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/*
* 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
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1992-2001 by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <AudioHdr.h>
// class AudioHdr basic methods
// This routine uses the byteorder network utilities to tell whether the
// current process uses network byte order or not.
AudioEndian AudioHdr::localByteOrder() const
{
short sTestHost;
short sTestNetwork;
static AudioEndian ae = UNDEFINED_ENDIAN;
if (ae == UNDEFINED_ENDIAN) {
sTestHost = MAXSHORT;
sTestNetwork = htons(sTestHost);
if (sTestNetwork != sTestHost) {
ae = LITTLE_ENDIAN;
} else {
ae = BIG_ENDIAN;
}
}
return (ae);
}
// Clear a header structure
void AudioHdr::
Clear()
{
sample_rate = 0;
samples_per_unit = 0;
bytes_per_unit = 0;
channels = 0;
encoding = NONE;
}
// Return error code (TRUE) if header is inconsistent or unrecognizable
// XXX - how do we support extensions?
AudioError AudioHdr::
Validate() const
{
// Check for uninitialized fields
if ((bytes_per_unit < 1) || (samples_per_unit < 1) ||
(sample_rate < 1) || (channels < 1))
return (AUDIO_ERR_BADHDR);
switch (encoding) {
case NONE:
return (AUDIO_ERR_BADHDR);
case LINEAR:
if (bytes_per_unit > 4)
return (AUDIO_ERR_PRECISION);
if (samples_per_unit != 1)
return (AUDIO_ERR_HDRINVAL);
break;
case FLOAT:
if ((bytes_per_unit != 4) && (bytes_per_unit != 8))
return (AUDIO_ERR_PRECISION);
if (samples_per_unit != 1)
return (AUDIO_ERR_HDRINVAL);
break;
case ULAW:
case ALAW:
case G722:
if (bytes_per_unit != 1)
return (AUDIO_ERR_PRECISION);
if (samples_per_unit != 1)
return (AUDIO_ERR_HDRINVAL);
break;
case G721:
case DVI:
// G.721 is a 4-bit encoding
if ((bytes_per_unit != 1) || (samples_per_unit != 2))
return (AUDIO_ERR_PRECISION);
break;
case G723:
// G.723 has 3-bit and 5-bit flavors
// 5-bit is currently unsupported
if ((bytes_per_unit != 3) || (samples_per_unit != 8))
return (AUDIO_ERR_PRECISION);
break;
}
return (AUDIO_SUCCESS);
}
// Convert a byte count into a floating-point time value, in seconds,
// using the encoding specified in the audio header.
Double AudioHdr::
Bytes_to_Time(
off_t cnt) const // byte count
{
if ((cnt == AUDIO_UNKNOWN_SIZE) || (Validate() != AUDIO_SUCCESS))
return (AUDIO_UNKNOWN_TIME);
// round off to nearest sample frame!
cnt -= (cnt % (bytes_per_unit * channels));
return (Double) ((double)cnt /
((double)(channels * bytes_per_unit * sample_rate) /
(double)samples_per_unit));
}
// Convert a floating-point time value, in seconds, to a byte count for
// the audio encoding in the audio header. Make sure that the byte count
// or offset does not span a sample frame.
off_t AudioHdr::
Time_to_Bytes(
Double sec) const // time, in seconds
{
off_t offset;
if (Undefined(sec) || (Validate() != AUDIO_SUCCESS))
return (AUDIO_UNKNOWN_SIZE);
offset = (off_t)(0.5 + (sec *
((double)(channels * bytes_per_unit * sample_rate) /
(double)samples_per_unit)));
// Round down to the start of the nearest sample frame
offset -= (offset % (bytes_per_unit * channels));
return (offset);
}
// Round a byte count down to a sample frame boundary.
off_t AudioHdr::
Bytes_to_Bytes(
off_t& cnt) const
{
if (Validate() != AUDIO_SUCCESS)
return (AUDIO_UNKNOWN_SIZE);
// Round down to the start of the nearest sample frame
cnt -= (cnt % (bytes_per_unit * channels));
return (cnt);
}
// Round a byte count down to a sample frame boundary.
size_t AudioHdr::
Bytes_to_Bytes(
size_t& cnt) const
{
if (Validate() != AUDIO_SUCCESS)
return (AUDIO_UNKNOWN_SIZE);
// Round down to the start of the nearest sample frame
cnt -= (cnt % (bytes_per_unit * channels));
return (cnt);
}
// Convert a count of sample frames into a floating-point time value,
// in seconds, using the encoding specified in the audio header.
Double AudioHdr::
Samples_to_Time(
unsigned long cnt) const // sample frame count
{
if ((cnt == AUDIO_UNKNOWN_SIZE) || (Validate() != AUDIO_SUCCESS))
return (AUDIO_UNKNOWN_TIME);
return ((Double)(((double)cnt * (double)samples_per_unit) /
(double)sample_rate));
}
// Convert a floating-point time value, in seconds, to a count of sample frames
// for the audio encoding in the audio header.
unsigned long AudioHdr::
Time_to_Samples(
Double sec) const // time, in seconds
{
if (Undefined(sec) || (Validate() != AUDIO_SUCCESS))
return (AUDIO_UNKNOWN_SIZE);
// Round down to sample frame boundary
return ((unsigned long) (AUDIO_MINFLOAT +
(((double)sec * (double)sample_rate) / (double)samples_per_unit)));
}
// Return the number of bytes in a sample frame for the audio encoding.
unsigned int AudioHdr::
FrameLength() const
{
return (bytes_per_unit * channels);
}
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