Welcome to Exploring Computing.
Today's video is Digital Music, Part 5, Perfect Music
and Alternative Formats.
So in this video, we're going to take
a look at some alternative ways of storing your music.
We've seen that MP3 files and its related cousins,
like AAC and WMA, lose information.
Is there a way we can store music and have
better-sounding files?
Well, there is.
And this particular format has been
gaining a lot in popularity.
It's called FLAC.
It stands for Free Lossless Audio Codec.
Apple and Microsoft have their own versions that
have similar characteristics.
Basically, what FLAC does is, it takes the original CD audio,
and it compresses it.
But similar to the PNG files we saw
when we were talking about images,
the FLAC compression does not lose any information.
So if you're using FLAC, your FLAC file
should sound every bit as good as the original CD.
Now, I should caution you-- and this is why I had the question
mark in the original title for this video--
you are still digitizing your music.
So the original music was digitized.
There are people that don't think 44.1 kilohertz
with 16-bit sound is good enough.
And in your homework, you'll get to play around
with a couple of alternative formats that store more bits
and have a higher sampling rate, but those really
haven't taken off.
But as far as what you can do with most digital recordings
that are available to you today, FLAC
is probably your best choice.
So here we can see the comparison
of how much space a five-minute FLAC
song takes, versus a five-minute MP3 song,
versus a CD audio song.
And we can see that the size of the FLAC file, 35.67 megabytes,
is actually a lot closer to the 50.47
megabytes of the original CD audio file
than it is to the 4.5 megabytes for MP3.
So we're not saving that much space.
We're saving some space, but not a huge amount of space.
But the good news is, if your dog's listening to your music,
and they miss those really high tones
that the MP3 cuts off, with FLAC,
they'll be able to hear them all.
OK, our next format is actually quite interesting.
I'm going to play you a original copy of Beethoven's "Fifth
Symphony" briefly.
[MUSIC - BEETHOVEN "FIFTH SYMPHONY"]
And here's Beethoven's "Fifth Symphony"
played with a different file format.
Let's see what you think of this one.
[MUSIC - BEETHOVEN "FIFTH SYMPHONY"]
Well, what did you think?
Which one did you like better?
So some of you are thinking, why in the world
would I want to use that second file format?
And that's actually a really great question.
Well, here's the answer.
In the original that we listened to,
Beethoven's "Fifth Symphony" was being stored as a sound wave.
And we've been talking about what
you can do with these sound waves
through the entire video sequence.
But that second recording of "Beethoven's Fifth"
was actually something quite different.
That was a MIDI file.
And what MIDI files do is, they store the individual notes
rather than storing sound wave.
So this has a number of advantages.
First of all, simply from a file-space perspective,
the MIDI file takes a much, much less space than a sound file
does.
Keep in mind that, with a sound file,
we've got 44,100 samples per second.
And so if a file is just a couple of seconds,
that's a huge number of samples.
And if you compare that to how many notes
those couple of seconds represent,
well, they don't represent that many notes.
And so you can certainly store a MIDI in much less space.
But that's not the real point of the MIDI file.
The real point of the MIDI file this.
What we're seeing here is, this is a program called Songworks.
And it's designed to work with and manipulate MIDI files.
And so you can see, when we're working with a MIDI file,
we're thinking of the music as individual notes.
We are able to manipulate the individual notes,
and we can see the individual notes.
And so, if you're a composer or musician,
you may find that MIDI files are much more
useful for your purposes than the formats based
on sound waves that we've been taking a look at, like CD
audio, MP3, and even FLAC.
So that's it for this week.
Next week, we're going to take a look at computer hardware.
CS106E is going to go into deep dive
on how central processing unit works
and how computer memory works.
And CS105 is going to start off with a look at computer
hardware and then move on to take a look at how
the internet works.
I look forward to seeing you then.