>> I've been reading up and experimenting on both the simple and async >> APIs. In one experiment, I used a CLI file that sets up a set of >> module-sine modules with output remapped by module-remap-sink modules >> to a stream fed to a module-null-sink module. >> >> I then wrote 2 programs, one using the simple API and the other the >> async API to read date from the module-null-sink monitor source and >> write the data to file (both based on examples to provide "parec" >> functionality). Then I could unload either all the module-sine >> modules or all the module-remap-sink modules to interrupt the data >> source to the module-null-sink module. >> >> Both programs gave the same result, which I don't completely understand. >> >> The issues I've found are: >> >> 1. After the data source is gone, the program continues to write data >> to file. There doesn't seem to be any way to detect a stream of >> "zero" data using the APIs. > That is expected behavior. null-sink.monitor is not different from other > sources, which means > if there is no input to the null-sink, it will generate silence. It's > like recording from an unplugged > mic or line-in input. And there's no silence detection? >> 2. If I run it for 20 seconds, with 10 seconds of sinusoidal data >> followed by 10 seconds of null data, the file ends up with anything >> from 30 to 40 seconds worth of data in it. >> >> 3. The files written from case 2, above, show the initial sinusoidal >> data as expected, but then, following data stream interruption, about >> 5 to 10 seconds of switching back and forth between segments of >> sinusoidal data and null data, before finally settling to null data >> only till the end of file. > Did you test if the same happens with parec? If yes, are there any log > messages > during the time? Just did it and the result is the same. Attached is the relevant part of the syslog. >> Can anyone explain to me why it behaves like this? Or if there's >> something in the async API that I'm missing in detecting null data? >> -------------- next part -------------- May 19 12:18:21 walnut02 pulseaudio[6305]: GetManagedObjects() failed: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. May 19 12:18:28 walnut02 gnome-session[3836]: (Audacity:6319): Gtk-WARNING **: gtk_disable_setlocale() must be called before gtk_init() May 19 12:18:29 walnut02 gnome-session[3836]: ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear May 19 12:18:29 walnut02 gnome-session[3836]: ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe May 19 12:18:29 walnut02 gnome-session[3836]: ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side May 19 12:18:29 walnut02 gnome-session[3836]: ALSA lib pcm_route.c:867:(find_matching_chmap) Found no matching channel map May 19 12:18:29 walnut02 gnome-session[3836]: Cannot connect to server socket err = No such file or directory May 19 12:18:29 walnut02 gnome-session[3836]: Cannot connect to server request channel May 19 12:18:29 walnut02 gnome-session[3836]: jack server is not running or cannot be started May 19 12:18:29 walnut02 gnome-session[3836]: JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for 4294967295, skipping unlock May 19 12:18:29 walnut02 gnome-session[3836]: JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for 4294967295, skipping unlock May 19 12:18:29 walnut02 gnome-session[3836]: Expression 'stream->playback.pcm' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 4611 May 19 12:18:29 walnut02 gnome-session[3836]: message repeated 4 times: [ Expression 'stream->playback.pcm' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 4611] May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'left' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'click/left' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unrecognized accel key 'drag', accel string ignored. May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'left' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unrecognized accel key 'click', accel string ignored. May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'right' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unrecognized accel key 'click', accel string ignored. May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'left' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'click/left' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unrecognized accel key 'drag', accel string ignored. May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'left' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unrecognized accel key 'click', accel string ignored. May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unknown accel modifier: 'right' May 19 12:18:29 walnut02 gnome-session[3836]: 12:18:29: Debug: Unrecognized accel key 'click', accel string ignored. May 19 12:18:29 walnut02 gnome-session[3836]: (Audacity:6319): Gdk-CRITICAL **: IA__gdk_window_get_origin: assertion 'GDK_IS_WINDOW (window)' failed May 19 12:18:29 walnut02 gnome-session[3836]: message repeated 51 times: [ (Audacity:6319): Gdk-CRITICAL **: IA__gdk_window_get_origin: assertion 'GDK_IS_WINDOW (window)' failed]
