ALSAAudioDevice.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 "SndPcm.hxx"
#include "AudioIO.hxx"
#include "AudioIn.hxx"
#include "AudioOut.hxx"
#include "AudioDeviceList.hxx"
#include "AudioDevice.hxx"
#include <sstream>

namespace CLAM {

        class ALSAAudioDevice: public AudioDevice
        {
        private:
                int mNChannelsWritten;
                bool mChannelsWritten[256];

                int mNChannelsRead;
                bool mChannelsRead[256];
                
                int mWriteBufSize;
                Array<short> mWriteBuf;

                int mReadBufSize;
                Array<short> mReadBuf;

                SndPcm* mSndpcm;
                std::string mDevice;

                int HighestChannelID();

        public:
                ALSAAudioDevice(const std::string& name,const std::string& device);
                ~ALSAAudioDevice();
                
                void Start(void) throw(Err);
                void Stop(void) throw(Err);
                void Read(Audio& audio,const int channelID);
                void Write(const Audio& audio,const int channelID);
        };

        ALSAAudioDevice::ALSAAudioDevice(const std::string& name,const std::string& device): 
                AudioDevice(name), 
                mSndpcm(0)
        {
                //printf("ALSAAudioDevice::ALSAAudioDevice\n");

                int i;
                
                mNChannelsWritten = 0;
                for (i=0;i<256;i++)
                        mChannelsWritten[i] = false;

                mNChannelsRead = 0;
                for (i=0;i<256;i++)
                        mChannelsRead[i] = false;
                        
                mDevice = device;
        }

        int ALSAAudioDevice::HighestChannelID(void)
        {
                int max_id = 0;

                std::vector<AudioIn*>::const_iterator in_it;
                for (in_it = mInputs.begin(); in_it != mInputs.end(); in_it++)
                {
                        if ( (*in_it)->GetChannelID() > max_id)
                                max_id = (*in_it)->GetChannelID();
                }

                std::vector<AudioOut*>::const_iterator out_it;
                for (out_it = mOutputs.begin(); out_it != mOutputs.end(); out_it++)
                {
                        if ( (*out_it)->GetChannelID() > max_id)
                                max_id = (*out_it)->GetChannelID();
                }

                return max_id;

        }

        void ALSAAudioDevice::Start(void) throw(Err)
        {
                int i;
                bool needs_start = false;

                mNReadChannels = mInputs.size();
                mNWriteChannels = mOutputs.size();
                        
                if (mForceNChannels)
                {
                        int used_channels = HighestChannelID() + 1;
                        if (used_channels > mNChannels)
                                throw Err("ALSAAudioDevice::Start(): more inputs or outputs than requested channels.");
                                
                }
                else
                {
                        if ( HighestChannelID() + 1 != mNChannels)
                        {
                                if (mSndpcm) {
                                        mSndpcm->Stop();
                                        delete mSndpcm;
                                        mSndpcm = 0;
                                }
                                mNChannels = HighestChannelID() + 1;
                        }
                }

                if (mSndpcm==0)
                {
                        try {
                                mSndpcm = new ::SndPcm(SampleRate(),mNReadChannels,mNWriteChannels,Latency(),mDevice.c_str(),mDevice.c_str());
                        }
                        catch (SndPcmError &e) {
                                Err ne("ALSAAudioDevice::Start(): Failed to create PCM device.");
                                ne.Embed(e);
                                throw(ne);
                        }
                        needs_start = true;
                }

                int bufSize = mSndpcm->latency * mNChannels;
                mReadBuf.Resize(bufSize);
                mWriteBuf.Resize(bufSize);
                mReadBuf.SetSize(bufSize);
                mWriteBuf.SetSize(bufSize);

                for (i=0; i<bufSize; i++) {
                        mReadBuf[i] = 0;
                        mWriteBuf[i] = 0;
                }

                // the following settings will be set at the first Read/Write
                // to the Audio buffer size that is passed.
                mReadBufSize = 0; 
                mWriteBufSize = 0;

                if (needs_start)
                        mSndpcm->Start();
        }

        void ALSAAudioDevice::Stop(void) throw(Err)
        {
                //printf("ALSAAudioDevice::Stop\n");
                if (mSndpcm) {
                        mSndpcm->Stop();
                }
        }
        ALSAAudioDevice::~ALSAAudioDevice()
        {
                //printf("ALSAAudioDevice::~ALSAAudioDevice\n");
                Stop();
                if (mSndpcm) {
                        delete mSndpcm;
                }
        }

        void ALSAAudioDevice::Read(Audio& audio,const int channelID)
        {
                CLAM_DEBUG_ASSERT(channelID < mNChannels,
                                  "ALSAAudioDevice::Read(): Invalid Channel ID");

                TData* ptrA = audio.GetBuffer().GetPtr();
                short* ptrB = mReadBuf.GetPtr() + channelID;
                int n;

                if (mChannelsRead[channelID]) 
                        throw Err("ALSAAudioDevice::Read(): Tried to read "
                                  "twice from a channel in a single time frame!");
                if (!mSndpcm)
                        throw Err("ALSAAudioDevice::Read(): Device not configured.");
                
                if (mReadBufSize==0) mReadBufSize=audio.GetSize();
                else{
                        CLAM_ASSERT(mReadBufSize==audio.GetSize(),"ALSADevice: Inconsistent Audio size");
                }
                if (mReadBufSize>mSndpcm->latency) 
                        throw Err("You are trying to read audio in blocks bigger than the latency");
                
                if (mNChannelsRead == 0)
                {
                        mSndpcm->Poll();
                        mSndpcm->ReadBuf(mReadBuf.GetPtr(),mReadBufSize);
                }

                n = mReadBufSize;
                while (n--)
                {
                        *ptrA++ = TData(*ptrB) / 32767.;
                        ptrB += mNChannels;
                }
                
                mChannelsRead[channelID] = true;
                mNChannelsRead++;

                if (mNChannelsRead==mNReadChannels)
                {
                        mNChannelsRead = 0;
                        for (int i=0;i<mNChannels;i++)
                                mChannelsRead[i] = false;
                }
        }

        void ALSAAudioDevice::Write(const Audio& audio,const int channelID)
        {
                CLAM_DEBUG_ASSERT(channelID < mNChannels,
                                  "ALSAAudioDevice::Write(): Invalid Channel ID");

                TData* ptrA = audio.GetBuffer().GetPtr();
                short* ptrB = mWriteBuf.GetPtr() + channelID;
                int i,n;

                //printf("alsaauduiodevice write. audio size: %d mWriteBufSize: %d\n", audio.GetSize(), mWriteBufSize);

                if (mWriteBufSize==0) mWriteBufSize=audio.GetSize();
                else{
                        CLAM_ASSERT(mWriteBufSize==audio.GetSize(),"ALSADevice Write: Inconsistent Audio size");
                }
                        
                if (mWriteBufSize>mSndpcm->latency) 
                        throw Err("You are trying to write audio in blocks bigger than the latency");


                if (mChannelsWritten[channelID])
                        throw Err("ALSAAudioDevice::Write(): Tried to write "
                                          "twice into a channel in a single time frame.");
                if (!mSndpcm)
                        throw Err("ALSAAudioDevice::Write(): Device not configured.");

                n = mWriteBufSize;
                while (n--)
                {
                        *ptrB = (short) (32767.*(*ptrA++));
                        ptrB += mNChannels;
                }

                mChannelsWritten[channelID] = true;
                mNChannelsWritten++;

                if (mNChannelsWritten==mNWriteChannels)
                {
                        if (mNReadChannels==0) mSndpcm->Poll();
                        mSndpcm->WriteBuf(mWriteBuf.GetPtr(),mWriteBufSize);
                                                
                        mNChannelsWritten = 0;
                        for (i=0;i<mNChannels;i++)
                                mChannelsWritten[i] = false;
                }
        }


        class ALSAAudioDeviceList: public AudioDeviceList
        {
                static ALSAAudioDeviceList sDevices;

                ALSAAudioDeviceList()
                        :AudioDeviceList(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_pcm_next_device(handle, &dev);
                                        if (dev < 0)
                                                break;
                                        std::stringstream dnamestr;
                                        dnamestr << name << "," << dev;
                                        std::string dname(dnamestr.str());
                                        mAvailableDevices.push_back(dname.c_str());

                                        std::stringstream plug;
                                        plug << "plug" << dname;
                                        mAvailableDevices.push_back(plug.str());
                                }
                                snd_ctl_close(handle);
                                if (snd_card_next(&card) < 0)
                                        break;
                        }
                        
                        AddMe();
                }
        public:

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

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

        ALSAAudioDeviceList ALSAAudioDeviceList::sDevices;
}