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Audio files contain actual sound recording while MIDI files are a type of computer program. Converting audio to midi is a nearly impossible task.

I would like to convert a .wmv file to a .mid file. All I want is the sound not the picture. I can't find any software to do this. Any ideas?

Ideas, yes. But not answers.

The problem is that there's a fundamental difference between .wmv files and .mid files - and I'm not even taking the video content into account.

They're so different that the conversion you're asking for is darned near impossible.

At least for today's computers.

I'll summarize it this way: what you're asking for is a program that can listen to a symphony and produce the sheet music that the musicians are playing from.

"Converting audio to MIDI ... is an enormous task"

To the best of my knowledge that program doesn't exist.

Now, let me explain what I mean by that statement.

Audio Recording

A .wmv file contains a recording of actual audio. Let's say it's a performance of a piano concerto; what the .wmv file contains is a recording of the sound that was produced when someone played that concerto on the piano.

Throw the video away and it's a recording of sound. Nothing more, nothing less.

In that respect, it's the same as a .mp3 file, a .wav file or any of a number of other audio formats.

A ".mid" file is very different.


A ".mid" file, short for MIDI which stands for Musical Instrument Digital Interface is most assuredly not a recording of audio. Rather, it's a series of instructions - not unlike a computer program.

For example a .mid file for our piano concerto might have instructions like:

  • Piano: A# quarter note

  • Piano: B quarter note

  • Piano: A# half note & C half note & E half note

Note: I am nowhere near being a musician - what I just wrote probably sounds awful. Smile

In addition to my lack of musical skills, that "music" is also a gross over-simplification; MIDI is an incredibly complex and rich language for instruction what should be played when.

And therein lies the difference: MIDI is a series of instructions - notes to be played by what instrument and how.

It's not a recording of a performance; it's not sound; it's instructions.

Hence MIDI is a kind of sheet music for computers. When a computer "plays" a MIDI file, it also has to have a synthesizer of some sort - and Windows typically has a rudimentary one built in. As a result when instructed to play "Piano: A# quarter note", it uses the built in synthesizer to generate the sound of something that kind-of, sort-of sounds like a piano.

Converting One To Another

Converting a MIDI file to sound is relatively easy: you run it through a midi player which drives either a synthesizer, or some computer-enabled instruments that then play the instructions contained in the file. If you want an audio recording file like a .mp3, you simply record the performance in some way.

Converting audio to MIDI, on the other hand, is an enormous task. It really is like listening to our piano concerto and writing down as it goes the extremely detailed instructions that would have resulted in that performance.

And that's just a piano concerto - one instrument. Imagine trying to write down the sheet music from simply listening to a symphony. Or a rock song.

It's just not something that can be done today.

Article C4484 - October 9, 2010 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

Greg Bulmash
October 9, 2010 6:03 PM

"It's just not something that can be done today."

Is that a challenge?

Sure. Let me know when you're done, will ya? Smile

Mark Jacobs
October 10, 2010 2:16 AM

In the Coreldraw there was a program called CorelTrace which converted a raster (bitmap) drawing into a vector drawing (.cdr). Isn't this an analogous process converting a .wav to mid. Of course the .wav is much more complex than a 2 dimensional drawing but isn't it a similar idea?

Kind of. I guess it'd be like taking a photo of the Mona Lisa and expecting the vector graphics conversion to produce acceptible results. Still unlikely given today's technology.

Ken B
October 11, 2010 1:42 PM

Actually, I think it's closer to taking a picture of the Mona Lisa, and having the program generate the instructions for painting it. (Remember, the MIDI file doesn't describe the sounds, but rather gives instructions to produce it.)

Consider, too, the fact that the .wmv file may not even be music, but might be animal sounds, or human speech, or any other sounds for that matter.

Well, vector graphics are, kind of, the instructions for generating a particular graphic image, but yes, your point is very well taken.

October 12, 2010 9:05 AM

I found these with a quck Google search (haven't tried them):
Says it converts .wmv to .mp3
Says it converts .mp3 to midi

Or am I misunderstanding something here?

Alex Tonna
October 12, 2010 9:51 AM

Actually the question I understood was basically "How to extract the Audio from an WMV file"
A WMV is in fact a video file ( Windows Media Video)
To seperate the audio from the video all you need is a good "medium level" Video Editing software. These normally have the option of seperating the audio from the video channel. I use Corel Video Studio x 2 and it does it in one clik. You will then find your Audio file in one of the working folders of the same program.
I believe Cyberlink Power Producer does that as well and certainly many others out there.
Good Luck

Jeff Turner
October 12, 2010 10:01 AM

I would record the music right off the sound card into a separate high end digital recorder, and then tweak that recording a little with compression, and some type of aural exciter when doing the final master. This will hide the audio shortcomings of the sound card. Also something like an Ebtech noise filter will help. It's your sound card that will give you the most trouble though. Converting wav to midi is easy, but unless you're going to replace or enhance separate tracks, why bother. It sounds liek you just want a particular audio recording without a visual reference.

Mike Castro`
October 12, 2010 10:21 AM

Leo is dead on. The best you will be able to do is insert a sound file into a sequencer like Cubase Studio 4 or Logic. Assume you have a midi file in a sequencer, you can add a soundfile for any source be it a guitar plyed straight in or an exsiting recording. The sequencer saves the resulting sound as a WAV file which is automatically inserted at the right place. If you recorded an existing record you could "play" along with it and add extra tracks ( take a John Lennon track like Imagine, you sould add strings to it. If you are after something which will turn the soundfile into midi tracks I am afriad you are going to unlucky, its the midi musicians holy grail. The best you can do is get a programme which strips out the lead vocal and you could then add the track to a sequencer midi file as a WAV insert. ( these work by working out which sounds are to the left and right, they then ignore everything which is dead centre, most lead vocals are centred. Its not an exact science, if the lead is dounble tracked and panned slightly left and right at say 11 and 1 o'clock it wont work. )

If you find something which does what you wnat please let us all know !

AG Wright
October 12, 2010 2:45 PM

I've been recording, printing and playing music on computers since DOS days. There is no program that will do what the original questioner wants done and won't be for quite a while.
WMV is a digital audio file.
A midi file has three types of data, what pitch, what duration and what instrument.
There are several programs that will convert midi into printed music and many recording programs can convert midi into audio.
Usually when I want a midi of any particular tune I put the title of the tune in a Google search like this "tune name" midi. It usually will find anything I need.

October 12, 2010 4:41 PM

If you only want to record sound{eg mp3} & not really midi as stated,
then play the Youtube music clip or other video format and use the free program Audacity to record the sound only whilst the vidoe clip plays.

Save the recorded sound as wav or mp3.
I do this regularly.


October 12, 2010 4:45 PM

however ..if you really do mean midi files as stated, I once used a free program that will emulate the audio sound and try to recreate a midi file ..but it is only an approximation and is not really that accurate.

October 12, 2010 6:56 PM

Sounds like Leo is saying that midi is to music what Postscript is to printing. A language
to describe what should be created.

October 12, 2010 7:54 PM

Not so, all wrong I'm afraid! The question appears to be clear, how to convert an audio file (.wmv in this case), to midi data or a .mid file?

Its a process nearly all midi users (apart from expert sequencers perhaps), would like to have access to, since it enables the generation of a midi sequence from an audio file such as an mp3 or wav file (say from a commercially available CD).

The problem is that the audio file is a polyphonic and multi-instrument source and the best that the most of the software that is available (to convert audio signals into midi data), can do, is to produce a midi data sequence from a single sound or instrument source.

The problem is (and always has been), that there are problems with pitch recognition and tracking of fast passages of notes, which is compounded by the fact that what is required to make this conversion effective and thus produce a useable midi file, is that the software must simultaneously recognise the pitches and note sequences of many instruments and produce an accurate sequence of midi data for each of these instruments, preferably in separate tracks (or more correctly, separate midi channels).

There are some examples of software that can convert an audio source, such as a microphone's output or electric guitar etc, into midi data sequences, but (for the reasons given above), they cannot (yet), consistently produce a useable midi sequence from an audio source which includes multi-instruments.

The software is getting better (I think "MagicEar" is one of the leaders in this field), it manages to produce multi channel, midi sequences from a multi-instrument audio source, but the process is difficult and frequently produces inconsistent or wrong results.

Its remarkable that it can be achieved at all, since the software has to guess at which instrument is which (ie separate the instruments out on the basis of pitch range, unique characteristics etc), and then has to simultaneously identify the pitch and duration of each note for each instrument and generate the appropriate, separate midi channel containing the instructions for the midi sound source to reproduce an approximation of the original audio sounds.

Long winded response I know, but midi is one of my passions. The "Intelliscore" software is different altogether, what it does is recognise notes etc (using Optical Character Recognition processes), from a musical score and generate the appropriate midi data to enable a midi sequencer to play back the score, it also has problems with multi tracks, recognition of the charaters and correctly generating the appropriate pitches and note divisions etc, but its easier than audio to midi, however you have to have the complete, accurate musical score of the audio file (song?), you wish to produce a midi sequence (file), for.

Good luck finding the software, I've been looking and trying for years, please let me know if you find something that works consistently and accurately.

PS: you CAN convert midi to audio, any midi sound source (or tone generator if you like), can do it (including, these days), the most basic computer sound cards. I think "RJ" might have stated it the wrong way around, in which case its difficult but not impossible.

There is software available that can generate a music score from a midi file, but not so far as I am aware and, as Leo says, from an audio source.

October 13, 2010 12:03 AM

Update to my previous post: I did not recall the names of the software programs correctly and was thinking of "Midi Notate" when I commented on "Intelliscore" saying that it was just a score recognition program. Similarly, I was thinking of "Digital Ear" when I said "Magic Ear".

Intelliscore is now in its 8th edition and if you try it out to convert even a simple (meaning few instruments, say a "rock quartet" - one of the ensembles Intelliscore suggests for multi-instrument conversion), audio track from a CD or an mp3 file you will find that the results are unuseable as a music track or backing sequence.

The timing is all over the place, the pitch is similarly inaccurate, the instruments are merged together and the relative volume of the various instruments appears to vary with the "beat" of the music, some drop out altogether.

Given the variables involved and the problems in getting a machine (computer + program and microphone), to be able to listen, identify and discern the difference between the individual intstruments in an "ensemble" the way that the human ear can, appears to be impossible at the present time.

October 25, 2010 3:16 PM

Midi's are so easy to find. just find the music in the midi format to start with. Then it is easy to convert it to another format.

December 19, 2010 11:32 AM

melodyne will convert audio to midi... for example, if i play a guitar solo, then it can convert the notes to their midi counterparts (does a pretty decent job)... the basic version of melodyne works only with monophonic sounds, but there is another version that will even deconstruct polyphonic stuff like chords and all that mess... yonzers

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