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livetrax/libs/backends/alsa/alsa_slave.h

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/*
* Copyright (C) 2017 Robin Gareus <robin@gareus.org>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef __libbackend_alsa_slave_h__
#define __libbackend_alsa_slave_h__
#include <atomic>
#include <pthread.h>
#include "pbd/ringbuffer.h"
#include "zita-resampler/vresampler.h"
#include "zita-alsa-pcmi.h"
namespace ARDOUR {
class AlsaAudioSlave
{
public:
AlsaAudioSlave (
const char *play_name,
const char *capt_name,
unsigned int master_rate,
unsigned int master_samples_per_period,
unsigned int slave_rate,
unsigned int slave_samples_per_period,
unsigned int periods_per_cycle);
virtual ~AlsaAudioSlave ();
bool start ();
void stop ();
void cycle_start (double, double, bool);
void cycle_end ();
uint32_t capt_chan (uint32_t chn, float* dst, uint32_t n_samples);
uint32_t play_chan (uint32_t chn, float* src, uint32_t n_samples);
bool running () const { return _active; }
void freewheel (bool);
int state (void) const { return _pcmi.state (); }
uint32_t nplay (void) const { return _pcmi.nplay (); }
uint32_t ncapt (void) const { return _pcmi.ncapt (); }
PBD::Signal0<void> Halted;
protected:
virtual void update_latencies (uint32_t, uint32_t) = 0;
private:
Alsa_pcmi _pcmi;
static void* _process_thread (void *);
void* process_thread ();
pthread_t _thread;
bool _run; /* keep going or stop, ardour thread */
bool _active; /* is running, process thread */
/* DLL, track slave process callback */
double _t0, _t1;
uint64_t _samples_since_dll_reset;
double _ratio;
uint32_t _capt_latency;
double _play_latency;
volatile double _slave_speed;
std::atomic<int> _draining;
PBD::RingBuffer<float> _rb_capture;
PBD::RingBuffer<float> _rb_playback;
size_t _samples_per_period; // master
float* _capt_buff;
float* _play_buff;
float* _src_buff;
ArdourZita::VResampler _src_capt;
ArdourZita::VResampler _src_play;
static void reset_resampler (ArdourZita::VResampler&);
}; // class AlsaAudioSlave
} // namespace
#endif /* __libbackend_alsa_slave_h__ */