vcd: Fix output for more than 8 channels.

[libsigrok.git] / output / vcd.c

diff --git a/output/vcd.c b/output/vcd.c
index 44a12dec37a8c2e2265ea499d4410d61443d5ac3..ffc753281a53f0f0b45c1bea8f2a53ae95da4546 100644 (file)
--- a/output/vcd.c
+++ b/output/vcd.c
@@ -35,6 +35,7 @@ struct context {
        uint8_t *prevsample;
        int period;
        uint64_t samplerate;
+       uint64_t samplecount;
        unsigned int unitsize;
 };
 
@@ -155,7 +156,6 @@ static int receive(struct sr_output *o, const struct sr_dev_inst *sdi,
        unsigned int i;
        int p, curbit, prevbit, index;
        uint8_t *sample;
-       static uint64_t samplecount = 0;
 
        (void)sdi;
 
@@ -174,31 +174,31 @@ static int receive(struct sr_output *o, const struct sr_dev_inst *sdi,
                /* 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);
        }
 
        logic = packet->payload;
        for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
-               samplecount++;
-
                sample = logic->data + i;
 
                for (p = 0; p < ctx->num_enabled_probes; p++) {
                        index = g_array_index(ctx->probeindices, int, p);
-                       curbit = (sample[p / 8] & (((uint8_t) 1) << index)) >> index;
-                       prevbit = (ctx->prevsample[p / 8] & (((uint8_t) 1) << index)) >> index;
+                       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)
+                       if (prevbit == curbit && ctx->samplecount > 0)
                                continue;
 
                        /* Output which signal changed to which value. */
-                       g_string_append_printf(*out, "#%" PRIu64 "\n%i%c\n",
-                                       (uint64_t)(((float)samplecount / ctx->samplerate)
-                                       * ctx->period), curbit, (char)('!' + p));
+                       g_string_append_printf(*out, "#%.0f\n%i%c\n",
+                               (double)ctx->samplecount / ctx->samplerate * ctx->period,
+                               curbit, (char)('!' + p));
                }
 
+               ctx->samplecount++;
                memcpy(ctx->prevsample, sample, ctx->unitsize);
        }