static void print_channels(const snd_pcm_chmap_t *map)
{
char tmp[128];
if (snd_pcm_chmap_print(map, sizeof(tmp), tmp) > 0)
printf(" %s\n", tmp);
}
bool OutputALSA::initialize(quint32 freq, ChannelMap map, Qmmp::AudioFormat format)
{
m_inited = false;
if (pcm_handle)
return false;
if (snd_pcm_open(&pcm_handle, pcm_name, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK) < 0)
{
qWarning ("OutputALSA: Error opening PCM device %s", pcm_name);
return false;
}
// we need to configure
uint rate = freq; /* Sample rate */
uint exact_rate = freq; /* Sample rate returned by */
/* load settings from config */
QSettings settings(Qmmp::configFile(), QSettings::IniFormat);
settings.beginGroup("ALSA");
uint buffer_time = settings.value("buffer_time",500).toUInt()*1000;
uint period_time = settings.value("period_time",100).toUInt()*1000;
bool use_pause = settings.value("use_snd_pcm_pause", false).toBool();
settings.endGroup();
snd_pcm_hw_params_t *hwparams = 0;
snd_pcm_sw_params_t *swparams = 0;
int err; //alsa error code
//hw params
snd_pcm_hw_params_alloca(&hwparams);
if ((err = snd_pcm_hw_params_any(pcm_handle, hwparams)) < 0)
{
qWarning("OutputALSA: Can not read configuration for PCM device: %s", snd_strerror(err));
return false;
}
if (m_use_mmap)
{
if ((err = snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_MMAP_INTERLEAVED)) < 0)
{
qWarning("OutputALSA: Error setting mmap access: %s", snd_strerror(err));
m_use_mmap = false;
}
}
if (!m_use_mmap)
{
if ((err = snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0)
{
qWarning("OutputALSA: Error setting access: %s", snd_strerror(err));
return false;
}
}
snd_pcm_format_t alsa_format = SND_PCM_FORMAT_UNKNOWN;
switch (format)
{
case Qmmp::PCM_S8:
alsa_format = SND_PCM_FORMAT_S8;
break;
case Qmmp::PCM_S16LE:
alsa_format = SND_PCM_FORMAT_S16_LE;
break;
case Qmmp::PCM_S24LE:
alsa_format = SND_PCM_FORMAT_S24_LE;
break;
case Qmmp::PCM_S32LE:
alsa_format = SND_PCM_FORMAT_S32_LE;
break;
default:
qWarning("OutputALSA: unsupported format detected");
return false;
}
if ((err = snd_pcm_hw_params_set_format(pcm_handle, hwparams, alsa_format)) < 0)
{
qDebug("OutputALSA: Error setting format: %s", snd_strerror(err));
return false;
}
exact_rate = rate;
if ((err = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &exact_rate, 0)) < 0)
{
qWarning("OutputALSA: Error setting rate: %s", snd_strerror(err));
return false;
}
if (rate != exact_rate)
{
qWarning("OutputALSA: The rate %d Hz is not supported by your hardware.\n==> Using %d Hz instead.", rate, exact_rate);
rate = exact_rate;
}
uint c = map.count();
if ((err = snd_pcm_hw_params_set_channels_near(pcm_handle, hwparams, &c)) < 0)
{
qWarning("OutputALSA: Error setting channels: %s", snd_strerror(err));
return false;
}
if (c != (uint)map.count())
{
qWarning("OutputALSA: The channel number %d is not supported by your hardware", map.count());
qWarning("==> Using %d instead.", c);
}
if ((err = snd_pcm_hw_params_set_period_time_near(pcm_handle, hwparams, &period_time ,0)) < 0)
{
qWarning("OutputALSA: Error setting period time: %s", snd_strerror(err));
return false;
}
if ((err = snd_pcm_hw_params_set_buffer_time_near(pcm_handle, hwparams, &buffer_time ,0)) < 0)
{
qWarning("OutputALSA: Error setting buffer time: %s", snd_strerror(err));
return false;
}
if ((err = snd_pcm_hw_params(pcm_handle, hwparams)) < 0)
{
qWarning("OutputALSA: Error setting HW params: %s", snd_strerror(err));
return false;
}
//read some alsa parameters
snd_pcm_uframes_t buffer_size = 0;
snd_pcm_uframes_t period_size = 0;
if ((err = snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size)) < 0)
{
qWarning("OutputALSA: Error reading buffer size: %s", snd_strerror(err));
return false;
}
if ((err = snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0)) < 0)
{
qWarning("OutputALSA: Error reading period size: %s", snd_strerror(err));
return false;
}
//swparams
snd_pcm_sw_params_alloca(&swparams);
snd_pcm_sw_params_current(pcm_handle, swparams);
if ((err = snd_pcm_sw_params_set_start_threshold(pcm_handle, swparams,
buffer_size - period_size)) < 0)
qWarning("OutputALSA: Error setting threshold: %s", snd_strerror(err));
if ((err = snd_pcm_sw_params(pcm_handle, swparams)) < 0)
{
qWarning("OutputALSA: Error setting SW params: %s", snd_strerror(err));
return false;
}
//setup needed values
m_chunk_size = period_size;
m_can_pause = snd_pcm_hw_params_can_pause(hwparams) && use_pause;
qDebug("OutputALSA: can pause: %d", m_can_pause);
ChannelMap out_map = map;
#if (SND_LIB_VERSION >= 0x01001B)
//channel map configuration
snd_pcm_chmap_t *chmap = snd_pcm_get_chmap(pcm_handle);
if(chmap)
{
out_map.clear();
char tmp[256];
memset(tmp,0,256);
snd_pcm_chmap_print(chmap, 256, tmp);
qDebug("OutputALSA: received channel map: %s",tmp);
for(uint i = 0; i < chmap->channels; ++i)
{
if(m_alsa_channels.keys().contains(chmap->pos[i]))
out_map.append(m_alsa_channels.value(chmap->pos[i]));
else
out_map.append(Qmmp::CHAN_NULL);
}
free(chmap);
}
else
qWarning("OutputALSA: Unable to receive current channel map");
#endif
configure(exact_rate, out_map, format); //apply configuration
//create alsa prebuffer;
m_prebuf_size = 2 * snd_pcm_frames_to_bytes(pcm_handle, m_chunk_size); //buffer for two periods
m_prebuf = (uchar *)malloc(m_prebuf_size);
m_inited = true;
return true;
}
