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/* -*- c++ -*- */
/*
* Copyright 2004-2011,2013 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#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 <gnuradio/audio/source.h>
#include <alsa/asoundlib.h>
#include <stdexcept>
#include <string>
namespace gr {
namespace audio {
class alsa_source;
typedef boost::shared_ptr<alsa_source> alsa_source_sptr;
/*!
* \brief audio source using ALSA
* \ingroup audio_blk
*
* 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 alsa_source : public source
{
// typedef for pointer to class work method
typedef int (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);
public:
alsa_source(int sampling_rate, const std::string device_name, bool ok_to_block);
~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);
};
} /* namespace audio */
} /* namespace gr */
#endif /* INCLUDED_AUDIO_ALSA_SOURCE_H */
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