But in this case the output is printed to stderr. I would like to print it to a separate pipe. Therefore I want use the "file"-option and the pipe protocol ("-" / "pipe:1", "pipe:4" etc.). For an example command see 2). The PowerShell stuff behind the "|" can be ignored (I just added it as an example):
Unfortunately, with the file option it does not print the audio levels for each frame separately to stdout/pipe:x. It kind of buffers a huge amount of values and then it releases them periodically. I suspect it's optimized for writing "normal" files but in this case a switch would be needed that allows immediate output of the values per frame.
Is it possible to achieve the same behaviour like in case 1) so that each frames audio levels are send asap to stdout/pipe:x ?