fix(Spoof video streams): Resolve occasional playback stuttering

Code adapted from:
2cf9db66ac
50d9c60374

extensions/shared/library/src/main/java/app/revanced/extension/shared/spoof/SpoofVideoStreamsPatch.java

@@ -97,6 +97,35 @@ public class SpoofVideoStreamsPatch {
         return playerRequestUri;
     }
 
+    /**
+     * Injection point.
+     *
+     * Blocks /get_watch requests by returning an unreachable URI.
+     * /att/get requests are used to obtain a PoToken challenge.
+     * See: <a href="https://github.com/FreeTubeApp/FreeTube/blob/4b7208430bc1032019a35a35eb7c8a84987ddbd7/src/botGuardScript.js#L15">botGuardScript.js#L15</a>
+     * <p>
+     * Since the Spoof streaming data patch was implemented because a valid PoToken cannot be obtained,
+     * Blocking /att/get requests are not a problem.
+     */
+    public static String blockGetAttRequest(String originalUrlString) {
+        if (SPOOF_STREAMING_DATA) {
+            try {
+                var originalUri = Uri.parse(originalUrlString);
+                String path = originalUri.getPath();
+
+                if (path != null && path.contains("att/get")) {
+                    Logger.printDebug(() -> "Blocking 'att/get' by returning internet connection check uri");
+
+                    return INTERNET_CONNECTION_CHECK_URI_STRING;
+                }
+            } catch (Exception ex) {
+                Logger.printException(() -> "blockGetAttRequest failure", ex);
+            }
+        }
+
+        return originalUrlString;
+    }
+
     /**
      * Injection point.
      * <p>
@@ -130,7 +159,7 @@ public class SpoofVideoStreamsPatch {
 
     /**
      * Injection point.
-     * Only invoked when playing a livestream on an iOS client.
+     * Only invoked when playing a livestream on an Apple client.
      */
     public static boolean fixHLSCurrentTime(boolean original) {
         if (!SPOOF_STREAMING_DATA) {
@@ -139,6 +168,14 @@ public class SpoofVideoStreamsPatch {
         return false;
     }
 
+    /*
+     * Injection point.
+     * Fix audio stuttering in YouTube Music.
+     */
+    public static boolean disableSABR() {
+        return SPOOF_STREAMING_DATA;
+    }
+
     /**
      * Injection point.
      * Turns off a feature flag that interferes with spoofing.

patches/src/main/kotlin/app/revanced/patches/shared/misc/spoof/Fingerprints.kt

@@ -1,12 +1,9 @@
 package app.revanced.patches.shared.misc.spoof
 
 import app.revanced.patcher.fingerprint
-import app.revanced.util.getReference
-import app.revanced.util.indexOfFirstInstruction
 import app.revanced.util.literal
 import com.android.tools.smali.dexlib2.AccessFlags
 import com.android.tools.smali.dexlib2.Opcode
-import com.android.tools.smali.dexlib2.iface.reference.MethodReference
 
 internal val buildInitPlaybackRequestFingerprint = fingerprint {
     returns("Lorg/chromium/net/UrlRequest\$Builder;")
@@ -40,10 +37,7 @@ internal val buildRequestFingerprint = fingerprint {
     accessFlags(AccessFlags.PUBLIC, AccessFlags.STATIC)
     returns("Lorg/chromium/net/UrlRequest") // UrlRequest; or UrlRequest$Builder;
     custom { methodDef, _ ->
-        if (methodDef.indexOfFirstInstruction {
+        if (indexOfNewUrlRequestBuilderInstruction(methodDef) < 0) {
-                val reference = getReference<MethodReference>()
-                reference?.name == "newUrlRequestBuilder"
-            } < 0) {
             return@custom false
         }
 
@@ -142,6 +136,17 @@ internal val hlsCurrentTimeFingerprint = fingerprint {
     }
 }
 
+internal const val DISABLED_BY_SABR_STREAMING_URI_STRING = "DISABLED_BY_SABR_STREAMING_URI"
+
+internal val mediaFetchEnumConstructorFingerprint = fingerprint {
+    returns("V")
+    strings(
+        "ENABLED",
+        "DISABLED_FOR_PLAYBACK",
+        DISABLED_BY_SABR_STREAMING_URI_STRING
+    )
+}
+
 internal val nerdsStatsVideoFormatBuilderFingerprint = fingerprint {
     accessFlags(AccessFlags.PUBLIC, AccessFlags.STATIC)
     returns("Ljava/lang/String;")

patches/src/main/kotlin/app/revanced/patches/shared/misc/spoof/SpoofVideoStreamsPatch.kt

@@ -5,23 +5,28 @@ import app.revanced.patcher.extensions.InstructionExtensions.addInstructions
 import app.revanced.patcher.extensions.InstructionExtensions.addInstructionsWithLabels
 import app.revanced.patcher.extensions.InstructionExtensions.getInstruction
 import app.revanced.patcher.extensions.InstructionExtensions.instructions
+import app.revanced.patcher.fingerprint
 import app.revanced.patcher.patch.BytecodePatchBuilder
 import app.revanced.patcher.patch.BytecodePatchContext
 import app.revanced.patcher.patch.bytecodePatch
+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.util.findFreeRegister
 import app.revanced.util.findInstructionIndicesReversedOrThrow
 import app.revanced.util.getReference
+import app.revanced.util.indexOfFirstInstruction
 import app.revanced.util.indexOfFirstInstructionOrThrow
 import app.revanced.util.insertLiteralOverride
 import app.revanced.util.returnEarly
 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.FiveRegisterInstruction
 import com.android.tools.smali.dexlib2.iface.instruction.OneRegisterInstruction
+import com.android.tools.smali.dexlib2.iface.instruction.ReferenceInstruction
 import com.android.tools.smali.dexlib2.iface.instruction.TwoRegisterInstruction
 import com.android.tools.smali.dexlib2.iface.reference.FieldReference
 import com.android.tools.smali.dexlib2.iface.reference.MethodReference
@@ -31,6 +36,9 @@ import com.android.tools.smali.dexlib2.immutable.ImmutableMethodParameter
 internal const val EXTENSION_CLASS_DESCRIPTOR =
     "Lapp/revanced/extension/shared/spoof/SpoofVideoStreamsPatch;"
 
+private lateinit var buildRequestMethod: MutableMethod
+private var buildRequestMethodUrlRegister = -1
+
 fun spoofVideoStreamsPatch(
     block: BytecodePatchBuilder.() -> Unit = {},
     fixMediaFetchHotConfigChanges: BytecodePatchBuilder.() -> Boolean = { false },
@@ -91,18 +99,17 @@ fun spoofVideoStreamsPatch(
         // region Get replacement streams at player requests.
 
         buildRequestFingerprint.method.apply {
-            val newRequestBuilderIndex = indexOfFirstInstructionOrThrow {
+            buildRequestMethod = this
-                opcode == Opcode.INVOKE_VIRTUAL &&
+
-                    getReference<MethodReference>()?.name == "newUrlRequestBuilder"
+            val newRequestBuilderIndex = indexOfNewUrlRequestBuilderInstruction(this)
-            }
+            buildRequestMethodUrlRegister = getInstruction<FiveRegisterInstruction>(newRequestBuilderIndex).registerD
-            val urlRegister = getInstruction<FiveRegisterInstruction>(newRequestBuilderIndex).registerD
+            val freeRegister = findFreeRegister(newRequestBuilderIndex, buildRequestMethodUrlRegister)
-            val freeRegister = findFreeRegister(newRequestBuilderIndex, urlRegister)
 
             addInstructions(
                 newRequestBuilderIndex,
                 """
                     move-object v$freeRegister, p1
-                    invoke-static { v$urlRegister, v$freeRegister }, $EXTENSION_CLASS_DESCRIPTOR->fetchStreams(Ljava/lang/String;Ljava/util/Map;)V
+                    invoke-static { v$buildRequestMethodUrlRegister, v$freeRegister }, $EXTENSION_CLASS_DESCRIPTOR->fetchStreams(Ljava/lang/String;Ljava/util/Map;)V
                 """
             )
         }
@@ -187,6 +194,21 @@ fun spoofVideoStreamsPatch(
 
         // endregion
 
+        // region block getAtt request
+
+        buildRequestMethod.apply {
+            val insertIndex = indexOfNewUrlRequestBuilderInstruction(this)
+
+            addInstructions(
+                insertIndex, """
+                    invoke-static { v$buildRequestMethodUrlRegister }, $EXTENSION_CLASS_DESCRIPTOR->blockGetAttRequest(Ljava/lang/String;)Ljava/lang/String;
+                    move-result-object v$buildRequestMethodUrlRegister
+                """
+            )
+        }
+
+        // endregion
+
         // region Remove /videoplayback request body to fix playback.
         // It is assumed, YouTube makes a request with a body tuned for Android.
         // Requesting streams intended for other platforms with a body tuned for Android could be the cause of 400 errors.
@@ -243,6 +265,50 @@ fun spoofVideoStreamsPatch(
 
         // endregion
 
+        // region Disable SABR playback.
+        // If SABR is disabled, it seems 'MediaFetchHotConfig' may no longer need an override (not confirmed).
+
+        val (mediaFetchEnumClass, sabrFieldReference) = with(mediaFetchEnumConstructorFingerprint.method) {
+            val stringIndex = mediaFetchEnumConstructorFingerprint.stringMatches!!.first {
+                it.string == DISABLED_BY_SABR_STREAMING_URI_STRING
+            }.index
+
+            val mediaFetchEnumClass = definingClass
+            val sabrFieldIndex = indexOfFirstInstructionOrThrow(stringIndex) {
+                opcode == Opcode.SPUT_OBJECT &&
+                        getReference<FieldReference>()?.type == mediaFetchEnumClass
+            }
+
+            Pair(
+                mediaFetchEnumClass,
+                getInstruction<ReferenceInstruction>(sabrFieldIndex).reference
+            )
+        }
+
+        fingerprint {
+            returns(mediaFetchEnumClass)
+            opcodes(
+                Opcode.SGET_OBJECT,
+                Opcode.RETURN_OBJECT,
+            )
+            custom { method, _ ->
+                !method.parameterTypes.isEmpty()
+            }
+        }.method.addInstructionsWithLabels(
+            0,
+            """
+                invoke-static { }, $EXTENSION_CLASS_DESCRIPTOR->disableSABR()Z
+                move-result v0
+                if-eqz v0, :ignore
+                sget-object v0, $sabrFieldReference
+                return-object v0
+                :ignore
+                nop
+            """
+        )
+
+        // endregion
+
         // region turn off stream config replacement feature flag.
 
         if (fixMediaFetchHotConfigChanges()) {
@@ -271,3 +337,12 @@ fun spoofVideoStreamsPatch(
         executeBlock()
     }
 }
+
+internal fun indexOfNewUrlRequestBuilderInstruction(method: Method) = method.indexOfFirstInstruction {
+    opcode == Opcode.INVOKE_VIRTUAL && getReference<MethodReference>().toString() ==
+        "Lorg/chromium/net/CronetEngine;" +
+            "->newUrlRequestBuilder(" +
+                "Ljava/lang/String;Lorg/chromium/net/UrlRequest${'$'}Callback;" +
+                "Ljava/util/concurrent/Executor;" +
+            ")Lorg/chromium/net/UrlRequest${'$'}Builder;"
+}