ad_oss.c

/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* ====================================================================
 * Copyright (c) 1999-2001 Carnegie Mellon University.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * This work was supported in part by funding from the Defense Advanced 
 * Research Projects Agency and the National Science Foundation of the 
 * United States of America, and the CMU Sphinx Speech Consortium.
 *
 * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND 
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 */
/* Sphinx II libad (Linux)
 * ^^^^^^^^^^^^^^^^^^^^^^^
 * $Id: ad_oss.c,v 1.9 2004/07/16 00:57:12 egouvea Exp $
 *
 * John G. Dorsey (jd5q+@andrew.cmu.edu)
 * Engineering Design Research Center
 * Carnegie Mellon University
 * ********************************************************************
 * 
 * REVISION HISTORY
 *
 * 09-Aug-1999  Kevin Lenzo (lenzo@cs.cmu.edu) at Cernegie Mellon University.
 *              Incorporated nickr@cs.cmu.edu's changes (marked below) and
 *              SPS_EPSILON to allow for sample rates that are "close enough".
 * 
 * 15-Jun-1999  M. K. Ravishankar (rkm@cs.cmu.edu) Consolidated all ad functions into
 *              this one file.  Added ad_open_sps().
 *              Other cosmetic changes for consistency (e.g., use of err.h).
 * 
 * 18-May-1999  Kevin Lenzo (lenzo@cs.cmu.edu) added <errno.h>.
 */

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/soundcard.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <unistd.h>
#include <config.h>

#include "prim_type.h"
#include "ad.h"

#define AUDIO_FORMAT AFMT_S16_LE        /* 16-bit signed, little endian */
#define INPUT_GAIN   (80)

#define SPS_EPSILON   200
#define SAMPLERATE_TOLERANCE 0.01

#define DEFAULT_DEVICE "/dev/dsp"

struct ad_rec_s {
    int32 dspFD;        /* Audio device descriptor */
    int32 recording;
    int32 sps;          /* Samples/sec */
    int32 bps;          /* Bytes/sample */
};

ad_rec_t *
ad_open_dev(const char *dev, int32 sps)
{
    ad_rec_t *handle;
    int32 dspFD, mixerFD;
    int32 nonBlocking = 1, sourceMic = SOUND_MASK_MIC, inputGain =
        INPUT_GAIN, devMask = 0;
    int32 audioFormat = AUDIO_FORMAT;
    int32 dspCaps = 0;
    int32 sampleRate;
    int32 numberChannels = 1;

    sampleRate = sps;

    if (dev == NULL)
        dev = DEFAULT_DEVICE;

    /* Used to have O_NDELAY. */
    if ((dspFD = open(dev, O_RDONLY)) < 0) {
        if (errno == EBUSY)
            fprintf(stderr, "%s(%d): Audio device(%s) busy\n",
                    __FILE__, __LINE__, dev);
        else
            fprintf(stderr,
                    "%s(%d): Failed to open audio device(%s): %s\n",
                    __FILE__, __LINE__, dev, strerror(errno));
        return NULL;
    }

    if (ioctl(dspFD, SNDCTL_DSP_SYNC, 0) < 0) {
        fprintf(stderr, "Audio ioctl(SYNC) failed: %s\n", strerror(errno));
        close(dspFD);
        return NULL;
    }

    if (ioctl(dspFD, SNDCTL_DSP_RESET, 0) < 0) {
        fprintf(stderr, "Audio ioctl(RESET) failed: %s\n",
                strerror(errno));
        close(dspFD);
        return NULL;
    }

    if (ioctl(dspFD, SNDCTL_DSP_SETFMT, &audioFormat) < 0) {
        fprintf(stderr, "Audio ioctl(SETFMT 0x%x) failed: %s\n",
                audioFormat, strerror(errno));
        close(dspFD);
        return NULL;
    }
    if (audioFormat != AUDIO_FORMAT) {
        fprintf(stderr,
                "Audio ioctl(SETFMT): 0x%x, expected: 0x%x\n",
                audioFormat, AUDIO_FORMAT);
        close(dspFD);
        return NULL;
    }

    if (ioctl(dspFD, SNDCTL_DSP_SPEED, &sampleRate) < 0) {
        fprintf(stderr, "Audio ioctl(SPEED %d) failed %s\n",
                sampleRate, strerror(errno));
        close(dspFD);
        return NULL;
    }
    if (sampleRate != sps) {
        if (abs(sampleRate - sps) <= (sampleRate * SAMPLERATE_TOLERANCE)) {
            fprintf(stderr,
                    "Audio ioctl(SPEED) not perfect, but is acceptable. "
                    "(Wanted %d, but got %d)\n", sampleRate, sps);
        }
        else {
            fprintf(stderr,
                    "Audio ioctl(SPEED): %d, expected: %d\n",
                    sampleRate, sps);
            close(dspFD);
            return NULL;
        }
    }

    if (ioctl(dspFD, SNDCTL_DSP_CHANNELS, &numberChannels) < 0) {
        fprintf(stderr, "Audio ioctl(CHANNELS %d) failed %s\n",
                numberChannels, strerror(errno));
        close(dspFD);
        return NULL;
    }

    if (ioctl(dspFD, SNDCTL_DSP_NONBLOCK, &nonBlocking) < 0) {
        fprintf(stderr, "ioctl(NONBLOCK) failed: %s\n", strerror(errno));
        close(dspFD);
        return NULL;
    }

    if (ioctl(dspFD, SNDCTL_DSP_GETCAPS, &dspCaps) < 0) {
        fprintf(stderr, "ioctl(GETCAPS) failed: %s\n", strerror(errno));
        close(dspFD);
        return NULL;
    }
#if 0
    printf("DSP Revision %d:\n", dspCaps & DSP_CAP_REVISION);
    printf("DSP %s duplex capability.\n",
           (dspCaps & DSP_CAP_DUPLEX) ? "has" : "does not have");
    printf("DSP %s real time capability.\n",
           (dspCaps & DSP_CAP_REALTIME) ? "has" : "does not have");
    printf("DSP %s batch capability.\n",
           (dspCaps & DSP_CAP_BATCH) ? "has" : "does not have");
    printf("DSP %s coprocessor capability.\n",
           (dspCaps & DSP_CAP_COPROC) ? "has" : "does not have");
    printf("DSP %s trigger capability.\n",
           (dspCaps & DSP_CAP_TRIGGER) ? "has" : "does not have");
    printf("DSP %s memory map capability.\n",
           (dspCaps & DSP_CAP_MMAP) ? "has" : "does not have");
#endif

    if ((dspCaps & DSP_CAP_DUPLEX)
        && (ioctl(dspFD, SNDCTL_DSP_SETDUPLEX, 0) < 0))
        fprintf(stderr, "ioctl(SETDUPLEX) failed: %s\n", strerror(errno));

    /* Patched by N. Roy (nickr@ri.cmu.edu), 99/7/23. 
       Previously, mixer was set through dspFD. This is incorrect. Should
       be set through mixerFD, /dev/mixer. 
       Also, only the left channel volume was being set.
     */

    if ((mixerFD = open("/dev/mixer", O_RDONLY)) < 0) {
        if (errno == EBUSY) {
            fprintf(stderr, "%s %d: mixer device busy.\n",
                    __FILE__, __LINE__);
            fprintf(stderr, "%s %d: Using current setting.\n",
                    __FILE__, __LINE__);
        }
        else {
            fprintf(stderr, "%s %d: %s\n", __FILE__, __LINE__,
                    strerror(errno));
            exit(1);
        }
    }

    if (mixerFD >= 0) {
        if (ioctl(mixerFD, SOUND_MIXER_WRITE_RECSRC, &sourceMic) < 0) {
            if (errno == ENXIO)
                fprintf(stderr,
                        "%s %d: can't set mic source for this device.\n",
                        __FILE__, __LINE__);
            else {
                fprintf(stderr,
                        "%s %d: mixer set to mic: %s\n",
                        __FILE__, __LINE__, strerror(errno));
                exit(1);
            }
        }

        /* Set the same gain for left and right channels. */
        inputGain = inputGain << 8 | inputGain;

        /* Some OSS devices have no input gain control, but do have a
           recording level control.  Find out if this is one of them and
           adjust accordingly. */
        if (ioctl(mixerFD, SOUND_MIXER_READ_DEVMASK, &devMask) < 0) {
            fprintf(stderr,
                    "%s %d: failed to read device mask: %s\n",
                    __FILE__, __LINE__, strerror(errno));
            exit(1);            /* FIXME: not a well-behaved-library thing to do! */
        }
        if (devMask & SOUND_MASK_IGAIN) {
            if (ioctl(mixerFD, SOUND_MIXER_WRITE_IGAIN, &inputGain) < 0) {
                fprintf(stderr,
                        "%s %d: mixer input gain to %d: %s\n",
                        __FILE__, __LINE__, inputGain, strerror(errno));
                exit(1);
            }
        }
        else if (devMask & SOUND_MASK_RECLEV) {
            if (ioctl(mixerFD, SOUND_MIXER_WRITE_RECLEV, &inputGain) < 0) {
                fprintf(stderr,
                        "%s %d: mixer record level to %d: %s\n",
                        __FILE__, __LINE__, inputGain, strerror(errno));
                exit(1);
            }
        }
        else {
            fprintf(stderr,
                    "%s %d: can't set input gain/recording level for this device.\n",
                    __FILE__, __LINE__);
        }

        close(mixerFD);
    }

    if ((handle = (ad_rec_t *) calloc(1, sizeof(ad_rec_t))) == NULL) {
        fprintf(stderr, "calloc(%ld) failed\n", sizeof(ad_rec_t));
        abort();
    }

    handle->dspFD = dspFD;
    handle->recording = 0;
    handle->sps = sps;
    handle->bps = sizeof(int16);

    return (handle);
}

ad_rec_t *
ad_open_sps(int32 sps)
{
    return ad_open_dev(DEFAULT_DEVICE, sps);
}

ad_rec_t *
ad_open(void)
{
    return ad_open_sps(DEFAULT_SAMPLES_PER_SEC);
}

int32
ad_close(ad_rec_t * handle)
{
    if (handle->dspFD < 0)
        return AD_ERR_NOT_OPEN;

    if (handle->recording) {
        if (ad_stop_rec(handle) < 0)
            return AD_ERR_GEN;
    }

    close(handle->dspFD);
    free(handle);

    return (0);
}

int32
ad_start_rec(ad_rec_t * handle)
{
    if (handle->dspFD < 0)
        return AD_ERR_NOT_OPEN;

    if (handle->recording)
        return AD_ERR_GEN;

    /* Sample rate, format, input mix settings, &c. are configured
     * with ioctl(2) calls under Linux. It makes more sense to handle
     * these at device open time and consider the state of the device
     * to be fixed until closed.
     */

    handle->recording = 1;

    /* rkm@cs: This doesn't actually do anything.  How do we turn recording on/off? */

    return (0);
}

int32
ad_stop_rec(ad_rec_t * handle)
{
    if (handle->dspFD < 0)
        return AD_ERR_NOT_OPEN;

    if (!handle->recording)
        return AD_ERR_GEN;

    if (ioctl(handle->dspFD, SNDCTL_DSP_SYNC, 0) < 0) {
        fprintf(stderr, "Audio ioctl(SYNC) failed: %s\n", strerror(errno));
        return AD_ERR_GEN;
    }

    handle->recording = 0;

    return (0);
}

int32
ad_read(ad_rec_t * handle, int16 * buf, int32 max)
{
    int32 length;

    length = max * handle->bps; /* #samples -> #bytes */

    if ((length = read(handle->dspFD, buf, length)) > 0) {
#if 0
        if ((length % handle->bps) != 0)
            fprintf(stderr,
                    "Audio read returned non-integral #sample bytes (%d)\n",
                    length);
#endif
        length /= handle->bps;
    }

    if (length < 0) {
        if (errno != EAGAIN) {
            fprintf(stderr, "Audio read error");
            return AD_ERR_GEN;
        }
        else {
            length = 0;
        }
    }

    if ((length == 0) && (!handle->recording))
        return AD_EOF;

    return length;
}