sr: sr_samplerate_string: Allow 3.15Hz etc. as output.

This is required for some hardware, e.g. ChronoVu LA8, where
33.333333 MHz or 2.439024 MHz are valid samplerates. This is because the
hardware takes a sampleperiod (in nanoseconds) as input, not a
samplerate (in Hz).

diff --git a/strutil.c b/strutil.c
index 9a791e1950f7c05e7f029bb99d509866e6f23007..9232ed2f56d96a28b608d9f52fb88cc0374d3c9e 100644 (file)
--- a/strutil.c
+++ b/strutil.c
@@ -27,7 +27,8 @@
 /**
  * Convert a numeric samplerate value to its "natural" string representation.
  *
- * E.g. a value of 3000000 would be converted to "3 MHz", 20000 to "20 kHz".
+ * E.g. a value of 3000000 would be converted to "3 MHz", 20000 to "20 kHz",
+ * 31500 would become "31.5 kHz".
  *
  * @param samplerate The samplerate in Hz.
  *
@@ -38,26 +39,30 @@
 SR_API char *sr_samplerate_string(uint64_t samplerate)
 {
        char *o;
-       int r;
+       uint64_t s = samplerate;
 
-       /* Allocate enough for a uint64_t as string + " GHz". */
-       if (!(o = g_try_malloc0(30 + 1))) {
-               sr_err("strutil: %s: o malloc failed", __func__);
-               return NULL;
+       if ((s >= SR_GHZ(1)) && (s % SR_GHZ(1) == 0)) {
+               o = g_strdup_printf("%" PRIu64 " GHz", s / SR_GHZ(1));
+       } else if ((s >= SR_GHZ(1)) && (s % SR_GHZ(1) != 0)) {
+               o = g_strdup_printf("%" PRIu64 ".%" PRIu64 " GHz",
+                                   s / SR_GHZ(1), s % SR_GHZ(1));
+       } else if ((s >= SR_MHZ(1)) && (s % SR_MHZ(1) == 0)) {
+               o = g_strdup_printf("%" PRIu64 " MHz", s / SR_MHZ(1));
+       } else if ((s >= SR_MHZ(1)) && (s % SR_MHZ(1) != 0)) {
+               o = g_strdup_printf("%" PRIu64 ".%" PRIu64 " MHz",
+                                   s / SR_MHZ(1), s % SR_MHZ(1));
+       } else if ((s >= SR_KHZ(1)) && (s % SR_KHZ(1) == 0)) {
+               o = g_strdup_printf("%" PRIu64 " kHz", s / SR_KHZ(1));
+       } else if ((s >= SR_KHZ(1)) && (s % SR_KHZ(1) != 0)) {
+               o = g_strdup_printf("%" PRIu64 ".%" PRIu64 " kHz",
+                                   s / SR_KHZ(1), s % SR_KHZ(1));
+       } else {
+               o = g_strdup_printf("%" PRIu64 " Hz", s);
        }
 
-       if (samplerate >= SR_GHZ(1))
-               r = snprintf(o, 30, "%" PRIu64 " GHz", samplerate / 1000000000);
-       else if (samplerate >= SR_MHZ(1))
-               r = snprintf(o, 30, "%" PRIu64 " MHz", samplerate / 1000000);
-       else if (samplerate >= SR_KHZ(1))
-               r = snprintf(o, 30, "%" PRIu64 " kHz", samplerate / 1000);
-       else
-               r = snprintf(o, 30, "%" PRIu64 " Hz", samplerate);
-
-       if (r < 0) {
-               /* Something went wrong... */
-               g_free(o);
+       if (!o) {
+               sr_err("strutil: %s: Error creating samplerate string.",
+                      __func__);
                return NULL;
        }