From 957f7f169b1d834875cd0b154c5459a108c5e75e Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jmvalin@jmvalin.ca>
Date: Thu, 1 Sep 2011 18:02:43 -0400
Subject: [PATCH] First attempt at global high-pass filter
Doesn't work for fixed-point for some unknown reason
---
silk/silk_HP_variable_cutoff.c | 6 +-
silk/silk_LP_variable_cutoff.c | 2 +-
silk/silk_SigProc_FIX.h | 3 +-
silk/silk_biquad_alt.c | 7 ++-
src/opus_encoder.c | 109 ++++++++++++++++++++++++++++++++-
5 files changed, 118 insertions(+), 9 deletions(-)
diff --git a/silk/silk_HP_variable_cutoff.c b/silk/silk_HP_variable_cutoff.c
index fb6c3665b..9bcd27ef8 100644
--- a/silk/silk_HP_variable_cutoff.c
+++ b/silk/silk_HP_variable_cutoff.c
@@ -84,6 +84,7 @@ void silk_HP_variable_cutoff(
psEncC1->variable_HP_smth1_Q15 = SKP_LSHIFT( silk_lin2log( cutoff_Hz ), 8 );
}
+#if 0
/* second smoother */
psEncC1->variable_HP_smth2_Q15 = SKP_SMLAWB( psEncC1->variable_HP_smth2_Q15,
psEncC1->variable_HP_smth1_Q15 - psEncC1->variable_HP_smth2_Q15, SILK_FIX_CONST( VARIABLE_HP_SMTH_COEF2, 16 ) );
@@ -117,9 +118,10 @@ void silk_HP_variable_cutoff(
/********************************/
/* High-Pass Filter */
/********************************/
- silk_biquad_alt( psEncC1->inputBuf, B_Q28, A_Q28, psEncC1->In_HP_State, psEncC1->inputBuf, psEncC1->frame_length );
+ silk_biquad_alt( psEncC1->inputBuf, B_Q28, A_Q28, psEncC1->In_HP_State, psEncC1->inputBuf, psEncC1->frame_length, 1 );
if( nChannels == 2 ) {
silk_biquad_alt( state_Fxx[ 1 ].sCmn.inputBuf, B_Q28, A_Q28, state_Fxx[ 1 ].sCmn.In_HP_State,
- state_Fxx[ 1 ].sCmn.inputBuf, state_Fxx[ 1 ].sCmn.frame_length );
+ state_Fxx[ 1 ].sCmn.inputBuf, state_Fxx[ 1 ].sCmn.frame_length, 1 );
}
+#endif
}
diff --git a/silk/silk_LP_variable_cutoff.c b/silk/silk_LP_variable_cutoff.c
index d679f92e5..0c758a034 100644
--- a/silk/silk_LP_variable_cutoff.c
+++ b/silk/silk_LP_variable_cutoff.c
@@ -131,6 +131,6 @@ void silk_LP_variable_cutoff(
/* ARMA low-pass filtering */
SKP_assert( TRANSITION_NB == 3 && TRANSITION_NA == 2 );
- silk_biquad_alt( frame, B_Q28, A_Q28, psLP->In_LP_State, frame, frame_length );
+ silk_biquad_alt( frame, B_Q28, A_Q28, psLP->In_LP_State, frame, frame_length, 1);
}
}
diff --git a/silk/silk_SigProc_FIX.h b/silk/silk_SigProc_FIX.h
index b30ead80c..222bc3129 100644
--- a/silk/silk_SigProc_FIX.h
+++ b/silk/silk_SigProc_FIX.h
@@ -126,7 +126,8 @@ void silk_biquad_alt(
const opus_int32 *A_Q28, /* I: AR coefficients [2] */
opus_int32 *S, /* I/O: State vector [2] */
opus_int16 *out, /* O: output signal */
- const opus_int32 len /* I: signal length (must be even) */
+ const opus_int32 len, /* I: signal length (must be even) */
+ int stride
);
/* Variable order MA prediction error filter. */
diff --git a/silk/silk_biquad_alt.c b/silk/silk_biquad_alt.c
index 9d394c008..966ba28f0 100644
--- a/silk/silk_biquad_alt.c
+++ b/silk/silk_biquad_alt.c
@@ -46,7 +46,8 @@ void silk_biquad_alt(
const opus_int32 *A_Q28, /* I: AR coefficients [2] */
opus_int32 *S, /* I/O: State vector [2] */
opus_int16 *out, /* O: Output signal */
- const opus_int32 len /* I: Signal length (must be even) */
+ const opus_int32 len, /* I: Signal length (must be even) */
+ int stride
)
{
/* DIRECT FORM II TRANSPOSED (uses 2 element state vector) */
@@ -61,7 +62,7 @@ void silk_biquad_alt(
for( k = 0; k < len; k++ ) {
/* S[ 0 ], S[ 1 ]: Q12 */
- inval = in[ k ];
+ inval = in[ k*stride ];
out32_Q14 = SKP_LSHIFT( SKP_SMLAWB( S[ 0 ], B_Q28[ 0 ], inval ), 2 );
S[ 0 ] = S[1] + SKP_RSHIFT_ROUND( SKP_SMULWB( out32_Q14, A0_L_Q28 ), 14 );
@@ -73,6 +74,6 @@ void silk_biquad_alt(
S[ 1 ] = SKP_SMLAWB( S[ 1 ], B_Q28[ 2 ], inval );
/* Scale back to Q0 and saturate */
- out[ k ] = (opus_int16)SKP_SAT16( SKP_RSHIFT( out32_Q14 + (1<<14) - 1, 14 ) );
+ out[ k*stride ] = (opus_int16)SKP_SAT16( SKP_RSHIFT( out32_Q14 + (1<<14) - 1, 14 ) );
}
}
diff --git a/src/opus_encoder.c b/src/opus_encoder.c
index ec8667253..f8c83d1ef 100644
--- a/src/opus_encoder.c
+++ b/src/opus_encoder.c
@@ -41,6 +41,13 @@
#include "opus_private.h"
#include "os_support.h"
+#include "silk_tuning_parameters.h"
+#ifdef FIXED_POINT
+#include "fixed/silk_structs_FIX.h"
+#else
+#include "float/silk_structs_FLP.h"
+#endif
+
#define MAX_ENCODER_BUFFER 480
struct OpusEncoder {
@@ -64,6 +71,8 @@ struct OpusEncoder {
#define OPUS_ENCODER_RESET_START stream_channels
int stream_channels;
int hybrid_stereo_width_Q14;
+ opus_int32 variable_HP_smth2_Q15;
+ opus_val32 hp_mem[4];
int mode;
int prev_mode;
int bandwidth;
@@ -179,6 +188,7 @@ int opus_encoder_init(OpusEncoder* st, int Fs, int channels, int application)
st->delay_compensation += 2;
st->hybrid_stereo_width_Q14 = 1 << 14;
+ st->variable_HP_smth2_Q15 = SKP_LSHIFT( silk_lin2log( VARIABLE_HP_MIN_CUTOFF_HZ ), 8 );
st->first = 1;
st->mode = MODE_HYBRID;
st->bandwidth = OPUS_BANDWIDTH_FULLBAND;
@@ -221,6 +231,82 @@ static unsigned char gen_toc(int mode, int framerate, int bandwidth, int silk_ba
toc |= (channels==2)<<2;
return toc;
}
+
+#ifndef FIXED_POINT
+void silk_biquad_float(
+ const opus_val16 *in, /* I: Input signal */
+ const opus_int32 *B_Q28, /* I: MA coefficients [3] */
+ const opus_int32 *A_Q28, /* I: AR coefficients [2] */
+ opus_val32 *S, /* I/O: State vector [2] */
+ opus_val16 *out, /* O: Output signal */
+ const opus_int32 len, /* I: Signal length (must be even) */
+ int stride
+)
+{
+ /* DIRECT FORM II TRANSPOSED (uses 2 element state vector) */
+ opus_int k;
+ opus_val32 vout;
+ opus_val32 inval;
+ opus_val32 A[2], B[3];
+
+ A[0] = A_Q28[0] * (1./((opus_int32)1<<28));
+ A[1] = A_Q28[1] * (1./((opus_int32)1<<28));
+ B[0] = B_Q28[0] * (1./((opus_int32)1<<28));
+ B[1] = B_Q28[1] * (1./((opus_int32)1<<28));
+ B[2] = B_Q28[2] * (1./((opus_int32)1<<28));
+
+ /* Negate A_Q28 values and split in two parts */
+
+ for( k = 0; k < len; k++ ) {
+ /* S[ 0 ], S[ 1 ]: Q12 */
+ inval = in[ k*stride ];
+ vout = S[ 0 ] + B[0]*inval;
+
+ S[ 0 ] = S[1] - vout*A[0] + B[1]*inval;
+
+ S[ 1 ] = - vout*A[1] + B[2]*inval;
+
+ /* Scale back to Q0 and saturate */
+ out[ k*stride ] = vout;
+ }
+}
+#endif
+
+static void hp_cutoff(const opus_val16 *in, opus_int32 cutoff_Hz, opus_val16 *out, opus_val32 *hp_mem, int len, int channels, opus_int32 Fs)
+{
+ opus_int32 B_Q28[ 3 ], A_Q28[ 2 ];
+ opus_int32 Fc_Q19, r_Q28, r_Q22;
+
+ SKP_assert( cutoff_Hz <= SKP_int32_MAX / SILK_FIX_CONST( 1.5 * 3.14159 / 1000, 19 ) );
+ Fc_Q19 = SKP_DIV32_16( SKP_SMULBB( SILK_FIX_CONST( 1.5 * 3.14159 / 1000, 19 ), cutoff_Hz ), Fs/1000 );
+ SKP_assert( Fc_Q19 > 0 && Fc_Q19 < 32768 );
+
+ r_Q28 = SILK_FIX_CONST( 1.0, 28 ) - SKP_MUL( SILK_FIX_CONST( 0.92, 9 ), Fc_Q19 );
+
+ /* b = r * [ 1; -2; 1 ]; */
+ /* a = [ 1; -2 * r * ( 1 - 0.5 * Fc^2 ); r^2 ]; */
+ B_Q28[ 0 ] = r_Q28;
+ B_Q28[ 1 ] = SKP_LSHIFT( -r_Q28, 1 );
+ B_Q28[ 2 ] = r_Q28;
+
+ /* -r * ( 2 - Fc * Fc ); */
+ r_Q22 = SKP_RSHIFT( r_Q28, 6 );
+ A_Q28[ 0 ] = SKP_SMULWW( r_Q22, SKP_SMULWW( Fc_Q19, Fc_Q19 ) - SILK_FIX_CONST( 2.0, 22 ) );
+ A_Q28[ 1 ] = SKP_SMULWW( r_Q22, r_Q22 );
+
+#ifdef FIXED_POINT
+ silk_biquad_alt( in, B_Q28, A_Q28, hp_mem, out, len, channels );
+ if( channels == 2 ) {
+ silk_biquad_alt( in+1, B_Q28, A_Q28, hp_mem+2, out+1, len, channels );
+ }
+#else
+ silk_biquad_float( in, B_Q28, A_Q28, hp_mem, out, len, channels );
+ if( channels == 2 ) {
+ silk_biquad_float( in+1, B_Q28, A_Q28, hp_mem+2, out+1, len, channels );
+ }
+#endif
+}
+
OpusEncoder *opus_encoder_create(int Fs, int channels, int mode, int *error)
{
int ret;
@@ -267,6 +353,7 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
int to_celt = 0;
opus_int32 mono_rate;
opus_uint32 redundant_rng = 0;
+ int cutoff_Hz, hp_freq_smth1;
ALLOC_STACK;
st->rangeFinal = 0;
@@ -470,8 +557,25 @@ int opus_encode_float(OpusEncoder *st, const opus_val16 *pcm, int frame_size,
ALLOC(pcm_buf, (st->delay_compensation+frame_size)*st->channels, opus_val16);
for (i=0;i<st->delay_compensation*st->channels;i++)
pcm_buf[i] = st->delay_buffer[(st->encoder_buffer-st->delay_compensation)*st->channels+i];
- for (i=0;i<frame_size*st->channels;i++)
- pcm_buf[st->delay_compensation*st->channels + i] = pcm[i];
+
+ if (st->mode == MODE_CELT_ONLY)
+ hp_freq_smth1 = SKP_LSHIFT( silk_lin2log( VARIABLE_HP_MIN_CUTOFF_HZ ), 8 );
+ else
+ hp_freq_smth1 = ((silk_encoder*)silk_enc)->state_Fxx[0].sCmn.variable_HP_smth1_Q15;
+
+ st->variable_HP_smth2_Q15 = SKP_SMLAWB( st->variable_HP_smth2_Q15,
+ hp_freq_smth1 - st->variable_HP_smth2_Q15, SILK_FIX_CONST( VARIABLE_HP_SMTH_COEF2, 16 ) );
+
+ /* convert from log scale to Hertz */
+ cutoff_Hz = silk_log2lin( SKP_RSHIFT( st->variable_HP_smth2_Q15, 8 ) );
+
+ if (st->application == OPUS_APPLICATION_VOIP)
+ {
+ hp_cutoff(pcm, cutoff_Hz, &pcm_buf[st->delay_compensation*st->channels], st->hp_mem, frame_size, st->channels, st->Fs);
+ } else {
+ for (i=0;i<frame_size*st->channels;i++)
+ pcm_buf[st->delay_compensation*st->channels + i] = pcm[i];
+ }
/* SILK processing */
if (st->mode != MODE_CELT_ONLY)
@@ -1003,6 +1107,7 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
st->first = 1;
st->mode = MODE_HYBRID;
st->bandwidth = OPUS_BANDWIDTH_FULLBAND;
+ st->variable_HP_smth2_Q15 = SKP_LSHIFT( silk_lin2log( VARIABLE_HP_MIN_CUTOFF_HZ ), 8 );
}
break;
default:
--
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