d_period_size (0),
d_buffer_size_bytes (0), d_buffer (0),
d_worker (0), d_special_case_mono_to_stereo (false),
- d_nunderuns (0), d_nsuspends (0)
+ d_nunderuns (0), d_nsuspends (0), d_ok_to_block(ok_to_block)
{
CHATTY_DEBUG = gr_prefs::singleton()->get_bool("audio_alsa", "verbose", false);
// open the device for playback
error = snd_pcm_open(&d_pcm_handle, d_device_name.c_str (),
SND_PCM_STREAM_PLAYBACK, 0);
+ if (ok_to_block == false)
+ snd_pcm_nonblock(d_pcm_handle, !ok_to_block);
if (error < 0){
fprintf (stderr, "audio_alsa_sink[%s]: %s\n",
d_device_name.c_str(), snd_strerror(error));
int nchan = ninputs;
int err;
- // FIXME check_topology may be called more than once.
+ // Check the state of the stream
// Ensure that the pcm is in a state where we can still mess with the hw_params
-
+ snd_pcm_state_t state;
+ state=snd_pcm_state(d_pcm_handle);
+ if ( state== SND_PCM_STATE_RUNNING)
+ return true; // If stream is running, don't change any parameters
+ else if(state == SND_PCM_STATE_XRUN )
+ snd_pcm_prepare ( d_pcm_handle ); // Prepare stream on underrun, and we can set parameters;
+
bool special_case = nchan == 1 && d_special_case_mono_to_stereo;
if (special_case)
nchan = 2;
default:
assert (0);
}
-
return true;
}
while (nframes > 0){
int r = snd_pcm_writei (d_pcm_handle, buffer, nframes);
if (r == -EAGAIN)
- continue; // try again
+ {
+ if (d_ok_to_block == true)
+ continue; // try again
+
+ break;
+ }
else if (r == -EPIPE){ // underrun
d_nunderuns++;