Replace fmod on Linux with SDL Audio or something similar

[slackmoehrle]

Users have stated that we are not truly open-source on Linux because we require fmod. This isn't free and they have no other options. During our weekly meeting @ricardoquesada suggested that we could offer SDL Audio as an alternative and let users turn on fmod if they choose to. @linshun agreed. The timing of this change is TBD.

@slackmoehrle is happy to test when ready.

[ricardoquesada]

yes, other alternatives are:

• use ALSA driver directly
• or use PulseAudio

[minggo]

Can refer to #16410. The PR use OpenAL for linux.

[JOOpdenhoevel]

I don't really know how powerful/fast/etc. those alternatives are, but from my point of view, OpenAL has a big advantage: It's a cross-platform library. The implementation for Windows only uses OpenAL, MPEG, and Vorbis, which are available for Windows as well as for Linux. Due to this fact, I could simply copy the source files and it worked. All tests were positive, the C++ test and the Lua test. Another option would be to merge those implementations into one which would make maintaining the engine way easier. I could do that for Linux and Windows if you like this idea.

[minggo]

@Janonard you are right. @dumganhar i think you can take a look too. I think it is better that we can use OpenAL as possible, then it is easy to main the codes.

[minggo]

Another option would be to merge those implementations into one which would make maintaining the engine way easier. I could do that for Linux and Windows if you like this idea.

Yep, it is better.

[dumganhar]

Agree this.

We only need OpenSLES for Android & OpenAL for other platforms. Easily maintaining our engine is really important.

BTW, we also need to improve New Audio Engine since I think the logic isn't very clear for developer to understand, we need to do more encapsulation, abstraction and documentation.

[chuckhacker]

OpenAL-soft has a OpenSLES driver built-in:

https://github.com/kcat/openal-soft/blob/2f1f7f4c6aaf54f9361865d508d82cdf027368bf/Alc/backends/opensl.c

[cirosantilli]

In particular, this blocks a Debian package from being created.

And creates problems that we can't solve properly because no source, e.g.:

• porting fmod: https://github.com/cocos2d/cocos2d-x/issues/18001
• binary file build option quirks: https://github.com/cocos2d/cocos2d-x/issues/15137#issuecomment-338345077

[v1993]

It also may create big problems with licensing target product.

[v1993]

Is there any progress in this direction?

[v1993]

Any progress?

[halx99]

@dumganhar Actual, OpenAL also can be use at android platform, recently, I have done it, and seems ok.

[minggo]

Any document about it?

[halx99]

Just compile openal, mpg123, ogg for android arm, then copy win32 implementation to android, and do some changes for log & file stream adapt.

[minggo]

I think OpenAL uses some system functions provided by Android, and i don't know if it has issue on some devices or some Android versions. It is not provided by Android, and also not Android documentation mention it, so it has big risk.

[halx99]

you can see it's backends has a opensl.c for android.

[halx99]

So, at android platform, OpenAL based on OpenSL. use it, we only needs maintains one audio engine framework.

[minggo]

Sounds good.

[halx99]

@minggo @dumganhar Recently, I finish this, you can see the patch: https://github.com/halx99/x-studio365/tree/master/cocos2d-x-patch

[minggo]

@halx99 It is great. @drelaptop please take a look. It is good if we can use OpenAL for all platforms.

[drelaptop]

OK, this week I will try to test and confirm OpenAL works or not on android platform. If works well, I can do replace recently.

[halx99]

@drelaptop By the way, I have test with ndkr14b + gcc, it work fine. maybe you need test ndkr16 + clang.

[halx99]

@drelaptop I create 2 pr, you can simple to apply it to test it. https://github.com/cocos2d/cocos2d-x/pull/18958 https://github.com/cocos2d/cocos2d-x-3rd-party-libs-bin/pull/317

I have test on ndk-r17 + clang, it also work fine.

[drelaptop]

you are so efficient, I will check it at once.

[crazyhappygame]

Please read my comments about Android OpenAL and mpg123 https://github.com/cocos2d/cocos2d-x/pull/18961#issuecomment-407562295 I think that we should not add new LGPL *.so libraries to Android!

I am fine with OpenAL and mpg123 for Linux (it is better than fmod :) )

[drelaptop]

@slackmoehrle could you help us check the License issue in your free time?

[ildar]

@halx99 , can I ask if it's any progress with Linux migration? BTW, @crazyhappygame , as windows part already uses OpenAL isn't it straightforward?

[crazyhappygame]

I am fine with OpenAL and mpg123 for Linux (it is better than fmod :) )

(nothing changed for Android I think that we should not add new LGPL *.so libraries to Android!)

[halx99]

I have test on ubuntu 18.04, the OpenAL works fine.

[ildar]

Could you please clarify how to build with OpenAL for Linux target?

[halx99]

Actually, LGPL.*.so allow free to use, and the apple os platform intrgrate OpenAL ad system framework, so, I think all platform, OpenAL is a good choice for audio framework backend.

[halx99]

And, in our project practice, OpenAL works well at android platform, and solve a deadlock bug on some android device when quickly stop/play music, see: https://github.com/cocos2d/cocos2d-x/issues/18000

[ildar]

Could you please clarify how to build with OpenAL for Linux target?

@HALX99 , do you build Cocos2d unpatched or with your patch? if the latter then where's the latest patch located?

[halx99]

I have build with cocos2d-x-3.17

[crazyhappygame]

@halx99 could you create PR for Linux only?

[halx99]

I will create when I have time

[drelaptop]

that will be better, if we do https://github.com/cocos2d/cocos2d-x/issues/16307 after this issue solved.

[halx99]

https://github.com/cocos2d/cocos2d-x/issues/18000, this is another reason why I recommand we also should use openal at android platform.