sintonia/library/ecasound-2.7.2/examples/ecidoc_example.c

60 lines
1.7 KiB
C

/*************************************************************************
* Implementation of the following:
*
* 1. Setup ECI to read audio from file, apply a 100Hz lowpass filter, and
* send it to the soundcard (/dev/dsp).
* 2. Every second, check the current position. If the stream has
* been running for over 15 seconds, exit immediately. Also,
* every second, increase the lowpass filter's cutoff frequency
* by 500Hz.
* 3. Stop the stream (if not already finished) and disconnect the
* chainsetup. Print chain operator status info.
************************************************************************/
#include <stdio.h>
#include <unistd.h>
#include <ecasoundc.h>
/* compile with:
*
* gcc -o ecidoc_example ecidoc_example.c `libecasoundc-config --cflags --libs`
*/
int main(int argc, char *argv[])
{
double cutoff_inc = 500.0;
eci_init();
eci_command("cs-add play_chainsetup");
eci_command("c-add 1st_chain");
eci_command("ai-add foo.wav");
eci_command("ao-add /dev/dsp");
eci_command("cop-add -efl:100");
eci_command("cop-select 1");
eci_command("copp-select 1");
eci_command("cs-connect");
eci_command("start");
while(1) {
double curpos, next_cutoff;
sleep(1);
eci_command("engine-status");
if (strcmp(eci_last_string(), "running") != 0) break;
eci_command("get-position");
curpos = eci_last_float();
if (curpos > 15.0) break;
eci_command("copp-get");
next_cutoff = cutoff_inc + eci_last_float();
eci_command_float_arg("copp-set", next_cutoff);
}
eci_command("stop");
eci_command("cs-disconnect");
eci_command("cop-status");
printf("Chain operator status: %s", eci_last_string());
eci_cleanup();
return(0);
}