jack2/linux/alsa/JackAlsaAdapter.cpp

/*
Copyright (C) 2008 Grame

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 "JackAlsaAdapter.h"

namespace Jack
{

int JackAlsaAdapter::Open()
{
    if (fAudioInterface.open() == 0) {
        fAudioInterface.longinfo();
        fThread.AcquireRealTime(85);
        fThread.StartSync();
        return 0;
    } else {
        return -1;
    }
}

int JackAlsaAdapter::Close()
{
#ifdef DEBUG
    fTable.Save();
#endif
    fThread.Stop();
    return fAudioInterface.close();
}

bool JackAlsaAdapter::Init()
{
    fAudioInterface.write();
    fAudioInterface.write();
    return true;
}
            
bool JackAlsaAdapter::Execute()
{
    if (fAudioInterface.read() < 0)
        return false;

    bool failure = false;
    jack_nframes_t time1, time2; 
    ResampleFactor(time1, time2);
  
    for (int i = 0; i < fCaptureChannels; i++) {
        fCaptureRingBuffer[i]->SetRatio(time1, time2);
        if (fCaptureRingBuffer[i]->WriteResample(fAudioInterface.fInputSoftChannels[i], fBufferSize) < fBufferSize)
            failure = true;
    }
    
    for (int i = 0; i < fPlaybackChannels; i++) {
        fPlaybackRingBuffer[i]->SetRatio(time2, time1);
        if (fPlaybackRingBuffer[i]->ReadResample(fAudioInterface.fOutputSoftChannels[i], fBufferSize) < fBufferSize)
            failure = true;
    }

#ifdef DEBUG
    fTable.Write(time1, time2, double(time1) / double(time2), double(time2) / double(time1),
        fCaptureRingBuffer[0]->ReadSpace(), fPlaybackRingBuffer[0]->WriteSpace());
#endif
        
    if (fAudioInterface.write() < 0)
        return false;
     
    // Reset all ringbuffers in case of failure
    if (failure) {
        jack_error("JackAlsaAdapter::Execute ringbuffer failure... reset");
        ResetRingBuffers();
    }
    return true;
}

int JackAlsaAdapter::SetBufferSize(jack_nframes_t buffer_size)
{
    JackAudioAdapterInterface::SetBufferSize(buffer_size);
    Close();
    return Open();
}
        
} // namespace

#ifdef __cplusplus
extern "C"
{
#endif

    EXPORT jack_driver_desc_t* jack_get_descriptor()
    {
        jack_driver_desc_t *desc;
        jack_driver_param_desc_t * params;
        unsigned int i;
        
        desc = (jack_driver_desc_t*)calloc(1, sizeof(jack_driver_desc_t));
        strcpy (desc->name, "alsa-adapter");
        desc->nparams = 7;
        params = (jack_driver_param_desc_t*)calloc(desc->nparams, sizeof(jack_driver_param_desc_t));
        
        i = 0;
        strcpy(params[i].name, "capture");
        params[i].character = 'C';
        params[i].type = JackDriverParamString;
        strcpy (params[i].value.str, "none");
        strcpy (params[i].short_desc,
                "Provide capture ports.  Optionally set device");
        strcpy (params[i].long_desc, params[i].short_desc);

        i++;
        strcpy(params[i].name, "playback");
        params[i].character = 'P';
        params[i].type = JackDriverParamString;
        strcpy(params[i].value.str, "none");
        strcpy(params[i].short_desc,
                "Provide playback ports.  Optionally set device");
        strcpy(params[i].long_desc, params[i].short_desc);

        i++;
        strcpy(params[i].name, "device");
        params[i].character = 'd';
        params[i].type = JackDriverParamString;
        strcpy(params[i].value.str, "hw:0");
        strcpy(params[i].short_desc, "ALSA device name");
        strcpy(params[i].long_desc, params[i].short_desc);

        i++;
        strcpy(params[i].name, "nperiods");
        params[i].character = 'n';
        params[i].type = JackDriverParamUInt;
        params[i].value.ui = 2U;
        strcpy(params[i].short_desc, "Number of periods of playback latency");
        strcpy(params[i].long_desc, params[i].short_desc);

        i++;
        strcpy(params[i].name, "duplex");
        params[i].character = 'D';
        params[i].type = JackDriverParamBool;
        params[i].value.i = 1;
        strcpy(params[i].short_desc,
                "Provide both capture and playback ports");
        strcpy(params[i].long_desc, params[i].short_desc);

        i++;
        strcpy(params[i].name, "inchannels");
        params[i].character = 'i';
        params[i].type = JackDriverParamUInt;
        params[i].value.i = 0;
        strcpy(params[i].short_desc,
                "Number of capture channels (defaults to hardware max)");
        strcpy(params[i].long_desc, params[i].short_desc);

        i++;
        strcpy(params[i].name, "outchannels");
        params[i].character = 'o';
        params[i].type = JackDriverParamUInt;
        params[i].value.i = 0;
        strcpy(params[i].short_desc,
                "Number of playback channels (defaults to hardware max)");
        strcpy(params[i].long_desc, params[i].short_desc);

        desc->params = params;
        return desc;
    }
   
#ifdef __cplusplus
}
#endif