audio/utilities/AudioStream.cc

	AudioStream.cc revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
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 */
/*
 * Copyright (c) 1990-2001 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <AudioStream.h>
#include <string.h>

// class AudioStream methods


// Constructor
AudioStream::
AudioStream(
    const char  *path):         // pathname
    Audio(path), length(AUDIO_UNKNOWN_TIME)
{
}

// Set the header structure, even if it is already set
AudioError AudioStream::
updateheader(
    const AudioHdr& h)          // new header to set
{
    AudioError  err;

    // Validate the header before stuffing it in
    err = h.Validate();
    if (err != AUDIO_SUCCESS)
        return (RaiseError(err));

    // Copy in the new header
    hdr = h;
    return (AUDIO_SUCCESS);
}

// Set the header structure
AudioError AudioStream::
SetHeader(
    const AudioHdr& h)          // new header to set
{
    // Once the header is set and the file is open, it cannot be changed
    // XXX - hdrset test might be redundant?
    if (hdrset() && opened())
        return (RaiseError(AUDIO_ERR_NOEFFECT));

    return (updateheader(h));
}

// Check the endian nature of the data, and change if necessary.
AudioError AudioStream::
coerceEndian(unsigned char *buf, size_t len,
            AudioEndian endian)
{
    // If the stream isn't endian sensitive, don't bother.
    if (! isEndianSensitive())
        return (AUDIO_SUCCESS);

    if (hdr.endian == endian) {
#ifdef DEBUG
        AUDIO_DEBUG((1, "AudioStream: endian swap not needed, byte"
            "order OK.\n"));
#endif
        return (AUDIO_SUCCESS);
    }

    // The endians don't match, lets swap bytes.
    unsigned char chTemp;
    for (int i = 0; i < len - 1; i += 2) {
        chTemp = buf[i];
        buf[i] = buf[i + 1];
        buf[i+1] = chTemp;
    }

#ifdef DEBUG
    AUDIO_DEBUG((1, "AudioStream: converting endian.\n"));
    // printf("AudioStream: converting endian.\n");
#endif
    return (AUDIO_SUCCESS);
}

// This routine knows if the current format is endian sensitive.
Boolean AudioStream::isEndianSensitive() const
{

    // Only these encodings have endian problems.
    if (hdr.encoding == LINEAR || hdr.encoding == FLOAT)
        return (TRUE);

    return (FALSE);
}