reduce analog_sample sizes.

[libsigrok.git] / output / output_vcd.c

diff --git a/output/output_vcd.c b/output/output_vcd.c
index 2157c1ba5c1cd4ab1fa4cba9109e7d2799991dad..b21bfb92d83d17b87816011ba84b0c9165b812fb 100644 (file)
--- 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;