Improved tutorial for sync audio with music, use two approaches.

audio/bpm_sync/Control.gd

@@ -7,18 +7,34 @@ var playing = false
 const COMPENSATE_FRAMES = 2
 const COMPENSATE_HZ = 60.0
 
+const SYNC_SOURCE_SYSTEM_CLOCK = 0
+const SYNC_SOURCE_SOUND_CLOCK = 1
+
+var sync_source = SYNC_SOURCE_SYSTEM_CLOCK
+
+
 func strsec(secs):
 	var s = str(secs)
 	if (s.length()==1):
 		s="0"+s
 	return s
 	
-# warning-ignore:unused_argument
+# used by system clock
+var time_begin 
+var time_delay
+
 func _process(delta):
 	if (!playing or !$Player.playing):
 		return
 	
-	var time = $Player.get_mix_time() + AudioServer.get_time_since_last_mix() - AudioServer.get_output_latency() + (1/COMPENSATE_HZ)*COMPENSATE_FRAMES
+	var time 
+	if (sync_source == SYNC_SOURCE_SYSTEM_CLOCK): 
+		# obtain from ticks
+		time = (OS.get_ticks_usec() - time_begin) / 1000000.0
+		# compensate
+		time -= time_delay		
+	elif (sync_source == SYNC_SOURCE_SOUND_CLOCK):		
+		time = $Player.get_playback_position() + AudioServer.get_time_since_last_mix() - AudioServer.get_output_latency() + (1/COMPENSATE_HZ)*COMPENSATE_FRAMES
 		
 	var beat = int(time * BPM / 60.0)
 	var seconds = int(time)
@@ -26,8 +42,18 @@ func _process(delta):
 	$Label.text = str("BEAT: ",beat % BARS +1,"/",BARS," TIME: ",seconds/60,":",strsec(seconds%60)," / ",seconds_total/60,":",strsec(seconds_total%60))
 	
 
-func _on_Button_pressed():
-	print(AudioServer.get_output_latency())
+
+func _on_PlaySystem_pressed():
+	pass # Replace with function body.
+	sync_source = SYNC_SOURCE_SYSTEM_CLOCK
+	time_begin = OS.get_ticks_usec()
+	time_delay = AudioServer.get_time_to_next_mix() + AudioServer.get_output_latency()
 	playing=true
 	$Player.play()
 
+
+func _on_PlaySound_pressed():
+	sync_source = SYNC_SOURCE_SOUND_CLOCK
+	playing=true
+	$Player.play()
+	

audio/bpm_sync/play_button.png.import → audio/bpm_sync/play_sound_button.png.import

@@ -2,15 +2,15 @@
 
 importer="texture"
 type="StreamTexture"
-path="res://.import/play_button.png-c6659eb2fbf2022d9e670864776e465a.stex"
+path="res://.import/play_sound_button.png-7e88216154de1a5cb6304cbd3751ed46.stex"
 metadata={
 "vram_texture": false
 }
 
 [deps]
 
-source_file="res://play_button.png"
-dest_files=[ "res://.import/play_button.png-c6659eb2fbf2022d9e670864776e465a.stex" ]
+source_file="res://play_sound_button.png"
+dest_files=[ "res://.import/play_sound_button.png-7e88216154de1a5cb6304cbd3751ed46.stex" ]
 
 [params]
 

audio/bpm_sync/play_sound_button_hl.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/play_sound_button_hl.png-8d86f81fe37a5f2959088b0948283133.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://play_sound_button_hl.png"
+dest_files=[ "res://.import/play_sound_button_hl.png-8d86f81fe37a5f2959088b0948283133.stex" ]
+
+[params]
+
+compress/mode=0
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=0
+flags/filter=true
+flags/mipmaps=false
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+stream=false
+size_limit=0
+detect_3d=true
+svg/scale=1.0

audio/bpm_sync/play_button_hl.png.import → audio/bpm_sync/play_system_button.png.import

@@ -2,15 +2,15 @@
 
 importer="texture"
 type="StreamTexture"
-path="res://.import/play_button_hl.png-63644aa33cad39ca169b518c7eed7ae2.stex"
+path="res://.import/play_system_button.png-683c51b4d13189b67bb57e75cbb8ef56.stex"
 metadata={
 "vram_texture": false
 }
 
 [deps]
 
-source_file="res://play_button_hl.png"
-dest_files=[ "res://.import/play_button_hl.png-63644aa33cad39ca169b518c7eed7ae2.stex" ]
+source_file="res://play_system_button.png"
+dest_files=[ "res://.import/play_system_button.png-683c51b4d13189b67bb57e75cbb8ef56.stex" ]
 
 [params]
 

audio/bpm_sync/play_system_button_hl.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path="res://.import/play_system_button_hl.png-1e926e5d1be4f71f60454646aaa44d20.stex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://play_system_button_hl.png"
+dest_files=[ "res://.import/play_system_button_hl.png-1e926e5d1be4f71f60454646aaa44d20.stex" ]
+
+[params]
+
+compress/mode=0
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=0
+flags/filter=true
+flags/mipmaps=false
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+stream=false
+size_limit=0
+detect_3d=true
+svg/scale=1.0

audio/bpm_sync/player.tscn

@@ -1,9 +1,12 @@
-[gd_scene load_steps=7 format=2]
+[gd_scene load_steps=10 format=2]
 
 [ext_resource path="res://the_comeback2.ogg" type="AudioStream" id=1]
 [ext_resource path="res://Control.gd" type="Script" id=2]
 [ext_resource path="res://lcd.ttf" type="DynamicFontData" id=3]
-[ext_resource path="res://play_button.png" type="Texture" id=4]
+[ext_resource path="res://play_system_button.png" type="Texture" id=4]
+[ext_resource path="res://play_sound_button.png" type="Texture" id=5]
+[ext_resource path="res://play_system_button_hl.png" type="Texture" id=6]
+[ext_resource path="res://play_sound_button_hl.png" type="Texture" id=7]
 
 [sub_resource type="StyleBoxFlat" id=1]
 bg_color = Color( 0, 0, 0, 1 )
@@ -29,14 +32,25 @@ custom_fonts/font = SubResource( 2 )
 custom_colors/font_color = Color( 0.552941, 0.984314, 0.501961, 1 )
 align = 1
 
-[node name="Button" type="TextureButton" parent="."]
-margin_left = 433.316
-margin_top = 244.158
-margin_right = 561.316
-margin_bottom = 372.158
+[node name="Player" type="AudioStreamPlayer" parent="."]
+stream = ExtResource( 1 )
+
+[node name="PlaySystem" type="TextureButton" parent="."]
+margin_left = 214.737
+margin_top = 187.368
+margin_right = 342.737
+margin_bottom = 315.368
 texture_normal = ExtResource( 4 )
 texture_pressed = ExtResource( 4 )
+texture_hover = ExtResource( 6 )
 
-[node name="Player" type="AudioStreamPlayer" parent="."]
-stream = ExtResource( 1 )
-[connection signal="pressed" from="Button" to="." method="_on_Button_pressed"]
+[node name="PlaySound" type="TextureButton" parent="."]
+margin_left = 622.105
+margin_top = 183.158
+margin_right = 750.105
+margin_bottom = 311.158
+texture_normal = ExtResource( 5 )
+texture_pressed = ExtResource( 5 )
+texture_hover = ExtResource( 7 )
+[connection signal="pressed" from="PlaySystem" to="." method="_on_PlaySystem_pressed"]
+[connection signal="pressed" from="PlaySound" to="." method="_on_PlaySound_pressed"]