qt-everywhere-src-5.15.1/qtmultimedia/src/plugins/alsa/qalsaaudiodeviceinfo.cpp

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//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of other Qt classes.  This header file may change from version to
// version without notice, or even be removed.
//
// INTERNAL USE ONLY: Do NOT use for any other purpose.
//

#include "qalsaaudiodeviceinfo.h"

#include <alsa/version.h>

QT_BEGIN_NAMESPACE

QAlsaAudioDeviceInfo::QAlsaAudioDeviceInfo(const QByteArray &dev, QAudio::Mode mode)
{
    handle = 0;

    device = QLatin1String(dev);
    this->mode = mode;

    checkSurround();
}

QAlsaAudioDeviceInfo::~QAlsaAudioDeviceInfo()
{
    close();
}

bool QAlsaAudioDeviceInfo::isFormatSupported(const QAudioFormat& format) const
{
    return testSettings(format);
}

QAudioFormat QAlsaAudioDeviceInfo::preferredFormat() const
{
    QAudioFormat nearest;
    if(mode == QAudio::AudioOutput) {
        nearest.setSampleRate(44100);
        nearest.setChannelCount(2);
        nearest.setByteOrder(QAudioFormat::LittleEndian);
        nearest.setSampleType(QAudioFormat::SignedInt);
        nearest.setSampleSize(16);
        nearest.setCodec(QLatin1String("audio/pcm"));
    } else {
        nearest.setSampleRate(8000);
        nearest.setChannelCount(1);
        nearest.setSampleType(QAudioFormat::UnSignedInt);
        nearest.setSampleSize(8);
        nearest.setCodec(QLatin1String("audio/pcm"));
        if(!testSettings(nearest)) {
            nearest.setChannelCount(2);
            nearest.setSampleSize(16);
            nearest.setSampleType(QAudioFormat::SignedInt);
        }
    }
    return nearest;
}

QString QAlsaAudioDeviceInfo::deviceName() const
{
    return device;
}

QStringList QAlsaAudioDeviceInfo::supportedCodecs()
{
    updateLists();
    return codecz;
}

QList<int> QAlsaAudioDeviceInfo::supportedSampleRates()
{
    updateLists();
    return sampleRatez;
}

QList<int> QAlsaAudioDeviceInfo::supportedChannelCounts()
{
    updateLists();
    return channelz;
}

QList<int> QAlsaAudioDeviceInfo::supportedSampleSizes()
{
    updateLists();
    return sizez;
}

QList<QAudioFormat::Endian> QAlsaAudioDeviceInfo::supportedByteOrders()
{
    updateLists();
    return byteOrderz;
}

QList<QAudioFormat::SampleType> QAlsaAudioDeviceInfo::supportedSampleTypes()
{
    updateLists();
    return typez;
}

QByteArray QAlsaAudioDeviceInfo::defaultDevice(QAudio::Mode mode)
{
    const auto &devices = availableDevices(mode);
    if (devices.size() == 0)
        return QByteArray();

    return devices.first();
}

bool QAlsaAudioDeviceInfo::open()
{
    int err = 0;
    QString dev;

    if (!availableDevices(mode).contains(device.toLocal8Bit()))
        return false;

#if SND_LIB_VERSION < 0x1000e  // 1.0.14
    if (device.compare(QLatin1String("default")) != 0)
        dev = deviceFromCardName(device);
    else
#endif
        dev = device;

    if(mode == QAudio::AudioOutput) {
        err=snd_pcm_open( &handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_PLAYBACK,0);
    } else {
        err=snd_pcm_open( &handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_CAPTURE,0);
    }
    if(err < 0) {
        handle = 0;
        return false;
    }
    return true;
}

void QAlsaAudioDeviceInfo::close()
{
    if(handle)
        snd_pcm_close(handle);
    handle = 0;
}

bool QAlsaAudioDeviceInfo::testSettings(const QAudioFormat& format) const
{
    // Set nearest to closest settings that do work.
    // See if what is in settings will work (return value).
    int err = -1;
    snd_pcm_t* pcmHandle;
    snd_pcm_hw_params_t *params;
    QString dev;

#if SND_LIB_VERSION < 0x1000e  // 1.0.14
    if (device.compare(QLatin1String("default")) != 0)
        dev = deviceFromCardName(device);
    else
#endif
        dev = device;

    snd_pcm_stream_t stream = mode == QAudio::AudioOutput
                            ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE;

    if (snd_pcm_open(&pcmHandle, dev.toLocal8Bit().constData(), stream, 0) < 0)
        return false;

    snd_pcm_nonblock(pcmHandle, 0);
    snd_pcm_hw_params_alloca(&params);
    snd_pcm_hw_params_any(pcmHandle, params);

    // set the values!
    snd_pcm_hw_params_set_channels(pcmHandle, params, format.channelCount());
    snd_pcm_hw_params_set_rate(pcmHandle, params, format.sampleRate(), 0);

    snd_pcm_format_t pcmFormat = SND_PCM_FORMAT_UNKNOWN;
    switch (format.sampleSize()) {
    case 8:
        if (format.sampleType() == QAudioFormat::SignedInt)
            pcmFormat = SND_PCM_FORMAT_S8;
        else if (format.sampleType() == QAudioFormat::UnSignedInt)
            pcmFormat = SND_PCM_FORMAT_U8;
        break;
    case 16:
        if (format.sampleType() == QAudioFormat::SignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_S16_LE : SND_PCM_FORMAT_S16_BE;
        } else if (format.sampleType() == QAudioFormat::UnSignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_U16_LE : SND_PCM_FORMAT_U16_BE;
        }
        break;
    case 32:
        if (format.sampleType() == QAudioFormat::SignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_S32_LE : SND_PCM_FORMAT_S32_BE;
        } else if (format.sampleType() == QAudioFormat::UnSignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_U32_LE : SND_PCM_FORMAT_U32_BE;
        } else if (format.sampleType() == QAudioFormat::Float) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_FLOAT_LE : SND_PCM_FORMAT_FLOAT_BE;
        }
    }

    if (pcmFormat != SND_PCM_FORMAT_UNKNOWN)
        err = snd_pcm_hw_params_set_format(pcmHandle, params, pcmFormat);

    // For now, just accept only audio/pcm codec
    if (!format.codec().startsWith(QLatin1String("audio/pcm")))
        err = -1;

    if (err >= 0 && format.channelCount() != -1) {
        err = snd_pcm_hw_params_test_channels(pcmHandle, params, format.channelCount());
        if (err >= 0)
            err = snd_pcm_hw_params_set_channels(pcmHandle, params, format.channelCount());
    }

    if (err >= 0 && format.sampleRate() != -1) {
        err = snd_pcm_hw_params_test_rate(pcmHandle, params, format.sampleRate(), 0);
        if (err >= 0)
            err = snd_pcm_hw_params_set_rate(pcmHandle, params, format.sampleRate(), 0);
    }

    if (err >= 0 && pcmFormat != SND_PCM_FORMAT_UNKNOWN)
        err = snd_pcm_hw_params_set_format(pcmHandle, params, pcmFormat);

    if (err >= 0)
        err = snd_pcm_hw_params(pcmHandle, params);

    snd_pcm_close(pcmHandle);

    return (err == 0);
}

void QAlsaAudioDeviceInfo::updateLists()
{
    // redo all lists based on current settings
    sampleRatez.clear();
    channelz.clear();
    sizez.clear();
    byteOrderz.clear();
    typez.clear();
    codecz.clear();

    if(!handle)
        open();

    if(!handle)
        return;

    for(int i=0; i<(int)MAX_SAMPLE_RATES; i++) {
        //if(snd_pcm_hw_params_test_rate(handle, params, SAMPLE_RATES[i], dir) == 0)
        sampleRatez.append(SAMPLE_RATES[i]);
    }
    channelz.append(1);
    channelz.append(2);
    if (surround40) channelz.append(4);
    if (surround51) channelz.append(6);
    if (surround71) channelz.append(8);
    sizez.append(8);
    sizez.append(16);
    sizez.append(32);
    byteOrderz.append(QAudioFormat::LittleEndian);
    byteOrderz.append(QAudioFormat::BigEndian);
    typez.append(QAudioFormat::SignedInt);
    typez.append(QAudioFormat::UnSignedInt);
    typez.append(QAudioFormat::Float);
    codecz.append(QLatin1String("audio/pcm"));
    close();
}

QList<QByteArray> QAlsaAudioDeviceInfo::availableDevices(QAudio::Mode mode)
{
    QList<QByteArray> devices;
    bool hasDefault = false;

#if SND_LIB_VERSION >= 0x1000e  // 1.0.14
    QByteArray filter;

    // Create a list of all current audio devices that support mode
    void **hints, **n;
    char *name, *descr, *io;

    if(snd_device_name_hint(-1, "pcm", &hints) < 0) {
        qWarning() << "no alsa devices available";
        return devices;
    }
    n = hints;

    if(mode == QAudio::AudioInput) {
        filter = "Input";
    } else {
        filter = "Output";
    }

    while (*n != NULL) {
        name = snd_device_name_get_hint(*n, "NAME");
        if (name != 0 && qstrcmp(name, "null") != 0) {
            descr = snd_device_name_get_hint(*n, "DESC");
            io = snd_device_name_get_hint(*n, "IOID");

            if ((descr != NULL) && ((io == NULL) || (io == filter))) {
                devices.append(name);
                if (strcmp(name, "default") == 0)
                    hasDefault = true;
            }

            free(descr);
            free(io);
        }
        free(name);
        ++n;
    }
    snd_device_name_free_hint(hints);
#else
    int idx = 0;
    char* name;

    while(snd_card_get_name(idx,&name) == 0) {
        devices.append(name);
        if (strcmp(name, "default") == 0)
            hasDefault = true;
        idx++;
    }
#endif

    if (!hasDefault && devices.size() > 0)
        devices.prepend("default");

    return devices;
}

void QAlsaAudioDeviceInfo::checkSurround()
{
    surround40 = false;
    surround51 = false;
    surround71 = false;

    void **hints, **n;
    char *name, *descr, *io;

    if(snd_device_name_hint(-1, "pcm", &hints) < 0)
        return;

    n = hints;

    while (*n != NULL) {
        name = snd_device_name_get_hint(*n, "NAME");
        descr = snd_device_name_get_hint(*n, "DESC");
        io = snd_device_name_get_hint(*n, "IOID");
        if((name != NULL) && (descr != NULL)) {
            QString deviceName = QLatin1String(name);
            if (mode == QAudio::AudioOutput) {
                if(deviceName.contains(QLatin1String("surround40")))
                    surround40 = true;
                if(deviceName.contains(QLatin1String("surround51")))
                    surround51 = true;
                if(deviceName.contains(QLatin1String("surround71")))
                    surround71 = true;
            }
        }
        if(name != NULL)
            free(name);
        if(descr != NULL)
            free(descr);
        if(io != NULL)
            free(io);
        ++n;
    }
    snd_device_name_free_hint(hints);
}

QString QAlsaAudioDeviceInfo::deviceFromCardName(const QString &card)
{
    int idx = 0;
    char *name;

    QStringRef shortName = card.midRef(card.indexOf(QLatin1String("="), 0) + 1);

    while (snd_card_get_name(idx, &name) == 0) {
        if (shortName.compare(QLatin1String(name)) == 0)
            break;
        idx++;
    }

    return QString(QLatin1String("hw:%1,0")).arg(idx);
}

QT_END_NAMESPACE