vcd: Output timestamp only once per change.

[libsigrok.git] / output / vcd.c

diff --git a/output/vcd.c b/output/vcd.c
index ffc753281a53f0f0b45c1bea8f2a53ae95da4546..49d2d195a409e5da702de6d2b00729ff9a1c4348 100644 (file)
--- a/output/vcd.c
+++ b/output/vcd.c
@@ -156,6 +156,7 @@ static int receive(struct sr_output *o, const struct sr_dev_inst *sdi,
        unsigned int i;
        int p, curbit, prevbit, index;
        uint8_t *sample;
+       gboolean timestamp_written;
 
        (void)sdi;
 
@@ -182,22 +183,37 @@ static int receive(struct sr_output *o, const struct sr_dev_inst *sdi,
        logic = packet->payload;
        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_probes; p++) {
                        index = g_array_index(ctx->probeindices, int, 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;
 
+                       /* 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_printf(*out, "#%.0f\n%i%c\n",
-                               (double)ctx->samplecount / ctx->samplerate * ctx->period,
-                               curbit, (char)('!' + p));
+                       g_string_append_c(*out, ' ');
+                       g_string_append_c(*out, '0' + curbit);
+                       g_string_append_c(*out, '!' + p);
+
+                       timestamp_written = TRUE;
                }
 
+               if (timestamp_written)
+                       g_string_append_c(*out, '\n');
+
                ctx->samplecount++;
                memcpy(ctx->prevsample, sample, ctx->unitsize);
        }