1 files changed, 179 insertions, 20 deletions
diff --git a/gr-vocoder/lib/codec2/c2dec.c b/gr-vocoder/lib/codec2/c2dec.c
index 3123e96fbc..df4e82f77a 100644
--- a/gr-vocoder/lib/codec2/c2dec.c
+++ b/gr-vocoder/lib/codec2/c2dec.c
@@ -27,54 +27,213 @@
 
 #include "codec2.h"
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 
-#define BITS_SIZE	((CODEC2_BITS_PER_FRAME + 7) / 8)
+#define NONE          0  /* no bit errors                          */
+#define UNIFORM       1  /* random bit errors                      */
+#define TWO_STATE     2  /* Two state error model                  */
+#define UNIFORM_RANGE 3  /* random bit errors over a certain range */
 
 int main(int argc, char *argv[])
 {
-    void *codec2;
-    FILE *fin;
-    FILE *fout;
-    short buf[CODEC2_SAMPLES_PER_FRAME];
-    unsigned char  bits[BITS_SIZE];
-
-    if (argc != 3) {
-	printf("usage: %s InputBitFile OutputRawSpeechFile\n", argv[0]);
+    int            mode;
+    void          *codec2;
+    FILE          *fin;
+    FILE          *fout;
+    FILE          *fber = NULL;
+    short         *buf;
+    unsigned char *bits, *prev_bits;
+    int            nsam, nbit, nbyte, i, byte, frames, bits_proc, bit_errors, error_mode;
+    int            nstart_bit, nend_bit, bit_rate;
+    int            state, next_state;
+    float          ber, r, burst_length, burst_period, burst_timer, ber_est;
+    unsigned char  mask;
+
+    if ((argc != 4) && (argc != 5) && (argc != 6) && (argc != 7)) {
+	printf("basic usage.................: c2dec 3200|2400|1600|1400|1300|1200 InputBitFile OutputRawSpeechFile\n");
+	printf("uniform errors usage........: c2dec 3200|2400|1600|1400|1300|1200 InputBitFile OutputRawSpeechFile uniformBER startBit endBit\n");
+	printf("uniform error on range usage: c2dec 3200|2400|1600|1400|1300|1200 InputBitFile OutputRawSpeechFile uniformBER\n");
+	printf("demod BER estimate..........: c2dec 3200|2400|1600|1400|1300|1200 InputBitFile OutputRawSpeechFile BERfile\n");
+	printf("two state fading usage......: c2dec 3200|2400|1600|1400|1300|1200 InputBitFile OutputRawSpeechFile burstLength burstPeriod\n");
+	printf("e.g    c2dec 1400 hts1a.c2 hts1a_1400.raw\n");
+	printf("e.g    c2dec 1400 hts1a.c2 hts1a_1400.raw 0.9\n");
+	printf("e.g    c2dec 1400 hts1a.c2 hts1a_1400.raw 0.99 0.9\n");
 	exit(1);
     }
 
-    if (strcmp(argv[1], "-")  == 0) fin = stdin;
-    else if ( (fin = fopen(argv[1],"rb")) == NULL ) {
+    if (strcmp(argv[1],"3200") == 0)
+	mode = CODEC2_MODE_3200;
+    else if (strcmp(argv[1],"2400") == 0)
+	mode = CODEC2_MODE_2400;
+    else if (strcmp(argv[1],"1600") == 0)
+	mode = CODEC2_MODE_1600;
+    else if (strcmp(argv[1],"1400") == 0)
+	mode = CODEC2_MODE_1400;
+    else if (strcmp(argv[1],"1300") == 0)
+	mode = CODEC2_MODE_1300;
+    else if (strcmp(argv[1],"1200") == 0)
+	mode = CODEC2_MODE_1200;
+    else {
+	fprintf(stderr, "Error in mode: %s.  Must be 3200, 2400, 1600, 1400, 1300 or 1200\n", argv[1]);
+	exit(1);
+    }
+    bit_rate = atoi(argv[1]);
+
+    if (strcmp(argv[2], "-")  == 0) fin = stdin;
+    else if ( (fin = fopen(argv[2],"rb")) == NULL ) {
 	fprintf(stderr, "Error opening input bit file: %s: %s.\n",
-         argv[1], strerror(errno));
+         argv[2], strerror(errno));
 	exit(1);
     }
 
-    if (strcmp(argv[2], "-") == 0) fout = stdout;
-    else if ( (fout = fopen(argv[2],"wb")) == NULL ) {
+    if (strcmp(argv[3], "-") == 0) fout = stdout;
+    else if ( (fout = fopen(argv[3],"wb")) == NULL ) {
 	fprintf(stderr, "Error opening output speech file: %s: %s.\n",
-         argv[2], strerror(errno));
+         argv[3], strerror(errno));
 	exit(1);
     }
 
-    codec2 = codec2_create();
+    error_mode = NONE;
+    ber = 0.0;
+    burst_length = burst_period = 0.0;
+    burst_timer = 0.0;
+
+    codec2 = codec2_create(mode);
+    nsam = codec2_samples_per_frame(codec2);
+    nbit = codec2_bits_per_frame(codec2);
+    buf = (short*)malloc(nsam*sizeof(short));
+    nbyte = (nbit + 7) / 8;
+    bits = (unsigned char*)malloc(nbyte*sizeof(char));
+    prev_bits = (unsigned char*)malloc(nbyte*sizeof(char));
+    frames = bit_errors = bits_proc = 0;
+    nstart_bit = 0;
+    nend_bit = nbit-1;
+
+    if (argc == 5) {
+        /* see if 4th argument is a valid file name */
+        if ( (fber = fopen(argv[4],"rb")) == NULL ) {
+            /* otherwise it must be BER value for uniform errors */
+            ber = atof(argv[4]);
+	    error_mode = UNIFORM;
+        }
+    }
+
+    if (argc == 6) {
+        error_mode = TWO_STATE;
+	burst_length = atof(argv[4]);
+	burst_period = atof(argv[5]);
+	nstart_bit = 0;
+	nend_bit = 2;
+        state = 0;
+    }
+
+    if (argc == 7) {
+        error_mode = UNIFORM_RANGE;
+	ber = atof(argv[4]);
+	nstart_bit = atoi(argv[5]);
+	nend_bit = atoi(argv[6]);
+        fprintf(stderr, "ber: %f nstart_bit: %d nend_bit: %d\n", ber, nstart_bit, nend_bit);
+        state = 0;
+    }
 
-    while(fread(bits, sizeof(char), BITS_SIZE, fin) == BITS_SIZE) {
-	codec2_decode(codec2, buf, bits);
- 	fwrite(buf, sizeof(short), CODEC2_SAMPLES_PER_FRAME, fout);
+    assert(nend_bit <= nbit);
+
+    while(fread(bits, sizeof(char), nbyte, fin) == (size_t)nbyte) {
+	frames++;
+
+        // apply bit errors, MSB of byte 0 is bit 0 in frame */
+
+	if ((error_mode == UNIFORM) || (error_mode == UNIFORM_RANGE)) {
+	    for(i=nstart_bit; i<nend_bit+1; i++) {
+		r = (float)rand()/RAND_MAX;
+		if (r < ber) {
+		    byte = i/8;
+		    //printf("nbyte %d nbit %d i %d byte %d bits[%d] 0x%0x ", nbyte, nbit, i, byte, byte, bits[byte]);
+		    mask = 1 << (7 - i + byte*8);
+                    bits[byte] ^= mask;
+		    //printf("shift: %d mask: 0x%0x bits[%d] 0x%0x\n", 7 - i + byte*8, mask, byte, bits[byte] );
+		    bit_errors++;
+ 		}
+                bits_proc++;
+	    }
+	}
+
+	if (error_mode == TWO_STATE) {
+            burst_timer += (float)nbit/bit_rate;
+            fprintf(stderr, "burst_timer: %f  state: %d\n", burst_timer, state);
+
+            next_state = state;
+            switch(state) {
+            case 0:
+
+                /* clear channel state - no bit errors */
+
+                if (burst_timer > (burst_period - burst_length))
+                    next_state = 1;
+                break;
+
+            case 1:
+
+                /* burst error state - 50% bit error rate */
+
+                for(i=nstart_bit; i<nend_bit+1; i++) {
+                    r = (float)rand()/RAND_MAX;
+                    if (r < 0.5) {
+                        byte = i/8;
+                        bits[byte] ^= 1 << (7 - i + byte*8);
+                        bit_errors++;
+                    }
+                    bits_proc++;
+		}
+
+                if (burst_timer > burst_period) {
+                    burst_timer = 0.0;
+                    next_state = 0;
+                }
+                break;
+
+	    }
+
+            state = next_state;
+        }
+
+        if (fber != NULL) {
+            if (fread(&ber_est, sizeof(float), 1, fber) != 1) {
+                fprintf(stderr, "ran out of BER estimates!\n");
+                exit(1);
+            }
+            //fprintf(stderr, "ber_est: %f\n", ber_est);
+        }
+        else
+            ber_est = 0.0;
+
+        /* frame repeat logic */
+        if (ber_est > 0.15) {
+            //memcpy(bits, prev_bits, nbyte);
+            // fprintf(stderr, "repeat\n");
+        }
+
+	codec2_decode(codec2, buf, bits, ber_est);
+ 	fwrite(buf, sizeof(short), nsam, fout);
 	//if this is in a pipeline, we probably don't want the usual
         //buffering to occur
         if (fout == stdout) fflush(stdout);
         if (fin == stdin) fflush(stdin);
 
- }
+        memcpy(prev_bits, bits, nbyte);
+    }
+
+    if (error_mode)
+	fprintf(stderr, "actual BER: %1.3f\n", (float)bit_errors/bits_proc);
 
     codec2_destroy(codec2);
 
+    free(buf);
+    free(bits);
     fclose(fin);
     fclose(fout);