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#include <u.h>
#include <libc.h>
char deffmt[] = "s16c2r44100";
char fmt[64];
uchar hdr[5];
uchar buf[2048];
int pfd[2];
char*
getformat(uchar hdr[5])
{
int freq, bits, chan;
if(hdr[0] & 0x80)
freq = 44100;
else
freq = 48000;
freq *= hdr[0] & 0x7F;
bits = hdr[1];
chan = hdr[2];
snprint(fmt, sizeof(fmt), "s%dc%dr%d", bits, chan, freq);
return fmt;
}
void
main(void)
{
int n;
for(;;){
alarm(500);
n = read(0, buf, sizeof(buf));
if(n < sizeof(hdr))
break;
if(pfd[1] == 0 || memcmp(buf, hdr, sizeof(hdr)) != 0){
if(pfd[1] > 1){
close(pfd[1]);
waitpid();
}
if(strcmp(getformat(buf), deffmt) == 0){
pfd[1] = 1;
} else {
if(pipe(pfd) < 0)
sysfatal("pipe: %r");
switch(fork()){
case -1:
sysfatal("fork: %r");
case 0:
close(pfd[1]);
dup(pfd[0], 0);
execl("/bin/audio/pcmconv", "pcmconv", "-i", fmt, nil);
sysfatal("exec: %r");
return;
}
close(pfd[0]);
}
memmove(hdr, buf, sizeof(hdr));
}
n -= sizeof(hdr);
if(n <= 0)
continue;
if(write(pfd[1], buf+sizeof(hdr), n) != n)
break;
}
exits(nil);
}
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