sfMidi 1.1 - Play MIDI in SFML

[zorexx]

What is sfMidi?
sfMidi is a static library for playing MIDI files with SoundFont 2 in SFML.
sfMidi uses FluidSynth (http://sourceforge.net/apps/trac/fluidsynth/) to load SoundFont 2 and MIDI files.

GitHub repository:
https://github.com/eXpl0it3r/sfMidi

Hand over to new maintainer:
After a long period of inactivity, I have decided to hand over this project to eXpl0it3r.
Please checkout the GitHub repository for the latest updates on this project.

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Note:
FluidSynth does not support seeking by itself, therefore, in order to seek forward, sfMidi reads and ignores the audio data from FluidSynth until it reaches the desired offset.
However, in order to seek backwards, sfMidi has to reload the MIDI data, and seek forward from the beginning again, hence, seeking backwards will be slower than seeking forward.

Naturally, stopping is considered seeking to the beginning and playing it again, which means the MIDI data has to be reloaded again if we want to stop the MIDI. Thankfully, reloading the MIDI data doesn't take much time.

Also, for looping, I've tried using both the SFML and FluidSynth's loop feature, but unfortunately they did not work at all, so I had to implement my own loop function, which again, requires reloading the MIDI data.

Edit:
I've added a feature to preload MIDI data into audio samples in version 1.0.1, this means you can load the entire MIDI data into memory as audio samples, and this will result in faster and more efficient playback (no more problems with seeking).
Preloading takes quite some time to load, so be careful in choosing whether to preload or not.
Of course, preloading the MIDI data into audio sample means you get to unload the sound font, so you get to save quite some memory, unless your song is long enough to be larger than the sound font.
Preloading takes about 10MB of memory per minute.

[Laurent]

Have you tried to render the MIDI music as audio samples instead of playing it directly? This way you could use it with the audio API (sf::Music, sf::Sound), and you wouldn't lose any feature.

http://fluidsynth.sourceforge.net/api/index.html#UsingSynth

[zorexx]

That is what sfMidi does, audio is played with an sf::SoundStream subclass, sf::Midi.

Edit:
Or did you mean rendering the whole midi file into memory first, then playing it from there? I thought of that before, but then I got the impression that, that would be very memory intensive. But I just did the calculation and it doesn't seem that bad actually, so maybe I'll add a PreloadMidi function or something tomorrow.

[Laurent]

Ok sorry, I should have looked at your code first, or at least read more carefully your description of the limitation :oops:

It's interesting, that makes it a good candidate for a future plugin system. I would even have integrated it directly if the license of FluidSynth was not LGPL (which implies an extra DLL on Windows).

[StormWingDelta]

I was wondering when someone would try to set this up.  Thanks!

By the way.. Where are you getting your Sound Fonts from?  Just wondering since I've never had to use sound fonts before in this way.  The only time I've worked with Midi files is in Java and I've never had to use sound fonts for it.  :?

An idea would be to have a default sound font in your project that doesn't change things too much.  This way someone won't have to download sound fonts if they don't want to or are easily confused like me.

[zorexx]

@Laurent: No problem. About integrating it into SFML, yes, the GPL family is quite a pain, but the only good alternative to this I can find is TiMIDIty++, which is GPL, there's also libjdkmidi but I didn't really look into it because it seems dead, and it's GPL again.

Actually, if the project does not use the MIDI functions, you won't have to include the dll file along with it, right?

@StormWingDelta: I got the sound font from a link in FluidSynth's website, @Stormhttp://sourceforge.net/apps/trac/fluidsynth/wiki/SoundFont
I do think you should include the SoundFont in your project, instead of expecting the user to have one, since they probably don't.

Also, before deciding to use MIDI in your project, do consider using mp3/ogg, or module files (tracker music, check out my other project, sfMod:http://www.sfml-dev.org/forum/viewtopic.php?t=6178) instead, SoundFonts are huge, putting the size on disk aside, take a look at the memory it takes up when you load it, and they are slow to load as well, so I honestly don't really recommend using MIDI in your projects unless you have to.

Edit:
Added the preloading feature and released as version 1.0.1.
Takes quite some time to preload, but you get to unload the sound font file when you're done preloading. Playing, stopping, seeking, and looping will work as if it's a normal sf::Music with preloaded data. Preloaded data is about 10MB per minute.

[Laurent]

Actually, if the project does not use the MIDI functions, you won't have to include the dll file along with it, right?

If it's compiled inside sfml-audio you will have to provide the DLL. That's why it has to be a plugin, so that people that don't need MIDI can just ignore it.

[zorexx]

Hmm, let's say if I'm using sfml-audio to play music, but the file handling and data feeding is done through my own program via SoundStream, in other words, I'm not using the audio file loading capability of sfml, which I presume uses libsndfile.
In this case, I do not need to include the dll of libsndfile in my project, or is this a different case?

[Laurent]

In this case, I do not need to include the dll of libsndfile in my project

You do, because sfml-audio is built with a dependency to libsndfile.dll. It would be optional if it was a dynamically loaded plugin.

[zorexx]

Really? I did not include libsndfile.dll in both sfMod and sfMidi example project, and they both work just fine. Or am I misunderstanding something?

[Laurent]

Can you upload one of these examples?

[zorexx]

It is already included in the full version:
http://www.zorexxlkl.com/files/downloads/sfMidi-1.0.1-full.zip

sfMidiTest folder

for the sfMod one:
http://www.zorexxlkl.com/files/downloads/sfMod-1.0.2-full.zip

sfModTest folder

[Laurent]

With your examples I get "missing DLL" errors for openal32.dll and libsndfile-1.dll, as expected.

If you don't, it means that you've put these DLLs in a directory which is in your PATH environment variable.

[zorexx]

Really? That's odd, because I even tried with libfluidsynth, which I just compiled, and I'm very sure it's not in any directory under my PATH environment variable.

I did this test:
In the sfMidi project, run as usual, works, delete libfluidsynth, does not work (missing dll), edit the file to exclude all the sfMidi functions, (actually, i put those in an if (false) scope), compile, now it works, no missing dll error.

Just wondering, did you recompile the project or run it directly?


Edit:
I just tested it on my sister's laptop, she does not do any sort of programming, and the only missing dlls are msvcp100.dll and msvcr100.dll (runs fine without libfluidsynth.dll as long as I don't call any function from sfMidi)

[Laurent]

You can check which DLLs an executable or DLL depends on with Dependency Walker.

And I find a little strange that your example can run without openal32.dll too -- this one is definitely needed

Just wondering, did you recompile the project or run it directly?

I ran it directly.

I did this test:
In the sfMidi project, run as usual, works, delete libfluidsynth, does not work (missing dll), edit the file to exclude all the sfMidi functions, (actually, i put those in an if (false) scope), compile, now it works, no missing dll error.

It depends how you build sfMidi and the application that uses it. I haven't looked, so I cannot say anything about it.

But anyway, sfml-audio calls functions of libsndfile and openal, so even if what you say was true it wouldn't change anything.

EDIT: do you link SFML statically or dynamically?