[Android] Crashes when proguard is enabled

[tonygentilcore]

When proguard is enabled on android the app crashes in JNI_OnLoad of libmobileffmpeg.so. The solution for me was to use a heavy hammer and add the line -keep class com.arthenica.mobileffmpeg.** { *; } to my proguard-rules.pro.

It might be the case that there are more exact rules. This issue is to track that and updating any documentation/examples to be proguard friendly.

[tanersener]

Can you please share proguard-rules.pro and build.gradle files used when the crash occurred?

[tonygentilcore]

proguard-rules.pro was empty and build.gradle had:

  buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
            signingConfig signingConfigs.release
        }
    }

I realized after filing this that I should have probably filed this under react-native-ffmpeg as that's what I'm using and it seems likely the issue only repros there.

[tanersener]

No problem, it is about mobile-ffmpeg, it should stay here.

Thank you for sharing it. I managed to reproduce it locally, unfortunately crash is there and you're right; a documentation update is needed for that.

I/mobile-ffmpeg: Loading mobile-ffmpeg.
CheckJNI: method to register "disableNativeRedirection" not in the given class. This is slow, consider changing your RegisterNatives calls.
Failed to register native method com.arthenica.mobileffmpeg.Config.disableNativeRedirection()V in /data/app/com.arthenica.mobileffmpeg.test-1/split_lib_dependencies_apk.apk:classes14.dex
----- class 'Lcom/arthenica/mobileffmpeg/Config;' cl=0x12c68c10 -----
  objectSize=453 (432 from super)
  access=0x0008.0001
  super='java.lang.Class<java.lang.Object>' (cl=0x0)
  vtable (0 entries, 11 in super):
  direct methods (15 entries):
     0: void com.arthenica.mobileffmpeg.Config.<clinit>()
     1: void com.arthenica.mobileffmpeg.Config.<init>()
     2: void com.arthenica.mobileffmpeg.Config.enableLogCallback(com.arthenica.mobileffmpeg.LogCallback)
     3: void com.arthenica.mobileffmpeg.Config.enableNativeRedirection()
     4: void com.arthenica.mobileffmpeg.Config.enableRedirection()
     5: void com.arthenica.mobileffmpeg.Config.enableStatisticsCallback(com.arthenica.mobileffmpeg.StatisticsCallback)
     6: java.lang.String com.arthenica.mobileffmpeg.Config.getNativeBuildConf()
     7: int com.arthenica.mobileffmpeg.Config.getNativeLogLevel()
     8: java.lang.String com.arthenica.mobileffmpeg.Config.getNativeVersion()
     9: java.lang.String com.arthenica.mobileffmpeg.Config.getPackageName()
    10: void com.arthenica.mobileffmpeg.Config.nativeCancel()
    11: int com.arthenica.mobileffmpeg.Config.nativeExecute(java.lang.String[])
    12: void com.arthenica.mobileffmpeg.Config.resetStatistics()
    13: void com.arthenica.mobileffmpeg.Config.setFontDirectory(android.content.Context, java.lang.String, java.util.Map)
    14: void com.arthenica.mobileffmpeg.Config.setFontconfigConfigurationPath(java.lang.String)
  static fields (6 entries):
     0: com.arthenica.mobileffmpeg.Level com.arthenica.mobileffmpeg.Config.activeLogLevel
     1: com.arthenica.mobileffmpeg.Statistics com.arthenica.mobileffmpeg.Config.lastReceivedStatistics
     2: com.arthenica.mobileffmpeg.LogCallback com.arthenica.mobileffmpeg.Config.logCallbackFunction
     3: boolean com.arthenica.mobileffmpeg.Config.runningSystemCommand
     4: com.arthenica.mobileffmpeg.StatisticsCallback com.arthenica.mobileffmpeg.Config.statisticsCallbackFunction
     5: java.util.concurrent.atomic.AtomicReference com.arthenica.mobileffmpeg.Config.systemCommandOutputReference
E/mobile-ffmpeg: OnLoad failed to RegisterNatives for class com/arthenica/mobileffmpeg/Config.
A/art: art/runtime/java_vm_ext.cc:470] JNI DETECTED ERROR IN APPLICATION: JNI NewGlobalRef called with pending exception java.lang.NoSuchMethodError: no static or non-static method "Lcom/arthenica/mobileffmpeg/Config;.disableNativeRedirection()V"

[tanersener]

Android test-application is updated, on develop branch, to include a proguard enabled release build type. Additionally a new ProGuard Configuration wiki page is added.

[tonygentilcore]

Thanks! I verified that the tighter rules worked for me.