fix(YouTube - Force original audio): Disable a/b feature flag that forces localized audio (#5582)

extensions/youtube/src/main/java/app/revanced/extension/youtube/patches/ForceOriginalAudioPatch.java

@@ -24,6 +24,16 @@ public class ForceOriginalAudioPatch {
         }
     }
 
+    /**
+     * Injection point.
+     */
+    public static boolean ignoreDefaultAudioStream(boolean original) {
+        if (Settings.FORCE_ORIGINAL_AUDIO.get()) {
+            return false;
+        }
+        return original;
+    }
+
     /**
      * Injection point.
      */
@@ -50,7 +60,6 @@ public class ForceOriginalAudioPatch {
             return isOriginal;
         } catch (Exception ex) {
             Logger.printException(() -> "isDefaultAudioStream failure", ex);
-
             return isDefault;
         }
     }

patches/src/main/kotlin/app/revanced/patches/youtube/video/audio/Fingerprints.kt

@@ -1,23 +1,27 @@
 package app.revanced.patches.youtube.video.audio
 
 import app.revanced.patcher.fingerprint
+import app.revanced.util.containsLiteralInstruction
 import com.android.tools.smali.dexlib2.AccessFlags
 
-internal val streamingModelBuilderFingerprint = fingerprint {
+internal val formatStreamModelToStringFingerprint = fingerprint {
     accessFlags(AccessFlags.PUBLIC, AccessFlags.FINAL)
-    returns("L")
-    strings("vprng")
+    returns("Ljava/lang/String;")
+    custom { method, classDef ->
+        method.name == "toString" && classDef.type ==
+                "Lcom/google/android/libraries/youtube/innertube/model/media/FormatStreamModel;"
+    }
 }
 
-internal val menuItemAudioTrackFingerprint = fingerprint {
-    accessFlags(AccessFlags.PUBLIC, AccessFlags.FINAL)
-    parameters("L")
-    returns("V")
-    strings("menu_item_audio_track")
+internal const val AUDIO_STREAM_IGNORE_DEFAULT_FEATURE_FLAG = 45666189L
+
+internal val selectAudioStreamFingerprint = fingerprint {
+    accessFlags(AccessFlags.PUBLIC, AccessFlags.STATIC)
+    returns("L")
+    custom { method, _ ->
+        method.parameters.size > 2 // Method has a large number of parameters and may change.
+                && method.parameters[1].type == "Lcom/google/android/libraries/youtube/innertube/model/media/PlayerConfigModel;"
+                && method.containsLiteralInstruction(AUDIO_STREAM_IGNORE_DEFAULT_FEATURE_FLAG)
+    }
 }
 
-internal val audioStreamingTypeSelector = fingerprint {
-    accessFlags(AccessFlags.PRIVATE, AccessFlags.FINAL)
-    returns("L")
-    strings("raw") // String is not unique
-}

patches/src/main/kotlin/app/revanced/patches/youtube/video/audio/ForceOriginalAudioPatch.kt

@@ -5,22 +5,22 @@ import app.revanced.patcher.extensions.InstructionExtensions.addInstructionsWith
 import app.revanced.patcher.extensions.InstructionExtensions.getInstruction
 import app.revanced.patcher.patch.bytecodePatch
 import app.revanced.patcher.util.proxy.mutableTypes.MutableField.Companion.toMutable
-import app.revanced.patcher.util.proxy.mutableTypes.MutableMethod
 import app.revanced.patcher.util.proxy.mutableTypes.MutableMethod.Companion.toMutable
 import app.revanced.patches.all.misc.resources.addResources
 import app.revanced.patches.all.misc.resources.addResourcesPatch
 import app.revanced.patches.shared.misc.settings.preference.SwitchPreference
 import app.revanced.patches.youtube.misc.extension.sharedExtensionPatch
+import app.revanced.patches.youtube.misc.playservice.is_20_07_or_greater
+import app.revanced.patches.youtube.misc.playservice.versionCheckPatch
 import app.revanced.patches.youtube.misc.settings.PreferenceScreen
 import app.revanced.patches.youtube.misc.settings.settingsPatch
-import app.revanced.util.getReference
+import app.revanced.util.findMethodFromToString
 import app.revanced.util.indexOfFirstInstructionOrThrow
+import app.revanced.util.insertLiteralOverride
 import com.android.tools.smali.dexlib2.AccessFlags
 import com.android.tools.smali.dexlib2.Opcode
 import com.android.tools.smali.dexlib2.builder.MutableMethodImplementation
-import com.android.tools.smali.dexlib2.iface.Method
 import com.android.tools.smali.dexlib2.iface.instruction.OneRegisterInstruction
-import com.android.tools.smali.dexlib2.iface.reference.MethodReference
 import com.android.tools.smali.dexlib2.immutable.ImmutableField
 import com.android.tools.smali.dexlib2.immutable.ImmutableMethod
 import com.android.tools.smali.dexlib2.immutable.ImmutableMethodParameter
@@ -37,6 +37,7 @@ val forceOriginalAudioPatch = bytecodePatch(
         sharedExtensionPatch,
         settingsPatch,
         addResourcesPatch,
+        versionCheckPatch
     )
 
     compatibleWith(
@@ -60,29 +61,25 @@ val forceOriginalAudioPatch = bytecodePatch(
             )
         )
 
-        fun Method.firstFormatStreamingModelCall(
-            returnType: String = "Ljava/lang/String;"
-        ): MutableMethod {
-            val audioTrackIdIndex = indexOfFirstInstructionOrThrow {
-                val reference = getReference<MethodReference>()
-                reference?.definingClass == "Lcom/google/android/libraries/youtube/innertube/model/media/FormatStreamModel;"
-                        && reference.returnType == returnType
-            }
-
-            return navigate(this).to(audioTrackIdIndex).stop()
+        // Disable feature flag that ignores the default track flag
+        // and instead overrides to the user region language.
+        if (is_20_07_or_greater) {
+            selectAudioStreamFingerprint.method.insertLiteralOverride(
+                AUDIO_STREAM_IGNORE_DEFAULT_FEATURE_FLAG,
+                "$EXTENSION_CLASS_DESCRIPTOR->ignoreDefaultAudioStream(Z)Z"
+            )
         }
 
-        // Accessor methods of FormatStreamModel have no string constants and
-        // opcodes are identical to other methods in the same class,
-        // so must walk from another class that use the methods.
-        val isDefaultMethod = streamingModelBuilderFingerprint.originalMethod.firstFormatStreamingModelCall("Z")
-        val audioTrackIdMethod = menuItemAudioTrackFingerprint.originalMethod.firstFormatStreamingModelCall()
-        val audioTrackDisplayNameMethod = audioStreamingTypeSelector.originalMethod.firstFormatStreamingModelCall()
-        val formatStreamModelClass = proxy(classes.first {
-            it.type == audioTrackIdMethod.definingClass
-        }).mutableClass
+        val isDefaultAudioTrackMethod = formatStreamModelToStringFingerprint.originalMethod
+            .findMethodFromToString("isDefaultAudioTrack=")
+        val audioTrackDisplayNameMethod = formatStreamModelToStringFingerprint.originalMethod
+            .findMethodFromToString("audioTrackDisplayName=")
+        val audioTrackIdMethod = formatStreamModelToStringFingerprint.originalMethod
+            .findMethodFromToString("audioTrackId=")
 
-        formatStreamModelClass.apply {
+        proxy(classes.first {
+            it.type == audioTrackIdMethod.definingClass
+        }).mutableClass.apply {
             // Add a new field to store the override.
             val helperFieldName = "isDefaultAudioTrackOverride"
             fields.add(
@@ -103,7 +100,7 @@ val forceOriginalAudioPatch = bytecodePatch(
 
             // Add a helper method because the isDefaultAudioTrack() has only 2 registers and 3 are needed.
             val helperMethodClass = type
-            val helperMethodName = "extension_isDefaultAudioTrack"
+            val helperMethodName = "patch_isDefaultAudioTrack"
             val helperMethod = ImmutableMethod(
                 helperMethodClass,
                 helperMethodName,
@@ -143,7 +140,7 @@ val forceOriginalAudioPatch = bytecodePatch(
             methods.add(helperMethod)
 
             // Modify isDefaultAudioTrack() to call extension helper method.
-            isDefaultMethod.apply {
+            isDefaultAudioTrackMethod.apply {
                 val index = indexOfFirstInstructionOrThrow(Opcode.RETURN)
                 val register = getInstruction<OneRegisterInstruction>(index).registerA
 

patches/src/main/kotlin/app/revanced/util/BytecodeUtils.kt

@@ -32,7 +32,10 @@ import com.android.tools.smali.dexlib2.iface.instruction.RegisterRangeInstructio
 import com.android.tools.smali.dexlib2.iface.instruction.ThreeRegisterInstruction
 import com.android.tools.smali.dexlib2.iface.instruction.TwoRegisterInstruction
 import com.android.tools.smali.dexlib2.iface.instruction.WideLiteralInstruction
+import com.android.tools.smali.dexlib2.iface.reference.FieldReference
+import com.android.tools.smali.dexlib2.iface.reference.MethodReference
 import com.android.tools.smali.dexlib2.iface.reference.Reference
+import com.android.tools.smali.dexlib2.iface.reference.StringReference
 import com.android.tools.smali.dexlib2.immutable.ImmutableField
 import com.android.tools.smali.dexlib2.util.MethodUtil
 import java.util.EnumSet
@@ -171,6 +174,79 @@ internal val Instruction.isBranchInstruction: Boolean
 internal val Instruction.isReturnInstruction: Boolean
     get() = this.opcode in returnOpcodes
 
+/**
+ * Find the instruction index used for a toString() StringBuilder write of a given String name.
+ *
+ * @param fieldName The name of the field to find.  Partial matches are allowed.
+ */
+private fun Method.findInstructionIndexFromToString(fieldName: String) : Int {
+    val stringIndex = indexOfFirstInstruction {
+        val reference = getReference<StringReference>()
+        reference?.string?.contains(fieldName) == true
+    }
+    if (stringIndex < 0) {
+        throw IllegalArgumentException("Could not find usage of string: '$fieldName'")
+    }
+    val stringRegister = getInstruction<OneRegisterInstruction>(stringIndex).registerA
+
+    // Find use of the string with a StringBuilder.
+    val stringUsageIndex = indexOfFirstInstruction(stringIndex) {
+        val reference = getReference<MethodReference>()
+        reference?.definingClass == "Ljava/lang/StringBuilder;" &&
+                (this as? FiveRegisterInstruction)?.registerD == stringRegister
+    }
+    if (stringUsageIndex < 0) {
+        throw IllegalArgumentException("Could not find StringBuilder usage in: $this")
+    }
+
+    // Find the next usage of StringBuilder, which should be the desired field.
+    val fieldUsageIndex = indexOfFirstInstruction(stringUsageIndex + 1) {
+        val reference = getReference<MethodReference>()
+        reference?.definingClass == "Ljava/lang/StringBuilder;" && reference.name == "append"
+    }
+    if (fieldUsageIndex < 0) {
+        // Should never happen.
+        throw IllegalArgumentException("Could not find StringBuilder append usage in: $this")
+    }
+    val fieldUsageRegister = getInstruction<FiveRegisterInstruction>(fieldUsageIndex).registerD
+
+    // Look backwards up the method to find the instruction that sets the register.
+    var fieldSetIndex = indexOfFirstInstructionReversedOrThrow(fieldUsageIndex - 1) {
+        fieldUsageRegister == writeRegister
+    }
+
+    // If the field is a method call, then adjust from MOVE_RESULT to the method call.
+    val fieldSetOpcode = getInstruction(fieldSetIndex).opcode
+    if (fieldSetOpcode == MOVE_RESULT ||
+        fieldSetOpcode == MOVE_RESULT_WIDE ||
+        fieldSetOpcode == MOVE_RESULT_OBJECT) {
+        fieldSetIndex--
+    }
+
+    return fieldSetIndex
+}
+
+/**
+ * Find the method used for a toString() StringBuilder write of a given String name.
+ *
+ * @param fieldName The name of the field to find.  Partial matches are allowed.
+ */
+context(BytecodePatchContext)
+internal fun Method.findMethodFromToString(fieldName: String) : MutableMethod {
+    val methodUsageIndex = findInstructionIndexFromToString(fieldName)
+    return navigate(this).to(methodUsageIndex).stop()
+}
+
+/**
+ * Find the field used for a toString() StringBuilder write of a given String name.
+ *
+ * @param fieldName The name of the field to find.  Partial matches are allowed.
+ */
+internal fun Method.findFieldFromToString(fieldName: String) : FieldReference {
+    val methodUsageIndex = findInstructionIndexFromToString(fieldName)
+    return getInstruction<ReferenceInstruction>(methodUsageIndex).getReference<FieldReference>()!!
+}
+
 /**
  * Adds public [AccessFlags] and removes private and protected flags (if present).
  */
@@ -594,7 +670,7 @@ fun Method.indexOfFirstInstructionReversed(targetOpcode: Opcode): Int = indexOfF
 
 /**
  * Get the index of matching instruction,
- * starting from and [startIndex] and searching down.
+ * starting from [startIndex] and searching down.
  *
  * @param startIndex Optional starting index to search down from. Searching includes the start index.
  * @return The index of the instruction.
@@ -617,7 +693,7 @@ fun Method.indexOfFirstInstructionReversedOrThrow(targetOpcode: Opcode): Int = i
 
 /**
  * Get the index of matching instruction,
- * starting from and [startIndex] and searching down.
+ * starting from [startIndex] and searching down.
  *
  * @param startIndex Optional starting index to search down from. Searching includes the start index.
  * @return The index of the instruction.