On Tue, 12 Jan 2016 03:21:16 +0100, Sergey wrote: > > Hello. > > I needed a tool to test if anything loud is playing right now. So I wrote > "ahwmon" - alsa hw monitoring tool. It's based on dmix idea: it gets "hw" > shared playback buffer, but reads from the buffer instead of writing. > > Code is mostly copied from alsa-lib, but it uses kernel /dev/snd/pcm* > files directly and doesn't depend on alsa-lib or dmix. May work for > other apps playing to "hw", including pulseaudio and jackd. > > What do you think about it? Can something like this get into alsa-lib or > alsa-utils or alsa-plugins? It could be a capture side of "dmix" plugin, > which has no capture now. Maybe someone with strong dmix knowledge > can port it to dmix? This is an interesting idea. I like the simplicity of your method, despite the known limitations. I suppose it can be well implemented as a normal alsa-lib plugin? thanks, Takashi > > Build: > gcc -o ahwmon ahwmon.c > > Usage: > ./ahwmon [-v] [-v] <card_index> <device_index> [<subdevice_index>] > subdevice 0 is used by default > it outputs .wav stream to stdout > > Use cases: > * Card VUmeter: > ./ahwmon 0 0 | aplay -V stereo -D null > * Dump what you hear: > ./ahwmon 0 0 > audiodump.wav > * Duplicate output of one card to another: > ./ahwmon 0 0 | aplay -D plughw:1,0 > * Stream what you hear to another pc: > ./ahwmon 0 0 | nc 192.168.1.10 12345 > > Known limitations: > * supports S16_LE and S32_LE only. > * breaks clients attempting to close and reopen "hw" > > Any ideas are welcome! > -- > Sergey _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
