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/* -*- c++ -*- */
/*
* Copyright 2004-2011 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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 3, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef INCLUDED_AUDIO_ALSA_SOURCE_H
#define INCLUDED_AUDIO_ALSA_SOURCE_H
// use new ALSA API
#define ALSA_PCM_NEW_HW_PARAMS_API
#define ALSA_PCM_NEW_SW_PARAMS_API
#include <gr_audio_source.h>
#include <string>
#include <alsa/asoundlib.h>
#include <stdexcept>
class audio_alsa_source;
typedef boost::shared_ptr<audio_alsa_source> audio_alsa_source_sptr;
/*!
* \brief audio source using ALSA
*
* The source has between 1 and N input streams of floats, where N is
* depends on the hardware characteristics of the selected device.
*
* Output samples will be in the range [-1,1].
*/
class audio_alsa_source : public audio_source {
// typedef for pointer to class work method
typedef int (audio_alsa_source::*work_t)(int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
unsigned int d_sampling_rate;
std::string d_device_name;
snd_pcm_t *d_pcm_handle;
snd_pcm_hw_params_t *d_hw_params;
snd_pcm_sw_params_t *d_sw_params;
snd_pcm_format_t d_format;
unsigned int d_nperiods;
unsigned int d_period_time_us; // microseconds
snd_pcm_uframes_t d_period_size; // in frames
unsigned int d_buffer_size_bytes; // sizeof of d_buffer
char *d_buffer;
work_t d_worker; // the work method to use
unsigned int d_hw_nchan; // # of configured h/w channels
bool d_special_case_stereo_to_mono;
// random stats
int d_noverruns; // count of overruns
int d_nsuspends; // count of suspends
void output_error_msg (const char *msg, int err);
void bail (const char *msg, int err) throw (std::runtime_error);
public:
audio_alsa_source (int sampling_rate, const std::string device_name,
bool ok_to_block);
~audio_alsa_source ();
bool check_topology (int ninputs, int noutputs);
int work (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
protected:
bool read_buffer (void *buffer, unsigned nframes, unsigned sizeof_frame);
int work_s16 (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
int work_s16_2x1 (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
int work_s32 (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
int work_s32_2x1 (int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
};
#endif /* INCLUDED_AUDIO_ALSA_SOURCE_H */
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