The coolest thing about OSS for me was when I finally realized that all I had to do was open a file (/dev/dsp), read from it and write to it to capture sound and play it back. I made a stupid little 'feedback' application in about 10 lines of code. Figuring that out took a while. I just knew it had to be harder than that! Coming from the Windows and Mac world, where you have to work with some sort of audio subsystem to do that kind of thing, this design was pretty exciting and seemed almost ingenious. It sounds like Jack is a system to learn like on Windows/Mac. ALSA can be such a system, or you can use its OSS emulation mode and do audio as described above through the file system. That said, it doesn't take long to grow out of the simple file i/o method. Pretty soon you have to learn OSSs hidden language --- of ioctls called in just the right order and so on --- at which point you are probably better off with a fuller featured, future looking and better supported open source system. - mo

JACK is arguably simpler than either OSS or anything else. you don't configure any device parameters, you don't use system calls to move data around, etc. the minimal JACK client (which copies 1 channel's worth of data from its input to its output): #include <stdio.h> #include <errno.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <jack/jack.h> jack_port_t *input_port; jack_port_t *output_port; int process (jack_nframes_t nframes, void *arg) { /* this is where the magic happens */ jack_default_audio_sample_t *out = (jack_default_audio_sample_t *) jack_port_get_buffer (output_port, nframes); jack_default_audio_sample_t *in = (jack_default_audio_sample_t *) jack_port_get_buffer (input_port, nframes); memcpy (out, in, sizeof (jack_default_audio_sample_t) * nframes); return 0; } int main (int argc, char *argv[]) { jack_client_t *client; const char **ports; /* try to become a client of the JACK server */ if ((client = jack_client_new (argv[1])) == 0) { fprintf (stderr, "jack server not running?\n"); return 1; } /* tell the JACK server to call `process()' whenever there is work to be done. */ jack_set_process_callback (client, process, 0); /* create two ports */ input_port = jack_port_register (client, "input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0); output_port = jack_port_register (client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0); /* tell the JACK server that we are ready to roll */ if (jack_activate (client)) { fprintf (stderr, "cannot activate client"); return 1; } /* Since this is just a toy, run for a few seconds, then finish */ sleep (10); jack_client_close (client); exit (0); }