X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=output%2Foutput_vcd.c;h=d8ce6ef063e9ad53eb068916d8505c9d5f8d0705;hb=c4fffe1e9606e3e63a4cd0b760a37beb1f122cc5;hp=e4ac7babffe1a780f0398a03a733fcb4c9255590;hpb=6b5e3ceefcdee5e942b9cbff5c697016dacee774;p=libsigrok.git

diff --git a/output/output_vcd.c b/output/output_vcd.c
index e4ac7bab..d8ce6ef0 100644
--- a/output/output_vcd.c
+++ b/output/output_vcd.c
@@ -33,7 +33,7 @@ struct context {
 };
 
 const char *vcd_header = "\
-$date\n  %s\n$end\n\
+$date\n  %s$end\n\
 $version\n  %s\n$end\n%s\
 $timescale\n  %i %s\n$end\n\
 $scope module %s $end\n\
@@ -57,6 +57,7 @@ static int init(struct output *o)
 	int i, b, num_probes;
 	char *c, *samplerate_s;
 	char wbuf[1000], comment[128];
+	time_t t;
 
 	if (!(ctx = calloc(1, sizeof(struct context))))
 		return SIGROK_ERR_MALLOC;
@@ -107,7 +108,8 @@ static int init(struct output *o)
 	}
 
 	/* TODO: Date: File or signals? Make y/n configurable. */
-	b = snprintf(ctx->header, MAX_HEADER_LEN, vcd_header, "TODO: Date",
+	t = time(NULL);
+	b = snprintf(ctx->header, MAX_HEADER_LEN, vcd_header, ctime(&t),
 		     PACKAGE_STRING, comment, 1, "ns", PACKAGE, (char *)&wbuf);
 	/* TODO: Handle snprintf() errors. */
 
@@ -153,9 +155,10 @@ static int data(struct output *o, char *data_in, uint64_t length_in,
 		char **data_out, uint64_t *length_out)
 {
 	struct context *ctx;
-	unsigned int offset, outsize;
+	unsigned int i, outsize;
 	int p, curbit, prevbit;
 	uint64_t sample, prevsample;
+	static uint64_t samplecount = 0;
 	char *outbuf, *c;
 
 	ctx = o->internal;
@@ -177,28 +180,26 @@ static int data(struct output *o, char *data_in, uint64_t length_in,
 
 	/* TODO: Are disabled probes handled correctly? */
 
-	for (offset = 0; offset <= length_in - ctx->unitsize;
-	     offset += ctx->unitsize) {
-		memcpy(&sample, data_in + offset, ctx->unitsize);
+	for (i = 0; i <= length_in - ctx->unitsize; i += ctx->unitsize) {
+		samplecount++;
+		memcpy(&sample, data_in + i, ctx->unitsize);
+		if (i == 0)
+			prevsample = sample;
+		else
+			memcpy(&prevsample, data_in + i - 1, ctx->unitsize);
+
 		for (p = 0; p < ctx->num_enabled_probes; p++) {
-			curbit = (sample & ((uint64_t) (1 << p))) != 0;
-			if (offset == 0) {
-				prevbit = ~curbit;
-			} else {
-				memcpy(&prevsample, data_in + offset - 1,
-				       ctx->unitsize);
-				prevbit =
-				    (prevsample & ((uint64_t) (1 << p))) != 0;
-			}
-
-			if (prevbit != curbit) {
-				/* FIXME: Only once per sample? */
-				c = outbuf + strlen(outbuf);
-				sprintf(c, "#%i\n", offset * 1 /* TODO */);
-
-				c = outbuf + strlen(outbuf);
-				sprintf(c, "%i%c\n", curbit, (char)('!' + p));
-			}
+			curbit = (sample & ((uint64_t) (1 << p))) >> p;
+			prevbit = (prevsample & ((uint64_t) (1 << p))) >> p;
+
+			/* VCD only contains deltas/changes of signals. */
+			if (prevbit == curbit)
+				continue;
+
+			/* Output which signal changed to which value. */
+			c = outbuf + strlen(outbuf);
+			sprintf(c, "#%" PRIu64 "\n%i%c\n", samplecount,
+				curbit, (char)('!' + p));
 		}
 
 		/* TODO: Use realloc() if strlen(outbuf) is almost "full"... */