update

git-svn-id: http://svn.openzap.org/svn/openzap/trunk@210 a93c3328-9c30-0410-af19-c9cd2b2d52af

libs/openzap/src/dsp/fsk.c

@@ -306,7 +306,39 @@ dsp_fsk_sample (dsp_fsk_handle_t *handle, double normalized_sample)
 
 	if (handle->cellpos > 1.0) {
 		handle->cellpos -= 1.0;
-		(*handle->attr.bithandler) (handle->attr.bithandler_arg, handle->current_bit);
+		
+
+		switch (handle->state) {
+		case FSK_STATE_DATA:
+			(*handle->attr.bithandler) (handle->attr.bithandler_arg, handle->current_bit);
+			break;
+		case FSK_STATE_CHANSEIZE:
+			if (handle->last_bit != handle->current_bit) {
+
+
+				handle->conscutive_state_bits++;
+			} else {
+				handle->conscutive_state_bits = 0;
+			}
+			if (handle->conscutive_state_bits > 15) {
+				handle->state = FSK_STATE_CARRIERSIG;
+				handle->conscutive_state_bits = 0;
+			}
+			break;
+		case FSK_STATE_CARRIERSIG:
+			if (handle->current_bit) {
+				handle->conscutive_state_bits++;
+			} else {
+				handle->conscutive_state_bits = 0;
+			}
+			if (handle->conscutive_state_bits > 15) {
+				handle->state = FSK_STATE_DATA;
+				handle->conscutive_state_bits = 0;
+			}
+			break;
+		}
+
+		handle->last_bit = handle->current_bit;
 	}
 }
 

libs/openzap/src/dsp/fsk.h

@@ -35,6 +35,12 @@
 #define	__FSK_H__
 #include "uart.h"
 
+typedef enum {
+	FSK_STATE_CHANSEIZE = 0,
+	FSK_STATE_CARRIERSIG,
+	FSK_STATE_DATA
+} fsk_state_t;
+
 typedef struct dsp_fsk_attr_s
 {
 	int					sample_rate;					/* sample rate in HZ */
@@ -46,7 +52,8 @@ typedef struct dsp_fsk_attr_s
 
 typedef struct
 {
-	dsp_fsk_attr_t	attr;							/* attributes structure */
+	fsk_state_t			state;
+	dsp_fsk_attr_t		attr;							/* attributes structure */
 	double				*correlates[4];					/* one for each of sin/cos for mark/space */
 	int					corrsize;						/* correlate size (also number of samples in ring buffer) */
 	double				*buffer;						/* sample ring buffer */
@@ -55,8 +62,10 @@ typedef struct
 	double				celladj;						/* bit cell adjustment for each sample */
 	int					previous_bit;					/* previous bit (for detecting a transition to sync-up cell position) */
 	int					current_bit;					/* current bit */
+	int					last_bit;
 	int					downsampling_count;				/* number of samples to skip */
 	int					current_downsample;				/* current skip count */
+	int					conscutive_state_bits;			/* number of bits in a row that matches the pattern for the current state */
 }	dsp_fsk_handle_t;
 
 /*