drivers/audio/AudioOutputDeviceAlsa.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *                                                                         *
 *   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 "AudioOutputDeviceAlsa.h"
#include "AudioOutputDeviceFactory.h"

namespace LinuxSampler {

    REGISTER_AUDIO_OUTPUT_DRIVER(AudioOutputDeviceAlsa);

    /* Common parameters for now they'll have to be registered here. */
    REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterActive);
    REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterSampleRate);
    REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterChannels);

    /* Driver specific parameters */
    REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterCard);
    REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterFragments);
    REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterFragmentSize);


// *************** ParameterCard ***************
// *

    AudioOutputDeviceAlsa::ParameterCard::ParameterCard() : DeviceCreationParameterString() {
        InitWithDefault(); // use default card
    }

    AudioOutputDeviceAlsa::ParameterCard::ParameterCard(String s) throw (LinuxSamplerException) : DeviceCreationParameterString(s) {
        SetValue(s); // try to use given card
    }

    String AudioOutputDeviceAlsa::ParameterCard::Description() {
        return "Sound card to be used";
    }

    bool AudioOutputDeviceAlsa::ParameterCard::Fix() {
        return true;
    }

    bool AudioOutputDeviceAlsa::ParameterCard::Mandatory() {
        return false;
    }

    std::map<String,DeviceCreationParameter*> AudioOutputDeviceAlsa::ParameterCard::DependsAsParameters() {
        return std::map<String,DeviceCreationParameter*>(); // no dependencies
    }

    optional<String> AudioOutputDeviceAlsa::ParameterCard::DefaultAsString(std::map<String,String> Parameters) {
        std::vector<String> cards = PossibilitiesAsString(Parameters);
        if (cards.empty()) throw LinuxSamplerException("AudioOutputDeviceAlsa: Can't find any card");
        return cards[0]; // first card by default
    }

    std::vector<String> AudioOutputDeviceAlsa::ParameterCard::PossibilitiesAsString(std::map<String,String> Parameters) {
        int err;
        std::vector<String> CardNames;

        // iterate through all cards
        int card_index = -1;
        while (snd_card_next(&card_index) >= 0 && card_index >= 0) {
            String hw_name = "hw:" + ToString(card_index);
            snd_ctl_t* hCardCtrl;
            if ((err = snd_ctl_open(&hCardCtrl, hw_name.c_str(), 0)) < 0) {
                std::cerr << "AudioOutputDeviceAlsa: Cannot open sound control for card " << card_index << " - " << snd_strerror(err) << std::endl;
                continue;
            }

            // iterate through all devices of that card
            int device_index = -1;
            while (!snd_ctl_pcm_next_device(hCardCtrl, &device_index) && device_index >= 0) {
                String name = ToString(card_index) + "," + ToString(device_index);
                //dmsg(1,("[possibility:%s]", name.c_str()));
                CardNames.push_back(name);
            }

            snd_ctl_close(hCardCtrl);
        }

        return CardNames;
    }

    void AudioOutputDeviceAlsa::ParameterCard::OnSetValue(String s) throw (LinuxSamplerException) {
        // not posssible, as parameter is fix
    }

    String AudioOutputDeviceAlsa::ParameterCard::Name() {
        return "CARD";
    }


// *************** ParameterFragments ***************
// *

    AudioOutputDeviceAlsa::ParameterFragments::ParameterFragments() : DeviceCreationParameterInt() {
        InitWithDefault();
    }

    AudioOutputDeviceAlsa::ParameterFragments::ParameterFragments(String s) throw (LinuxSamplerException) : DeviceCreationParameterInt(s) {
    }

    String AudioOutputDeviceAlsa::ParameterFragments::Description() {
        return "Number of buffer fragments";
    }

    bool AudioOutputDeviceAlsa::ParameterFragments::Fix() {
        return true;
    }

    bool AudioOutputDeviceAlsa::ParameterFragments::Mandatory() {
        return false;
    }

    std::map<String,DeviceCreationParameter*> AudioOutputDeviceAlsa::ParameterFragments::DependsAsParameters() {
        static ParameterCard card;
        std::map<String,DeviceCreationParameter*> dependencies;
        dependencies[card.Name()] = &card;
        return dependencies;
    }

    optional<int> AudioOutputDeviceAlsa::ParameterFragments::DefaultAsInt(std::map<String,String> Parameters) {
        return 2; // until done
    }

    optional<int> AudioOutputDeviceAlsa::ParameterFragments::RangeMinAsInt(std::map<String,String> Parameters) {
        return optional<int>::nothing;
    }

    optional<int> AudioOutputDeviceAlsa::ParameterFragments::RangeMaxAsInt(std::map<String,String> Parameters) {
        return optional<int>::nothing;
    }

    std::vector<int> AudioOutputDeviceAlsa::ParameterFragments::PossibilitiesAsInt(std::map<String,String> Parameters) {
        return std::vector<int>();
    }

    void AudioOutputDeviceAlsa::ParameterFragments::OnSetValue(int i) throw (LinuxSamplerException) {
        // not posssible, as parameter is fix
    }

    String AudioOutputDeviceAlsa::ParameterFragments::Name() {
        return "FRAGMENTS";
    }


// *************** ParameterFragmentSize ***************
// *

    AudioOutputDeviceAlsa::ParameterFragmentSize::ParameterFragmentSize() : DeviceCreationParameterInt() {
        InitWithDefault();
    }

    AudioOutputDeviceAlsa::ParameterFragmentSize::ParameterFragmentSize(String s) throw (LinuxSamplerException) : DeviceCreationParameterInt(s) {
    }

    String AudioOutputDeviceAlsa::ParameterFragmentSize::Description() {
        return "Size of each buffer fragment";
    }

    bool AudioOutputDeviceAlsa::ParameterFragmentSize::Fix() {
        return true;
    }

    bool AudioOutputDeviceAlsa::ParameterFragmentSize::Mandatory() {
        return false;
    }

    std::map<String,DeviceCreationParameter*> AudioOutputDeviceAlsa::ParameterFragmentSize::DependsAsParameters() {
        static ParameterCard card;
        std::map<String,DeviceCreationParameter*> dependencies;
        dependencies[card.Name()] = &card;
        return dependencies;
    }

    optional<int> AudioOutputDeviceAlsa::ParameterFragmentSize::DefaultAsInt(std::map<String,String> Parameters) {
        return 128; // until done
    }

    optional<int> AudioOutputDeviceAlsa::ParameterFragmentSize::RangeMinAsInt(std::map<String,String> Parameters) {
        return optional<int>::nothing;
    }

    optional<int> AudioOutputDeviceAlsa::ParameterFragmentSize::RangeMaxAsInt(std::map<String,String> Parameters) {
        return optional<int>::nothing;
    }

    std::vector<int> AudioOutputDeviceAlsa::ParameterFragmentSize::PossibilitiesAsInt(std::map<String,String> Parameters) {
        return std::vector<int>();
    }

    void AudioOutputDeviceAlsa::ParameterFragmentSize::OnSetValue(int i) throw (LinuxSamplerException) {
        // not posssible, as parameter is fix
    }

    String AudioOutputDeviceAlsa::ParameterFragmentSize::Name() {
        return "FRAGMENTSIZE";
    }


// *************** AudioOutputDeviceAlsa ***************
// *

    /**
     * Create and initialize Alsa audio output device with given parameters.
     *
     * @param Parameters - optional parameters
     * @throws AudioOutputException  if output device cannot be opened
     */
    AudioOutputDeviceAlsa::AudioOutputDeviceAlsa(std::map<String,DeviceCreationParameter*> Parameters) : AudioOutputDevice(Parameters), Thread(true, 1, 0) {
        pcm_handle           = NULL;
        stream               = SND_PCM_STREAM_PLAYBACK;
        this->uiAlsaChannels = ((DeviceCreationParameterInt*)Parameters["CHANNELS"])->ValueAsInt();
        this->uiSamplerate   = ((DeviceCreationParameterInt*)Parameters["SAMPLERATE"])->ValueAsInt();
        this->FragmentSize   = ((DeviceCreationParameterInt*)Parameters["FRAGMENTSIZE"])->ValueAsInt();
        uint Fragments       = ((DeviceCreationParameterInt*)Parameters["FRAGMENTS"])->ValueAsInt();
        String Card          = ((DeviceCreationParameterString*)Parameters["CARD"])->ValueAsString();

        dmsg(1,("Checking if hw parameters supported...\n"));
        if (HardwareParametersSupported(Card, uiAlsaChannels, uiSamplerate, Fragments, FragmentSize)) {
            pcm_name = "hw:" + Card;
        }
        else {
            printf("Warning: your soundcard doesn't support chosen hardware parameters; ");
            printf("trying to compensate support lack with plughw...");
            fflush(stdout);
            pcm_name = "plughw:" + Card;
        }
        dmsg(1,("HW check completed.\n"));

        int err;

        snd_pcm_hw_params_alloca(&hwparams);  // Allocate the snd_pcm_hw_params_t structure on the stack.

        /* Open PCM. The last parameter of this function is the mode. */
        /* If this is set to 0, the standard mode is used. Possible   */
        /* other values are SND_PCM_NONBLOCK and SND_PCM_ASYNC.       */
        /* If SND_PCM_NONBLOCK is used, read / write access to the    */
        /* PCM device will return immediately. If SND_PCM_ASYNC is    */
        /* specified, SIGIO will be emitted whenever a period has     */
        /* been completely processed by the soundcard.                */
        if ((err = snd_pcm_open(&pcm_handle, pcm_name.c_str(), stream, 0)) < 0) {
            throw AudioOutputException(String("Error opening PCM device ") + pcm_name + ": " + snd_strerror(err));
        }

        if ((err = snd_pcm_hw_params_any(pcm_handle, hwparams)) < 0) {
            throw AudioOutputException(String("Error, cannot initialize hardware parameter structure: ") + snd_strerror(err));
        }

        /* Set access type. This can be either    */
        /* SND_PCM_ACCESS_RW_INTERLEAVED or       */
        /* SND_PCM_ACCESS_RW_NONINTERLEAVED.      */
        if ((err = snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
            throw AudioOutputException(String("Error snd_pcm_hw_params_set_access: ") + snd_strerror(err));
        }

        /* Set sample format */
        #if WORDS_BIGENDIAN
        if ((err = snd_pcm_hw_params_set_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_BE)) < 0)
        #else // little endian
        if ((err = snd_pcm_hw_params_set_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE)) < 0)
        #endif
        {
            throw AudioOutputException(String("Error setting sample format: ") + snd_strerror(err));
        }

        int dir = 0;

        /* Set sample rate. If the exact rate is not supported */
        /* by the hardware, use nearest possible rate.         */
        #if ALSA_MAJOR > 0
        if((err = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &uiSamplerate, &dir)) < 0)
        #else
        if((err = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, uiSamplerate, &dir)) < 0)
        #endif
        {
            throw AudioOutputException(String("Error setting sample rate: ") + snd_strerror(err));
        }

        if ((err = snd_pcm_hw_params_set_channels(pcm_handle, hwparams, uiAlsaChannels)) < 0) {
            throw AudioOutputException(String("Error setting number of channels: ") + snd_strerror(err));
        }

        /* Set number of periods. Periods used to be called fragments. */
        if ((err = snd_pcm_hw_params_set_periods(pcm_handle, hwparams, Fragments, dir)) < 0) {
            throw AudioOutputException(String("Error setting number of periods: ") + snd_strerror(err));
        }

        /* Set buffer size (in frames). The resulting latency is given by */
        /* latency = periodsize * periods / (rate * bytes_per_frame)     */
        if ((err = snd_pcm_hw_params_set_buffer_size(pcm_handle, hwparams, (FragmentSize * Fragments))) < 0) {
            throw AudioOutputException(String("Error setting buffersize: ") + snd_strerror(err));
        }

        /* Apply HW parameter settings to */
        /* PCM device and prepare device  */
        if ((err = snd_pcm_hw_params(pcm_handle, hwparams)) < 0) {
            throw AudioOutputException(String("Error setting HW params: ") + snd_strerror(err));
        }

        if (snd_pcm_sw_params_malloc(&swparams) != 0) {
            throw AudioOutputException(String("Error in snd_pcm_sw_params_malloc: ") + snd_strerror(err));
        }

        if (snd_pcm_sw_params_current(pcm_handle, swparams) != 0) {
            throw AudioOutputException(String("Error in snd_pcm_sw_params_current: ") + snd_strerror(err));
        }

        if (snd_pcm_sw_params_set_stop_threshold(pcm_handle, swparams, 0xffffffff) != 0) {
            throw AudioOutputException(String("Error in snd_pcm_sw_params_set_stop_threshold: ") + snd_strerror(err));
        }

        if (snd_pcm_sw_params(pcm_handle, swparams) != 0) {
            throw AudioOutputException(String("Error in snd_pcm_sw_params: ") + snd_strerror(err));
        }

        if ((err = snd_pcm_prepare(pcm_handle)) < 0) {
            throw AudioOutputException(String("Error snd_pcm_prepare: ") + snd_strerror(err));
        }

        // allocate Alsa output buffer
        pAlsaOutputBuffer = new int16_t[uiAlsaChannels * FragmentSize];

        // create audio channels for this audio device to which the sampler engines can write to
        for (int i = 0; i < uiAlsaChannels; i++) this->Channels.push_back(new AudioChannel(FragmentSize));

        if (((DeviceCreationParameterBool*)Parameters["ACTIVE"])->ValueAsBool()) {
                Play();
        }
    }

    AudioOutputDeviceAlsa::~AudioOutputDeviceAlsa() {
        //dmsg(0,("Stopping Alsa Thread..."));
        //StopThread();  //FIXME: commented out due to a bug in thread.cpp (StopThread() doesn't return at all)
        //dmsg(0,("OK\n"));

        //FIXME: currently commented out due to segfault
        //snd_pcm_close(pcm_handle);

        // destroy all audio channels
        for (int c = 0; c < Channels.size(); c++) delete Channels[c];

        if (pAlsaOutputBuffer) {
            //FIXME: currently commented out due to segfault
            //delete[] pOutputBuffer;
        }
    }

    /**
     *  Checks if sound card supports the chosen parameters.
     *
     *  @returns  true if hardware supports it
     */
    bool AudioOutputDeviceAlsa::HardwareParametersSupported(String card, uint channels, int samplerate, uint numfragments, uint fragmentsize) {
        pcm_name = "hw:" + card;
        if (snd_pcm_open(&pcm_handle, pcm_name.c_str(), stream, 0) < 0) return false;
        snd_pcm_hw_params_alloca(&hwparams);
        if (snd_pcm_hw_params_any(pcm_handle, hwparams) < 0) {
            snd_pcm_close(pcm_handle);
            return false;
        }
        if (snd_pcm_hw_params_test_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
            snd_pcm_close(pcm_handle);
            return false;
        }
        #if WORDS_BIGENDIAN
        if (snd_pcm_hw_params_test_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_BE) < 0)
        #else // little endian
        if (snd_pcm_hw_params_test_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE) < 0)
        #endif
        {
            snd_pcm_close(pcm_handle);
            return false;
        }
        int dir = 0;
        if (snd_pcm_hw_params_test_rate(pcm_handle, hwparams, samplerate, dir) < 0) {
            snd_pcm_close(pcm_handle);
            return false;
        }
        if (snd_pcm_hw_params_test_channels(pcm_handle, hwparams, channels) < 0) {
            snd_pcm_close(pcm_handle);
            return false;
        }
        if (snd_pcm_hw_params_test_periods(pcm_handle, hwparams, numfragments, dir) < 0) {
            snd_pcm_close(pcm_handle);
            return false;
        }
        if (snd_pcm_hw_params_test_buffer_size(pcm_handle, hwparams, (fragmentsize * numfragments)) < 0) {
            snd_pcm_close(pcm_handle);
            return false;
        }

        snd_pcm_close(pcm_handle);
        return true;
    }

    void AudioOutputDeviceAlsa::Play() {
        StartThread();
    }

    bool AudioOutputDeviceAlsa::IsPlaying() {
        return IsRunning(); // if Thread is running
    }

    void AudioOutputDeviceAlsa::Stop() {
        StopThread();
    }

    void AudioOutputDeviceAlsa::AcquireChannels(uint Channels) {
        if (Channels > uiAlsaChannels) {
            // just create mix channel(s)
            for (int i = uiAlsaChannels; i < Channels; i++) {
                AudioChannel* pNewChannel = new AudioChannel(this->Channels[i % uiAlsaChannels]);
                this->Channels.push_back(pNewChannel);
            }
        }
    }

    uint AudioOutputDeviceAlsa::MaxSamplesPerCycle() {
        return FragmentSize;
    }

    uint AudioOutputDeviceAlsa::SampleRate() {
        return uiSamplerate;
    }

    String AudioOutputDeviceAlsa::Name() {
        return "ALSA";
    }

    String AudioOutputDeviceAlsa::Driver() {
        return Name();
    }

    String AudioOutputDeviceAlsa::Description() {
        return "Advanced Linux Sound Architecture";
    }

    String AudioOutputDeviceAlsa::Version() {
       String s = "$Revision: 1.13 $";
       return s.substr(11, s.size() - 13); // cut dollar signs, spaces and CVS macro keyword
    }

    /**
     * Entry point for the thread.
     */
    int AudioOutputDeviceAlsa::Main() {
        while (true) {

            // let all connected engines render 'FragmentSize' sample points
            RenderAudio(FragmentSize);

            // convert from DSP value range (-1.0..+1.0) to 16 bit integer value
            // range (-32768..+32767), check clipping  and copy to Alsa output buffer
            // (note: we use interleaved output method to Alsa)
            for (int c = 0; c < uiAlsaChannels; c++) {
                float* in  = Channels[c]->Buffer();
                for (int i = 0, o = c; i < FragmentSize; i++ , o += uiAlsaChannels) {
                    float sample_point = in[i] * 32768.0f;
                    if (sample_point < -32768.0) sample_point = -32768.0;
                    if (sample_point >  32767.0) sample_point =  32767.0;
                    pAlsaOutputBuffer[o] = (int16_t) sample_point;
                }
            }

            // output sound
            int res = Output();
            if (res < 0) {
                fprintf(stderr, "Alsa: Audio output error, exiting.\n");
                exit(EXIT_FAILURE);
            }
        }
    }

    /**
     *  Will be called after every audio fragment cycle, to output the audio data
     *  of the current fragment to the soundcard.
     *
     *  @returns  0 on success, a value < 0 on error
     */
    int AudioOutputDeviceAlsa::Output() {
        int err = snd_pcm_writei(pcm_handle, pAlsaOutputBuffer, FragmentSize);
        if (err < 0) {
            fprintf(stderr, "Error snd_pcm_writei failed: %s\n", snd_strerror(err));
            return -1;
        }
        return 0;
    }

} // namespace LinuxSampler
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* *
7	* This program is free software; you can redistribute it and/or modify *
8	* it under the terms of the GNU General Public License as published by *
9	* the Free Software Foundation; either version 2 of the License, or *
10	* (at your option) any later version. *
11	* *
12	* This program is distributed in the hope that it will be useful, *
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15	* GNU General Public License for more details. *
16	* *
17	* You should have received a copy of the GNU General Public License *
18	* along with this program; if not, write to the Free Software *
19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20	* MA 02111-1307 USA *
21	***************************************************************************/
22
23	#include "AudioOutputDeviceAlsa.h"
24	#include "AudioOutputDeviceFactory.h"
25
26	namespace LinuxSampler {
27
28	REGISTER_AUDIO_OUTPUT_DRIVER(AudioOutputDeviceAlsa);
29
30	/* Common parameters for now they'll have to be registered here. */
31	REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterActive);
32	REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterSampleRate);
33	REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterChannels);
34
35	/* Driver specific parameters */
36	REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterCard);
37	REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterFragments);
38	REGISTER_AUDIO_OUTPUT_DRIVER_PARAMETER(AudioOutputDeviceAlsa, ParameterFragmentSize);
39
40
41
42	// ************* ParameterCard *************
43	// *
44
45	AudioOutputDeviceAlsa::ParameterCard::ParameterCard() : DeviceCreationParameterString() {
46	InitWithDefault(); // use default card
47	}
48
49	AudioOutputDeviceAlsa::ParameterCard::ParameterCard(String s) throw (LinuxSamplerException) : DeviceCreationParameterString(s) {
50	SetValue(s); // try to use given card
51	}
52
53	String AudioOutputDeviceAlsa::ParameterCard::Description() {
54	return "Sound card to be used";
55	}
56
57	bool AudioOutputDeviceAlsa::ParameterCard::Fix() {
58	return true;
59	}
60
61	bool AudioOutputDeviceAlsa::ParameterCard::Mandatory() {
62	return false;
63	}
64
65	std::map<String,DeviceCreationParameter*> AudioOutputDeviceAlsa::ParameterCard::DependsAsParameters() {
66	return std::map<String,DeviceCreationParameter*>(); // no dependencies
67	}
68
69	optional<String> AudioOutputDeviceAlsa::ParameterCard::DefaultAsString(std::map<String,String> Parameters) {
70	std::vector<String> cards = PossibilitiesAsString(Parameters);
71	if (cards.empty()) throw LinuxSamplerException("AudioOutputDeviceAlsa: Can't find any card");
72	return cards[0]; // first card by default
73	}
74
75	std::vector<String> AudioOutputDeviceAlsa::ParameterCard::PossibilitiesAsString(std::map<String,String> Parameters) {
76	int err;
77	std::vector<String> CardNames;
78
79	// iterate through all cards
80	int card_index = -1;
81	while (snd_card_next(&card_index) >= 0 && card_index >= 0) {
82	String hw_name = "hw:" + ToString(card_index);
83	snd_ctl_t* hCardCtrl;
84	if ((err = snd_ctl_open(&hCardCtrl, hw_name.c_str(), 0)) < 0) {
85	std::cerr << "AudioOutputDeviceAlsa: Cannot open sound control for card " << card_index << " - " << snd_strerror(err) << std::endl;
86	continue;
87	}
88
89	// iterate through all devices of that card
90	int device_index = -1;
91	while (!snd_ctl_pcm_next_device(hCardCtrl, &device_index) && device_index >= 0) {
92	String name = ToString(card_index) + "," + ToString(device_index);
93	//dmsg(1,("[possibility:%s]", name.c_str()));
94	CardNames.push_back(name);
95	}
96
97	snd_ctl_close(hCardCtrl);
98	}
99
100	return CardNames;
101	}
102
103	void AudioOutputDeviceAlsa::ParameterCard::OnSetValue(String s) throw (LinuxSamplerException) {
104	// not posssible, as parameter is fix
105	}
106
107	String AudioOutputDeviceAlsa::ParameterCard::Name() {
108	return "CARD";
109	}
110
111
112
113	// ************* ParameterFragments *************
114	// *
115
116	AudioOutputDeviceAlsa::ParameterFragments::ParameterFragments() : DeviceCreationParameterInt() {
117	InitWithDefault();
118	}
119
120	AudioOutputDeviceAlsa::ParameterFragments::ParameterFragments(String s) throw (LinuxSamplerException) : DeviceCreationParameterInt(s) {
121	}
122
123	String AudioOutputDeviceAlsa::ParameterFragments::Description() {
124	return "Number of buffer fragments";
125	}
126
127	bool AudioOutputDeviceAlsa::ParameterFragments::Fix() {
128	return true;
129	}
130
131	bool AudioOutputDeviceAlsa::ParameterFragments::Mandatory() {
132	return false;
133	}
134
135	std::map<String,DeviceCreationParameter*> AudioOutputDeviceAlsa::ParameterFragments::DependsAsParameters() {
136	static ParameterCard card;
137	std::map<String,DeviceCreationParameter*> dependencies;
138	dependencies[card.Name()] = &card;
139	return dependencies;
140	}
141
142	optional<int> AudioOutputDeviceAlsa::ParameterFragments::DefaultAsInt(std::map<String,String> Parameters) {
143	return 2; // until done
144	}
145
146	optional<int> AudioOutputDeviceAlsa::ParameterFragments::RangeMinAsInt(std::map<String,String> Parameters) {
147	return optional<int>::nothing;
148	}
149
150	optional<int> AudioOutputDeviceAlsa::ParameterFragments::RangeMaxAsInt(std::map<String,String> Parameters) {
151	return optional<int>::nothing;
152	}
153
154	std::vector<int> AudioOutputDeviceAlsa::ParameterFragments::PossibilitiesAsInt(std::map<String,String> Parameters) {
155	return std::vector<int>();
156	}
157
158	void AudioOutputDeviceAlsa::ParameterFragments::OnSetValue(int i) throw (LinuxSamplerException) {
159	// not posssible, as parameter is fix
160	}
161
162	String AudioOutputDeviceAlsa::ParameterFragments::Name() {
163	return "FRAGMENTS";
164	}
165
166
167
168	// ************* ParameterFragmentSize *************
169	// *
170
171	AudioOutputDeviceAlsa::ParameterFragmentSize::ParameterFragmentSize() : DeviceCreationParameterInt() {
172	InitWithDefault();
173	}
174
175	AudioOutputDeviceAlsa::ParameterFragmentSize::ParameterFragmentSize(String s) throw (LinuxSamplerException) : DeviceCreationParameterInt(s) {
176	}
177
178	String AudioOutputDeviceAlsa::ParameterFragmentSize::Description() {
179	return "Size of each buffer fragment";
180	}
181
182	bool AudioOutputDeviceAlsa::ParameterFragmentSize::Fix() {
183	return true;
184	}
185
186	bool AudioOutputDeviceAlsa::ParameterFragmentSize::Mandatory() {
187	return false;
188	}
189
190	std::map<String,DeviceCreationParameter*> AudioOutputDeviceAlsa::ParameterFragmentSize::DependsAsParameters() {
191	static ParameterCard card;
192	std::map<String,DeviceCreationParameter*> dependencies;
193	dependencies[card.Name()] = &card;
194	return dependencies;
195	}
196
197	optional<int> AudioOutputDeviceAlsa::ParameterFragmentSize::DefaultAsInt(std::map<String,String> Parameters) {
198	return 128; // until done
199	}
200
201	optional<int> AudioOutputDeviceAlsa::ParameterFragmentSize::RangeMinAsInt(std::map<String,String> Parameters) {
202	return optional<int>::nothing;
203	}
204
205	optional<int> AudioOutputDeviceAlsa::ParameterFragmentSize::RangeMaxAsInt(std::map<String,String> Parameters) {
206	return optional<int>::nothing;
207	}
208
209	std::vector<int> AudioOutputDeviceAlsa::ParameterFragmentSize::PossibilitiesAsInt(std::map<String,String> Parameters) {
210	return std::vector<int>();
211	}
212
213	void AudioOutputDeviceAlsa::ParameterFragmentSize::OnSetValue(int i) throw (LinuxSamplerException) {
214	// not posssible, as parameter is fix
215	}
216
217	String AudioOutputDeviceAlsa::ParameterFragmentSize::Name() {
218	return "FRAGMENTSIZE";
219	}
220
221
222
223	// ************* AudioOutputDeviceAlsa *************
224	// *
225
226	/**
227	* Create and initialize Alsa audio output device with given parameters.
228	*
229	* @param Parameters - optional parameters
230	* @throws AudioOutputException if output device cannot be opened
231	*/
232	AudioOutputDeviceAlsa::AudioOutputDeviceAlsa(std::map<String,DeviceCreationParameter*> Parameters) : AudioOutputDevice(Parameters), Thread(true, 1, 0) {
233	pcm_handle = NULL;
234	stream = SND_PCM_STREAM_PLAYBACK;
235	this->uiAlsaChannels = ((DeviceCreationParameterInt*)Parameters["CHANNELS"])->ValueAsInt();
236	this->uiSamplerate = ((DeviceCreationParameterInt*)Parameters["SAMPLERATE"])->ValueAsInt();
237	this->FragmentSize = ((DeviceCreationParameterInt*)Parameters["FRAGMENTSIZE"])->ValueAsInt();
238	uint Fragments = ((DeviceCreationParameterInt*)Parameters["FRAGMENTS"])->ValueAsInt();
239	String Card = ((DeviceCreationParameterString*)Parameters["CARD"])->ValueAsString();
240
241	dmsg(1,("Checking if hw parameters supported...\n"));
242	if (HardwareParametersSupported(Card, uiAlsaChannels, uiSamplerate, Fragments, FragmentSize)) {
243	pcm_name = "hw:" + Card;
244	}
245	else {
246	printf("Warning: your soundcard doesn't support chosen hardware parameters; ");
247	printf("trying to compensate support lack with plughw...");
248	fflush(stdout);
249	pcm_name = "plughw:" + Card;
250	}
251	dmsg(1,("HW check completed.\n"));
252
253	int err;
254
255	snd_pcm_hw_params_alloca(&hwparams); // Allocate the snd_pcm_hw_params_t structure on the stack.
256
257	/* Open PCM. The last parameter of this function is the mode. */
258	/* If this is set to 0, the standard mode is used. Possible */
259	/* other values are SND_PCM_NONBLOCK and SND_PCM_ASYNC. */
260	/* If SND_PCM_NONBLOCK is used, read / write access to the */
261	/* PCM device will return immediately. If SND_PCM_ASYNC is */
262	/* specified, SIGIO will be emitted whenever a period has */
263	/* been completely processed by the soundcard. */
264	if ((err = snd_pcm_open(&pcm_handle, pcm_name.c_str(), stream, 0)) < 0) {
265	throw AudioOutputException(String("Error opening PCM device ") + pcm_name + ": " + snd_strerror(err));
266	}
267
268	if ((err = snd_pcm_hw_params_any(pcm_handle, hwparams)) < 0) {
269	throw AudioOutputException(String("Error, cannot initialize hardware parameter structure: ") + snd_strerror(err));
270	}
271
272	/* Set access type. This can be either */
273	/* SND_PCM_ACCESS_RW_INTERLEAVED or */
274	/* SND_PCM_ACCESS_RW_NONINTERLEAVED. */
275	if ((err = snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
276	throw AudioOutputException(String("Error snd_pcm_hw_params_set_access: ") + snd_strerror(err));
277	}
278
279	/* Set sample format */
280	#if WORDS_BIGENDIAN
281	if ((err = snd_pcm_hw_params_set_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_BE)) < 0)
282	#else // little endian
283	if ((err = snd_pcm_hw_params_set_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE)) < 0)
284	#endif
285	{
286	throw AudioOutputException(String("Error setting sample format: ") + snd_strerror(err));
287	}
288
289	int dir = 0;
290
291	/* Set sample rate. If the exact rate is not supported */
292	/* by the hardware, use nearest possible rate. */
293	#if ALSA_MAJOR > 0
294	if((err = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &uiSamplerate, &dir)) < 0)
295	#else
296	if((err = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, uiSamplerate, &dir)) < 0)
297	#endif
298	{
299	throw AudioOutputException(String("Error setting sample rate: ") + snd_strerror(err));
300	}
301
302	if ((err = snd_pcm_hw_params_set_channels(pcm_handle, hwparams, uiAlsaChannels)) < 0) {
303	throw AudioOutputException(String("Error setting number of channels: ") + snd_strerror(err));
304	}
305
306	/* Set number of periods. Periods used to be called fragments. */
307	if ((err = snd_pcm_hw_params_set_periods(pcm_handle, hwparams, Fragments, dir)) < 0) {
308	throw AudioOutputException(String("Error setting number of periods: ") + snd_strerror(err));
309	}
310
311	/* Set buffer size (in frames). The resulting latency is given by */
312	/* latency = periodsize * periods / (rate * bytes_per_frame) */
313	if ((err = snd_pcm_hw_params_set_buffer_size(pcm_handle, hwparams, (FragmentSize * Fragments))) < 0) {
314	throw AudioOutputException(String("Error setting buffersize: ") + snd_strerror(err));
315	}
316
317	/* Apply HW parameter settings to */
318	/* PCM device and prepare device */
319	if ((err = snd_pcm_hw_params(pcm_handle, hwparams)) < 0) {
320	throw AudioOutputException(String("Error setting HW params: ") + snd_strerror(err));
321	}
322
323	if (snd_pcm_sw_params_malloc(&swparams) != 0) {
324	throw AudioOutputException(String("Error in snd_pcm_sw_params_malloc: ") + snd_strerror(err));
325	}
326
327	if (snd_pcm_sw_params_current(pcm_handle, swparams) != 0) {
328	throw AudioOutputException(String("Error in snd_pcm_sw_params_current: ") + snd_strerror(err));
329	}
330
331	if (snd_pcm_sw_params_set_stop_threshold(pcm_handle, swparams, 0xffffffff) != 0) {
332	throw AudioOutputException(String("Error in snd_pcm_sw_params_set_stop_threshold: ") + snd_strerror(err));
333	}
334
335	if (snd_pcm_sw_params(pcm_handle, swparams) != 0) {
336	throw AudioOutputException(String("Error in snd_pcm_sw_params: ") + snd_strerror(err));
337	}
338
339	if ((err = snd_pcm_prepare(pcm_handle)) < 0) {
340	throw AudioOutputException(String("Error snd_pcm_prepare: ") + snd_strerror(err));
341	}
342
343	// allocate Alsa output buffer
344	pAlsaOutputBuffer = new int16_t[uiAlsaChannels * FragmentSize];
345
346	// create audio channels for this audio device to which the sampler engines can write to
347	for (int i = 0; i < uiAlsaChannels; i++) this->Channels.push_back(new AudioChannel(FragmentSize));
348
349	if (((DeviceCreationParameterBool*)Parameters["ACTIVE"])->ValueAsBool()) {
350	Play();
351	}
352	}
353
354	AudioOutputDeviceAlsa::~AudioOutputDeviceAlsa() {
355	//dmsg(0,("Stopping Alsa Thread..."));
356	//StopThread(); //FIXME: commented out due to a bug in thread.cpp (StopThread() doesn't return at all)
357	//dmsg(0,("OK\n"));
358
359	//FIXME: currently commented out due to segfault
360	//snd_pcm_close(pcm_handle);
361
362	// destroy all audio channels
363	for (int c = 0; c < Channels.size(); c++) delete Channels[c];
364
365	if (pAlsaOutputBuffer) {
366	//FIXME: currently commented out due to segfault
367	//delete[] pOutputBuffer;
368	}
369	}
370
371	/**
372	* Checks if sound card supports the chosen parameters.
373	*
374	* @returns true if hardware supports it
375	*/
376	bool AudioOutputDeviceAlsa::HardwareParametersSupported(String card, uint channels, int samplerate, uint numfragments, uint fragmentsize) {
377	pcm_name = "hw:" + card;
378	if (snd_pcm_open(&pcm_handle, pcm_name.c_str(), stream, 0) < 0) return false;
379	snd_pcm_hw_params_alloca(&hwparams);
380	if (snd_pcm_hw_params_any(pcm_handle, hwparams) < 0) {
381	snd_pcm_close(pcm_handle);
382	return false;
383	}
384	if (snd_pcm_hw_params_test_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED) < 0) {
385	snd_pcm_close(pcm_handle);
386	return false;
387	}
388	#if WORDS_BIGENDIAN
389	if (snd_pcm_hw_params_test_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_BE) < 0)
390	#else // little endian
391	if (snd_pcm_hw_params_test_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE) < 0)
392	#endif
393	{
394	snd_pcm_close(pcm_handle);
395	return false;
396	}
397	int dir = 0;
398	if (snd_pcm_hw_params_test_rate(pcm_handle, hwparams, samplerate, dir) < 0) {
399	snd_pcm_close(pcm_handle);
400	return false;
401	}
402	if (snd_pcm_hw_params_test_channels(pcm_handle, hwparams, channels) < 0) {
403	snd_pcm_close(pcm_handle);
404	return false;
405	}
406	if (snd_pcm_hw_params_test_periods(pcm_handle, hwparams, numfragments, dir) < 0) {
407	snd_pcm_close(pcm_handle);
408	return false;
409	}
410	if (snd_pcm_hw_params_test_buffer_size(pcm_handle, hwparams, (fragmentsize * numfragments)) < 0) {
411	snd_pcm_close(pcm_handle);
412	return false;
413	}
414
415	snd_pcm_close(pcm_handle);
416	return true;
417	}
418
419	void AudioOutputDeviceAlsa::Play() {
420	StartThread();
421	}
422
423	bool AudioOutputDeviceAlsa::IsPlaying() {
424	return IsRunning(); // if Thread is running
425	}
426
427	void AudioOutputDeviceAlsa::Stop() {
428	StopThread();
429	}
430
431	void AudioOutputDeviceAlsa::AcquireChannels(uint Channels) {
432	if (Channels > uiAlsaChannels) {
433	// just create mix channel(s)
434	for (int i = uiAlsaChannels; i < Channels; i++) {
435	AudioChannel* pNewChannel = new AudioChannel(this->Channels[i % uiAlsaChannels]);
436	this->Channels.push_back(pNewChannel);
437	}
438	}
439	}
440
441	uint AudioOutputDeviceAlsa::MaxSamplesPerCycle() {
442	return FragmentSize;
443	}
444
445	uint AudioOutputDeviceAlsa::SampleRate() {
446	return uiSamplerate;
447	}
448
449	String AudioOutputDeviceAlsa::Name() {
450	return "ALSA";
451	}
452
453	String AudioOutputDeviceAlsa::Driver() {
454	return Name();
455	}
456
457	String AudioOutputDeviceAlsa::Description() {
458	return "Advanced Linux Sound Architecture";
459	}
460
461	String AudioOutputDeviceAlsa::Version() {
462	String s = "$Revision: 1.13 $";
463	return s.substr(11, s.size() - 13); // cut dollar signs, spaces and CVS macro keyword
464	}
465
466	/**
467	* Entry point for the thread.
468	*/
469	int AudioOutputDeviceAlsa::Main() {
470	while (true) {
471
472	// let all connected engines render 'FragmentSize' sample points
473	RenderAudio(FragmentSize);
474
475	// convert from DSP value range (-1.0..+1.0) to 16 bit integer value
476	// range (-32768..+32767), check clipping and copy to Alsa output buffer
477	// (note: we use interleaved output method to Alsa)
478	for (int c = 0; c < uiAlsaChannels; c++) {
479	float* in = Channels[c]->Buffer();
480	for (int i = 0, o = c; i < FragmentSize; i++ , o += uiAlsaChannels) {
481	float sample_point = in[i] * 32768.0f;
482	if (sample_point < -32768.0) sample_point = -32768.0;
483	if (sample_point > 32767.0) sample_point = 32767.0;
484	pAlsaOutputBuffer[o] = (int16_t) sample_point;
485	}
486	}
487
488	// output sound
489	int res = Output();
490	if (res < 0) {
491	fprintf(stderr, "Alsa: Audio output error, exiting.\n");
492	exit(EXIT_FAILURE);
493	}
494	}
495	}
496
497	/**
498	* Will be called after every audio fragment cycle, to output the audio data
499	* of the current fragment to the soundcard.
500	*
501	* @returns 0 on success, a value < 0 on error
502	*/
503	int AudioOutputDeviceAlsa::Output() {
504	int err = snd_pcm_writei(pcm_handle, pAlsaOutputBuffer, FragmentSize);
505	if (err < 0) {
506	fprintf(stderr, "Error snd_pcm_writei failed: %s\n", snd_strerror(err));
507	return -1;
508	}
509	return 0;
510	}
511
512	} // namespace LinuxSampler