diff options
| -rw-r--r-- | Alc/bs2b.c | 13 | ||||
| -rw-r--r-- | OpenAL32/Include/bs2b.h | 29 |
2 files changed, 16 insertions, 26 deletions
@@ -38,7 +38,7 @@ static void init(struct bs2b *bs2b) { float Fc_lo, Fc_hi; float G_lo, G_hi; - float x; + float x, g; bs2b->srate = clampi(bs2b->srate, 2000, 192000); @@ -89,21 +89,20 @@ static void init(struct bs2b *bs2b) break; } /* switch */ + g = 1.0f / (1.0f - G_hi + G_lo); + /* $fc = $Fc / $s; * $d = 1 / 2 / pi / $fc; * $x = exp(-1 / $d); */ - x = expf(-2.0f * F_PI * Fc_lo / bs2b->srate); bs2b->b1_lo = x; - bs2b->a0_lo = G_lo * (1.0f - x); + bs2b->a0_lo = G_lo * (1.0f - x) * g; x = expf(-2.0f * F_PI * Fc_hi / bs2b->srate); bs2b->b1_hi = x; - bs2b->a0_hi = 1.0f - G_hi * (1.0f - x); - bs2b->a1_hi = -x; - - bs2b->gain = 1.0f / (1.0f - G_hi + G_lo); + bs2b->a0_hi = (1.0f - G_hi * (1.0f - x)) * g; + bs2b->a1_hi = -x * g; } /* init */ /* Exported functions. diff --git a/OpenAL32/Include/bs2b.h b/OpenAL32/Include/bs2b.h index 47d9d674..f1f3627a 100644 --- a/OpenAL32/Include/bs2b.h +++ b/OpenAL32/Include/bs2b.h @@ -59,9 +59,6 @@ struct bs2b { float a1_hi; float b1_hi; - /* Global gain against overloading */ - float gain; - /* Buffer of last filtered sample. * [0] - first channel, [1] - second channel */ @@ -93,11 +90,9 @@ void bs2b_clear(struct bs2b *bs2b); /* Crossfeeds one stereo sample that are pointed by sample. * [0] - first channel, [1] - second channel. - * Returns crossfided samle by sample pointer. + * Returns crossfided sample by sample pointer. */ - -/* sample points to floats */ -inline void bs2b_cross_feed(struct bs2b *bs2b, float *restrict samples) +inline void bs2b_cross_feed(struct bs2b *bs2b, float *restrict sample) { /* Single pole IIR filter. * O[n] = a0*I[n] + a1*I[n-1] + b1*O[n-1] @@ -110,22 +105,18 @@ inline void bs2b_cross_feed(struct bs2b *bs2b, float *restrict samples) #define hi_filter(in, in_1, out_1) (bs2b->a0_hi*(in) + bs2b->a1_hi*(in_1) + bs2b->b1_hi*(out_1)) /* Lowpass filter */ - bs2b->last_sample.lo[0] = lo_filter(samples[0], bs2b->last_sample.lo[0]); - bs2b->last_sample.lo[1] = lo_filter(samples[1], bs2b->last_sample.lo[1]); + bs2b->last_sample.lo[0] = lo_filter(sample[0], bs2b->last_sample.lo[0]); + bs2b->last_sample.lo[1] = lo_filter(sample[1], bs2b->last_sample.lo[1]); /* Highboost filter */ - bs2b->last_sample.hi[0] = hi_filter(samples[0], bs2b->last_sample.asis[0], bs2b->last_sample.hi[0]); - bs2b->last_sample.hi[1] = hi_filter(samples[1], bs2b->last_sample.asis[1], bs2b->last_sample.hi[1]); - bs2b->last_sample.asis[0] = samples[0]; - bs2b->last_sample.asis[1] = samples[1]; + bs2b->last_sample.hi[0] = hi_filter(sample[0], bs2b->last_sample.asis[0], bs2b->last_sample.hi[0]); + bs2b->last_sample.hi[1] = hi_filter(sample[1], bs2b->last_sample.asis[1], bs2b->last_sample.hi[1]); + bs2b->last_sample.asis[0] = sample[0]; + bs2b->last_sample.asis[1] = sample[1]; /* Crossfeed */ - samples[0] = bs2b->last_sample.hi[0] + bs2b->last_sample.lo[1]; - samples[1] = bs2b->last_sample.hi[1] + bs2b->last_sample.lo[0]; - - /* Bass boost cause allpass attenuation */ - samples[0] *= bs2b->gain; - samples[1] *= bs2b->gain; + sample[0] = bs2b->last_sample.hi[0] + bs2b->last_sample.lo[1]; + sample[1] = bs2b->last_sample.hi[1] + bs2b->last_sample.lo[0]; #undef hi_filter #undef lo_filter } /* bs2b_cross_feed */ |