From: Bert Vermeulen <redacted>
Date: Wed, 30 Apr 2014 14:40:56 +0000 (-0700)
Subject: output/vcd: Support getting samplerate from meta packets.
X-Git-Tag: libsigrok-0.3.0~56
X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=6cb45d96c802190aef675e96c6037ee6ab0a8622

output/vcd: Support getting samplerate from meta packets.
---

diff --git a/output/vcd.c b/output/vcd.c
index 4d853057..87f80496 100644
--- a/output/vcd.c
+++ b/output/vcd.c
@@ -31,9 +31,10 @@
 struct context {
 	int num_enabled_channels;
 	GArray *channelindices;
-	GString *header;
 	uint8_t *prevsample;
+	gboolean header_done;
 	int period;
+	int *channel_index;
 	uint64_t samplerate;
 	uint64_t samplecount;
 };
@@ -46,62 +47,81 @@ static int init(struct sr_output *o)
 	struct context *ctx;
 	struct sr_channel *ch;
 	GSList *l;
-	GVariant *gvar;
-	int num_channels, i;
-	char *samplerate_s, *frequency_s, *timestamp;
-	time_t t;
-
-	if (!(ctx = g_malloc0(sizeof(struct context)))) {
-		sr_err("%s: ctx malloc failed", __func__);
-		return SR_ERR_MALLOC;
-	}
-
-	o->internal = ctx;
-	ctx->num_enabled_channels = 0;
-	ctx->channelindices = g_array_new(FALSE, FALSE, sizeof(int));
+	int num_enabled_channels, i;
 
+	num_enabled_channels = 0;
 	for (l = o->sdi->channels; l; l = l->next) {
 		ch = l->data;
 		if (ch->type != SR_CHANNEL_LOGIC)
 			continue;
 		if (!ch->enabled)
 			continue;
-		ctx->channelindices = g_array_append_val(
-				ctx->channelindices, ch->index);
-		ctx->num_enabled_channels++;
+		num_enabled_channels++;
 	}
-	if (ctx->num_enabled_channels > 94) {
+	if (num_enabled_channels > 94) {
 		sr_err("VCD only supports 94 channels.");
 		return SR_ERR;
 	}
 
-	ctx->header = g_string_sized_new(512);
+	ctx = g_malloc0(sizeof(struct context));
+	o->internal = ctx;
+	ctx->num_enabled_channels = num_enabled_channels;
+	ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
+
+	/* Once more to map the enabled channels. */
+	for (i = 0, l = o->sdi->channels; l; l = l->next) {
+		ch = l->data;
+		if (ch->type != SR_CHANNEL_LOGIC)
+			continue;
+		if (!ch->enabled)
+			continue;
+		ctx->channel_index[i++] = ch->index;
+	}
+
+	return SR_OK;
+}
+
+static GString *gen_header(struct sr_output *o)
+{
+	struct context *ctx;
+	struct sr_channel *ch;
+	GVariant *gvar;
+	GString *header;
+	GSList *l;
+	time_t t;
+	int num_channels, i;
+	char *samplerate_s, *frequency_s, *timestamp;
+
+	ctx = o->internal;
+	header = g_string_sized_new(512);
 	num_channels = g_slist_length(o->sdi->channels);
 
 	/* timestamp */
 	t = time(NULL);
 	timestamp = g_strdup(ctime(&t));
 	timestamp[strlen(timestamp)-1] = 0;
-	g_string_printf(ctx->header, "$date %s $end\n", timestamp);
+	g_string_printf(header, "$date %s $end\n", timestamp);
 	g_free(timestamp);
 
 	/* generator */
-	g_string_append_printf(ctx->header, "$version %s %s $end\n",
+	g_string_append_printf(header, "$version %s %s $end\n",
 			PACKAGE, PACKAGE_VERSION);
-
-	if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
-			&gvar) == SR_OK) {
-		ctx->samplerate = g_variant_get_uint64(gvar);
-		g_variant_unref(gvar);
-		if (!((samplerate_s = sr_samplerate_string(ctx->samplerate)))) {
-			g_string_free(ctx->header, TRUE);
-			g_free(ctx);
-			return SR_ERR;
+	g_string_append_printf(header, "$comment\n  Acquisition with "
+			"%d/%d channels", ctx->num_enabled_channels, num_channels);
+
+	if (ctx->samplerate == 0) {
+		if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
+				&gvar) == SR_OK) {
+			ctx->samplerate = g_variant_get_uint64(gvar);
+			g_variant_unref(gvar);
 		}
-		g_string_append_printf(ctx->header, vcd_header_comment,
-				 ctx->num_enabled_channels, num_channels, samplerate_s);
+	}
+	if (ctx->samplerate != 0) {
+		samplerate_s = sr_samplerate_string(ctx->samplerate);
+		g_string_append_printf(header, " at %s", samplerate_s);
 		g_free(samplerate_s);
 	}
+	g_string_append_printf(header, "\n$end\n");
 
 	/* timescale */
 	/* VCD can only handle 1/10/100 (s - fs), so scale up first */
@@ -111,16 +131,12 @@ static int init(struct sr_output *o)
 		ctx->period = SR_MHZ(1);
 	else
 		ctx->period = SR_KHZ(1);
-	if (!(frequency_s = sr_period_string(ctx->period))) {
-		g_string_free(ctx->header, TRUE);
-		g_free(ctx);
-		return SR_ERR;
-	}
-	g_string_append_printf(ctx->header, "$timescale %s $end\n", frequency_s);
+	frequency_s = sr_period_string(ctx->period);
+	g_string_append_printf(header, "$timescale %s $end\n", frequency_s);
 	g_free(frequency_s);
 
 	/* scope */
-	g_string_append_printf(ctx->header, "$scope module %s $end\n", PACKAGE);
+	g_string_append_printf(header, "$scope module %s $end\n", PACKAGE);
 
 	/* Wires / channels */
 	for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
@@ -129,20 +145,22 @@ static int init(struct sr_output *o)
 			continue;
 		if (!ch->enabled)
 			continue;
-		g_string_append_printf(ctx->header, "$var wire 1 %c %s $end\n",
+		g_string_append_printf(header, "$var wire 1 %c %s $end\n",
 				(char)('!' + i), ch->name);
 	}
 
-	g_string_append(ctx->header, "$upscope $end\n"
-			"$enddefinitions $end\n");
+	g_string_append(header, "$upscope $end\n$enddefinitions $end\n");
 
-	return SR_OK;
+	return header;
 }
 
 static int receive(struct sr_output *o, const struct sr_datafeed_packet *packet,
 		GString **out)
 {
+	const struct sr_datafeed_meta *meta;
 	const struct sr_datafeed_logic *logic;
+	const struct sr_config *src;
+	GSList *l;
 	struct context *ctx;
 	unsigned int i;
 	int p, curbit, prevbit, index;
@@ -154,70 +172,74 @@ static int receive(struct sr_output *o, const struct sr_datafeed_packet *packet,
 		return SR_ERR_BUG;
 	ctx = o->internal;
 
-	if (ctx->header) {
-		/* The header is still here, this must be the first packet. */
-		*out = ctx->header;
-		ctx->header = NULL;
-		ctx->samplecount = 0;
-	} else {
-		*out = g_string_sized_new(512);
-	}
-
-	if (packet->type != SR_DF_LOGIC) {
-		if (packet->type == SR_DF_END)
-			/* Write final timestamp as length indicator. */
-			g_string_append_printf(*out, "#%.0f\n",
-				(double)ctx->samplecount /
-					ctx->samplerate * ctx->period);
-		return SR_OK;
-	}
-
-	logic = packet->payload;
+	switch (packet->type) {
+	case SR_DF_META:
+		meta = packet->payload;
+		for (l = meta->config; l; l = l->next) {
+			src = l->data;
+			if (src->key != SR_CONF_SAMPLERATE)
+				continue;
+			ctx->samplerate = g_variant_get_uint64(src->data);
+		}
+		break;
+	case SR_DF_LOGIC:
+		logic = packet->payload;
+
+		if (!ctx->header_done) {
+			*out = gen_header(o);
+			ctx->header_done = TRUE;
+		} else {
+			*out = g_string_sized_new(512);
+		}
 
-	if (!ctx->prevsample) {
-		/* Can't allocate this until we know the stream's unitsize. */
-		if (!(ctx->prevsample = g_malloc0(logic->unitsize))) {
-			g_free(ctx);
-			sr_err("%s: ctx->prevsample malloc failed", __func__);
-			return SR_ERR_MALLOC;
+		if (!ctx->prevsample) {
+			/* Can't allocate this until we know the stream's unitsize. */
+			ctx->prevsample = g_malloc0(logic->unitsize);
 		}
-	}
 
-	for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
-		sample = logic->data + i;
-		timestamp_written = FALSE;
+		for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
+			sample = logic->data + i;
+			timestamp_written = FALSE;
 
-		for (p = 0; p < ctx->num_enabled_channels; p++) {
-			index = g_array_index(ctx->channelindices, int, p);
+			for (p = 0; p < ctx->num_enabled_channels; p++) {
+				index = ctx->channel_index[p];
 
-			curbit = ((unsigned)sample[index / 8]
-					>> (index % 8)) & 1;
-			prevbit = ((unsigned)ctx->prevsample[index / 8]
-					>> (index % 8)) & 1;
+				curbit = ((unsigned)sample[index / 8]
+						>> (index % 8)) & 1;
+				prevbit = ((unsigned)ctx->prevsample[index / 8]
+						>> (index % 8)) & 1;
 
-			/* VCD only contains deltas/changes of signals. */
-			if (prevbit == curbit && ctx->samplecount > 0)
-				continue;
+				/* VCD only contains deltas/changes of signals. */
+				if (prevbit == curbit && ctx->samplecount > 0)
+					continue;
 
-			/* Output timestamp of subsequent signal changes. */
-			if (!timestamp_written)
-				g_string_append_printf(*out, "#%.0f",
-					(double)ctx->samplecount /
-						ctx->samplerate * ctx->period);
+				/* Output timestamp of subsequent signal changes. */
+				if (!timestamp_written)
+					g_string_append_printf(*out, "#%.0f",
+						(double)ctx->samplecount /
+							ctx->samplerate * ctx->period);
 
-			/* Output which signal changed to which value. */
-			g_string_append_c(*out, ' ');
-			g_string_append_c(*out, '0' + curbit);
-			g_string_append_c(*out, '!' + p);
+				/* Output which signal changed to which value. */
+				g_string_append_c(*out, ' ');
+				g_string_append_c(*out, '0' + curbit);
+				g_string_append_c(*out, '!' + p);
 
-			timestamp_written = TRUE;
-		}
+				timestamp_written = TRUE;
+			}
 
-		if (timestamp_written)
-			g_string_append_c(*out, '\n');
+			if (timestamp_written)
+				g_string_append_c(*out, '\n');
 
-		ctx->samplecount++;
-		memcpy(ctx->prevsample, sample, logic->unitsize);
+			ctx->samplecount++;
+			memcpy(ctx->prevsample, sample, logic->unitsize);
+		}
+		break;
+	case SR_DF_END:
+		/* Write final timestamp as length indicator. */
+		*out = g_string_sized_new(512);
+		g_string_printf(*out, "#%.0f\n",
+				(double)ctx->samplecount / ctx->samplerate * ctx->period);
+		break;
 	}
 
 	return SR_OK;
@@ -232,7 +254,7 @@ static int cleanup(struct sr_output *o)
 
 	ctx = o->internal;
 	g_free(ctx->prevsample);
-	g_array_free(ctx->channelindices, TRUE);
+	g_free(ctx->channel_index);
 	g_free(ctx);
 
 	return SR_OK;