jackclient.cc

// ----------------------------------------------------------------------------
//
//  Copyright (C) 2012-2018 Fons Adriaensen <fons@linuxaudio.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 3 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, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------


#include <stdio.h>
#include <math.h>
#include "jackclient.h"
#include "alsathread.h"
#include "timers.h"


Jackclient::Jackclient (jack_client_t* cl, const char *jserv, int mode, int nchan, bool sync, void *arg) :
    _client (cl),
    _arg (arg),
    _mode (mode),
    _nchan (nchan),     
    _state (INIT),
    _freew (false),
    _resamp (0)
{
    init (jserv);
    if (!sync) _resamp = new VResampler ();
}


Jackclient::~Jackclient (void)
{
    fini ();
}


bool Jackclient::init (const char *jserv)
{
    int                 i, spol, flags;
    char                s [64];
    struct sched_param  spar;

    if (_client == 0)
    {
        fprintf (stderr, "Can't connect to Jack, is the server running ?\n");
        return false;
    }
    jack_set_process_callback (_client, jack_static_process, (void *) this);
    jack_set_latency_callback (_client, jack_static_latency, (void *) this);
    jack_set_freewheel_callback (_client, jack_static_freewheel, (void *) this);
    jack_set_buffer_size_callback (_client, jack_static_buffsize, (void *) this);
    jack_on_shutdown (_client, jack_static_shutdown, (void *) this);

    _bsize = 0;
    _fsamp = 0;
    if (jack_activate (_client))
    {
        fprintf(stderr, "Can't activate Jack");
        return false;
    }
    _jname = jack_get_client_name (_client);
    _bsize = jack_get_buffer_size (_client);
    _fsamp = jack_get_sample_rate (_client);

    flags = JackPortIsTerminal | JackPortIsPhysical;
    for (i = 0; i < _nchan; i++)
    {
	if (_mode == PLAY)
	{
            sprintf (s, "playback_%d", i + 1);
            _ports [i] = jack_port_register (_client, s, JACK_DEFAULT_AUDIO_TYPE,
                                             flags | JackPortIsInput, 0);
	}
	else
	{
            sprintf (s, "capture_%d", i + 1);
            _ports [i] = jack_port_register (_client, s, JACK_DEFAULT_AUDIO_TYPE,
                                             flags | JackPortIsOutput, 0);
	}
    }
    pthread_getschedparam (jack_client_thread_id (_client), &spol, &spar);
    _rprio = spar.sched_priority -  sched_get_priority_max (spol);
    _buff = new float [_bsize * _nchan];
    return true;
}


void Jackclient::fini (void)
{
    delete[] _buff;
    delete _resamp;
}


void Jackclient::jack_static_shutdown (void *arg)
{
    ((Jackclient *) arg)->sendinfo (TERM, 0, 0);
}


int Jackclient::jack_static_buffsize (jack_nframes_t nframes, void *arg)
{
    Jackclient *J = (Jackclient *) arg;

    if (J->_bsize == 0)	J->_bsize = nframes;
    else if (J->_bsize != (int) nframes) J->_state = Jackclient::TERM;
    return 0;
}


void Jackclient::jack_static_freewheel (int state, void *arg)
{
    ((Jackclient *) arg)->jack_freewheel (state);
}


void Jackclient::jack_static_latency (jack_latency_callback_mode_t jlcm, void *arg)
{
    ((Jackclient *) arg)->jack_latency (jlcm);
}


int Jackclient::jack_static_process (jack_nframes_t nframes, void *arg)
{
    return ((Jackclient *) arg)->jack_process (nframes);
}


void Jackclient::start (Lfq_audio   *audioq,
                        Lfq_int32   *commq, 
                        Lfq_adata   *alsaq,
                        Lfq_jdata   *infoq,
                        double      ratio,
                        int         delay,
			int         ltcor,
                        int         rqual)
{
    double d;

    _audioq = audioq;
    _commq = commq;
    _alsaq = alsaq;
    _infoq = infoq;
    _ratio = ratio;
    _delay = delay;
    _rcorr = 1.0;
    if (_resamp)
    {
        _resamp->setup (_ratio, _nchan, rqual);
        _resamp->set_rrfilt (100);
        d = _resamp->inpsize () / 2.0;
        if (_mode == PLAY) d *= _ratio;
        _delay += d;
    }
    _ltcor = ltcor;
    _ppsec = (_fsamp + _bsize / 2) / _bsize;
    initwait (_ppsec / 2);
    jack_recompute_total_latencies (_client);
}


void Jackclient::initwait (int nwait)
{
    _count = -nwait;
    _commq->wr_int32 (Alsathread::WAIT);
    _state = WAIT;
    if (nwait > _ppsec) sendinfo (WAIT, 0, 0);
}


void Jackclient::initsync (void)
{
    // Reset all lock-free queues.
    _commq->reset ();
    _alsaq->reset ();
    _audioq->reset ();
    if (_resamp)
    {
        // Reset and prefill the resampler.
	_resamp->reset ();
	_resamp->inp_count = _resamp->inpsize () / 2 - 1;
	_resamp->out_count = 99999;
	_resamp->process ();
    }
    // Initialise state variables.
    _t_a0 = _t_a1 = 0;
    _k_a0 = _k_a1 = 0;
    // Initialise loop filter state.
    _z1 = _z2 = _z3 = 0;
    // Activate the ALSA thread,
    _commq->wr_int32 (Alsathread::PROC);
    _state = SYNC0;
    sendinfo (SYNC0, 0, 0);
}


void Jackclient::setloop (double bw)
{
    double w;

    // Set the loop bandwidth to bw Hz.
    w = 6.28 * bw * _bsize / _fsamp;
    _w0 = 1.0 - exp (-20.0 * w);
    _w1 = w * 2 / _bsize;
    _w2 = w / 2;
    if (_mode == PLAY) _w1 /= _ratio;
    else               _w1 *= _ratio;
}


void Jackclient::playback (int nframes)
{
    int    i, j, n;
    float  *p, *q;
    float  *inp [MAXCHAN];

    _bstat = _audioq->rd_avail ();
    for (i = 0; i < _nchan; i++)
    {
        inp [i] = (float *)(jack_port_get_buffer (_ports [i], nframes));
    }
    if (_resamp)
    {    
	// Interleave inputs into _buff.
	for (i = 0; i < _nchan; i++)
	{
	    p = inp [i];
	    q = _buff + i;
	    for (j = 0; j < _bsize; j++) q [j * _nchan] = p [j];
	}       
	// Resample _buff and write to audio queue.
	// The while loop takes care of wraparound.
	_resamp->inp_count = _bsize;
	_resamp->inp_data  = _buff;
	while (_resamp->inp_count)
	{
	    _resamp->out_count = _audioq->wr_linav ();
	    _resamp->out_data  = _audioq->wr_datap ();
	    n = _resamp->out_count;
	    _resamp->process ();
	    n -= _resamp->out_count;
	    _audioq->wr_commit (n);
	}
    }
    else
    {
        // Interleave inputs into audio queue.
	// The while loop takes care of wraparound.
	while (nframes)
	{
	    q = _audioq->wr_datap ();
	    n = _audioq->wr_linav ();
	    if (n > nframes) n = nframes;
	    for (i = 0; i < _nchan; i++)
	    {
	        p = inp [i];
	        for (j = 0; j < n; j++) q [j * _nchan] = p [j];
		inp [i] += n;
		q += 1;
	    }
	    _audioq->wr_commit (n);
	    nframes -= n;
	}
    }
}


void Jackclient::capture (int nframes)
{
    int    i, j, n;
    float  *p, *q;
    float  *out [MAXCHAN];

    for (i = 0; i < _nchan; i++)
    {
        out [i] = (float *)(jack_port_get_buffer (_ports [i], nframes));
    }
    if (_resamp)
    {
	// Read from audio queue and resample.
	// The while loop takes care of wraparound.
	_resamp->out_count = _bsize;
	_resamp->out_data  = _buff;
	while (_resamp->out_count)
	{
	    _resamp->inp_count = _audioq->rd_linav ();
	    _resamp->inp_data  = _audioq->rd_datap ();
	    n = _resamp->inp_count;
	    _resamp->process ();
	    n -= _resamp->inp_count;
	    _audioq->rd_commit (n);
	}
	// Deinterleave _buff to outputs.
	for (i = 0; i < _nchan; i++)
	{
	    p = _buff + i;
	    q = out [i];
	    for (j = 0; j < _bsize; j++) q [j] = p [j * _nchan];
	}
    }
    else
    {
        // Deinterleave audio queue to outputs.
	// The while loop takes care of wraparound.
	while (nframes)
	{
	    p = _audioq->rd_datap ();
	    n = _audioq->rd_linav ();
	    if (n > nframes) n = nframes;
	    for (i = 0; i < _nchan; i++)
	    {
	        q = out [i];
	        for (j = 0; j < n; j++) q [j] = p [j * _nchan];
		out [i] += n;
		p += 1;
	    }
	    _audioq->rd_commit (n);
	    nframes -= n;
	}
    }
    _bstat = _audioq->rd_avail ();
}


void Jackclient::silence (int nframes)
{
    int    i;
    float  *q;

    // Write silence to all jack ports.
    for (i = 0; i < _nchan; i++)
    {
        q = (float *)(jack_port_get_buffer (_ports [i], nframes));
        memset (q, 0, nframes * sizeof (float));
    }
}


void Jackclient::sendinfo (int state, double error, double ratio)
{
    Jdata *J;

    if (_infoq->wr_avail ())
    {
	J = _infoq->wr_datap ();
	J->_state = state;
	J->_error = error;
	J->_ratio = ratio;
	J->_bstat = _bstat;
	_infoq->wr_commit ();
    }
}


void Jackclient::jack_freewheel (int state)
{
    _freew = state ? true : false;
    if (_freew) initwait (_ppsec / 4);
}


void Jackclient::jack_latency (jack_latency_callback_mode_t jlcm)
{
    jack_latency_range_t R;
    int i;

    if (_state < WAIT) return;
    if (_mode == PLAY)
    {
	if (jlcm != JackPlaybackLatency) return;
	R.min = R.max = (int)(_delay / _ratio) + _ltcor;
    }
    else
    {
	if (jlcm != JackCaptureLatency) return;
	R.min = R.max = (int)(_delay * _ratio) + _ltcor;
    }
    for (i = 0; i < _nchan; i++)
    {
	jack_port_set_latency_range (_ports [i], jlcm, &R);
    }
}


int Jackclient::jack_process (int nframes)
{
    int             dk, n;
    Adata           *D;
    jack_time_t     t0, t1;
    jack_nframes_t  ft;
    float           us;
    double          tj, err, d1, d2, rd;

    // Buffer size change or other evil.
    if (_state == TERM)
    {
	sendinfo (TERM, 0, 0);
	return 0;
    }
    // Skip cylce if ports may not yet exist.
    if (_state < WAIT) return 0;

    // Start synchronisation 1/2 second after entering
    // the WAIT state. This delay allows the ALSA thread
    // to restart cleanly if necessary. Disabled while
    // freewheeling.
    if (_state == WAIT)
    {
	if (_freew) return 0;
	if (_mode == CAPT) silence (nframes);
        if (++_count == 0) initsync ();
        else return 0;
    }

    // Get the start time of the current cycle.
    jack_get_cycle_times (_client, &ft, &t0, &t1, &us);
    tj = tjack (t0);

    // Check for any skipped cycles.
    if (_state >= SYNC1)
    {
        dk = ft - _ft - _bsize;
        if (_mode == PLAY)
	{
	    dk = (int)(dk * _ratio + 0.5);
            _audioq->wr_commit (dk);
	}
	else
	{
	    dk = (int)(dk / _ratio + 0.5);    
            _audioq->rd_commit (dk);
	}
    }
    _ft = ft;
    
    // Check if we have timing data from the ALSA thread.
    n = _alsaq->rd_avail ();
    // If the data queue is full restart synchronisation.
    // This can happen e.g. on a jack engine timeout, or
    // when too many cycles have been skipped.
    if (n == _alsaq->size ())
    {
        initwait (_ppsec / 2);
        return 0;
    }
    if (n)
    {
        // Else move interval end to start, and update the
        // interval end keeping only the most recent data.
        if (_state < SYNC2) _state++;
        _t_a0 = _t_a1;
        _k_a0 = _k_a1;
        while (_alsaq->rd_avail ())
        {
            D = _alsaq->rd_datap ();
            // Restart synchronisation in case of
            // an error in the ALSA interface.
   	    if (D->_state == Alsathread::WAIT)
            {
                initwait (_ppsec / 2);
                return 0;
            }
            _t_a1 =  D->_timer;
            _k_a1 += D->_nsamp;
            _alsaq->rd_commit ();
        }
    }

    err = 0;
    if (_state >= SYNC2)
    {
        // Compute the delay error.
        d1 = tjack_diff (tj, _t_a0);
        d2 = tjack_diff (_t_a1, _t_a0);
	rd = _resamp ? _resamp->inpdist () : 0.0;

	if (_mode == PLAY)
	{
            n = _audioq->nwr () - _k_a0; // Must be done as integer as both terms will overflow.
            err = n - (_k_a1 - _k_a0) * d1 / d2  + rd * _ratio - _delay;
	}
	else
	{
            n = _k_a0 - _audioq->nrd (); // Must be done as integer as both terms will overflow.
            err = n + (_k_a1 - _k_a0) * d1 / d2  + rd - _delay ;
	}
        n = (int)(floor (err + 0.5));
        if (_state == SYNC2)
        {
            // We have the first delay error value. Adjust the audio
	    // queue to obtain the actually wanted delay, and start
	    // tracking.
	    if (_mode == PLAY) _audioq->wr_commit (-n);
	    else               _audioq->rd_commit (n);
            err -= n;
            setloop (1.0);
            _state = PROC1;
        }    
    }

    // Switch to lower bandwidth after 4 seconds.
    if ((_state == PROC1) && (++_count == 4 * _ppsec))
    {
        _state = PROC2;
        setloop (0.05);
    } 

    if (_state >= PROC1)
    {
        _z1 += _w0 * (_w1 * err - _z1);
        _z2 += _w0 * (_z1 - _z2);
        _z3 += _w2 * _z2;
        // Check error conditions.
        if (fabs (_z3) > 0.05)
        {
            // Something is really wrong, wait 10 seconds then restart.
            initwait (10 * _ppsec);
            return 0;
        }
        // Run loop filter and set resample ratio.
	if (_resamp)
	{
            _rcorr = 1 - (_z2 + _z3);
	    if (_rcorr > 1.05) _rcorr = 1.05;
	    if (_rcorr < 0.95) _rcorr = 0.95;
            _resamp->set_rratio (_rcorr);
	}
	sendinfo (_state, err, _rcorr);

	// Resample and transfer between audio
        // queue and jack ports.
	if (_mode == PLAY) playback (nframes);
	else               capture (nframes);
    }
    else if (_mode == CAPT) silence (nframes);

    return 0; 
}