On 17.05.2017 04:28, Steven Wawryk wrote: > Hello, > > 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. > > 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? > > 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? > > Thanks, > > Steve > > _______________________________________________ > pulseaudio-discuss mailing list > pulseaudio-discuss at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
