output/csv: complete and improve timestamp construction support

[libsigrok.git] / src / output / csv.c

diff --git a/src/output/csv.c b/src/output/csv.c
index ea328c4b092a8eee5c498c71ea946ce8e4dd8594..296d9a06b0ab541037b588b63a42f7d62b13a619 100644 (file)
--- a/src/output/csv.c
+++ b/src/output/csv.c
@@ -93,8 +93,9 @@ struct context {
        uint32_t num_samples;
        uint32_t channel_count, logic_channel_count;
        uint32_t channels_seen;
-       uint64_t period;
-       uint64_t sample_time;
+       uint64_t sample_rate;
+       uint64_t sample_scale;
+       uint64_t out_sample_count;
        uint8_t *previous_sample;
        float *analog_samples;
        uint8_t *logic_samples;
@@ -218,31 +219,28 @@ static GString *gen_header(const struct sr_output *o,
        GString *header;
        GSList *channels, *l;
        unsigned int num_channels, i;
-       uint64_t samplerate = 0, sr;
        char *samplerate_s;
 
        ctx = o->priv;
        header = g_string_sized_new(512);
 
-       if (ctx->period == 0) {
+       if (ctx->sample_rate == 0) {
                if (sr_config_get(o->sdi->driver, o->sdi, NULL,
                                  SR_CONF_SAMPLERATE, &gvar) == SR_OK) {
-                       samplerate = g_variant_get_uint64(gvar);
+                       ctx->sample_rate = g_variant_get_uint64(gvar);
                        g_variant_unref(gvar);
                }
 
                i = 0;
-               sr = 1;
-               while (sr < samplerate) {
+               ctx->sample_scale = 1;
+               while (ctx->sample_scale < ctx->sample_rate) {
                        i++;
-                       sr *= 1000;
+                       ctx->sample_scale *= 1000;
                }
-               if (samplerate)
-                       ctx->period = sr / samplerate;
                if (i < ARRAY_SIZE(xlabels))
                        ctx->xlabel = xlabels[i];
-               sr_info("Set sample period to %" PRIu64 " %s",
-                       ctx->period, ctx->xlabel);
+               sr_info("Set sample rate, scale to %" PRIu64 ", %" PRIu64 " %s",
+                       ctx->sample_rate, ctx->sample_scale, ctx->xlabel);
        }
        ctx->title = (o->sdi && o->sdi->driver) ? o->sdi->driver->longname : "unknown";
 
@@ -271,8 +269,8 @@ static GString *gen_header(const struct sr_output *o,
                        g_string_truncate(header, header->len - 1);
                }
                g_string_append_printf(header, "\n");
-               if (samplerate != 0) {
-                       samplerate_s = sr_samplerate_string(samplerate);
+               if (ctx->sample_rate != 0) {
+                       samplerate_s = sr_samplerate_string(ctx->sample_rate);
                        g_string_append_printf(header, "%s Samplerate: %s\n",
                                               ctx->comment, samplerate_s);
                        g_free(samplerate_s);
@@ -280,6 +278,10 @@ static GString *gen_header(const struct sr_output *o,
                ctx->did_header = TRUE;
        }
 
+       /* Time column requested but samplerate unknown. Emit a warning. */
+       if (ctx->time && !ctx->sample_rate)
+               sr_warn("Samplerate unknown, cannot provide timestamps.");
+
        return header;
 }
 
@@ -401,6 +403,8 @@ static void process_logic(struct context *ctx,
 static void dump_saved_values(struct context *ctx, GString **out)
 {
        unsigned int i, j, analog_size, num_channels;
+       double sample_time_dbl;
+       uint64_t sample_time_u64;
        float *analog_sample, value;
        uint8_t *logic_sample;
 
@@ -418,8 +422,8 @@ static void dump_saved_values(struct context *ctx, GString **out)
                if (ctx->label_do) {
                        if (ctx->time)
                                g_string_append_printf(*out, "%s%s",
-                                       ctx->label_names ? "Time" :
-                                       ctx->xlabel, ctx->value);
+                                       ctx->label_names ? "Time" : ctx->xlabel,
+                                       ctx->value);
                        for (i = 0; i < num_channels; i++) {
                                g_string_append_printf(*out, "%s%s",
                                        ctx->channels[i].label, ctx->value);
@@ -442,7 +446,6 @@ static void dump_saved_values(struct context *ctx, GString **out)
                        ctx->previous_sample = g_malloc0(analog_size + ctx->num_logic_channels);
 
                for (i = 0; i < ctx->num_samples; i++) {
-                       ctx->sample_time += ctx->period;
                        analog_sample =
                            &ctx->analog_samples[i * ctx->num_analog_channels];
                        logic_sample =
@@ -464,9 +467,16 @@ static void dump_saved_values(struct context *ctx, GString **out)
                                       analog_sample, analog_size);
                        }
 
-                       if (ctx->time)
+                       if (ctx->time && !ctx->sample_rate) {
+                               g_string_append_printf(*out, "0%s", ctx->value);
+                       } else if (ctx->time) {
+                               sample_time_dbl = ctx->out_sample_count++;
+                               sample_time_dbl /= ctx->sample_rate;
+                               sample_time_dbl *= ctx->sample_scale;
+                               sample_time_u64 = sample_time_dbl;
                                g_string_append_printf(*out, "%" PRIu64 "%s",
-                                       ctx->sample_time, ctx->value);
+                                       sample_time_u64, ctx->value);
+                       }
 
                        for (j = 0; j < num_channels; j++) {
                                if (ctx->channels[j].ch->type == SR_CHANNEL_ANALOG) {