Godot Tutorial -- Playing Sound FX and Music Video Lecture | Godot Game: Learn and Master - Game Development

hello this is my key game scratch
welcome back to our I'm going to do
tutorial series today's lesson we're
going to be taking a look at playing
streams and samples in Godot to
translate that back into normal English
you can more or less think of a stream
as music and a sample as sound effects
it's a little bit different than that
we'll cover the differences shortly but
those are the basics in your - we're
gonna be looking at playing sound
effects and music sound effects a lot of
times are things that you things like
the ding when Mario jumps in to power up
or the the sound where your gun makes
when it shoots a lot of times they'll be
concurrent you need them to play
instantaneously so the big thing with
those then when they're called samples
and Godot parlance but a sample is
memory resident it's uncompressed and
loaded into memory which means it's
quick to load it takes up some resources
but they're faster to play less
intensive to play but they do take up
more memory on the other hand streamed
is your longer form sound effects
basically it's your soundtrack you can
think of it as mp3 file type things the
sounds are the music that will play in
the background as you go they're
generally stored on disk in a compressed
form so they're more CPU intensive to
use but they take up a lot less space
since they're compressed they're not as
fast to retrieve they're not something
that's appropriate for a real-time
playback then we probably could play
them real time but it's not a really
efficient way to do things but your
sound effect or your music playing in
the background
generally isn't that real time intensive
so that's the trade-off between to tune
between the two so just in your mind
think of a sample as a sound effect
stored in memory generally uncompressed
although there's an option to keep it
compressed so it is processor intensive
but memory intensive and you can do
multiple instances at the same time on
the other hand then you've got your
streams which are stored on disk in a
compressed form and generally this is
where your music is stored let's look at
the two they're very simple to use in
Godot however you do have
a bit of a multi-step process you've got
to jump through first off we're actually
gonna need a couple of files the
cross-platform nature get though kind of
dictates that you use two formats for
samples it actually imports WAV file WAV
was more or less a raw waveform format
each bit within the waveform is actually
replicating the waveform that the sound
wave makes so there's no compression
going on by default and you can have up
to two channels so stereo sound up to
forty four point one kilohertz which is
the amount of fidelity in the way form
or in more normal English how good this
thing sounds but with Godot you actually
import the sample in and it does
whatever conversion you need so you
probably want to keep your waveform if
you're recording or making WAV files for
your for your game at your end you
probably want to record them as high a
detail as possible and then do the
conversion into Godot which we'll cover
in a second the streaming files however
generally you want to store them either
in OGG for OGG Vorbis format which is an
open source alternative to mp3 mp3
itself probably the most common formula
format for music encoding it's also an
incumbent it so it's something you
should probably want to stay away from
technically if your game makes a lot of
money you have to pay the mp3 board
royalties for it so a lot of people are
actually staying away from mp3 format
now unfortunately certain hardware
especially in the Apple world really
wants to use mp3 so from the DOS side of
things loose according to their
documentation the number two formats the
two formats to use for encoding your
streaming audio or your long-form your
songs and such are aughh so OGG Vorbis
or MPC now if you don't have your files
in those formats no problem at all
there's actually a program that you
should get to know and it's called
audacity I don't know if I've already
talked about this or not this is a
completely free format so a completely
free program that allows you to edit
your waveforms and transfer between any
file format you want so don't get overly
hung up on what format you're working in
you can use audacity to easily
convert them but what you want is your
scientific to follow along here for your
samples you're going to want WAV files
and for your sound effects you're going
to want so Gigi or MPC now what I often
use to get them there's a sound here
called freesound.org thesaurus right
here called freesound.org it's a free
sign up but then you can basically
download that well probably thousands
maybe tens of thousands or even hundreds
of thousands of different song samples
or sound sample sorry or even songs that
people have done we're gonna need an OGG
format song you come in here you can
press play and sample whatever it is on
the tropical isle alright that one's bad
come on
all right actually I don't even care so
we'll just go in here we'll grab whoops
I'll download one of these as song one
on
I'm on burial and scribe a different one
one a song two very popular songs here
okay so I got a pair of songs here if I
go into my as always download folder I
already got a song too
okay so I'll just go ahead and rename
this one assuming it plays just a sec
there we go
we'll call that one song one now with
your songs or your your streamed audio
you actually just copy it into your file
into your file hierarchy so like so and
sound demo to you just drop them in like
that
now for your waveforms rush you're going
to cover off first they need to be
imported so now let's just get a couple
of sound effects here
firearm reloading sounds good to me and
let's describe something else random
cannon that's open o w MV just a second
that was a wave I got right okay gunshot
let's hope it's good alright so I got
two waveforms I think I actually only
need one but back to my download here
I'll use this one from before so I got
siren and let's go with shot dot wave
alright so now that we have our sound
effects to work with they know obviously
you can get your files from wherever you
want but you just need to be in the wav
format or ODG format and once again
freesound.org is a very good resource
for that as you just saw so you have
your sound effect you want to go ahead
and play them in your 2d scene all you
do is actually go ahead and create
something called a sample player you'll
notice there's there's actually three of
them there's the sample player 2d which
has two deep auditioning information
attached you can actually physically put
it you see here it inherits from node to
D that means it has positional
information it can be dropped in your 2d
world and then you can have left-right
stereo effects being done with it
spatial here is a 3d player so you can
actually drop it in a 3d physical world
but we're actually just going to go
ahead with a standard plain-jane
sample player so just come on in here
create a note of sample player obviously
you normally wouldn't do it as your root
node but this is a demo so obviously I'm
just illustrating it that way
so we've added in there's no graphic
attached because it's not inherited from
node so it's not a visible place Abal
item which is just fine so now we have a
sample player we need to go ahead and
create a sample library this is a step
that's a little bit different from other
game engines if you've worked in the
past you more or less you bring in all
the your sound effect files into sample
libraries and start playing from there
aught to create one you just select your
sample player that you created over here
and go into your inspector down here and
see what it says samples you just drop
this down and say create a new sample
library alright now that you got that go
ahead and then edit it this brings you
into the editor view for your sample
library now there's a bit of a catch
here that you should be wearing right
away
you can't get out of here a bit of a UI
overlook hopefully it's something that
they'll fix in an upcoming fruit version
but you'll notice as I switch between
things it doesn't do anything so if you
actually want to get out up here you
just go back to and then pick a note and
you're back in your world alright so
once you're in the editor mode for
sample library there's not an easy way
to jump out of it it's just a little
strange but and if so here is your where
you edit your samples here's where you
bring them in and port them etc I'm just
gonna go up here to import we're gonna
import an audio sample and you just find
the file in your drive hierarchy it
doesn't need to be directly in your
folder so just go ahead with no it's not
windows it's downloads so users me
downloads and we want shot and siren you
can control click to multiple select and
go ahead with open you know what that
might be a very bad idea I was going to
do a single select for now
to him so then once you've actually
picked a sound effect like so then
you've got a number of options you can
set down here from the top basically you
can do 8-bit encoding by default there
will be 16 bits so you'll have your size
but you'll also will more than have your
fidelity doodle for mono if you do not
need a stereo sound effect if there's no
left and right channel if it's just like
a gunshot that doesn't pan you might as
well make it model because there you're
doubling up the size for no gain at all
so mono is one channel as opposed to
stereo so again if you don't have any
positional information in your sound if
it doesn't pan left to right if there's
no variant click this you'll have your
size this is got controlling the actual
fidelity that it's recorded at 44 point
1 kilohertz is the same quality as a CD
CDs are recorded at you could do some
editing here you can make this sound
loop over and over again you can trim it
down a bit
plus you can like I said you can have
them compressed don't so there you go
ahead you import it and last thing you
do is you know you just pick where you
want it to go will put it in the route
you could create a folder for your sound
effects or whatever but to go ahead
choose that okay so we just imported the
shot WAV file I accidentally opened this
up I don't know how all right so that
was just import if you come over here
you're looking your file system you'll
now see you now have an SMP file this is
a sample file that Godot is actually
generated from that wave we just passed
in and now well back in your your audio
of library right here I'm just going
here and go open and we'll add it so
there you go you can see we now have a
sound effect in our library it's called
shot and that was taken from the file
name and this name is very important and
it's also case sensitive so when you're
bringing in your file that is actually
what determines this and I'm not sure if
you can actually oh yeah you can't edit
it okay so this name right here is
important and is case sensitive alright
so let's move on a little bit so now
that we have our our sample player over
here let's go back down to the inspector
you can see we've set the samples in it
there's a number of things you can set
for audio specific we're not going to do
really any of these things right now but
we aren't going to do is go ahead and
attach a script to this guy and we'll
put it in the root so and create and I'm
going to show you how to go ahead and
play an audio effect very simple ready
all you do is call play and that's in
that case sensitive
sound effect name alright so we will
save that so save the scene and
configure it as I run scene this should
all be familiar by now
those now let's go ahead and run and pop
there you go so that is how you play an
audio file very very simple now what
you're gonna often run into though is
wanting to play it from somewhere you
aren't like we just played it in terms
of inside of the audio player itself
that's not gonna happen very often what
you're normally going to do is call the
sample player from other code let's do a
quick demo of that I don't know if I've
covered UI components at all if if I
haven't I apologize and I'm actually
gonna cover this a little bit more in
the future so I'm not gonna go into much
detail what I'm doing I'm gonna be
adding a button to the world and we're
gonna then play our sound when you press
the button the details of how this is
working
oops the details of how this is working
don't get overly plussed on them why are
you now work okay button create there we
go so there's our button play sound
that's that stupid press ENTER to commit
play the sound enter ah there we go so
now what we want to do is actually play
this sound on this button press let's
add a script to our button over here my
button so alright I head back to our
scene our button and we want to connect
it so once again I will cover this the
UI components a little bit more detail
later on I think I've already gone
through a little bit of this but if this
is completely Greek to you don't worry
we will look at this a little bit more
detail later on so here's the function
it's going to be called on that button
is pressed and now when you actually
want to call a node from elsewhere like
if you want to call the sample player
from somewhere else in your code well
you'll notice the sample player was
created off the root of our tree or our
scene graph so all we need to do is do
get tree it's like this that will
basically be the root well technically
that will be the root and now we just
got to get the node and get it by name
and we called it sample player as you
can see here and then now like so okay
so when you press the button you're
going to get the very top of our scenery
at the root node find the node name
sample player and then we now have a
handle to our sample player which we
just call play for the sound effect
named shot once again shot is the
case-sensitive name of the particular
sound effect within our sound library
and we run this oh yeah I still calling
it unload and each time we press our
button our sound effect plays
I'll stop playing now now one thing you
probably didn't hear from that sound
effect it's the fact that each time I
press the button there it was starting
it again and that's because we're
actually doing it as unique sound so
each time you play a unique sound
it literally if it's already playing
start it again now there is something
you can play multiple times much so you
have say seven or eight concurrent
gunshots you want to have the sound
effects all play independently you don't
want the sound effect to start over you
want to play them in parallel in Godot
this comes back to something called
voices you see right here basically you
can think of voices as channels or
concurrent sounds and let's go ahead
Jack that up the four like so so now we
can play up the four sound effects at
the same time there's a little bit more
work to be done now the catch is that
sound effect for the gunshot is way too
short so let's go back into our library
and add another one
Amy import and I want siren this time
and everything else is fine
alright why did you not okay that's what
we got okay now bring that in alright so
again now I have another side effect
called siren and see look at the
waveform here in the preview you notice
how they're identical so this one
they're a little bit different each each
channel is actually doing something
different in this one they're the exact
same way for both channels this is all
those cases where I should have made it
mono and my father size would actually
be halved your other values here are
your decibel and your oh come on brain
work I'll P scale is pitch playback
speed more or less so if you want to do
it all Mickey Mouse you can increase
this up if you want to slow it down you
can turn this down but you can see a
sample of your waveform right here and
you can actually play it right there
you can stop playing it up here and you
can delete it using this so that's how
you add another sound effect so we've
added siren which as you heard goes on
much longer now let's head on back to
our code here hi
so switch this up to siren like so and
we just want to add one more parameter
here if we go here the second value is
unique and what you're saying is yes
this is a unique instance so when I call
it again it's going to play another one
until I have up to four playing so now
when I go ahead and play this alright
each time I press the button it'll start
a siren so I'm gonna have multiple
sirens going at the same time up to four
all right
am i backwards in my logic sorry my
logic was incredibly reversed that true
value is actually saying it's unique
it's not the value it is is unique so if
you say yes it means it's a unique
instance that sounds so that every place
you would be the same version so by
saying false you're saying nope create a
new one so sorry my logical in there was
reversed but that is what you got to do
if you want to play multiple at the same
time all you do is pass in false for
that second parameter there now you've
got some times is you're gonna want to
control that instance once it's playing
so you have your sound effect itself
which is stored in our library but each
instance can actually be controlled
differently can have a different volume
and so on and this is something you
handily do with something called a voice
ID and this play call is actually
returning an ID to us each time so let's
just let's break this code up make it a
little bit easier to read so if our
player equals get it reference to our
player player dot play and then we'll
play our siren sound like so
but it's returning a value called voice
ID so for each unique instance we will
get
a voice ID back like so and then using
that voice ID we can now control
individual values of that so for example
set volume and you pass into the set
volume the ID to manipulate and the
amount as a value I believe from 0 to 1
so here let's have the volume of our
sirens and pipe so to illustrate that a
little bit better
that's tenth of the volume there you go
so using voice ideas how did you allows
you to manipulate an instance of a
playing sound that's kind of it really
playing sound effects is very simple you
create your sample you import your
sample into a sample library samples can
be shared between multiple sample
libraries sample libraries can be reused
although I don't can't really think of
why you'd want to offhand but that's
kind of it you bring your your wave WAV
file in as a sample library you either
imported a stereo mono and depending on
your resolution or each one adds to the
amount of space taken combined on mobile
devices or HTML targeting when that
comes you're going to want to keep the
file size down if you can help it so if
it doesn't need to be stereo if it
doesn't need to be forty four point one
kilohertz that's a weight of really
optimized space there so consider when
you're doing your import to set those
values down you saw it was part of the
import sample process so when you're
encoding or recording or whatever you're
doing as high fidelity as you could ever
want and I'll let good--do take care of
the resizing for you if you wish now
let's take a look at music music is
actually incredibly simple as you saw
earlier we just dropped a couple of
files into IR to our file system okay
they've not been imported they
definitely should be there sound demo -
okay so we got song 1 and suck - there
alright so song one song - dot o GG so
we just want to go ahead and play them
the process is almost identical
instead of
the sample player however let's uh let's
purge a bit here by bit I mean pretty
much let's get rid of everything and
which go in here and we will grab
instead Stream player once again you've
got one that can exist in the 3d world
or just the regular plain Jane well
we're just gonna go ahead with the plain
Jane one the logic between the different
players is actually not that not that
different there's more functionality in
this 2d and spatial version but that's
pretty much the extent so you can
obviously figure that stuff out on your
own no problem so there's our stream
player added to the scene I'm probably
gonna have make a save now alright okay
and now we just want to set up our
stream so let's pick our stream player
go over to inspector here and you'll see
this value here for stream and we just
drop it down the different up player
types supported we want to just go ahead
with the opechee so GG version right
here like so and we want to load one
yeah we will go with song one like so
and you can actually without any code at
all you can just come in here go
autoplay and that might be enough that's
good there you go so there's your song
just playing you want to loop it you'd
set that to true let's we start now go
and play again so no code version
literally just drop it in and off you go
however a lot of times you're gonna
actually want to queue one song to play
after another song after another song
just as easy let's look at that process
first thing let's go here and add sure
for our stream player then we're going
to add a little bit of code here we're
gonna have it so after your one song
finishes we're gonna go ahead and play
another one now let me just show you how
that works let's go back to our scene
get him set so we don't want a loop and
we don't want to
autoplay anymore so we've got song 1 set
as our stream you can only set one
stream at a time however you can quite
easily load and change them on your own
and let's show you that so in the code
behind for our stream player here let's
create song one song two and current
song is currently set to SOG one okay
yeah it's scared of all this and we will
put this in our process so we need to
tell it we want a process and next up
we're going to go ahead and load song to
loading things yourself is super simple
and Godot so long - equals guess how you
do it you call load yeah that's it so
loading files in Godot very very simple
and that will return it an instance of a
song for us
so now let's implement our process and
all we want to do here is check if our
current song is done playing if it is
swap it very simple logic so self that
is playing so as any song playing
you
oh sorry if there's no song fight so we
want to detect that the playing is done
as opposed to currently playing so first
we're checking are we currently not
playing any songs so it means we've
stopped play if that's the case we will
go and get the stream which is the value
we set over here and that's just got the
get stream like so and we check to see
if it is song one if it is we will go
self dot set stream and set it to song
two like so otherwise we set it to song
like so and finally we play now once
again I am actually in the stream player
doing this code which is why I'm getting
away with the self dot calling you can
get the stream player as a note just
like we did with the sample player so
you could call this what I think is
quite common to do is to put a stream
player and a song plow sort of stream
player and a sample player in near the
root of your scene hierarchy and call it
wherever you need it as opposed to
calling it itself like this but you can
do it either way and as you see this one
will now go ahead it'll give me an error
because I forgot a semicolon there saw
one over maybe I should
uhh
strong one set of the song to set aside
one loading song to overhear I am
loading song obviously have a logic
error here living song one
let me just check to see what see what
each one of these things is alright saw
one - ah I bad where you don't ever
actually play someone
ends use some - song - ends a song -
ending in queueing song
if kids dream equals song one set stream
to song who you are never returning the
song one
ah
I am never defining song 1 alright
that's a bit of an oversight song 1
equals self thought get straight alright
song 1 never actually had any meaning
song 1 finished playing song 2 goes so
I'm 2 finishes playing song 1 goes why 1
finishes playing and back and this will
go on literally forever sorry a bit of a
bit of a mistake on my end so quickly go
through the code right here obviously
I'm setting it so we have a per frame
update I load the second song using the
load function of Godot the first one we
already loaded via the in store right
here so I simply get a reference to it
and I start off playing this also could
be achieved using auto play right here
but here I'm doing it in code instead so
then each frame we check to see if we
are currently not playing a song so in
other words the song that was playing is
done and in case it is done we flip
between our two songs it helps to
actually define what both songs are
otherwise it will always evaluate to the
else condition which is what was
happening there and then finally once
we've once we've solved our swapped our
strong sad that can't speak once we've
swapped our songs to be playing we then
start the streaming player off playing
again but basically that's the extent of
it the playing sound effects and music
in Godot is a very very very
straightforward you basically either use
a string player or a sample player add
it somewhere in your scene graph you can
call it to auto load using the inspector
to change it when bringing your samples
in samples are uncompressed WAV files
which then you can either compress them
which will have a performance hit but
will make your file sizes a bit smaller
so if you have a very very large which
probably shouldn't but if you have a
very large sound sample you're playing a
lot you might make sense to compress it
but it probably makes more sense to not
make it so large to be honest whereas
your stream player your stuff your music
your background stuff is stored on disk
you literally just copy it into your
folder hierarchy and then you use a
stream player to play it
as you saw from where we very first
started you don't need to use code at
all you could literally just set it as
the stream player set the stream setup
to autoplay and loop and then you've got
infinite music playing with no code at
all on top of what we all looked at
right here there's actually some more
advanced versions of each one there is
also a stream player space spatial as
well as a sample player 2d and a sample
player spatial the biggest difference is
those ones have positional information
and can mimic some positional panning in
your headset itself so they allow
themselves to be placed in a world
spacial being 3d 2d being CBD but for
the most part they work exactly the same
otherwise so you create your your
library for the sample players you add
all your files to it and that's about it
I hope that was useful I hope you
enjoyed that thank you very much bye