J. Pauli wrote: > Christian Brink wrote: > >> How can you programmatically tell that audio is playing or at least >> being sent to the soundcard? >> >> I've got an application that occasionally fails to pick up a remote >> stream, but the process hangs around so I can't tell that it failed just >> by checking the process list. I would like to be able to tell if the >> application is sending audio or not so I can retry. >> >> I've checked the archives, googled, and tried cat'ing /dev/audio (which >> seems to return data whether or not audio is playing). >> >> > > Check the files > /proc/asound/cardX/pcmYp/subZ/[status|hw_params|sw_params], where X,Y > and Z is the soundcard, device and subdevice you want to monitor. If > nothing is being sent to the soundcard it should contain "closed". > Unfortunately you need to activate "verbose proc something" in your > kernel, which most distributions don't have by default. > > I've also written some small (and really buggy) program to monitor all > devices and subdevices of a soundcard but you still need that kernel > option or it will crash. You can get it here: > http://stinfwww.informatik.uni-leipzig.de/~mai00bgn/aproc/ (source code > only). Sorry for the propaganda. > > Jan - Thanks for the info, it's been a great help. I had a couple more questions if you'd being willing to help. I've been doing some testing on a couple of different machines (Fedora and Deb). 'closed' only seems to show up when the card is not "open" by an application. So if I have a mp3 player app open (Rhythmbox for example) but not playing or paused, it shows the card not "closed" even though no music is playing. Is this normal? or is this the difference between having the kernel flag on and not? or is my application sending "silence" while it is open but not "playing"? I wanted to confirm before I start custom compiling a kernel on a large number of machines :) -- Christian Brink cbrink@xxxxxxxxxxxx ------------------------------------------------------------------------------ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
