diff options
Diffstat (limited to 'src/util/dsp.c')
| -rw-r--r-- | src/util/dsp.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/util/dsp.c b/src/util/dsp.c index 3b156d1..8c3ae5c 100644 --- a/src/util/dsp.c +++ b/src/util/dsp.c @@ -440,6 +440,61 @@ resamp_init(struct resamp *p, unsigned int iblksz, #endif } +static inline unsigned int +adata_to_f32(int x) +{ + union { + float f; // assumes ieee754 + unsigned int x; + } u = { .f = (float)x / ADATA_UNIT }; + return u.x; +} + +void +enc_do_float(struct conv *p, unsigned char *in, unsigned char *out, int todo) +{ + unsigned int f; + adata_t *idata; + unsigned int s; + unsigned int obps; + unsigned int i; + unsigned char *odata; + int obnext; + int osnext; + +#ifdef DEBUG + if (log_level >= 4) { + log_puts("enc: copying "); + log_putu(todo); + log_puts(" frames\n"); + } +#endif + /* + * Partially copy structures into local variables, to avoid + * unnecessary indirections; this also allows the compiler to + * order local variables more "cache-friendly". + */ + idata = (adata_t *)in; + odata = out; + obps = p->bps; + obnext = p->bnext; + osnext = p->snext; + + /* + * Start conversion. + */ + odata += p->bfirst; + for (f = todo * p->nch; f > 0; f--) { + s = adata_to_f32((int)*idata++); + for (i = obps; i > 0; i--) { + *odata = (unsigned char)s; + s >>= 8; + odata += obnext; + } + odata += osnext; + } +} + /* * encode "todo" frames from native to foreign encoding */ |