObject(module, "control_labels", labels) == -1)
        goto error2;
    if (PyModule_AddObject(module, "control_names", names) == -1)
        goto error1;

    return 0;

error2:
    Py_XDECREF(labels);
error1:
    Py_XDECREF(names);
    return -1;
}


void
initossaudiodev(void)
{
    PyObject *m;

    m = Py_InitModule("ossaudiodev", ossaudiodev_methods);
    if (m == NULL)
	return;

    OSSAudioError = PyErr_NewException("ossaudiodev.OSSAudioError",
				       NULL, NULL);
    if (OSSAudioError) {
        /* Each call to PyModule_AddObject decrefs it; compensate: */
        Py_INCREF(OSSAudioError);
        Py_INCREF(OSSAudioError);
        PyModule_AddObject(m, "error", OSSAudioError);
        PyModule_AddObject(m, "OSSAudioError", OSSAudioError);
    }

    /* Build 'control_labels' and 'control_names' lists and add them
       to the module. */
    if (build_namelists(m) == -1)       /* XXX what to do here? */
        return;

    /* Expose the audio format numbers -- essential! */
    _EXPORT_INT(m, AFMT_QUERY);
    _EXPORT_INT(m, AFMT_MU_LAW);
    _EXPORT_INT(m, AFMT_A_LAW);
    _EXPORT_INT(m, AFMT_IMA_ADPCM);
    _EXPORT_INT(m, AFMT_U8);
    _EXPORT_INT(m, AFMT_S16_LE);
    _EXPORT_INT(m, AFMT_S16_BE);
    _EXPORT_INT(m, AFMT_S8);
    _EXPORT_INT(m, AFMT_U16_LE);
    _EXPORT_INT(m, AFMT_U16_BE);
    _EXPORT_INT(m, AFMT_MPEG);
#ifdef AFMT_AC3
    _EXPORT_INT(m, AFMT_AC3);
#endif
#ifdef AFMT_S16_NE
    _EXPORT_INT(m, AFMT_S16_NE);
#endif
#ifdef AFMT_U16_NE
    _EXPORT_INT(m, AFMT_U16_NE);
#endif
#ifdef AFMT_S32_LE
    _EXPORT_INT(m, AFMT_S32_LE);
#endif
#ifdef AFMT_S32_BE
    _EXPORT_INT(m, AFMT_S32_BE);
#endif
#ifdef AFMT_MPEG
    _EXPORT_INT(m, AFMT_MPEG);
#endif

    /* Expose the sound mixer device numbers. */
    _EXPORT_INT(m, SOUND_MIXER_NRDEVICES);
    _EXPORT_INT(m, SOUND_MIXER_VOLUME);
    _EXPORT_INT(m, SOUND_MIXER_BASS);
    _EXPORT_INT(m, SOUND_MIXER_TREBLE);
    _EXPORT_INT(m, SOUND_MIXER_SYNTH);
    _EXPORT_INT(m, SOUND_MIXER_PCM);
    _EXPORT_INT(m, SOUND_MIXER_SPEAKER);
    _EXPORT_INT(m, SOUND_MIXER_LINE);
    _EXPORT_INT(m, SOUND_MIXER_MIC);
    _EXPORT_INT(m, SOUND_MIXER_CD);
    _EXPORT_INT(m, SOUND_MIXER_IMIX);
    _EXPORT_INT(m, SOUND_MIXER_ALTPCM);
    _EXPORT_INT(m, SOUND_MIXER_RECLEV);
    _EXPORT_INT(m, SOUND_MIXER_IGAIN);
    _EXPORT_INT(m, SOUND_MIXER_OGAIN);
    _EXPORT_INT(m, SOUND_MIXER_LINE1);
    _EXPORT_INT(m, SOUND_MIXER_LINE2);
    _EXPORT_INT(m, SOUND_MIXER_LINE3);
#ifdef SOUND_MIXER_DIGITAL1
    _EXPORT_INT(m, SOUND_MIXER_DIGITAL1);
#endif
#ifdef SOUND_MIXER_DIGITAL2
    _EXPORT_INT(m, SOUND_MIXER_DIGITAL2);
#endif
#ifdef SOUND_MIXER_DIGITAL3
    _EXPORT_INT(m, SOUND_MIXER_DIGITAL3);
#endif
#ifdef SOUND_MIXER_PHONEIN
    _EXPORT_INT(m, SOUND_MIXER_PHONEIN);
#endif
#ifdef SOUND_MIXER_PHONEOUT
    _EXPORT_INT(m, SOUND_MIXER_PHONEOUT);
#endif
#ifdef SOUND_MIXER_VIDEO
    _EXPORT_INT(m, SOUND_MIXER_VIDEO);
#endif
#ifdef SOUND_MIXER_RADIO
    _EXPORT_INT(m, SOUND_MIXER_RADIO);
#endif
#ifdef SOUND_MIXER_MONITOR
    _EXPORT_INT(m, SOUND_MIXER_MONITOR);
#endif

    /* Expose all the ioctl numbers for masochists who like to do this
       stuff directly. */
    _EXPORT_INT(m, SNDCTL_COPR_HALT);
    _EXPORT_INT(m, SNDCTL_COPR_LOAD);
    _EXPORT_INT(m, SNDCTL_COPR_RCODE);
    _EXPORT_INT(m, SNDCTL_COPR_RCVMSG);
    _EXPORT_INT(m, SNDCTL_COPR_RDATA);
    _EXPORT_INT(m, SNDCTL_COPR_RESET);
    _EXPORT_INT(m, SNDCTL_COPR_RUN);
    _EXPORT_INT(m, SNDCTL_COPR_SENDMSG);
    _EXPORT_INT(m, SNDCTL_COPR_WCODE);
    _EXPORT_INT(m, SNDCTL_COPR_WDATA);
#ifdef SNDCTL_DSP_BIND_CHANNEL
    _EXPORT_INT(m, SNDCTL_DSP_BIND_CHANNEL);
#endif
    _EXPORT_INT(m, SNDCTL_DSP_CHANNELS);
    _EXPORT_INT(m, SNDCTL_DSP_GETBLKSIZE);
    _EXPORT_INT(m, SNDCTL_DSP_GETCAPS);
#ifdef SNDCTL_DSP_GETCHANNELMASK
    _EXPORT_INT(m, SNDCTL_DSP_GETCHANNELMASK);
#endif
    _EXPORT_INT(m, SNDCTL_DSP_GETFMTS);
    _EXPORT_INT(m, SNDCTL_DSP_GETIPTR);
    _EXPORT_INT(m, SNDCTL_DSP_GETISPACE);
#ifdef SNDCTL_DSP_GETODELAY
    _EXPORT_INT(m, SNDCTL_DSP_GETODELAY);
#endif
    _EXPORT_INT(m, SNDCTL_DSP_GETOPTR);
    _EXPORT_INT(m, SNDCTL_DSP_GETOSPACE);
#ifdef SNDCTL_DSP_GETSPDIF
    _EXPORT_INT(m, SNDCTL_DSP_GETSPDIF);
#endif
    _EXPORT_INT(m, SNDCTL_DSP_GETTRIGGER);
    _EXPORT_INT(m, SNDCTL_DSP_MAPINBUF);
    _EXPORT_INT(m, SNDCTL_DSP_MAPOUTBUF);
    _EXPORT_INT(m, SNDCTL_DSP_NONBLOCK);
    _EXPORT_INT(m, SNDCTL_DSP_POST);
#ifdef SNDCTL_DSP_PROFILE
    _EXPORT_INT(m, SNDCTL_DSP_PROFILE);
#endif
    _EXPORT_INT(m, SNDCTL_DSP_RESET);
    _EXPORT_INT(m, SNDCTL_DSP_SAMPLESIZE);
    _EXPORT_INT(m, SNDCTL_DSP_SETDUPLEX);
    _EXPORT_INT(m, SNDCTL_DSP_SETFMT);
    _EXPORT_INT(m, SNDCTL_DSP_SETFRAGMENT);
#ifdef SNDCTL_DSP_SETSPDIF
    _EXPORT_INT(m, SNDCTL_DSP_SETSPDIF);
#endif
    _EXPORT_INT(m, SNDCTL_DSP_SETSYNCRO);
    _EXPORT_INT(m, SNDCTL_DSP_SETTRIGGER);
    _EXPORT_INT(m, SNDCTL_DSP_SPEED);
    _EXPORT_INT(m, SNDCTL_DSP_STEREO);
    _EXPORT_INT(m, SNDCTL_DSP_SUBDIVIDE);
    _EXPORT_INT(m, SNDCTL_DSP_SYNC);
    _EXPORT_INT(m, SNDCTL_FM_4OP_ENABLE);
    _EXPORT_INT(m, SNDCTL_FM_LOAD_INSTR);
    _EXPORT_INT(m, SNDCTL_MIDI_INFO);
    _EXPORT_INT(m, SNDCTL_MIDI_MPUCMD);
    _EXPORT_INT(m, SNDCTL_MIDI_MPUMODE);
    _EXPORT_INT(m, SNDCTL_MIDI_PRETIME);
    _EXPORT_INT(m, SNDCTL_SEQ_CTRLRATE);
    _EXPORT_INT(m, SNDCTL_SEQ_GETINCOUNT);
    _EXPORT_INT(m, SNDCTL_SEQ_GETOUTCOUNT);
#ifdef SNDCTL_SEQ_GETTIME
    _EXPORT_INT(m, SNDCTL_SEQ_GETTIME);
#endif
    _EXPORT_INT(m, SNDCTL_SEQ_NRMIDIS);
    _EXPORT_INT(m, SNDCTL_SEQ_NRSYNTHS);
    _EXPORT_INT(m, SNDCTL_SEQ_OUTOFBAND);
    _EXPORT_INT(m, SNDCTL_SEQ_PANIC);
    _EXPORT_INT(m, SNDCTL_SEQ_PERCMODE);
    _EXPORT_INT(m, SNDCTL_SEQ_RESET);
    _EXPORT_INT(m, SNDCTL_SEQ_RESETSAMPLES);
    _EXPORT_INT(m, SNDCTL_SEQ_SYNC);
    _EXPORT_INT(m, SNDCTL_SEQ_TESTMIDI);
    _EXPORT_INT(m, SNDCTL_SEQ_THRESHOLD);
#ifdef SNDCTL_SYNTH_CONTROL
    _EXPORT_INT(m, SNDCTL_SYNTH_CONTROL);
#endif
#ifdef SNDCTL_SYNTH_ID
    _EXPORT_INT(m, SNDCTL_SYNTH_ID);
#endif
    _EXPORT_INT(m, SNDCTL_SYNTH_INFO);
    _EXPORT_INT(m, SNDCTL_SYNTH_MEMAVL);
#ifdef SNDCTL_SYNTH_REMOVESAMPLE
    _EXPORT_INT(m, SNDCTL_SYNTH_REMOVESAMPLE);
#endif
    _EXPORT_INT(m, SNDCTL_TMR_CONTINUE);
    _EXPORT_INT(m, SNDCTL_TMR_METRONOME);
    _EXPORT_INT(m, SNDCTL_TMR_SELECT);
    _EXPORT_INT(m, SNDCTL_TMR_SOURCE);
    _EXPORT_INT(m, SNDCTL_TMR_START);
    _EXPORT_INT(m, SNDCTL_TMR_STOP);
    _EXPORT_INT(m, SNDCTL_TMR_TEMPO);
    _EXPORT_INT(m, SNDCTL_TMR_TIMEBASE);
}