Add code to read audio_backend_silent_lead_in_time settings.

audio_ao.c

@@ -54,6 +54,19 @@ static int init(int argc, char **argv) {
   // get settings from settings file first, allow them to be overridden by command line options
 
   if (config.cfg != NULL) {
+      /* Get the desired length of the period of silence before the audio starts. */
+    if (config_lookup_float(config.cfg, "ao.audio_backend_silent_lead_in_time",
+                            &dvalue)) {
+      if ((dvalue < 0.05) || (dvalue > 4)) {
+        pthread_mutex_unlock(&alsa_mutex);
+        die("Invalid ao audio_backend_silent_lead_in_time \"%f\". It "
+            "must be between 0.050 and 4.0 seconds. Omit setting to use the default value, which is approximately the latency specified by the source (typically 2 seconds). A value greater than the latency is ignored.",
+            dvalue);
+      } else {
+        config.audio_backend_silent_lead_in_time = dvalue;
+      }
+    }
+
     /* Get the desired buffer size setting. */
     if (config_lookup_int(config.cfg, "ao.audio_backend_buffer_desired_length", &value)) {
       if ((value < 0) || (value > 66150)) {