ALSAMIDIDevice.cxx

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/*
 * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "MIDIIn.hxx"
#include <alsa/asoundlib.h>
#include "MIDIDeviceList.hxx"
#include "MIDIDevice.hxx"
#include <sstream>

namespace CLAM {

        class ALSAMIDIDevice: public MIDIDevice
        {
        private:
                std::string mDevice;
                snd_rawmidi_t *mHandleIn;
                snd_rawmidi_t *mHandleOut;
                snd_rawmidi_status_t *mStatusIn;
        public:
                ALSAMIDIDevice(const std::string& name,const std::string& device);
                ~ALSAMIDIDevice();

                void ConcreteStart(void) throw(Err);
                void ConcreteStop(void) throw(Err);

                void Read(void) throw(Err);
                void Write(unsigned char* msg,int size) throw(Err);
        };

        ALSAMIDIDevice::ALSAMIDIDevice(const std::string& name,const std::string& device): 
                MIDIDevice(name)
        {
                mHandleIn = NULL;
                mHandleOut = NULL;
                mStatusIn = NULL;
                mDevice = device;
        }

        void ALSAMIDIDevice::ConcreteStart(void) throw(Err)
        {
                        snd_rawmidi_t** handleInRef = NULL;
                        snd_rawmidi_t** handleOutRef = NULL;
                        
                        if (mInputs.size()) handleInRef = &mHandleIn;
                        if (mOutputs.size()) handleOutRef = &mHandleOut;
                        
                        int err = snd_rawmidi_open(handleInRef,handleOutRef,mDevice.c_str(),
                                                                           SND_RAWMIDI_NONBLOCK);
                        if (err)
                        {
                                        std::string str("Could not open ALSAMIDIDevice ");
                                        str += mDevice;
                                        throw Err(str.c_str());
                        }
                        snd_rawmidi_status_malloc(&mStatusIn);

        }

        void ALSAMIDIDevice::ConcreteStop(void) throw(Err)
        {
                if (mHandleIn) {
                        snd_rawmidi_drain(mHandleIn); 
                        snd_rawmidi_close(mHandleIn);
                        snd_rawmidi_status_free(mStatusIn);
                }
                
                if(mHandleOut){
                    snd_rawmidi_drain(mHandleOut);
                    snd_rawmidi_close(mHandleOut);
                }
        }

        void ALSAMIDIDevice::Write(unsigned char* msg,int size) throw(Err)
        {
                snd_rawmidi_write(mHandleOut,msg,size);
                snd_rawmidi_drain(mHandleOut);
        }

        void ALSAMIDIDevice::Read(void) throw(Err)
        {
                unsigned char ch;
                size_t n;
                do
                {
                        int err = snd_rawmidi_read(mHandleIn,&ch,1);
                        if (err!=-EAGAIN)
                        {
                                HandleRawByte(ch);
                        }
                        snd_rawmidi_status(mHandleIn,mStatusIn);
                        n = snd_rawmidi_status_get_avail(mStatusIn);
                } while (n);
        }

        ALSAMIDIDevice::~ALSAMIDIDevice()
        {
                Stop();
        }

        class ALSAMIDIDeviceList: public MIDIDeviceList
        {
                static ALSAMIDIDeviceList sDevices;

                ALSAMIDIDeviceList()
                        :MIDIDeviceList(std::string("alsa"))
                {
                        int card, dev;
                        snd_ctl_t *handle;
                        snd_ctl_card_info_t *info;

                        snd_ctl_card_info_alloca(&info);
                        card = -1;
                        if (snd_card_next(&card) < 0 || card < 0)
                                return; // No cards found
                        while (card >= 0) {
                                std::stringstream namestr;
                                namestr << "hw:" << card;       
                                std::string name(namestr.str());
                                if (snd_ctl_open(&handle, name.c_str(), 0) < 0)
                                        continue; // Card control open error!

                                if (snd_ctl_card_info(handle, info) < 0) {
                                        snd_ctl_close(handle); // Card control read error!
                                        continue;
                                }
                                dev = -1;
                                while (1) {
                                        snd_ctl_rawmidi_next_device(handle, &dev);
                                        if (dev < 0)
                                                break;
                                        std::stringstream dname;
                                        dname << name << "," << dev;
                                        mAvailableDevices.push_back(dname.str());
                                }
                                snd_ctl_close(handle);
                                if (snd_card_next(&card) < 0)
                                        break;
                        }

                        AddMe();
                }
        public:

                std::string DefaultDevice(void)
                {
                        return "hw:0,0";
                }

                MIDIDevice* Create(
                        const std::string& name,const std::string& device)
                {
                        return new ALSAMIDIDevice(name,device);
                }
        };

        ALSAMIDIDeviceList ALSAMIDIDeviceList::sDevices;
}