Exploring a World of Sound and Text - SFML Essentials - page 114

Sound versus music
At first glance, the existence of these two classes might seem odd, but they ultimately serve
different purposes, and it's all due to how they are implemented.
The Sound class loads all of its data into system memory, and this makes playing the au-
dio sample very quick. The Music class, on the other hand, opens a stream to a file on the
hard drive (or the RAM) and loads small chunks of data, which are played one after the
other. Due to its design, the Music class has a playback delay due to transferring the data
at such a slow place.
Both the classes provide different benefits—the Sound class almost instantly plays, but
takes a lot of system memory, whereas the Music class is slower to play, but doesn't use
much RAM at all. As such, both the classes are useful in different situations. For example,
if the audio file is small enough to store in system memory, we should load it using the
Sound class. This is applicable when the sound is to be played instantaneously after we
call its play() method. Sometimes, we have to make memory sacrifices when the file is
too big, and it has to be played immediately—that's why resource management is important
(to remove unused assets and load new ones). The Music class, on the other hand, is
mostly used for big audio files, where it is not important even if their playback is delayed a
bit at the start. This class is mostly used for the background music in the game.
Sound and Music have the same class in their inheritance tree, SoundSource , which
provides a common audio functionality, such as altering the pitch and 3D positioning.The
Sound class derives from it directly, whereas Music derives from SoundStream . Fin-
ally SoundStream derives from SoundSource . The following diagram demonstrates
their relation:
We will find out more about SoundSource and SoundStream later in this chapter.