ref: 025a2d172ebfe36bc0da32f5712dd250916c73f1
dir: /sys/src/libpcm/desc.c/
#include <u.h> #include <libc.h> #include <pcm.h> Pcmdesc pcmdescdef = { .rate = 44100, .channels = 2, .framesz = 4, .abits = 16, .bits = 16, .fmt = L's', }; int pcmdescfmt(Fmt *f) { Pcmdesc d; d = va_arg(f->args, Pcmdesc); return fmtprint(f, "%C%dc%dr%d", d.fmt, d.bits, d.channels, d.rate); } int mkpcmdesc(char *f, Pcmdesc *d) { Rune r; char *p; memset(d, 0, sizeof(*d)); p = f; while(*p != 0){ p += chartorune(&r, p); switch(r){ case L'r': d->rate = strtol(p, &p, 10); break; case L'c': d->channels = strtol(p, &p, 10); break; case L'm': r = L'µ'; case L's': case L'S': case L'u': case L'U': case L'f': case L'a': case L'µ': d->fmt = r; d->bits = d->abits = strtol(p, &p, 10); break; default: goto Bad; } } if(d->rate <= 0 || d->channels <= 0) goto Bad; if(d->fmt == L'a' || d->fmt == L'µ'){ if(d->bits != 8) goto Bad; d->abits = 16; } else if(d->fmt == L'f'){ if(d->bits != 32 && d->bits != 64) goto Bad; d->abits = sizeof(int)*8; } else if(d->bits <= 0 || d->bits > 32) goto Bad; d->framesz = ((d->bits+7)/8) * d->channels; if(d->framesz <= 0) goto Bad; return 0; Bad: werrstr("bad format: %s", f); return -1; }