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-rw-r--r--gr-vocoder/lib/codec2/codec2.c342
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diff --git a/gr-vocoder/lib/codec2/codec2.c b/gr-vocoder/lib/codec2/codec2.c
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+/*---------------------------------------------------------------------------*\
+
+ FILE........: codec2.c
+ AUTHOR......: David Rowe
+ DATE CREATED: 21/8/2010
+
+ Codec2 fully quantised encoder and decoder functions. If you want use
+ codec2, the codec2_xxx functions are for you.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+ Copyright (C) 2010 David Rowe
+
+ All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License version 2.1, as
+ published by the Free Software Foundation. This program is
+ distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#include "defines.h"
+#include "sine.h"
+#include "nlp.h"
+#include "dump.h"
+#include "lpc.h"
+#include "quantise.h"
+#include "phase.h"
+#include "interp.h"
+#include "postfilter.h"
+#include "codec2.h"
+#include "codec2_internal.h"
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTIONS
+
+\*---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTION....: codec2_create
+ AUTHOR......: David Rowe
+ DATE CREATED: 21/8/2010
+
+ Create and initialise an instance of the codec. Returns a pointer
+ to the codec states or NULL on failure. One set of states is
+ sufficient for a full duuplex codec (i.e. an encoder and decoder).
+ You don't need separate states for encoders and decoders. See
+ c2enc.c and c2dec.c for examples.
+
+\*---------------------------------------------------------------------------*/
+
+void *codec2_create()
+{
+ CODEC2 *c2;
+ int i,l;
+
+ c2 = (CODEC2*)malloc(sizeof(CODEC2));
+ if (c2 == NULL)
+ return NULL;
+
+ for(i=0; i<M; i++)
+ c2->Sn[i] = 1.0;
+ c2->hpf_states[0] = c2->hpf_states[1] = 0.0;
+ for(i=0; i<2*N; i++)
+ c2->Sn_[i] = 0;
+ make_analysis_window(c2->w,c2->W);
+ make_synthesis_window(c2->Pn);
+ quantise_init();
+ c2->prev_Wo = 0.0;
+ c2->bg_est = 0.0;
+ c2->ex_phase = 0.0;
+
+ for(l=1; l<MAX_AMP; l++)
+ c2->prev_model.A[l] = 0.0;
+ c2->prev_model.Wo = TWO_PI/P_MAX;
+ c2->prev_model.L = PI/c2->prev_model.Wo;
+ c2->prev_model.voiced = 0;
+
+ for(i=0; i<LPC_ORD; i++) {
+ c2->prev_lsps[i] = i*PI/(LPC_ORD+1);
+ }
+ c2->prev_energy = 1;
+
+ c2->nlp = nlp_create();
+ if (c2->nlp == NULL) {
+ free (c2);
+ return NULL;
+ }
+
+ return (void*)c2;
+}
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTION....: codec2_create
+ AUTHOR......: David Rowe
+ DATE CREATED: 21/8/2010
+
+ Destroy an instance of the codec.
+
+\*---------------------------------------------------------------------------*/
+
+void codec2_destroy(void *codec2_state)
+{
+ CODEC2 *c2;
+
+ assert(codec2_state != NULL);
+ c2 = (CODEC2*)codec2_state;
+ nlp_destroy(c2->nlp);
+ free(codec2_state);
+}
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTION....: codec2_encode
+ AUTHOR......: David Rowe
+ DATE CREATED: 21/8/2010
+
+ Encodes 160 speech samples (20ms of speech) into 51 bits.
+
+ The codec2 algorithm actually operates internally on 10ms (80
+ sample) frames, so we run the encoding algorithm twice. On the
+ first frame we just send the voicing bit. One the second frame we
+ send all model parameters.
+
+ The bit allocation is:
+
+ Parameter bits/frame
+ --------------------------------------
+ Harmonic magnitudes (LSPs) 36
+ Low frequency LPC correction 1
+ Energy 5
+ Wo (fundamental frequnecy) 7
+ Voicing (10ms update) 2
+ TOTAL 51
+
+\*---------------------------------------------------------------------------*/
+
+void codec2_encode(void *codec2_state, unsigned char * bits, short speech[])
+{
+ CODEC2 *c2;
+ MODEL model;
+ int voiced1, voiced2;
+ int lsp_indexes[LPC_ORD];
+ int energy_index;
+ int Wo_index;
+ int i;
+ unsigned int nbit = 0;
+
+ assert(codec2_state != NULL);
+ c2 = (CODEC2*)codec2_state;
+
+ /* first 10ms analysis frame - we just want voicing */
+
+ analyse_one_frame(c2, &model, speech);
+ voiced1 = model.voiced;
+
+ /* second 10ms analysis frame */
+
+ analyse_one_frame(c2, &model, &speech[N]);
+ voiced2 = model.voiced;
+
+ Wo_index = encode_Wo(model.Wo);
+ encode_amplitudes(lsp_indexes,
+ &energy_index,
+ &model,
+ c2->Sn,
+ c2->w);
+ memset(bits, '\0', ((CODEC2_BITS_PER_FRAME + 7) / 8));
+ pack(bits, &nbit, Wo_index, WO_BITS);
+ for(i=0; i<LPC_ORD; i++) {
+ pack(bits, &nbit, lsp_indexes[i], lsp_bits(i));
+ }
+ pack(bits, &nbit, energy_index, E_BITS);
+ pack(bits, &nbit, voiced1, 1);
+ pack(bits, &nbit, voiced2, 1);
+
+ assert(nbit == CODEC2_BITS_PER_FRAME);
+}
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTION....: codec2_decode
+ AUTHOR......: David Rowe
+ DATE CREATED: 21/8/2010
+
+ Decodes frames of 51 bits into 160 samples (20ms) of speech.
+
+\*---------------------------------------------------------------------------*/
+
+void codec2_decode(void *codec2_state, short speech[],
+ const unsigned char * bits)
+{
+ CODEC2 *c2;
+ MODEL model;
+ int voiced1, voiced2;
+ int lsp_indexes[LPC_ORD];
+ float lsps[LPC_ORD];
+ int energy_index;
+ float energy;
+ int Wo_index;
+ float ak[LPC_ORD+1];
+ float ak_interp[LPC_ORD+1];
+ int i;
+ unsigned int nbit = 0;
+ MODEL model_interp;
+
+ assert(codec2_state != NULL);
+ c2 = (CODEC2*)codec2_state;
+
+ /* unpack bit stream to integer codes */
+
+ Wo_index = unpack(bits, &nbit, WO_BITS);
+ for(i=0; i<LPC_ORD; i++) {
+ lsp_indexes[i] = unpack(bits, &nbit, lsp_bits(i));
+ }
+ energy_index = unpack(bits, &nbit, E_BITS);
+ voiced1 = unpack(bits, &nbit, 1);
+ voiced2 = unpack(bits, &nbit, 1);
+ assert(nbit == CODEC2_BITS_PER_FRAME);
+
+ /* decode integer codes to model parameters */
+
+ model.Wo = decode_Wo(Wo_index);
+ model.L = PI/model.Wo;
+ memset(&model.A, 0, (model.L+1)*sizeof(model.A[0]));
+ decode_amplitudes(&model,
+ ak,
+ lsp_indexes,
+ energy_index,
+ lsps,
+ &energy);
+
+ model.voiced = voiced2;
+ model_interp.voiced = voiced1;
+ model_interp.Wo = P_MAX/2;
+ memset(&model_interp.A, 0, MAX_AMP*sizeof(model_interp.A[0]));
+
+ /* interpolate middle frame's model parameters for adjacent frames */
+
+ interpolate_lsp(&model_interp, &c2->prev_model, &model,
+ c2->prev_lsps, c2->prev_energy, lsps, energy, ak_interp);
+ apply_lpc_correction(&model_interp);
+
+ /* synthesis two 10ms frames */
+
+ synthesise_one_frame(c2, speech, &model_interp, ak_interp);
+ synthesise_one_frame(c2, &speech[N], &model, ak);
+
+ /* update memories (decode states) for next time */
+
+ memcpy(&c2->prev_model, &model, sizeof(MODEL));
+ memcpy(c2->prev_lsps, lsps, sizeof(lsps));
+ c2->prev_energy = energy;
+}
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTION....: synthesise_one_frame()
+ AUTHOR......: David Rowe
+ DATE CREATED: 23/8/2010
+
+ Synthesise 80 speech samples (10ms) from model parameters.
+
+\*---------------------------------------------------------------------------*/
+
+void synthesise_one_frame(CODEC2 *c2, short speech[], MODEL *model, float ak[])
+{
+ int i;
+
+ phase_synth_zero_order(model, ak, &c2->ex_phase, LPC_ORD);
+ postfilter(model, &c2->bg_est);
+ synthesise(c2->Sn_, model, c2->Pn, 1);
+
+ for(i=0; i<N; i++) {
+ if (c2->Sn_[i] > 32767.0)
+ speech[i] = 32767;
+ else if (c2->Sn_[i] < -32767.0)
+ speech[i] = -32767;
+ else
+ speech[i] = c2->Sn_[i];
+ }
+
+}
+
+/*---------------------------------------------------------------------------*\
+
+ FUNCTION....: analyse_one_frame()
+ AUTHOR......: David Rowe
+ DATE CREATED: 23/8/2010
+
+ Extract sinusoidal model parameters from 80 speech samples (10ms of
+ speech).
+
+\*---------------------------------------------------------------------------*/
+
+void analyse_one_frame(CODEC2 *c2, MODEL *model, short speech[])
+{
+ COMP Sw[FFT_ENC];
+ COMP Sw_[FFT_ENC];
+ COMP Ew[FFT_ENC];
+ float pitch;
+ int i;
+
+ /* Read input speech */
+
+ for(i=0; i<M-N; i++)
+ c2->Sn[i] = c2->Sn[i+N];
+ for(i=0; i<N; i++)
+ c2->Sn[i+M-N] = speech[i];
+
+ dft_speech(Sw, c2->Sn, c2->w);
+
+ /* Estimate pitch */
+
+ nlp(c2->nlp,c2->Sn,N,M,P_MIN,P_MAX,&pitch,Sw,&c2->prev_Wo);
+ model->Wo = TWO_PI/pitch;
+ model->L = PI/model->Wo;
+
+ /* estimate model parameters */
+
+ two_stage_pitch_refinement(model, Sw);
+ estimate_amplitudes(model, Sw, c2->W);
+ est_voicing_mbe(model, Sw, c2->W, Sw_, Ew, c2->prev_Wo);
+
+ c2->prev_Wo = model->Wo;
+}
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