added comments and edited README

README.md

@@ -70,6 +70,7 @@ target/release/librespot --username USERNAME --cache CACHEDIR --name DEVICENAME
 | Option   |       | backend             | Audio backend to use. Use '?' to list options   | BACKEND     |
 | Option   |       | device              | Audio device to use. Use '?' to list options    | DEVICE      |
 | Option   |       | mixer               | Mixer to use                                    | MIXER       |
+| Option   |       | initial-volume      | Initial volume in %, once connected [0-100]     | VOLUME      |
 
 Taken from here:
 https://github.com/ComlOnline/librespot/blob/master/src/main.rs#L88

src/main.rs

@@ -135,27 +135,32 @@ fn setup(args: &[String]) -> Setup {
     let mixer = mixer::find(mixer_name.as_ref())
         .expect("Invalid mixer");
     let initial_volume;
+    // check if initial-volume argument is present
     if matches.opt_present("initial-volume"){
+        // check if value is a number
         if matches.opt_str("initial-volume").unwrap().parse::<i32>().is_ok(){
+            // check if value is in [0-100] range, otherwise put the bound values
             if matches.opt_str("initial-volume").unwrap().parse::<i32>().unwrap() < 0 {
                 initial_volume = 0 as i32;
             }
             else if matches.opt_str("initial-volume").unwrap().parse::<i32>().unwrap() > 100{
                 initial_volume = 0xFFFF as i32;
             }
+            // checks ok
             else{
                 initial_volume = matches.opt_str("initial-volume").unwrap().parse::<i32>().unwrap()* 0xFFFF as i32 / 100 ;
             }
-
         }
+        // if value is not a number use default value (50%)
         else {
             initial_volume = 0x8000 as i32;
         }
     }
+    // if argument not present use default values (50%)
     else{
         initial_volume = 0x8000 as i32;
         }
-    info!("Volume \"{}\" !", initial_volume);
+    debug!("Volume \"{}\" !", initial_volume);
 
     let name = matches.opt_str("name").unwrap();
     let use_audio_cache = !matches.opt_present("disable-audio-cache");