Extra Sound Device Hotplug Problem

[Shany Guetta <shanyguetta93@xxxxxxxxx>]

Hello,

I am trying to develop a pjsip app which will manage more usb sound devices concurrently.

I am using PJSIP 2.8 .

I am trying to manage the case in which a device is disconnected by fault at runtime and reconnected again without restarting the application.

What I do today is at the startup I start a timer and at each timeout I call :

##

AudDevManager& mgr = Endpoint::instance().audDevManager();

mgr.refreshDevs();

##

I iterate over the available devices and if I didn't create them before I create them in this way:

##

bool VCSSoundDevMgr::createAudioDevice(int deviceID, AudioDevInfo info)
{
    try
    {
        pj_status_t status;
        pjsua_ext_snd_dev * snd_dev;
        /* Generate sound device port param */
        pjmedia_snd_port_param param;
        pjmedia_snd_port_param_default(&param);
        status = pjmedia_aud_dev_default_param(deviceID, &param.base);
        if(status!= PJ_SUCCESS)
        {
            qDebug()<<"VCSSoundDevMgr::createAudioDevice - pjmedia_aud_dev_default_param error";
        }

        param.base.dir = PJMEDIA_DIR_CAPTURE_PLAYBACK;
        param.base.play_id = deviceID;
        param.base.rec_id = deviceID;
        param.base.clock_rate = master_info.clock_rate;
        param.base.channel_count = master_info.channel_count;
        param.base.samples_per_frame = master_info.samples_per_frame;
        param.base.bits_per_sample = master_info.bits_per_sample;

        status = pjsua_ext_snd_dev_create(&param, &snd_dev);
        if(status!= PJ_SUCCESS) 
        {
           qDebug()<<"VCSSoundDevMgr::createAudioDevice - cannot create device:"<<deviceID;
        }
        else
        {
            int slotID = pjsua_ext_snd_dev_get_conf_port(snd_dev);
            AudioDeviceInfo *s = new AudioDeviceInfo();
            QString devName = QString::fromStdString(info.name);
            s->device = snd_dev;
            s->info = info;
            s->slot = slotID;
            s->friendly_name = mDeviceNames.value(devName,devName);
            mAudioDevices.insert(devName, s);
            qDebug()<<"VCSSoundDevMgr::createAudioDevice - created Sound Dev:"<<devName<<" ID:"<<deviceID<<" slot:"<<slotID;
        } 
    }
    catch(Error &err)
    {
        qDebug()<<"VCSSoundDevMgr::createSoundDeviceSlot() - error:"
               << err.info().c_str();
      return false;
    }
    return true;
}

##

At each timeout i also iterate over the devices already created to check if they are still connected simply by calling :

##

bool VCSSoundDevMgr::isDeviceConnected(QString name)
{
    AudDevManager& mgr = Endpoint::instance().audDevManager();
    try
    {
        mgr.lookupDev("ALSA", name.toStdString());
        return true;
    }
    catch (Error& e)
    {
        return false;
    }
}
##

In case it is disconnected, I create a thread to destroy the sound device in this way:

##
void VCSSoundDevMgr::destroyAudioDevice(AudioDeviceInfo *info)
{
    qDebug()<<"Destroying device..";
    pj_status_t status;
    try
    {
        AudioMediaVector vector = Endpoint::instance().mediaEnumPorts();
        foreach(AudioMedia * media, vector)
        {
            if(media->getType() == PJMEDIA_TYPE_AUDIO)
            {
                pjsua_conf_disconnect(media->getPortId(), info->slot);
                pjsua_conf_disconnect(info->slot, media->getPortId());
            }
        }
        qDebug()<<"Disconnected calls..";


        pj_pool_t	*pool = pjsua_pool_create("pool",4000,4000);
        pj_thread_t *pjThread;
        //CREATE THREAD
        status = pj_thread_create (pool,
                                   "soundevmgr_destroy",
                                   threadDestroy,
                                   info->device,
                                   0, //ZERO,
                                   0,
                                   &pjThread);
        if (status != PJ_SUCCESS)
        {
            qDebug() << "VCSSoundDevMgr::destroySoundDevices() - WARNING: pj_thread_create is not created.";
            pj_thread_join(pjThread);
            pj_thread_destroy(pjThread);
        }

        mAudioDevices.remove(QString::fromStdString(info->info.name));
        delete info;
        info = NULL;
        qDebug()<<"DEVICE DELETED";
    }catch(Error &err)
    {
        qDebug() << "VCSSoundDevMgr::destroyAudioDevice() - ERROR: "
                 << err.info().c_str();
    }
}

static int threadDestroy (void *arg)
{
    /* Check if we have sound stream device. */
    pj_status_t status;
    //REGISTERING THREAD
    pj_thread_desc aPJThreadDesc;
    pj_thread_t *pjThread;
    if (!pj_thread_is_registered()) {
        status = pj_thread_register("soundevmgr_destroy", aPJThreadDesc, &pjThread);
        qDebug()<<"VCSSoundDevMgr::destroySoundDevices() - registered thread";
        if (status != PJ_SUCCESS) {
            qDebug() << "VCSSoundDevMgr::destroySoundDevices() - WARNING: pjthread is not registered.";
        }
    }
    pjsua_ext_snd_dev * dev = (pjsua_ext_snd_dev *)arg;
    status = pjsua_ext_snd_dev_destroy(dev);
    if(status != PJ_SUCCESS)
    {
        qDebug() << "VCSSoundDevMgr::destroyAudioDevice - "
                 << "pjsua_ext_snd_dev_destroy  error";
    }
    qDebug()<<"THREAD TERMINATED..";
    return PJ_SUCCESS;
}
##

Until here, everything works great!

I turn on the application, the devices are created, I disconnect a device from the USB, the application destroy the sound device.

MY PROBLEM COMES NOW:

When I plug-in the device that I previously disconnected the AudioDeviceManager sees the device, try to create it but this step in the creation returns an error:

status = pjmedia_aud_dev_default_param(deviceID, &param.base);

And the device cannot be created because it results it has zero output and zero input count.

Basically after some investigation I think that alsa_dev.c is setting those counts to zero because

it fails to do snd_pcm_open on this device. But how come at the beginning it was possible to open it and when I plug it in again not?

Is there any one that can help me understand why this happens?

Thanks in advance.

Shani

_______________________________________________
Visit our blog: http://blog.pjsip.org

pjsip mailing list
pjsip@xxxxxxxxxxxxxxx
http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org