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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set et sw=2 ts=2: */
/***************************************************************************
* mixer.h
*
* Tue Sep 23 14:38:54 CEST 2014
* Copyright 2014 Bent Bisballe Nyeng
* deva@aasimon.org
****************************************************************************/
/*
* This file is part of LibAudioIO.
*
* LibAudioIO is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* LibAudioIO 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with LibAudioIO; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __LIBAUDIOIO_MIXER_H__
#define __LIBAUDIOIO_MIXER_H__
// Make API behave like ALSA 1.x.x with ALSA 0.9.x
#define ALSA_PCM_NEW_HW_PARAMS_API
#include <asoundlib.h>
#include <exception>
#include <string>
#include <vector>
/**
* A Mixer object represents a single group of channels, for example the two
* channels of a stereo mixer.
*/
class Mixer {
public:
/**
* Mixer constructor is not to be called "manually" is is invoked by
* Device::getMixer()
*/
Mixer(snd_mixer_t *handle, snd_mixer_elem_t *elem);
~Mixer();
/**
* Get number of channels in this mixer 'strip'
*/
int numberOfChannels();
/**
* Return true if this mixer is a capture device, false otherwise.
*/
bool isCapture();
/**
* Return true if this mixer is a playback device, false otherwise.
*/
bool isPlayback();
/**
* Return true if this mixer is a enum, false otherwise.
*/
bool isEnum();
/**
* For capture channels only!
* Set arm for recording flag on all mixer channels.
*/
void setCapture(bool capture);
/**
* Return true if all channels are armed for recording.
* Return false if not a capture channels strip, or if at least one channel
* is not armed.
*/
bool capture();
/**
* Set enum value.
*/
void setEnumValue(std::string value);
/**
* Get enum value.
*/
std::string enumValue();
/**
* Get list of possible enum values.
*/
std::vector<std::string> enumValues();
/**
* Get/set mixer volume level in dB.
* On error (no such channel) -INF is returned.
*/
int setLevel(int channel, float level);
// 0 on success, 1 on error.
float level(int channel);
typedef struct {
float min;
float max;
} range_t;
/**
* Poll the valid volume range of this mixer in dB.
*/
range_t range();
private:
snd_mixer_selem_channel_id_t chanId(int idx);
snd_mixer_t *handle;
snd_mixer_elem_t *elem;
};
#endif/*__LIBAUDIOIO_MIXER_H__*/
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