jamulus-r3_8_1/linux/sound.cpp

/******************************************************************************\
 * Copyright (c) 2004-2020
 *
 * Author(s):
 *  Volker Fischer
 *
 * This code is based on the simple_client example of the Jack audio interface.
 *
 ******************************************************************************
 *
 * 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
 *
\******************************************************************************/

#include "sound.h"

#ifdef WITH_JACK
void CSound::OpenJack ( const bool bNoAutoJackConnect, const char* jackClientName )
{
    jack_status_t JackStatus;
    const char*   serverName;

    if ( ( serverName = getenv ( "JACK_DEFAULT_SERVER" ) ) == NULL )
    {
        serverName = "default";
    }
    qInfo() << qUtf8Printable (
        QString ( "Connecting to JACK \"%1\" instance (use the JACK_DEFAULT_SERVER environment variable to change this)." ).arg ( serverName ) );

    // try to become a client of the JACK server
    pJackClient = jack_client_open ( jackClientName, JackNullOption, &JackStatus );

    if ( pJackClient == nullptr )
    {
        throw CGenErr ( tr ( "JACK couldn't be started automatically. "
                             "Please start JACK manually and check for error messages." ) );
    }

    // tell the JACK server to call "process()" whenever
    // there is work to be done
    jack_set_process_callback ( pJackClient, process, this );

    // register a "buffer size changed" callback function
    jack_set_buffer_size_callback ( pJackClient, bufferSizeCallback, this );

    // register shutdown callback function
    jack_on_shutdown ( pJackClient, shutdownCallback, this );

    // check sample rate, if not correct, just fire error
    if ( jack_get_sample_rate ( pJackClient ) != SYSTEM_SAMPLE_RATE_HZ )
    {
        throw CGenErr ( QString ( tr ( "JACK isn't running at a sample rate of <b>%1 Hz</b>. Please use "
                                       "a tool like <i><a href=\"https://qjackctl.sourceforge.io\">QjackCtl</a></i> to set the "
                                       "the JACK sample rate to %1 Hz." ) )
                            .arg ( SYSTEM_SAMPLE_RATE_HZ ) );
    }

    // create four ports (two for input, two for output -> stereo)
    input_port_left = jack_port_register ( pJackClient, "input left", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0 );

    input_port_right = jack_port_register ( pJackClient, "input right", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0 );

    output_port_left = jack_port_register ( pJackClient, "output left", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0 );

    output_port_right = jack_port_register ( pJackClient, "output right", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0 );

    if ( ( input_port_left == nullptr ) || ( input_port_right == nullptr ) || ( output_port_left == nullptr ) || ( output_port_right == nullptr ) )
    {
        throw CGenErr ( QString ( tr ( "The JACK port registration failed. This is probably an error with JACK. Please stop %1 and JACK. "
                                       "Afterwards check if another program at a sample rate of %2 Hz can connect to JACK." ) )
                            .arg ( APP_NAME )
                            .arg ( SYSTEM_SAMPLE_RATE_HZ ) );
    }

    // optional MIDI initialization
    if ( iCtrlMIDIChannel != INVALID_MIDI_CH )
    {
        input_port_midi = jack_port_register ( pJackClient, "input midi", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0 );

        if ( input_port_midi == nullptr )
        {
            throw CGenErr ( QString ( tr ( "The JACK port registration failed. This is probably an error with JACK. Please stop %1 and JACK. "
                                           "Afterwards, check if another MIDI program can connect to JACK." ) )
                                .arg ( APP_NAME ) );
        }
    }
    else
    {
        input_port_midi = nullptr;
    }

    // tell the JACK server that we are ready to roll
    if ( jack_activate ( pJackClient ) )
    {
        throw CGenErr ( QString ( tr ( "Can't activate the JACK client. This is probably an error with JACK. Please check the JACK output." ) )
                            .arg ( APP_NAME ) );
    }

    if ( !bNoAutoJackConnect )
    {
        // connect the ports, note: you cannot do this before
        // the client is activated, because we cannot allow
        // connections to be made to clients that are not
        // running
        const char** ports;

        // try to connect physical input ports
        if ( ( ports = jack_get_ports ( pJackClient, nullptr, nullptr, JackPortIsPhysical | JackPortIsOutput ) ) != nullptr )
        {
            jack_connect ( pJackClient, ports[0], jack_port_name ( input_port_left ) );

            // before connecting the second stereo channel, check if the input is not mono
            if ( ports[1] )
            {
                jack_connect ( pJackClient, ports[1], jack_port_name ( input_port_right ) );
            }

            jack_free ( ports );
        }

        // try to connect physical output ports
        if ( ( ports = jack_get_ports ( pJackClient, nullptr, nullptr, JackPortIsPhysical | JackPortIsInput ) ) != nullptr )
        {
            jack_connect ( pJackClient, jack_port_name ( output_port_left ), ports[0] );

            // before connecting the second stereo channel, check if the output is not mono
            if ( ports[1] )
            {
                jack_connect ( pJackClient, jack_port_name ( output_port_right ), ports[1] );
            }

            jack_free ( ports );
        }

        // input latency
        jack_latency_range_t latrange;
        latrange.min = 0;
        latrange.max = 0;

        jack_port_get_latency_range ( input_port_left, JackCaptureLatency, &latrange );
        int inLatency = latrange.min; // be optimistic

        // output latency
        latrange.min = 0;
        latrange.max = 0;

        jack_port_get_latency_range ( output_port_left, JackPlaybackLatency, &latrange );
        int outLatency = latrange.min; // be optimistic

        // compute latency by using the first input and first output
        // ports and using the most optimistic values
        fInOutLatencyMs = static_cast<float> ( inLatency + outLatency ) * 1000 / SYSTEM_SAMPLE_RATE_HZ;
    }
}

void CSound::CloseJack()
{
    // deactivate client
    jack_deactivate ( pJackClient );

    // unregister ports
    jack_port_unregister ( pJackClient, input_port_left );
    jack_port_unregister ( pJackClient, input_port_right );
    jack_port_unregister ( pJackClient, output_port_left );
    jack_port_unregister ( pJackClient, output_port_right );

    // close client connection to jack server
    jack_client_close ( pJackClient );
}

void CSound::Start()
{
    // call base class
    CSoundBase::Start();
}

void CSound::Stop()
{
    // call base class
    CSoundBase::Stop();
}

int CSound::Init ( const int /* iNewPrefMonoBufferSize */ )
{

    // clang-format off
// try setting buffer size
// TODO seems not to work! -> no audio after this operation!
// Doesn't this give an infinite loop? The set buffer size function will call our
// registered callback which calls "EmitReinitRequestSignal()". In that function
// this CSound::Init() function is called...
//jack_set_buffer_size ( pJackClient, iNewPrefMonoBufferSize );
    // clang-format on

    // without a Jack server, Jamulus makes no sense to run, throw an error message
    if ( bJackWasShutDown )
    {
        throw CGenErr ( QString ( tr ( "JACK was shut down. %1 "
                                       "requires JACK to run. Please restart %1 to "
                                       "start JACK again. " ) )
                            .arg ( APP_NAME ) );
    }

    // get actual buffer size
    iJACKBufferSizeMono = jack_get_buffer_size ( pJackClient );

    // init base class
    CSoundBase::Init ( iJACKBufferSizeMono );

    // set internal buffer size value and calculate stereo buffer size
    iJACKBufferSizeStero = 2 * iJACKBufferSizeMono;

    // create memory for intermediate audio buffer
    vecsTmpAudioSndCrdStereo.Init ( iJACKBufferSizeStero );

    return iJACKBufferSizeMono;
}

// JACK callbacks --------------------------------------------------------------
int CSound::process ( jack_nframes_t nframes, void* arg )
{
    CSound* pSound = static_cast<CSound*> ( arg );
    int     i;

    // make sure we are locked during execution
    QMutexLocker locker ( &pSound->MutexAudioProcessCallback );

    if ( pSound->IsRunning() && ( nframes == static_cast<jack_nframes_t> ( pSound->iJACKBufferSizeMono ) ) )
    {
        // get input data pointer
        jack_default_audio_sample_t* in_left = (jack_default_audio_sample_t*) jack_port_get_buffer ( pSound->input_port_left, nframes );

        jack_default_audio_sample_t* in_right = (jack_default_audio_sample_t*) jack_port_get_buffer ( pSound->input_port_right, nframes );

        // copy input audio data
        if ( ( in_left != nullptr ) && ( in_right != nullptr ) )
        {
            for ( i = 0; i < pSound->iJACKBufferSizeMono; i++ )
            {
                pSound->vecsTmpAudioSndCrdStereo[2 * i]     = Float2Short ( in_left[i] * _MAXSHORT );
                pSound->vecsTmpAudioSndCrdStereo[2 * i + 1] = Float2Short ( in_right[i] * _MAXSHORT );
            }
        }

        // call processing callback function
        pSound->ProcessCallback ( pSound->vecsTmpAudioSndCrdStereo );

        // get output data pointer
        jack_default_audio_sample_t* out_left = (jack_default_audio_sample_t*) jack_port_get_buffer ( pSound->output_port_left, nframes );

        jack_default_audio_sample_t* out_right = (jack_default_audio_sample_t*) jack_port_get_buffer ( pSound->output_port_right, nframes );

        // copy output data
        if ( ( out_left != nullptr ) && ( out_right != nullptr ) )
        {
            for ( i = 0; i < pSound->iJACKBufferSizeMono; i++ )
            {
                out_left[i] = (jack_default_audio_sample_t) pSound->vecsTmpAudioSndCrdStereo[2 * i] / _MAXSHORT;

                out_right[i] = (jack_default_audio_sample_t) pSound->vecsTmpAudioSndCrdStereo[2 * i + 1] / _MAXSHORT;
            }
        }
    }
    else
    {
        // get output data pointer
        jack_default_audio_sample_t* out_left = (jack_default_audio_sample_t*) jack_port_get_buffer ( pSound->output_port_left, nframes );

        jack_default_audio_sample_t* out_right = (jack_default_audio_sample_t*) jack_port_get_buffer ( pSound->output_port_right, nframes );

        // clear output data
        if ( ( out_left != nullptr ) && ( out_right != nullptr ) )
        {
            memset ( out_left, 0, sizeof ( jack_default_audio_sample_t ) * nframes );

            memset ( out_right, 0, sizeof ( jack_default_audio_sample_t ) * nframes );
        }
    }

    // akt on MIDI data if MIDI is enabled
    if ( pSound->input_port_midi != nullptr )
    {
        void* in_midi = jack_port_get_buffer ( pSound->input_port_midi, nframes );

        if ( in_midi != 0 )
        {
            jack_nframes_t event_count = jack_midi_get_event_count ( in_midi );

            for ( jack_nframes_t j = 0; j < event_count; j++ )
            {
                jack_midi_event_t in_event;

                jack_midi_event_get ( &in_event, in_midi, j );

                // copy packet and send it to the MIDI parser
                // clang-format off
// TODO do not call malloc in real-time callback
                // clang-format on
                CVector<uint8_t> vMIDIPaketBytes ( in_event.size );

                for ( i = 0; i < static_cast<int> ( in_event.size ); i++ )
                {
                    vMIDIPaketBytes[i] = static_cast<uint8_t> ( in_event.buffer[i] );
                }
                pSound->ParseMIDIMessage ( vMIDIPaketBytes );
            }
        }
    }

    return 0; // zero on success, non-zero on error
}

int CSound::bufferSizeCallback ( jack_nframes_t, void* arg )
{
    CSound* pSound = static_cast<CSound*> ( arg );

    pSound->EmitReinitRequestSignal ( RS_ONLY_RESTART_AND_INIT );

    return 0; // zero on success, non-zero on error
}

void CSound::shutdownCallback ( void* arg )
{
    CSound* pSound = static_cast<CSound*> ( arg );

    pSound->bJackWasShutDown = true;
    pSound->EmitReinitRequestSignal ( RS_ONLY_RESTART_AND_INIT );
}
#endif // WITH_JACK