jack2/solaris/oss/JackOSSAdapter.cpp

/*
Copyright (C) 2008 Grame & RTL 2008

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 "JackOSSAdapter.h"
#include "JackServerGlobals.h"
#include "JackEngineControl.h"
#include "memops.h"

#include <sys/ioctl.h>
#include <sys/soundcard.h>
#include <fcntl.h>
#include <iostream>
#include <assert.h>

namespace Jack
{

inline int int2pow2(int x)	{ int r = 0; while ((1 << r) < x) r++; return r; }

static inline void CopyAndConvertIn(jack_sample_t *dst, void *src, size_t nframes, int channel, int chcount, int bits)
{
    switch (bits) {

		case 16: {
		    signed short *s16src = (signed short*)src;
            s16src += channel;
            sample_move_dS_s16(dst, (char*)s16src, nframes, chcount<<1);
			break;
        }
		case 24: {
			signed short *s32src = (signed short*)src;
            s32src += channel;
            sample_move_dS_s24(dst, (char*)s32src, nframes, chcount<<2);
			break;
        }
		case 32: {
			signed short *s32src = (signed short*)src;
            s32src += channel;
            sample_move_dS_s32u24(dst, (char*)s32src, nframes, chcount<<2);
			break;
        }
	}
}

static inline void CopyAndConvertOut(void *dst, jack_sample_t *src, size_t nframes, int channel, int chcount, int bits)
{
	switch (bits) {

		case 16: {
			signed short *s16dst = (signed short*)dst;
            s16dst += channel;
            sample_move_d16_sS((char*)s16dst, src, nframes, chcount<<1, NULL); // No dithering for now...
			break;
        }
		case 24: {
			signed int *s32dst = (signed int*)dst;
            s32dst += channel;
            sample_move_d24_sS((char*)s32dst, src, nframes, chcount<<2, NULL); // No dithering for now...
			break;
        }    
		case 32: {
            signed int *s32dst = (signed int*)dst;
            s32dst += channel;
            sample_move_d32u24_sS((char*)s32dst, src, nframes, chcount<<2, NULL);
			break;  
        }
	}
}

void JackOSSAdapter::SetSampleFormat()
{
    switch (fBits) {

	    case 24:	/* native-endian LSB aligned 24-bits in 32-bits  integer */
            fSampleFormat = AFMT_S24_NE;
            fSampleSize = sizeof(int);
			break;
		case 32:	/* native-endian 32-bit integer */
            fSampleFormat = AFMT_S32_NE; 
            fSampleSize = sizeof(int);
			break;
		case 16:	/* native-endian 16-bit integer */
		default:
            fSampleFormat = AFMT_S16_NE;
            fSampleSize = sizeof(short);
			break;
    }
}

JackOSSAdapter::JackOSSAdapter(jack_nframes_t buffer_size, jack_nframes_t sample_rate, const JSList* params)
                :JackAudioAdapterInterface(buffer_size, sample_rate)
                ,fThread(this), 
                fInFD(-1), fOutFD(-1), fBits(OSS_DRIVER_DEF_BITS), 
                fSampleFormat(0), fNperiods(OSS_DRIVER_DEF_NPERIODS), fRWMode(0), fIgnoreHW(true), fExcl(false),
                fInputBufferSize(0), fOutputBufferSize(0),
                fInputBuffer(NULL), fOutputBuffer(NULL), fFirstCycle(true)
{
    const JSList* node;
    const jack_driver_param_t* param;
   
    fCaptureChannels = 2;
    fPlaybackChannels = 2;

    strcpy(fCaptureDriverName, OSS_DRIVER_DEF_DEV);
    strcpy(fPlaybackDriverName, OSS_DRIVER_DEF_DEV);
    
    for (node = params; node; node = jack_slist_next(node)) {
        param = (const jack_driver_param_t*) node->data;
        
        switch (param->character) {

            case 'r':
                SetAdaptedSampleRate(param->value.ui);
                break;
   
            case 'p':
                SetAdaptedBufferSize(param->value.ui);
                break;

            case 'n':
                fNperiods = param->value.ui;
                break;
     
            case 'w':
                fBits = param->value.i;
                break;
     
            case 'i':
                fCaptureChannels = param->value.ui;
                break;
       
            case 'o':
                fPlaybackChannels = param->value.ui;
                break;

            case 'e':
                fExcl = true;
                break;
                
            case 'C':
                fRWMode |= kRead;
                if (strcmp(param->value.str, "none") != 0) {
                   strcpy(fCaptureDriverName, param->value.str);
                }
                break;
                
            case 'P':
                fRWMode |= kWrite;
                if (strcmp(param->value.str, "none") != 0) {
                   strcpy(fPlaybackDriverName, param->value.str);
                }
                break;
                
            case 'd':
               fRWMode |= kRead;
               fRWMode |= kWrite;
               strcpy(fCaptureDriverName, param->value.str);
               strcpy(fPlaybackDriverName, param->value.str);
               break;

            case 'b':
                fIgnoreHW = true;
                break;
                
            case 'q':
                fQuality = param->value.ui;
                break;
                
            case 'g':
                fRingbufferSize = param->value.ui;
                break;

           }
    }

    fRWMode |= kRead;
    fRWMode |= kWrite;
}

void JackOSSAdapter::DisplayDeviceInfo()
{
    audio_buf_info info;
    oss_audioinfo ai_in, ai_out;
    memset(&info, 0, sizeof(audio_buf_info));
    int cap = 0;
    
    // Duplex cards : http://manuals.opensound.com/developer/full_duplex.html
    
    jack_info("Audio Interface Description :");
    jack_info("Sampling Frequency : %d, Sample Format : %d, Mode : %d", fAdaptedSampleRate, fSampleFormat, fRWMode);
    
    if (fRWMode & kWrite) {
    
       oss_sysinfo si;
        if (ioctl(fOutFD, OSS_SYSINFO, &si) == -1) {
            jack_error("JackOSSAdapter::DisplayDeviceInfo OSS_SYSINFO failed : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        } else {
            jack_info("OSS product %s", si.product);
            jack_info("OSS version %s", si.version);
            jack_info("OSS version num %d", si.versionnum);
            jack_info("OSS numaudios %d", si.numaudios);
            jack_info("OSS numaudioengines %d", si.numaudioengines);
            jack_info("OSS numcards %d", si.numcards);
        }
    
        jack_info("Output capabilities - %d channels : ", fPlaybackChannels);
        jack_info("Output block size = %d", fOutputBufferSize);
    
        if (ioctl(fOutFD, SNDCTL_DSP_GETOSPACE, &info) == -1)  {
            jack_error("JackOSSAdapter::DisplayDeviceInfo SNDCTL_DSP_GETOSPACE failed : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        } else {
            jack_info("output space info: fragments = %d, fragstotal = %d, fragsize = %d, bytes = %d", 
                info.fragments, info.fragstotal, info.fragsize, info.bytes);
        }
    
        if (ioctl(fOutFD, SNDCTL_DSP_GETCAPS, &cap) == -1)  {
            jack_error("JackOSSAdapter::DisplayDeviceInfo SNDCTL_DSP_GETCAPS failed : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        } else {
            if (cap & DSP_CAP_DUPLEX) 	jack_info(" DSP_CAP_DUPLEX");
            if (cap & DSP_CAP_REALTIME) jack_info(" DSP_CAP_REALTIME");
            if (cap & DSP_CAP_BATCH) 	jack_info(" DSP_CAP_BATCH");
            if (cap & DSP_CAP_COPROC) 	jack_info(" DSP_CAP_COPROC");
            if (cap & DSP_CAP_TRIGGER)  jack_info(" DSP_CAP_TRIGGER");
            if (cap & DSP_CAP_MMAP) 	jack_info(" DSP_CAP_MMAP");
            if (cap & DSP_CAP_MULTI) 	jack_info(" DSP_CAP_MULTI");
            if (cap & DSP_CAP_BIND) 	jack_info(" DSP_CAP_BIND");
        }
    }	
    
    if (fRWMode & kRead) {
    
        oss_sysinfo si;
        if (ioctl(fInFD, OSS_SYSINFO, &si) == -1) {
            jack_error("JackOSSAdapter::DisplayDeviceInfo OSS_SYSINFO failed : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        } else {
            jack_info("OSS product %s", si.product);
            jack_info("OSS version %s", si.version);
            jack_info("OSS version num %d", si.versionnum);
            jack_info("OSS numaudios %d", si.numaudios);
            jack_info("OSS numaudioengines %d", si.numaudioengines);
            jack_info("OSS numcards %d", si.numcards);
        }
   
        jack_info("Input capabilities - %d channels : ", fCaptureChannels);
        jack_info("Input block size = %d", fInputBufferSize);
    
        if (ioctl(fInFD, SNDCTL_DSP_GETOSPACE, &info) == -1) { 
            jack_error("JackOSSAdapter::DisplayDeviceInfo SNDCTL_DSP_GETOSPACE failed : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        } else {
            jack_info("input space info: fragments = %d, fragstotal = %d, fragsize = %d, bytes = %d", 
                info.fragments, info.fragstotal, info.fragsize, info.bytes);
        }

        if (ioctl(fInFD, SNDCTL_DSP_GETCAPS, &cap) == -1) {
            jack_error("JackOSSAdapter::DisplayDeviceInfo SNDCTL_DSP_GETCAPS failed : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        } else {
            if (cap & DSP_CAP_DUPLEX) 	jack_info(" DSP_CAP_DUPLEX");
            if (cap & DSP_CAP_REALTIME) jack_info(" DSP_CAP_REALTIME");
            if (cap & DSP_CAP_BATCH) 	jack_info(" DSP_CAP_BATCH");
            if (cap & DSP_CAP_COPROC) 	jack_info(" DSP_CAP_COPROC");
            if (cap & DSP_CAP_TRIGGER)  jack_info(" DSP_CAP_TRIGGER");
            if (cap & DSP_CAP_MMAP) 	jack_info(" DSP_CAP_MMAP");
            if (cap & DSP_CAP_MULTI) 	jack_info(" DSP_CAP_MULTI");
            if (cap & DSP_CAP_BIND) 	jack_info(" DSP_CAP_BIND");
        }
    }
    
    if (ioctl(fInFD, SNDCTL_AUDIOINFO, &ai_in) != -1) {
        jack_info("Using audio engine %d = %s for input", ai_in.dev, ai_in.name);
    }
    
    if (ioctl(fOutFD, SNDCTL_AUDIOINFO, &ai_out) != -1) {
        jack_info("Using audio engine %d = %s for output", ai_out.dev, ai_out.name);
    }
    
    if (ai_in.rate_source != ai_out.rate_source) {
        jack_info("Warning : input and output are not necessarily driven by the same clock!");
    }
}

int JackOSSAdapter::OpenInput()
{
    int flags = 0;
    int gFragFormat;
    int cur_sample_format, cur_capture_channels;
    jack_nframes_t cur_sample_rate;
  
    if (fCaptureChannels == 0) fCaptureChannels = 2;
  
    if ((fInFD = open(fCaptureDriverName, O_RDONLY | ((fExcl) ? O_EXCL : 0))) < 0) {
        jack_error("JackOSSAdapter::OpenInput failed to open device : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        return -1;
    }

jack_log("JackOSSAdapter::OpenInput input fInFD = %d", fInFD);

    if (fExcl) {
        if (ioctl(fInFD, SNDCTL_DSP_COOKEDMODE, &flags) == -1) {
            jack_error("JackOSSAdapter::OpenInput failed to set cooked mode : %s@%i, errno = %d", __FILE__, __LINE__, errno);
            goto error;
        }
    }

printf("fAdaptedBufferSize %d %d %d %d %s\n", fExcl, fAdaptedBufferSize, fSampleSize, fCaptureChannels, fCaptureDriverName);

    gFragFormat = (2 << 16) + int2pow2(fAdaptedBufferSize * fSampleSize * fCaptureChannels);	
    if (ioctl(fInFD, SNDCTL_DSP_SETFRAGMENT, &gFragFormat) == -1) {
        jack_error("JackOSSAdapter::OpenInput failed to set fragments : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }

    cur_sample_format = fSampleFormat;
    if (ioctl(fInFD, SNDCTL_DSP_SETFMT, &fSampleFormat) == -1) {
        jack_error("JackOSSAdapter::OpenInput failed to set format : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
    if (cur_sample_format != fSampleFormat) {
        jack_info("JackOSSAdapter::OpenInput driver forced the sample format %ld", fSampleFormat);
    }
    
    cur_capture_channels = fCaptureChannels;
    if (ioctl(fInFD, SNDCTL_DSP_CHANNELS, &fCaptureChannels) == -1) {
        jack_error("JackOSSAdapter::OpenInput failed to set channels : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
    if (cur_capture_channels != fCaptureChannels) {
        jack_info("JackOSSAdapter::OpenInput driver forced the number of capture channels %ld", fCaptureChannels);
    }
       
    cur_sample_rate = fAdaptedSampleRate;
    if (ioctl(fInFD, SNDCTL_DSP_SPEED, &fAdaptedSampleRate) == -1) {
        jack_error("JackOSSAdapter::OpenInput failed to set sample rate : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
    if (cur_sample_rate != fAdaptedSampleRate) {
        jack_info("JackOSSAdapter::OpenInput driver forced the sample rate %ld", fAdaptedSampleRate);
    }

    fInputBufferSize = 0;
    if (ioctl(fInFD, SNDCTL_DSP_GETBLKSIZE, &fInputBufferSize) == -1) {
        jack_error("JackOSSAdapter::OpenInput failed to get fragments : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
        
    if (fInputBufferSize != fAdaptedBufferSize * fSampleSize * fCaptureChannels) {
       if (fIgnoreHW) {
           jack_info("JackOSSAdapter::OpenInput driver forced buffer size %ld", fOutputBufferSize);
       } else {
           jack_error("JackOSSAdapter::OpenInput wanted buffer size cannot be obtained");
           goto error;
       }
    }

    fInputBuffer = (void*)calloc(fInputBufferSize, 1);
    assert(fInputBuffer);
    
    fInputSampleBuffer = (float**)malloc(fCaptureChannels * sizeof(float*));
    assert(fInputSampleBuffer);
    
    for (int i = 0; i < fCaptureChannels; i++) {
        fInputSampleBuffer[i] = (float*)malloc(fAdaptedBufferSize * sizeof(float));
        assert(fInputSampleBuffer[i]);
    }
    return 0;
    
error:
    ::close(fInFD);
    return -1;
}

int JackOSSAdapter::OpenOutput()
{
    int flags = 0;
    int gFragFormat;
    int cur_sample_format, cur_playback_channels;
    jack_nframes_t cur_sample_rate;
 
    if (fPlaybackChannels == 0) fPlaybackChannels = 2;
    
    if ((fOutFD = open(fPlaybackDriverName, O_WRONLY | ((fExcl) ? O_EXCL : 0))) < 0) {
       jack_error("JackOSSAdapter::OpenOutput failed to open device : %s@%i, errno = %d", __FILE__, __LINE__, errno);
       return -1;
    }
    
    if (fExcl) {
        if (ioctl(fOutFD, SNDCTL_DSP_COOKEDMODE, &flags) == -1) {
            jack_error("JackOSSAdapter::OpenOutput failed to set cooked mode : %s@%i, errno = %d", __FILE__, __LINE__, errno);
            goto error;
        }  
    } 

printf("fAdaptedBufferSize %d %d %d %d %s\n", fExcl, fAdaptedBufferSize, fSampleSize, fPlaybackChannels, fPlaybackDriverName);


    gFragFormat = (2 << 16) + int2pow2(fAdaptedBufferSize * fSampleSize * fPlaybackChannels);	
    if (ioctl(fOutFD, SNDCTL_DSP_SETFRAGMENT, &gFragFormat) == -1) {
        jack_error("JackOSSAdapter::OpenOutput failed to set fragments : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }

    cur_sample_format = fSampleFormat;
    if (ioctl(fOutFD, SNDCTL_DSP_SETFMT, &fSampleFormat) == -1) {
        jack_error("JackOSSAdapter::OpenOutput failed to set format : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
    if (cur_sample_format != fSampleFormat) {
        jack_info("JackOSSAdapter::OpenOutput driver forced the sample format %ld", fSampleFormat);
    }
    
    cur_playback_channels = fPlaybackChannels;
    if (ioctl(fOutFD, SNDCTL_DSP_CHANNELS, &fPlaybackChannels) == -1) {
        jack_error("JackOSSAdapter::OpenOutput failed to set channels : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
    if (cur_playback_channels != fPlaybackChannels) {
        jack_info("JackOSSAdapter::OpenOutput driver forced the number of playback channels %ld", fPlaybackChannels);
    }

    cur_sample_rate = fAdaptedSampleRate;
    if (ioctl(fOutFD, SNDCTL_DSP_SPEED, &fAdaptedSampleRate) == -1) {
        jack_error("JackOSSAdapter::OpenOutput failed to set sample rate : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
    if (cur_sample_rate != fAdaptedSampleRate) {
        jack_info("JackOSSAdapter::OpenInput driver forced the sample rate %ld", fAdaptedSampleRate);
    }

    fOutputBufferSize = 0;
    if (ioctl(fOutFD, SNDCTL_DSP_GETBLKSIZE, &fOutputBufferSize) == -1) {
        jack_error("JackOSSAdapter::OpenOutput failed to get fragments : %s@%i, errno = %d", __FILE__, __LINE__, errno);
        goto error;
    }
         
    if (fOutputBufferSize != fAdaptedBufferSize * fSampleSize * fPlaybackChannels) {
       if (fIgnoreHW) {
           jack_info("JackOSSAdapter::OpenOutput driver forced buffer size %ld", fOutputBufferSize);
       } else {
           jack_error("JackOSSAdapter::OpenInput wanted buffer size cannot be obtained");
           goto error;
       }
    }

    fOutputBuffer = (void*)calloc(fOutputBufferSize, 1);
    assert(fOutputBuffer);
    
    fOutputSampleBuffer = (float**)malloc(fPlaybackChannels * sizeof(float*));
    assert(fOutputSampleBuffer);
    
    for (int i = 0; i < fPlaybackChannels; i++) {
        fOutputSampleBuffer[i] = (float*)malloc(fAdaptedBufferSize * sizeof(float));
        assert(fOutputSampleBuffer[i]);
    }
    
    fFirstCycle = true;
    return 0;
    
error:
    ::close(fOutFD);
    return -1;
}

int JackOSSAdapter::Open()
{
    SetSampleFormat();
    
    if ((fRWMode & kRead) && (OpenInput() < 0)) {
        return -1;
    }
    
    if ((fRWMode & kWrite) && (OpenOutput() < 0)) { 
       return -1;
    }
    
    // In duplex mode, check that input and output use the same buffer size
    if ((fRWMode & kRead) && (fRWMode & kWrite) && (fInputBufferSize != fOutputBufferSize)) {
       jack_error("JackOSSAdapter::OpenAux input and output buffer size are not the same!!");
       goto error;
    }

    DisplayDeviceInfo(); 
    
    fThread.AcquireRealTime(JackServerGlobals::fInstance->GetEngineControl()->fClientPriority);
    return fThread.StartSync();
    
error:
    CloseAux();
    return -1;
}

 
int JackOSSAdapter::Close()
{
#ifdef JACK_MONITOR
    fTable.Save(fHostBufferSize, fHostSampleRate, fAdaptedSampleRate, fAdaptedBufferSize);
#endif
    fThread.Stop();
    CloseAux();  
    return 0;
}

void JackOSSAdapter::CloseAux()
{
    if (fRWMode & kRead) {
        close(fInFD);
        fInFD = -1;
    }
    
    if (fRWMode & kWrite) {
        close(fOutFD);
        fOutFD = -1;
    }
    
    free(fInputBuffer);
    fInputBuffer = NULL;
    
    free(fOutputBuffer);
    fOutputBuffer = NULL;
    
    for (int i = 0; i < fCaptureChannels; i++) {
        free(fInputSampleBuffer[i]);
    }
    free(fInputSampleBuffer);
    
    for (int i = 0; i < fPlaybackChannels; i++) {
        free(fOutputSampleBuffer[i]);
    }
    free(fOutputSampleBuffer);
 }

int JackOSSAdapter::Read()
{
    ssize_t count = ::read(fInFD, fInputBuffer, fInputBufferSize);
    
    if (count < fInputBufferSize) {
        jack_error("JackOSSAdapter::Read error bytes read = %ld", count);
        return -1;
    } else {
        for (int i = 0; i < fCaptureChannels; i++) {
             CopyAndConvertIn(fInputSampleBuffer[i], fInputBuffer, fAdaptedBufferSize, i, fCaptureChannels, fBits);        
        }
        return 0;
    }
}

int JackOSSAdapter::Write()
{
    ssize_t count;
   
    // Maybe necessay to write an empty output buffer first time : see http://manuals.opensound.com/developer/fulldup.c.html
    if (fFirstCycle) {
    
        fFirstCycle = false;
        memset(fOutputBuffer, 0, fOutputBufferSize);

        // Prefill ouput buffer
        for (int i = 0; i < fNperiods; i++) {
           count = ::write(fOutFD, fOutputBuffer, fOutputBufferSize);
           if (count < fOutputBufferSize) {
                jack_error("JackOSSDriver::Write error bytes written = %ld", count);
                return -1;
            }
        }
        
        int delay;
        if (ioctl(fOutFD, SNDCTL_DSP_GETODELAY, &delay) == -1) {
            jack_error("JackOSSDriver::Write error get out delay : %s@%i, errno = %d", __FILE__, __LINE__, errno);
            return -1;
        }
        
        delay /= fSampleSize * fPlaybackChannels;
        jack_info("JackOSSDriver::Write output latency frames = %ld", delay);
    }
    
    for (int i = 0; i < fPlaybackChannels; i++) {
        CopyAndConvertOut(fOutputBuffer, fOutputSampleBuffer[i], fAdaptedBufferSize, i, fCaptureChannels, fBits);
    }
    
    count = ::write(fOutFD, fOutputBuffer, fOutputBufferSize);
  
    if (count < fOutputBufferSize) {
        jack_error("JackOSSAdapter::Write error bytes written = %ld", count);
        return -1;
    } else {
        return 0;
    }
}

bool JackOSSAdapter::Execute()
{
    //read data from audio interface
    if (Read() < 0)
        return false;
        
    PushAndPull(fInputSampleBuffer, fOutputSampleBuffer, fAdaptedBufferSize);
        
    //write data to audio interface
    if (Write() < 0)
        return false;
   
    return true;
}

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

#ifdef __cplusplus
extern "C"
{
#endif

    SERVER_EXPORT jack_driver_desc_t* jack_get_descriptor()
    {
        jack_driver_desc_t *desc;
        unsigned int i;
        desc = (jack_driver_desc_t*)calloc(1, sizeof(jack_driver_desc_t));

        strcpy(desc->name, "audioadapter");                              // size MUST be less then JACK_DRIVER_NAME_MAX + 1
        strcpy(desc->desc, "netjack audio <==> net backend adapter");    // size MUST be less then JACK_DRIVER_PARAM_DESC + 1
           
        desc->nparams = OSS_DRIVER_N_PARAMS;
        desc->params = (jack_driver_param_desc_t*)calloc(desc->nparams, sizeof(jack_driver_param_desc_t));

        i = 0;
        strcpy(desc->params[i].name, "rate");
        desc->params[i].character = 'r';
        desc->params[i].type = JackDriverParamUInt;
        desc->params[i].value.ui = OSS_DRIVER_DEF_FS;
        strcpy(desc->params[i].short_desc, "Sample rate");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy(desc->params[i].name, "period");
        desc->params[i].character = 'p';
        desc->params[i].type = JackDriverParamUInt;
        desc->params[i].value.ui = OSS_DRIVER_DEF_BLKSIZE;
        strcpy(desc->params[i].short_desc, "Frames per period");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy(desc->params[i].name, "nperiods");
        desc->params[i].character = 'n';
        desc->params[i].type = JackDriverParamUInt;
        desc->params[i].value.ui = OSS_DRIVER_DEF_NPERIODS;
        strcpy(desc->params[i].short_desc, "Number of periods to prefill output buffer");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy(desc->params[i].name, "wordlength");
        desc->params[i].character = 'w';
        desc->params[i].type = JackDriverParamInt;
        desc->params[i].value.i = OSS_DRIVER_DEF_BITS;
        strcpy(desc->params[i].short_desc, "Word length");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy(desc->params[i].name, "inchannels");
        desc->params[i].character = 'i';
        desc->params[i].type = JackDriverParamUInt;
        desc->params[i].value.ui = OSS_DRIVER_DEF_INS;
        strcpy(desc->params[i].short_desc, "Capture channels");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);
        
        i++;
        strcpy(desc->params[i].name, "outchannels");
        desc->params[i].character = 'o';
        desc->params[i].type = JackDriverParamUInt;
        desc->params[i].value.ui = OSS_DRIVER_DEF_OUTS;
        strcpy(desc->params[i].short_desc, "Playback channels");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy(desc->params[i].name, "excl");
        desc->params[i].character = 'e';
        desc->params[i].type = JackDriverParamBool;
        desc->params[i].value.i = false;
        strcpy(desc->params[i].short_desc, "Exclusif (O_EXCL) access mode");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy(desc->params[i].name, "capture");
        desc->params[i].character = 'C';
        desc->params[i].type = JackDriverParamString;
        strcpy(desc->params[i].value.str, OSS_DRIVER_DEF_DEV);
        strcpy(desc->params[i].short_desc, "Input device");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);
        
        i++;
        strcpy(desc->params[i].name, "playback");
        desc->params[i].character = 'P';
        desc->params[i].type = JackDriverParamString;
        strcpy(desc->params[i].value.str, OSS_DRIVER_DEF_DEV);
        strcpy(desc->params[i].short_desc, "Output device");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);

        i++;
        strcpy (desc->params[i].name, "device");
        desc->params[i].character = 'd';
        desc->params[i].type = JackDriverParamString;
        strcpy(desc->params[i].value.str, OSS_DRIVER_DEF_DEV);
        strcpy(desc->params[i].short_desc, "OSS device name");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);
      
        i++;
        strcpy(desc->params[i].name, "ignorehwbuf");
        desc->params[i].character = 'b';
        desc->params[i].type = JackDriverParamBool;
        desc->params[i].value.i = true;
        strcpy(desc->params[i].short_desc, "Ignore hardware period size");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);
        
        i++;
        strcpy(desc->params[i].name, "quality");
        desc->params[i].character = 'q';
        desc->params[i].type = JackDriverParamInt;
        desc->params[i].value.ui = 0;
        strcpy(desc->params[i].short_desc, "Resample algorithm quality (0 - 4)");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);
        
        i++;
        strcpy(desc->params[i].name, "ring-buffer");
        desc->params[i].character = 'g';
        desc->params[i].type = JackDriverParamInt;
        desc->params[i].value.ui = 0;
        strcpy(desc->params[i].short_desc, "Resampling ringbuffer size in frames (default = 16384)");
        strcpy(desc->params[i].long_desc, desc->params[i].short_desc);
    
        return desc;
    }
   
#ifdef __cplusplus
}
#endif