X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=output%2Foutput_vcd.c;h=b21bfb92d83d17b87816011ba84b0c9165b812fb;hb=c3579621d569f4b1ef3c21c7e2ed3bdc855c617b;hp=2157c1ba5c1cd4ab1fa4cba9109e7d2799991dad;hpb=fbf1ff5d2268c0fbf35b6210afa11da351b9b2ba;p=libsigrok.git

diff --git a/output/output_vcd.c b/output/output_vcd.c
index 2157c1ba..b21bfb92 100644
--- a/output/output_vcd.c
+++ b/output/output_vcd.c
@@ -31,6 +31,9 @@ struct context {
 	char *probelist[65];
 	int *prevbits;
 	GString *header;
+	uint64_t prevsample;
+	int period;
+	uint64_t samplerate;
 };
 
 const char *vcd_header = "\
@@ -51,8 +54,7 @@ static int init(struct output *o)
 	struct context *ctx;
 	struct probe *probe;
 	GSList *l;
-	uint64_t samplerate;
-	int num_probes, period, i;
+	int num_probes, i;
 	char *samplerate_s, *frequency_s, *timestamp;
 	time_t t;
 
@@ -90,9 +92,9 @@ static int init(struct output *o)
 			PACKAGE, PACKAGE_VERSION);
 
 	if (o->device->plugin) {
-		samplerate = *((uint64_t *) o->device->plugin->get_device_info(
+		ctx->samplerate = *((uint64_t *) o->device->plugin->get_device_info(
 				o->device->plugin_index, DI_CUR_SAMPLERATE));
-		if (!((samplerate_s = sigrok_samplerate_string(samplerate)))) {
+		if (!((samplerate_s = sigrok_samplerate_string(ctx->samplerate)))) {
 			g_string_free(ctx->header, TRUE);
 			free(ctx);
 			return SIGROK_ERR;
@@ -104,13 +106,13 @@ static int init(struct output *o)
 
 	/* timescale */
 	/* VCD can only handle 1/10/100 (s - fs), so scale up first */
-	if (samplerate > MHZ(1))
-		period = GHZ(1);
-	else if (samplerate > KHZ(1))
-		period = MHZ(1);
+	if (ctx->samplerate > MHZ(1))
+		ctx->period = GHZ(1);
+	else if (ctx->samplerate > KHZ(1))
+		ctx->period = MHZ(1);
 	else
-		period = KHZ(1);
-	if (!(frequency_s = sigrok_period_string(period))) {
+		ctx->period = KHZ(1);
+	if (!(frequency_s = sigrok_period_string(ctx->period))) {
 		g_string_free(ctx->header, TRUE);
 		free(ctx);
 		return SIGROK_ERR;
@@ -169,9 +171,10 @@ static int data(struct output *o, char *data_in, uint64_t length_in,
 	struct context *ctx;
 	unsigned int i;
 	int p, curbit, prevbit;
-	uint64_t sample, prevsample;
+	uint64_t sample;
 	static uint64_t samplecount = 0;
 	GString *out;
+	int first_sample = 0;
 
 	ctx = o->internal;
 	out = g_string_sized_new(512);
@@ -181,28 +184,35 @@ static int data(struct output *o, char *data_in, uint64_t length_in,
 		g_string_append(out, ctx->header->str);
 		g_string_free(ctx->header, TRUE);
 		ctx->header = NULL;
+		first_sample = 1;
 	}
 
 	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);
+
+		if (first_sample) {
+			/* First packet. We neg to make sure sample is stored. */
+			ctx->prevsample = ~sample;
+			first_sample = 0;
+		}
 
 		for (p = 0; p < ctx->num_enabled_probes; p++) {
 			curbit = (sample & ((uint64_t) (1 << p))) >> p;
-			prevbit = (prevsample & ((uint64_t) (1 << p))) >> p;
+			prevbit = (ctx->prevsample & ((uint64_t) (1 << p))) >> p;
 
 			/* VCD only contains deltas/changes of signals. */
 			if (prevbit == curbit)
 				continue;
 
 			/* Output which signal changed to which value. */
-			g_string_append_printf(out, "#%" PRIu64 "\n%i%c\n", samplecount,
-					curbit, (char)('!' + p));
+			g_string_append_printf(out, "#%" PRIu64 "\n%i%c\n",
+					(uint64_t)(((float)samplecount / ctx->samplerate)
+					* ctx->period), curbit, (char)('!' + p));
 		}
+
+		ctx->prevsample = sample;
 	}
 
 	*data_out = out->str;