starting to code up freedv modes that combine codec and modem and fec in an easy...

git-svn-id: https://svn.code.sf.net/p/freetel/code@1782 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/src/freedv.c b/codec2-dev/src/freedv.c
new file mode 100644 (file)
index 0000000..aca990c
--- /dev/null
+++ b/codec2-dev/src/freedv.c
@@ -0,0 +1,254 @@
+/*---------------------------------------------------------------------------*\
+                                                                             
+  FILE........: freedv.c
+  AUTHOR......: David Rowe
+  DATE CREATED: August 2014
+                                                                             
+  Functions that implement FreeDV "modes" (or waveforms), useful for
+  embedding in other programs.
+                                                                             
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2012 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/>.
+*/
+
+#define FREEDV_1600       0
+#define FREEDV_NSAMPLES 320
+
+#include "codec2.h"
+#include "codec2_fdmdv.h"
+#include "golay23.h"
+
+
+struct freedv {
+    int           mode;
+    void         *codec2;
+    struct FDMDV *fdmdv
+    char         *packed_codec_bits;
+    int          *codec_bits;
+    int          *tx_bits;
+    int          *fdmdv_bits;
+    int          *rx_bits;
+    int           tx_sync_bit;
+};
+
+
+struct freedv *freedv_open(int mode) {
+    struct freedv *f;
+    int            Nc, codec2_mode, nbit, nbyte;
+
+    f = (struct freedv*)malloc(sizeof(struct freedv));
+    if (f == NULL)
+        return NULL;
+
+    f->mode = mode;
+    f->tx_sync = 0;
+
+    if (mode == FREEDV_1600) {
+        Nc = 16;
+        codec2_mode = CODEC2_MODE_1300;
+    }
+
+    f->codec2 = codec2_create(Nc);
+    if (f->codec2 == NULL)
+        return NULL;
+
+    f->fdmdv = fdmdv_create(codec2_mode);
+    if (f->fdmdv == NULL)
+        return NULL;
+
+    nbit = codec2_bits_per_frame(f->codec2);
+    nbyte = (nbit + 7) / 8;
+    f->packed_codec_bits = (unsigned char*)malloc(nbyte*sizeof(char));
+    f->codec_bits = (int*)malloc(nbit*sizeof(int));
+
+    nbit = 2*fdmdv_bits_per_frame(fdmdv);
+    f->tx_bits = (int*)malloc(nbit*sizeof(int));
+    f->rx_bits = (int*)malloc(nbit*sizeof(int));
+ 
+    nbit = fdmdv_bits_per_frame(fdmdv);
+    f->fdmdv_bits = (int*)malloc(nbit*sizeof(int));
+
+    if ((f->packed_codec_bits == NULL) || (f->codec_bits == NULL) 
+        || (f->tx_bits == NULL) || (f->rx_bits == NULL) || (f->fdmdv_bits == NULL))
+        return NULL;
+
+    golay23_init();
+
+    return f;
+}
+
+void freedv_close(struct freedv *freedv) {
+    free(freedv->packed_codec_bits);
+    free(freedv->codec_bits);
+    free(freedv->tx_bits);
+    fdmdv_destroy(freedv->fdmdv);
+    codec2_destroy(freedv->codec2);
+    free(freedv);
+}
+
+int freedv_tx(struct freedv *f, short speech_in[], short mod_out[]) {
+    int    bit, byte, i, j;
+    int    bits_per_codec_frame, bits_per_fdmdv_frame;
+    int    data, codeword1, codeword2;
+    COMP   tx_fdm[2*FDMDV_NOM_SAMPLES_PER_FRAME];
+    short  tx_fdm_scaled[2*FDMDV_NOM_SAMPLES_PER_FRAME];
+     
+    bits_per_codec_frame = codec2_bits_per_frame(freedv->codec2);
+    bits_per_fdmdv_frame = fdmdv_bits_per_frame(freedv->codec2);
+
+    codec2_encode(f->codec2, f->packet_codec_bits, speech_in);
+
+    /* unpack bits, MSB first */
+
+    bit = 7; byte = 0;
+    for(i=0; i<bits_per_input_frame; i++) {
+        f->codec_bits[i] = (f->packed_codec_bits[byte] >> bit) & 0x1;
+        bit--;
+        if (bit < 0) {
+            bit = 7;
+            byte++;
+        }
+    }
+    
+    if (f->mode == MODE_1600) {
+            
+        /* Protect first 12 out of first 16 excitation bits with (23,12) Golay Code:
+
+           0,1,2,3: v[0]..v[1]
+           4,5,6,7: MSB of pitch
+           11,12,13,14: MSB of energy
+
+        */
+
+        data = 0;
+        for(i=0; i<8; i++) {
+            data <<= 1;
+            data |= f->codec_bits[i];
+        }
+        for(i=11; i<15; i++) {
+            data <<= 1;
+            data |= f->codec_bits[i];
+        }
+        codeword1 = golay23_encode(data);
+
+        /* now pack output frame with parity bits at end to make them
+           as far apart as possible from the data they protect.  Parity
+           bits are LSB of the Golay codeword */
+
+        for(i=0; i<bits_per_codec_frame; i++)
+            f->tx_bits[i] = f->codec_bits[i];
+        for(j=0; i<bits_per_codec_frame+11; i++,j++) {
+            f->tx_bits[i] = (codeword1 >> (10-j)) & 0x1;
+        }
+        f->tx_bits[i] = 0; /* spare bit */
+    }
+
+    /* modulate even and odd frames */
+
+    fdmdv_mod(f->fdmdv, tx_fdm, f->tx_bits, &f->tx_sync_bit);
+    assert(sync_bit == 1);
+
+    fdmdv_mod(f->fdmdv, &tx_fdm[FDMDV_NOM_SAMPLES_PER_FRAME], &f->tx_bits[bits_per_fdmdv_frame], &f->tx_sync_bit);
+    assert(sync_bit == 0);
+
+    for(i=0; i<2*FDMDV_NOM_SAMPLES_PER_FRAME; i++)
+        mod_out[i] = FDMDV_SCALE * tx_fdm[i].real;
+}
+
+int freedv_nin(struct freedv *f) {
+    return f->nin;
+}
+
+/* TODO: sync code, SNR threshold (default but can be changed), unit test program */
+
+int freedv_rx(struct freedv *f, short demod_in[], short speech_out[]) {
+    COMP  rx_fdm[FDMDV_MAX_SAMPLES_PER_FRAME];
+    int   bits_per_codec_frame, bytes_per_codec_frame, bits_per_fdmdv_frame;
+    int   reliable_sync_bit, i, j, bit, byte, ;
+    int   recd_codeword, codeword1, codeword2;
+
+    bits_per_codec_frame  = codec2_bits_per_frame(freedv->codec2);
+    bytes_per_codec_frame = (bits_per_codec_frame + 7) / 8;
+    bits_per_fdmdv_frame  = fdmdv_bits_per_frame(freedv->codec2);
+
+    for(i=0; i<f->nin; i++) {
+        rx_fdm[i].real = (float)demod_in[i]/FDMDV_SCALE;
+        rx_fdm[i].imag = 0;
+    }
+    nin_prev = nin;
+    fdmdv_demod(f->fdmdv, f->fdmdv_bits, &reliable_sync_bit, rx_fdm, &f->nin);
+    
+    if (reliable_sync_bit == 0) {
+        memcpy(f->rx_bits, f->fdmdv_bits, bits_per_fdmdv_frame*sizeof(int));
+    }
+    else {
+        memcpy(&f->rx_bits[bits_per_fdmdv_frame], f->fdmdv_bits, bits_per_fdmdv_frame*sizeof(int));
+    }
+
+    if (f->mode == MODE_1600) {
+        recd_codeword = 0;
+        for(i=0; i<8; i++) {
+            recd_codeword <<= 1;
+            recd_codeword |= f->rx_bits[i];
+        }
+        for(i=11; i<15; i++) {
+            recd_codeword <<= 1;
+            recd_codeword |= f->rx_bits[i];
+        }
+        for(i=bits_per_codec_frame; i<bits_per_codec_frame+11; i++) {
+            recd_codeword <<= 1;
+            recd_codeword |= f->rx_bits[i];
+        }
+        codeword1 = golay23_decode(recd_codeword);
+        //codeword1 = recd_codeword;
+        //fprintf(stderr, "received codeword1: 0x%x  decoded codeword1: 0x%x\n", recd_codeword, codeword1);
+           
+        for(i=0; i<bits_per_codec_frame; i++)
+            f->codec_bits[i] = f->rx_bits[i];
+
+        for(i=0; i<8; i++) {
+            f->codec_bits[i] = (codeword1 >> (22-i)) & 0x1;
+        }
+        for(i=8,j=11; i<12; i++,j++) {
+            f->codec_bits[j] = (codeword1 >> (22-i)) & 0x1;
+        }
+    }
+ 
+    // pack bits, MSB received first
+
+    bit  = 7;
+    byte = 0;
+    memset(f->packed_codec_bits, 0,  bytes_per_codec_frame);
+    for(i=0; i<bits_per_codec_frame; i++) {
+        f->packed_codec_bits[byte] |= (f->codec_bits[i] << bit);
+        bit--;
+        if(bit < 0) {
+            bit = 7;
+            byte++;
+        }
+    }
+
+    codec2_decode(f->codec2, speech_out, f->packed_codec_bits);
+}
+
+int freedv_tx_text(struct freedv_mode *mode, char c) {
+}
+
+int freedv_rx_text(struct freedv_mode *mode, char *c) {
+}
+