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/* audiodevs: Abstraction layer for audio hardware & samples
Copyright (C) 2003-2004 Nemosoft Unv.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
For questions, remarks, patches, etc. for this program, the author can be
reached at camstream@smcc.demon.nl.
*/
/**
\struct SoundAttributes
\brief A struct for storage of audio device or audio file parameters.
\par Sample definition
A sample is defined as one or more audio values that are measured at
the same point in time. So, for a normal stereo track, a sample
consists of two values, one for the Left and one for the Right channel.
A number of successive samples is called a stream.
Up to 32 channels can be present in an audio sample/stream; each channel
can be associated with a position (Left, Right, Center, Subwoofer, etc),
or, in case Position is < Mono, a channel is defined as a single
unassociated stream (but can still be numbered from 0 to 31). There is no
pre-defined order for the channel positions; a stereo sample could be
stored as |Left|Right| or |Right|Left|.
Each channel must have the same format (8 bit, 16 bit, signed,
unsigned, etc.).
*/
#include "SoundAttributes.h"
SoundAttributes::SoundAttributes()
{
Reset();
}
void SoundAttributes::Reset()
{
SampleRate = 0;
SampleFormat = Unknown;
Channels = 0;
for (int i = 0; i < 32; i++)
ChannelPosition[i] = NotUsed;
}
void SoundAttributes::SetPreset(Preset p)
{
switch(p)
{
case Speech:
SampleRate = 8000;
SampleFormat = Unsigned8;
Channels = 1;
ChannelPosition[0] = Mono;
break;
case Radio:
SampleRate = 22025;
SampleFormat = Signed16;
Channels = 1;
ChannelPosition[0] = Mono;
break;
case CD:
SampleRate = 44100;
SampleFormat = Signed16;
Channels = 2;
ChannelPosition[0] = Left;
ChannelPosition[1] = Right;
break;
case DAT:
SampleRate = 48000;
SampleFormat = Signed16;
Channels = 2;
ChannelPosition[0] = Left;
ChannelPosition[1] = Right;
break;
case Dolby51:
SampleRate = 44100;
SampleFormat = Signed16;
Channels = 6;
ChannelPosition[0] = Left;
ChannelPosition[1] = Right;
ChannelPosition[2] = Center;
ChannelPosition[3] = LeftRear;
ChannelPosition[4] = RightRear;
ChannelPosition[5] = LFE;
break;
};
}
/** \brief Returns number of bits for current format.
Note: all channels in a sample(stream) have the same format.
*/
unsigned int SoundAttributes::FormatWidth() const
{
switch(SampleFormat)
{
case Signed8:
case Unsigned8:
return 8;
case Signed16:
case Unsigned16:
return 16;
case Signed24:
case Unsigned24:
case Signed32:
case Unsigned32:
case Float:
return 32;
}
return 0;
}
/** \brief Returns number of bytes required for a single sample in current format. */
unsigned int SoundAttributes::BytesPerSample() const
{
return (FormatWidth() * Channels) / 8;
}
/** Returns true if all parameters and channels are equal */
bool SoundAttributes::operator ==(const struct SoundAttributes &comp) const
{
if (SampleRate != comp.SampleRate ||
SampleFormat != comp.SampleFormat ||
Channels != comp.Channels)
return false;
for (unsigned int i = 0; i < Channels; i++)
if (ChannelPosition[i] != comp.ChannelPosition[i])
return false;
return true;
}
/** Returns false if any of the parameters or channels are unequal */
bool SoundAttributes::operator !=(const struct SoundAttributes &comp) const
{
if (SampleRate != comp.SampleRate ||
SampleFormat != comp.SampleFormat ||
Channels != comp.Channels)
return true;
for (unsigned int i = 0; i < Channels; i++)
if (ChannelPosition[i] != comp.ChannelPosition[i])
return true;
return false;
}
SoundAttributes SoundAttributes ::GetFormat(Preset fmt)
{
SoundAttributes at;
at.SetPreset(fmt);
return at;
}
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