diff options
Diffstat (limited to 'libspeexdsp/scal.c')
| -rw-r--r-- | libspeexdsp/scal.c | 36 |
1 files changed, 18 insertions, 18 deletions
diff --git a/libspeexdsp/scal.c b/libspeexdsp/scal.c index d2ea59c..807cb51 100644 --- a/libspeexdsp/scal.c +++ b/libspeexdsp/scal.c @@ -33,8 +33,8 @@ /* The algorithm implemented here is described in: -* J.-M. Valin, Perceptually-Motivated Nonlinear Channel Decorrelation For - Stereo Acoustic Echo Cancellation, Accepted for Joint Workshop on +* J.-M. Valin, Perceptually-Motivated Nonlinear Channel Decorrelation For + Stereo Acoustic Echo Cancellation, Accepted for Joint Workshop on Handsfree Speech Communication and Microphone Arrays (HSCMA), 2008. http://people.xiph.org/~jm/papers/valin_hscma2008.pdf @@ -71,7 +71,7 @@ struct SpeexDecorrState_ { float *vorbis_win; int seed; float *y; - + /* Per-channel stuff */ float *buff; float (*ring)[ALLPASS_ORDER]; @@ -102,13 +102,13 @@ EXPORT SpeexDecorrState *speex_decorrelate_new(int rate, int channels, int frame st->order = speex_alloc(channels*sizeof(int)); st->alpha = speex_alloc(channels*sizeof(float)); st->ring = speex_alloc(channels*ALLPASS_ORDER*sizeof(float)); - + /*FIXME: The +20 is there only as a kludge for ALL_PASS_OLA*/ st->vorbis_win = speex_alloc((2*frame_size+20)*sizeof(float)); for (i=0;i<2*frame_size;i++) st->vorbis_win[i] = sin(.5*M_PI* sin(M_PI*i/(2*frame_size))*sin(M_PI*i/(2*frame_size)) ); st->seed = rand(); - + for (ch=0;ch<channels;ch++) { for (i=0;i<ALLPASS_ORDER;i++) @@ -142,12 +142,12 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i { int ch; float amount; - + if (strength<0) strength = 0; if (strength>100) strength = 100; - + amount = .01*strength; for (ch=0;ch<st->channels;ch++) { @@ -156,7 +156,7 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i float beta, beta2; float *x; float max_alpha = 0; - + float *buff; float *ring; int ringID; @@ -168,7 +168,7 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i ringID = st->ringID[ch]; order = st->order[ch]; alpha = st->alpha[ch]; - + for (i=0;i<st->frame_size;i++) buff[i] = buff[i+st->frame_size]; for (i=0;i<st->frame_size;i++) @@ -182,12 +182,12 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i beta = 1-0.63246*amount; if (beta<0) beta = 0; - + beta2 = beta; for (i=0;i<st->frame_size;i++) { - st->y[i] = alpha*(x[i-ALLPASS_ORDER+order]-beta*x[i-ALLPASS_ORDER+order-1])*st->vorbis_win[st->frame_size+i+order] - + x[i-ALLPASS_ORDER]*st->vorbis_win[st->frame_size+i] + st->y[i] = alpha*(x[i-ALLPASS_ORDER+order]-beta*x[i-ALLPASS_ORDER+order-1])*st->vorbis_win[st->frame_size+i+order] + + x[i-ALLPASS_ORDER]*st->vorbis_win[st->frame_size+i] - alpha*(ring[ringID] - beta*ring[ringID+1>=order?0:ringID+1]); ring[ringID++]=st->y[i]; @@ -204,7 +204,7 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i max_alpha = pow(.96+.04*(amount-1),order); if (max_alpha > .98/(1.+beta2)) max_alpha = .98/(1.+beta2); - + alpha = alpha + .4*uni_rand(&st->seed); if (alpha > max_alpha) alpha = max_alpha; @@ -215,8 +215,8 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i ringID = 0; for (i=0;i<st->frame_size;i++) { - float tmp = alpha*(x[i-ALLPASS_ORDER+order]-beta*x[i-ALLPASS_ORDER+order-1])*st->vorbis_win[i+order] - + x[i-ALLPASS_ORDER]*st->vorbis_win[i] + float tmp = alpha*(x[i-ALLPASS_ORDER+order]-beta*x[i-ALLPASS_ORDER+order-1])*st->vorbis_win[i+order] + + x[i-ALLPASS_ORDER]*st->vorbis_win[i] - alpha*(ring[ringID] - beta*ring[ringID+1>=order?0:ringID+1]); ring[ringID++]=tmp; @@ -225,7 +225,7 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i ringID=0; st->y[i] += tmp; } - + #ifdef VORBIS_PSYCHO float frame[N]; float scale = 1./N; @@ -252,7 +252,7 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i for (i=0;i<2*st->frame_size;i++) frame[i] *= st->vorbis_win[i]; #endif - + for (i=0;i<st->frame_size;i++) { #ifdef VORBIS_PSYCHO @@ -267,7 +267,7 @@ EXPORT void speex_decorrelate(SpeexDecorrState *st, const spx_int16_t *in, spx_i tmp = -32767; out[i*st->channels+ch] = tmp; } - + st->ringID[ch] = ringID; st->order[ch] = order; st->alpha[ch] = alpha; |