Prototype using additional ALSA devices (w/resampling).

This commit is contained in:
Robin Gareus 2017-09-18 16:13:47 +02:00
parent 128a985361
commit 8337982766
5 changed files with 914 additions and 2 deletions

View File

@ -23,12 +23,17 @@
#include <glibmm.h>
#include <boost/foreach.hpp>
#include <boost/tokenizer.hpp>
#include "alsa_audiobackend.h"
#include "pbd/compose.h"
#include "pbd/convert.h"
#include "pbd/error.h"
#include "pbd/file_utils.h"
#include "pbd/pthread_utils.h"
#include "ardour/filesystem_paths.h"
#include "ardour/port_manager.h"
#include "ardouralsautil/devicelist.h"
@ -668,6 +673,11 @@ AlsaAudioBackend::set_midi_device_enabled (std::string const device, bool enable
nfo->enabled = enable;
if (_run && prev_enabled != enable) {
// XXX actually we should not change system-ports while running,
// because iterators in main_process_thread will become invalid.
//
// Luckily the engine dialog does not call this while the engine is running,
// This code is currently not used.
if (enable) {
// add ports for the given device
register_system_midi_ports(device);
@ -940,6 +950,34 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
return ProcessThreadStartError;
}
#if 1
if (NULL != getenv ("ALSAEXT")) {
boost::char_separator<char> sep (";");
boost::tokenizer<boost::char_separator<char> > devs (std::string(getenv ("ALSAEXT")), sep);
BOOST_FOREACH (const std::string& tmp, devs) {
std::string dev (tmp);
std::string::size_type n = dev.find ('@');
unsigned int sr = _samplerate;
unsigned int spp = _samples_per_period;
unsigned int duplex = 3; // TODO parse 1: play, 2: capt, 3:both
if (n != std::string::npos) {
std::string opt (dev.substr (n + 1));
sr = PBD::atoi (opt);
dev = dev.substr (0, n);
std::string::size_type n = opt.find ('/');
if (n != std::string::npos) {
spp = PBD::atoi (opt.substr (n + 1));
}
}
if (add_slave (dev.c_str(), sr, spp, duplex)) {
PBD::info << string_compose (_("ALSA slave '%1' added"), dev) << endmsg;
} else {
PBD::error << string_compose (_("ALSA failed to add '%1' as slave"), dev) << endmsg;
}
}
}
#endif
return NoError;
}
@ -970,6 +1008,12 @@ AlsaAudioBackend::stop ()
delete m;
}
while (!_slaves.empty ()) {
AudioSlave* s = _slaves.back ();
_slaves.pop_back ();
delete s;
}
unregister_ports();
delete _pcmi; _pcmi = 0;
_midi_ins = _midi_outs = 0;
@ -1819,8 +1863,14 @@ AlsaAudioBackend::main_process_thread ()
{
AudioEngine::thread_init_callback (this);
_active = true;
bool reset_dll = true;
int last_n_periods = 0;
_processed_samples = 0;
double dll_dt = (double) _samples_per_period / (double) _samplerate;
double dll_w1 = 2 * M_PI * 0.1 * dll_dt;
double dll_w2 = dll_w1 * dll_w1;
uint64_t clock1;
_pcmi->pcm_start ();
int no_proc_errors = 0;
@ -1829,18 +1879,70 @@ AlsaAudioBackend::main_process_thread ()
manager.registration_callback();
manager.graph_order_callback();
const double sr_norm = 1e-6 * (double) _samplerate / (double)_samples_per_period;
while (_run) {
long nr;
bool xrun = false;
bool drain_slaves = false;
if (_freewheeling != _freewheel) {
_freewheel = _freewheeling;
engine.freewheel_callback (_freewheel);
for (AudioSlaves::iterator s = _slaves.begin (); s != _slaves.end (); ++s) {
(*s)->freewheel (_freewheel);
}
if (!_freewheel) {
_pcmi->pcm_stop ();
_pcmi->pcm_start ();
drain_slaves = true;
}
}
if (!_freewheel) {
nr = _pcmi->pcm_wait ();
/* update DLL */
uint64_t clock0 = g_get_monotonic_time();
if (reset_dll || last_n_periods != 1) {
reset_dll = false;
drain_slaves = true;
dll_dt = 1e6 * (double) _samples_per_period / (double)_samplerate;
_t0 = clock0;
_t1 = clock0 + dll_dt;
} else {
const double er = clock0 - _t1;
_t0 = _t1;
_t1 = _t1 + dll_w1 * er + dll_dt;
dll_dt += dll_w2 * er;
}
for (AudioSlaves::iterator s = _slaves.begin (); s != _slaves.end (); ++s) {
if ((*s)->dead) {
continue;
}
if ((*s)->halt) {
/* slave died, unregister its ports (not rt-safe, but no matter) */
PBD::error << _("ALSA Slave device halted") << endmsg;
for (std::vector<AlsaPort*>::const_iterator it = (*s)->inputs.begin (); it != (*s)->inputs.end (); ++it) {
unregister_port (*it);
}
for (std::vector<AlsaPort*>::const_iterator it = (*s)->outputs.begin (); it != (*s)->outputs.end (); ++it) {
unregister_port (*it);
}
(*s)->inputs.clear ();
(*s)->outputs.clear ();
(*s)->active = false;
(*s)->dead = true;
continue;
}
(*s)->active = (*s)->running () && (*s)->state () >= 0;
if (!(*s)->active) {
continue;
}
(*s)->cycle_start (_t0, (_t1 - _t0) * sr_norm, drain_slaves);
}
if (_pcmi->state () > 0) {
++no_proc_errors;
xrun = true;
@ -1858,6 +1960,7 @@ AlsaAudioBackend::main_process_thread ()
break;
}
last_n_periods = 0;
while (nr >= (long)_samples_per_period && _freewheeling == _freewheel) {
uint32_t i = 0;
clock1 = g_get_monotonic_time();
@ -1869,6 +1972,16 @@ AlsaAudioBackend::main_process_thread ()
}
_pcmi->capt_done (_samples_per_period);
for (AudioSlaves::iterator s = _slaves.begin (); s != _slaves.end (); ++s) {
if (!(*s)->active) {
continue;
}
i = 0;
for (std::vector<AlsaPort*>::const_iterator it = (*s)->inputs.begin (); it != (*s)->inputs.end (); ++it, ++i) {
(*s)->capt_chan (i, (float*)((*it)->get_buffer(_samples_per_period)), _samples_per_period);
}
}
/* de-queue incoming midi*/
i = 0;
for (std::vector<AlsaPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it, ++i) {
@ -1924,6 +2037,18 @@ AlsaAudioBackend::main_process_thread ()
_pcmi->clear_chan (i, _samples_per_period);
}
_pcmi->play_done (_samples_per_period);
for (AudioSlaves::iterator s = _slaves.begin (); s != _slaves.end (); ++s) {
if (!(*s)->active) {
continue;
}
i = 0;
for (std::vector<AlsaPort*>::const_iterator it = (*s)->outputs.begin (); it != (*s)->outputs.end (); ++it, ++i) {
(*s)->play_chan (i, (float*)((*it)->get_buffer(_samples_per_period)), _samples_per_period);
}
(*s)->cycle_end ();
}
nr -= _samples_per_period;
_processed_samples += _samples_per_period;
@ -1931,10 +2056,12 @@ AlsaAudioBackend::main_process_thread ()
_dsp_load_calc.set_start_timestamp_us (clock1);
_dsp_load_calc.set_stop_timestamp_us (g_get_monotonic_time());
_dsp_load = _dsp_load_calc.get_dsp_load ();
++last_n_periods;
}
if (xrun && (_pcmi->capt_xrun() > 0 || _pcmi->play_xrun() > 0)) {
engine.Xrun ();
reset_dll = true;
#if 0
fprintf(stderr, "ALSA x-run read: %.2f ms, write: %.2f ms\n",
_pcmi->capt_xrun() * 1000.0, _pcmi->play_xrun() * 1000.0);
@ -1980,6 +2107,7 @@ AlsaAudioBackend::main_process_thread ()
}
_dsp_load = 1.0;
reset_dll = true;
Glib::usleep (100); // don't hog cpu
}
@ -2021,6 +2149,119 @@ AlsaAudioBackend::main_process_thread ()
return 0;
}
/******************************************************************************/
bool
AlsaAudioBackend::add_slave (const char* device,
unsigned int slave_rate,
unsigned int slave_spp,
unsigned int duplex)
{
AudioSlave* s = new AudioSlave (device, duplex,
_samplerate, _samples_per_period,
slave_rate, slave_spp, 2);
if (s->state ()) {
// TODO parse error status
PBD::error << string_compose (_("Failed to create slave device '%1' error %2\n"), device, s->state ()) << endmsg;
goto errout;
}
for (uint32_t i = 0, n = 1; i < s->ncapt (); ++i) {
char tmp[64];
do {
snprintf(tmp, sizeof(tmp), "extern:capture_%d", n);
if (find_port (tmp)) {
++n;
} else {
break;
}
} while (1);
PortHandle p = add_port(std::string(tmp), DataType::AUDIO, static_cast<PortFlags>(IsOutput | IsPhysical | IsTerminal));
if (!p) goto errout;
AlsaPort *ap = static_cast<AlsaPort*>(p);
s->inputs.push_back (ap);
}
for (uint32_t i = 0, n = 1; i < s->nplay (); ++i) {
char tmp[64];
do {
snprintf(tmp, sizeof(tmp), "extern:playback_%d", n);
if (find_port (tmp)) {
++n;
} else {
break;
}
} while (1);
PortHandle p = add_port(std::string(tmp), DataType::AUDIO, static_cast<PortFlags>(IsInput | IsPhysical | IsTerminal));
if (!p) goto errout;
AlsaPort *ap = static_cast<AlsaPort*>(p);
s->outputs.push_back (ap);
}
if (!s->start ()) {
PBD::error << string_compose (_("Failed to start slave device '%1'\n"), device) << endmsg;
goto errout;
}
s->UpdateLatency.connect_same_thread (s->latency_connection, boost::bind (&AlsaAudioBackend::update_latencies, this));
_slaves.push_back (s);
return true;
errout:
delete s; // releases device
return false;
}
AlsaAudioBackend::AudioSlave::AudioSlave (
const char* device,
unsigned int duplex,
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)
: AlsaDeviceReservation (device)
, AlsaAudioSlave (
(duplex & 1) ? device : NULL /* playback */,
(duplex & 2) ? device : NULL /* capture */,
master_rate, master_samples_per_period,
slave_rate, slave_samples_per_period, periods_per_cycle)
, active (false)
, halt (false)
, dead (false)
{
Halted.connect_same_thread (_halted_connection, boost::bind (&AudioSlave::halted, this));
}
AlsaAudioBackend::AudioSlave::~AudioSlave ()
{
stop ();
}
void
AlsaAudioBackend::AudioSlave::halted ()
{
// Note: Halted() is emitted from the Slave's process thread.
release_device ();
halt = true;
}
void
AlsaAudioBackend::AudioSlave::update_latencies (uint32_t play, uint32_t capt)
{
LatencyRange lr;
lr.min = lr.max = (capt);
for (std::vector<AlsaPort*>::const_iterator it = inputs.begin (); it != inputs.end (); ++it) {
(*it)->set_latency_range (lr, false);
}
lr.min = lr.max = play;
for (std::vector<AlsaPort*>::const_iterator it = outputs.begin (); it != outputs.end (); ++it) {
(*it)->set_latency_range (lr, true);
}
printf (" ----- SLAVE LATENCY play=%d capt=%d\n", play, capt); // XXX DEBUG
UpdateLatency (); /* EMIT SIGNAL */
}
/******************************************************************************/

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@ -41,6 +41,7 @@
#include "zita-alsa-pcmi.h"
#include "alsa_rawmidi.h"
#include "alsa_sequencer.h"
#include "alsa_slave.h"
namespace ARDOUR {
@ -397,6 +398,9 @@ class AlsaAudioBackend : public AudioBackend {
framecnt_t _processed_samples;
pthread_t _main_thread;
/* DLL, track main process callback timing */
double _t0, _t1;
/* process threads */
static void* alsa_process_thread (void *);
std::vector<pthread_t> _threads;
@ -480,6 +484,46 @@ class AlsaAudioBackend : public AudioBackend {
void update_systemic_audio_latencies ();
void update_systemic_midi_latencies ();
/* additional re-sampled I/O */
bool add_slave (const char* slave_device,
unsigned int slave_rate,
unsigned int slave_spp,
unsigned int duplex = 3);
class AudioSlave : public AlsaDeviceReservation, public AlsaAudioSlave {
public:
AudioSlave (
const char* device,
unsigned int duplex,
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);
~AudioSlave ();
bool active; // set in sync with process-cb
bool halt;
bool dead;
std::vector<AlsaPort *> inputs;
std::vector<AlsaPort *> outputs;
PBD::Signal0<void> UpdateLatency;
PBD::ScopedConnection latency_connection;
protected:
void update_latencies (uint32_t, uint32_t);
private:
PBD::ScopedConnection _halted_connection;
void halted ();
};
typedef std::vector<AudioSlave*> AudioSlaves;
AudioSlaves _slaves;
}; // class AlsaAudioBackend
} // namespace

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@ -0,0 +1,523 @@
/*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <cmath>
#include <glibmm.h>
#include "pbd/compose.h"
#include "pbd/error.h"
#include "pbd/pthread_utils.h"
#include "alsa_slave.h"
#include "pbd/i18n.h"
using namespace ARDOUR;
AlsaAudioSlave::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)
: _pcmi (play_name, capt_name, 0, slave_rate, slave_samples_per_period, periods_per_cycle, 2, /* Alsa_pcmi::DEBUG_ALL */ 0)
, _run (false)
, _active (false)
, _samples_since_dll_reset (0)
, _ratio (1.0)
, _slave_speed (1.0)
, _draining (1)
, _rb_capture (4 * /* AlsaAudioBackend::_max_buffer_size */ 8192 * _pcmi.ncapt ())
, _rb_playback (4 * /* AlsaAudioBackend::_max_buffer_size */ 8192 * _pcmi.nplay ())
, _samples_per_period (master_samples_per_period)
, _capt_buff (0)
, _play_buff (0)
, _src_buff (0)
{
if (0 != _pcmi.state()) {
return;
}
/* from alsa-slave to master */
_ratio = (double) master_rate / (double) _pcmi.fsamp();
#ifndef NDEBUG
fprintf (stdout, " --[[ ALSA Slave %s/%s ratio: %.4f\n", play_name, capt_name, _ratio);
_pcmi.printinfo ();
fprintf (stdout, " --]]\n");
#endif
_src_capt.setup (_ratio, _pcmi.ncapt (), /*quality*/ 32); // save capture to master
_src_play.setup (1.0 / _ratio, _pcmi.nplay (), /*quality*/ 32); // master to slave play
_src_capt.set_rrfilt (100);
_src_play.set_rrfilt (100);
_capt_buff = (float*) malloc (sizeof(float) * _pcmi.ncapt () * _samples_per_period);
_play_buff = (float*) malloc (sizeof(float) * _pcmi.nplay () * _samples_per_period);
_src_buff = (float*) malloc (sizeof(float) * std::max (_pcmi.nplay (), _pcmi.ncapt ()));
}
AlsaAudioSlave::~AlsaAudioSlave ()
{
stop ();
free (_capt_buff);
free (_play_buff);
free (_src_buff);
}
void
AlsaAudioSlave::reset_resampler (ArdourZita::VResampler& src)
{
src.reset ();
src.inp_count = src.inpsize () - 1;
src.out_count = 200000;
src.process ();
}
bool
AlsaAudioSlave::start ()
{
if (_run) {
return false;
}
_run = true;
if (pbd_realtime_pthread_create (PBD_SCHED_FIFO, -20, 100000,
&_thread, _process_thread, this))
{
if (pthread_create (&_thread, NULL, _process_thread, this)) {
_run = false;
PBD::error << _("AlsaAudioBackend: failed to create slave process thread.") << endmsg;
return false;
}
}
int timeout = 5000;
while (!_active && --timeout > 0) { Glib::usleep (1000); }
if (timeout == 0 || !_active) {
_run = false;
PBD::error << _("AlsaAudioBackend: failed to start slave process thread.") << endmsg;
return false;
}
return true;
}
void
AlsaAudioSlave::stop ()
{
void *status;
if (!_run) {
return;
}
_run = false;
if (pthread_join (_thread, &status)) {
PBD::error << _("AlsaAudioBackend: slave failed to terminate properly.") << endmsg;
}
_pcmi.pcm_stop ();
}
void*
AlsaAudioSlave::_process_thread (void* arg)
{
AlsaAudioSlave* aas = static_cast<AlsaAudioSlave*> (arg);
return aas->process_thread ();
}
void*
AlsaAudioSlave::process_thread ()
{
_active = true;
bool reset_dll = true;
int last_n_periods = 0;
int no_proc_errors = 0;
const int bailout = 2 * _pcmi.fsamp () / _pcmi.fsize ();
double dll_dt = (double) _pcmi.fsize () / (double)_pcmi.fsamp ();
double dll_w1 = 2 * M_PI * 0.1 * dll_dt;
double dll_w2 = dll_w1 * dll_w1;
const double sr_norm = 1e-6 * (double) _pcmi.fsamp () / (double) _pcmi.fsize ();
_pcmi.pcm_start ();
while (_run) {
bool xrun = false;
long nr = _pcmi.pcm_wait ();
/* update DLL */
uint64_t clock0 = g_get_monotonic_time();
if (reset_dll || last_n_periods != 1) {
reset_dll = false;
dll_dt = 1e6 * (double) _pcmi.fsize () / (double) _pcmi.fsamp();
_t0 = clock0;
_t1 = clock0 + dll_dt;
_samples_since_dll_reset = 0;
} else {
const double er = clock0 - _t1;
_t0 = _t1;
_t1 = _t1 + dll_w1 * er + dll_dt;
dll_dt += dll_w2 * er;
_samples_since_dll_reset += _pcmi.fsize ();
}
_slave_speed = (_t1 - _t0) * sr_norm; // XXX atomic
if (_pcmi.state () > 0) {
++no_proc_errors;
xrun = true;
}
if (_pcmi.state () < 0) {
PBD::error << _("AlsaAudioBackend: Slave I/O error.") << endmsg;
break;
}
if (no_proc_errors > bailout) {
PBD::error << _("AlsaAudioBackend: Slave terminated due to continuous x-runs.") << endmsg;
break;
}
const size_t spp = _pcmi.fsize ();
const bool drain = g_atomic_int_get (&_draining);
last_n_periods = 0;
while (nr >= (long)spp) {
no_proc_errors = 0;
_pcmi.capt_init (spp);
if (drain) {
/* do nothing */
} else if (_rb_capture.write_space () >= _pcmi.ncapt () * spp) {
#if 0 // failsafe: write interleave sample by sample
for (uint32_t s = 0; s < spp; ++s) {
for (uint32_t c = 0; c < _pcmi.ncapt (); ++c) {
float d;
_pcmi.capt_chan (c, &d, 1);
_rb_capture.write (&d, 1);
}
}
#else
unsigned int nchn = _pcmi.ncapt ();
PBD::RingBuffer<float>::rw_vector vec;
_rb_capture.get_write_vector (&vec);
if (vec.len[0] >= nchn * spp) {
for (uint32_t c = 0; c < nchn; ++c) {
_pcmi.capt_chan (c, vec.buf[0] + c, spp, nchn);
}
} else {
uint32_t c;
/* first copy continuous area */
uint32_t k = vec.len[0] / nchn;
for (c = 0; c < nchn; ++c) {
_pcmi.capt_chan (c, vec.buf[0] + c, k, nchn);
}
/* possible samples at end of first buffer chunk,
* incomplete audio-frame */
uint32_t s = vec.len[0] - k * nchn;
assert (s < nchn);
for (c = 0; c < s; ++c) {
_pcmi.capt_chan (c, vec.buf[0] + k * nchn + c, 1, nchn);
}
/* cont'd audio-frame at second ringbuffer chunk */
for (; c < nchn; ++c) {
_pcmi.capt_chan (c, vec.buf[1] + c - s, spp - k, nchn);
}
/* remaining data in 2nd area */
for (c = 0; c < s; ++c) {
_pcmi.capt_chan (c, vec.buf[1] + c + nchn - s, spp - k, nchn);
}
}
_rb_capture.increment_write_idx (spp * nchn);
#endif
} else {
g_atomic_int_set(&_draining, 1);
}
_pcmi.capt_done (spp);
if (drain) {
_rb_playback.increment_read_idx (_rb_playback.read_space ());
}
_pcmi.play_init (spp);
if (_rb_playback.read_space () >= _pcmi.nplay () * spp) {
#if 0 // failsafe: read sample by sample de-interleave
for (uint32_t s = 0; s < spp; ++s) {
for (uint32_t c = 0; c < _pcmi.nplay (); ++c) {
float d;
_rb_playback.read (&d, 1);
_pcmi.play_chan (c, (const float*)&d, 1);
}
}
#else
unsigned int nchn = _pcmi.nplay ();
PBD::RingBuffer<float>::rw_vector vec;
_rb_playback.get_read_vector (&vec);
if (vec.len[0] >= nchn * spp) {
for (uint32_t c = 0; c < nchn; ++c) {
_pcmi.play_chan (c, vec.buf[0] + c, spp, nchn);
}
} else {
uint32_t c;
uint32_t k = vec.len[0] / nchn;
for (c = 0; c < nchn; ++c) {
_pcmi.play_chan (c, vec.buf[0] + c, k, nchn);
}
uint32_t s = vec.len[0] - k * nchn;
assert (s < nchn);
for (c = 0; c < s; ++c) {
_pcmi.play_chan (c, vec.buf[0] + k * nchn + c, 1, nchn);
}
for (; c < nchn; ++c) {
_pcmi.play_chan (c, vec.buf[1] + c - s, spp - k, nchn);
}
for (c = 0; c < s; ++c) {
_pcmi.play_chan (c, vec.buf[1] + c + nchn - s, spp - k, nchn);
}
}
_rb_playback.increment_read_idx (spp * nchn);
#endif
} else {
if (!drain) {
printf ("Slave Process: Playback Buffer Underflow, have %u want %lu\n", _rb_playback.read_space (), _pcmi.nplay () * spp); // XXX DEBUG
_play_latency += spp * _ratio;
update_latencies (_play_latency, _capt_latency);
}
/* silence outputs */
for (uint32_t c = 0; c < _pcmi.nplay (); ++c) {
_pcmi.clear_chan (c, spp);
}
}
_pcmi.play_done (spp);
nr -= spp;
++last_n_periods;
}
if (xrun && (_pcmi.capt_xrun() > 0 || _pcmi.play_xrun() > 0)) {
reset_dll = true;
_samples_since_dll_reset = 0;
g_atomic_int_set(&_draining, 1);
}
}
_pcmi.pcm_stop ();
_active = false;
if (_run) {
Halted (); /* Emit Signal */
}
return 0;
}
void
AlsaAudioSlave::cycle_start (double tme, double mst_speed, bool drain)
{
//printf ("SRC %f / %f = %f\n", mst_speed, _slave_speed, mst_speed / _slave_speed);
//printf ("DRIFT (mst) %11.1f - (slv) %11.1f = %.1f us = %.1f spl\n", tme, _t0, tme - _t0, (tme - _t0) * _pcmi.fsamp () * 1e-6);
//printf ("Slave capt: %u play: %u\n", _rb_capture.read_space (), _rb_playback.read_space ());
// TODO LPF filter ratios, atomic _slave_speed
const double slave_speed = _slave_speed;
_src_capt.set_rratio (mst_speed / slave_speed);
_src_play.set_rratio (slave_speed / mst_speed);
memset (_capt_buff, 0, sizeof(float) * _pcmi.ncapt () * _samples_per_period);
if (drain) {
g_atomic_int_set(&_draining, 1);
return;
}
if (g_atomic_int_get (&_draining)) {
_rb_capture.increment_read_idx (_rb_capture.read_space());
return;
}
/* resample slave capture data from ringbuffer */
unsigned int nchn = _pcmi.ncapt ();
_src_capt.out_count = _samples_per_period;
_src_capt.out_data = _capt_buff;
/* estimate required samples */
const double rratio = _ratio * mst_speed / slave_speed;
if (_rb_capture.read_space() < ceil (nchn * _samples_per_period / rratio)) {
printf ("--- UNDERFLOW --- have %u want %.1f\n", _rb_capture.read_space(), ceil (nchn * _samples_per_period / rratio)); // XXX DEBUG
_capt_latency += _samples_per_period;
update_latencies (_play_latency, _capt_latency);
return;
}
bool underflow = false;
while (_src_capt.out_count && _active) {
if (_rb_capture.read_space() < nchn) {
underflow = true;
break;
}
unsigned int n;
PBD::RingBuffer<float>::rw_vector vec;
_rb_capture.get_read_vector (&vec);
if (vec.len[0] < nchn) {
_rb_capture.read (_src_buff, nchn);
_src_capt.inp_count = 1;
_src_capt.inp_data = _src_buff;
_src_capt.process ();
} else {
_src_capt.inp_count = n = vec.len[0] / nchn;
_src_capt.inp_data = vec.buf[0];
_src_capt.process ();
n -= _src_capt.inp_count;
_rb_capture.increment_read_idx (n * _pcmi.ncapt ());
}
}
if (underflow) {
std::cerr << "ALSA Slave: Capture Ringbuffer Underflow\n"; // XXX
g_atomic_int_set(&_draining, 1);
}
if (!_active || underflow) {
memset (_capt_buff, 0, sizeof(float) * _pcmi.ncapt () * _samples_per_period);
}
memset (_play_buff, 0, sizeof(float) * _pcmi.nplay () * _samples_per_period);
}
void
AlsaAudioSlave::cycle_end ()
{
bool drain_done = false;
bool overflow = false;
if (g_atomic_int_get (&_draining)) {
if (_rb_capture.read_space() == 0 && _rb_playback.read_space() == 0 && _samples_since_dll_reset > _pcmi.fsamp ()) {
reset_resampler (_src_capt);
reset_resampler (_src_play);
memset (_src_buff, 0, sizeof (float) * _pcmi.nplay());
/* prefill ringbuffers, resampler variance */
for (int i = 0; i < 16; ++i) {
_rb_playback.write (_src_buff, _pcmi.nplay());
}
memset (_src_buff, 0, sizeof (float) * _pcmi.ncapt());
// It's safe to write here, process-thread NO-OPs while draining.
for (int i = 0; i < 16; ++i) {
_rb_capture.write (_src_buff, _pcmi.ncapt());
}
_capt_latency = 16;
_play_latency = 16 + _ratio * _pcmi.fsize () * (_pcmi.play_nfrag () - 1);
update_latencies (_play_latency, _capt_latency);
drain_done = true;
} else {
return;
}
}
/* resample collected playback data into ringbuffer */
unsigned int nchn = _pcmi.nplay ();
_src_play.inp_count = _samples_per_period;
_src_play.inp_data = _play_buff;
while (_src_play.inp_count && _active) {
unsigned int n;
PBD::RingBuffer<float>::rw_vector vec;
_rb_playback.get_write_vector (&vec);
if (vec.len[0] < nchn) {
_src_play.out_count = 1;
_src_play.out_data = _src_buff;
_src_play.process ();
if (_rb_playback.write_space() < nchn) {
overflow = true;
break;
} else if (_src_play.out_count == 0) {
_rb_playback.write (_src_buff, nchn);
}
} else {
_src_play.out_count = n = vec.len[0] / nchn;
_src_play.out_data = vec.buf[0];
_src_play.process ();
n -= _src_play.out_count;
if (_rb_playback.write_space() < n * nchn) {
overflow = true;
break;
}
_rb_playback.increment_write_idx (n * nchn);
}
}
if (overflow) {
std::cerr << "ALSA Slave: Playback Ringbuffer Overflow\n"; // XXX
g_atomic_int_set(&_draining, 1);
return;
}
if (drain_done) {
g_atomic_int_set(&_draining, 0);
}
}
void
AlsaAudioSlave::freewheel (bool onoff)
{
if (onoff) {
g_atomic_int_set(&_draining, 1);
}
}
/* master read slave's capture.
* resampled at cycle_start, before master can call this
*/
uint32_t
AlsaAudioSlave::capt_chan (uint32_t chn, float* dst, uint32_t n_samples)
{
uint32_t nchn = _pcmi.ncapt ();
assert (chn < nchn && n_samples == _samples_per_period);
float* src = &_capt_buff[chn];
for (uint32_t s = 0; s < n_samples; ++s) {
dst[s] = src[s * nchn];
}
return n_samples;
}
/* write from master to slave output,
* resampled at cycle_end, after master called this.
*/
uint32_t
AlsaAudioSlave::play_chan (uint32_t chn, float* src, uint32_t n_samples)
{
uint32_t nchn = _pcmi.nplay ();
assert (chn < nchn && n_samples == _samples_per_period);
float* dst = &_play_buff[chn];
for (uint32_t s = 0; s < n_samples; ++s) {
dst[s * nchn] = src[s];
}
return n_samples;
}

View File

@ -0,0 +1,103 @@
/*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __libbackend_alsa_slave_h__
#define __libbackend_alsa_slave_h__
#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;
volatile gint _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__ */

View File

@ -23,13 +23,14 @@ def build(bld):
'alsa_midi.cc',
'alsa_rawmidi.cc',
'alsa_sequencer.cc',
'alsa_slave.cc',
'zita-alsa-pcmi.cc',
]
obj.includes = ['.']
obj.name = 'alsa_audiobackend'
obj.target = 'alsa_audiobackend'
obj.use = 'libardour libpbd ardouralsautil'
obj.uselib = 'ALSA GLIBMM XML'
obj.use = 'libardour libpbd ardouralsautil zita-resampler'
obj.uselib = 'ALSA GLIBMM XML LIBZRESAMPLER'
obj.install_path = os.path.join(bld.env['LIBDIR'], 'backends')
obj.defines = ['PACKAGE="' + I18N_PACKAGE + '"',
'ARDOURBACKEND_DLL_EXPORTS'