Make minor improvements for IAMF decoder module

- Create `LibiamfAudioRenderer` with `DefaultRenderersFactory` in `ExoPlayerModuleProguard`.
- Remove redundant library availability check from `IamfModuleProguard`.
- Move `proguard-rules.txt` to the root folder.
- Removed unused `cryptoType` parameter from `setLibraries()` method in `IamfLibrary`.
- Added log when `LibiamfAudioRenderer` is loaded in `DefaultRenderersFactory`.
- Annotated missing classes with `@UnstableApi`.
- Check for library availability and throw exception in `IamfDecoder` constructor.

#cherrypick

PiperOrigin-RevId: 689330016

libraries/decoder_iamf/src/main/java/androidx/media3/decoder/iamf/IamfDecoder.java

@@ -56,6 +56,9 @@ public final class IamfDecoder
   public IamfDecoder(List<byte[]> initializationData, boolean spatializationSupported)
       throws IamfDecoderException {
     super(new DecoderInputBuffer[1], new SimpleDecoderOutputBuffer[1]);
+    if (!IamfLibrary.isAvailable()) {
+      throw new IamfDecoderException("Failed to load decoder native libraries.");
+    }
     if (initializationData.size() != 1) {
       throw new IamfDecoderException("Initialization data must contain a single element.");
     }

libraries/decoder_iamf/src/main/java/androidx/media3/decoder/iamf/IamfDecoderException.java

@@ -15,10 +15,12 @@
  */
 package androidx.media3.decoder.iamf;
 
+import androidx.media3.common.util.UnstableApi;
 import androidx.media3.decoder.DecoderException;
 
 /** Thrown when an IAMF decoder error occurs. */
-final class IamfDecoderException extends DecoderException {
+@UnstableApi
+public final class IamfDecoderException extends DecoderException {
 
   /* package */ IamfDecoderException(String message) {
     super(message);

libraries/decoder_iamf/src/main/java/androidx/media3/decoder/iamf/IamfLibrary.java

@@ -15,7 +15,6 @@
  */
 package androidx.media3.decoder.iamf;
 
-import androidx.media3.common.C;
 import androidx.media3.common.MediaLibraryInfo;
 import androidx.media3.common.util.LibraryLoader;
 import androidx.media3.common.util.UnstableApi;
@@ -43,12 +42,9 @@ public final class IamfLibrary {
    * it must do so before calling any other method defined by this class, and before instantiating a
    * {@link LibiamfAudioRenderer} instance.
    *
-   * @param cryptoType The {@link C.CryptoType} for which the decoder library supports decrypting
-   *     protected content, or {@link C#CRYPTO_TYPE_UNSUPPORTED} if the library does not support
-   *     decryption.
    * @param libraries The names of the IAMF native libraries.
    */
-  public static void setLibraries(@C.CryptoType int cryptoType, String... libraries) {
+  public static void setLibraries(String... libraries) {
     LOADER.setLibraries(libraries);
   }
 

libraries/decoder_iamf/src/main/java/androidx/media3/decoder/iamf/LibiamfAudioRenderer.java

@@ -27,6 +27,7 @@ import androidx.media3.common.C;
 import androidx.media3.common.Format;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.util.TraceUtil;
+import androidx.media3.common.util.UnstableApi;
 import androidx.media3.common.util.Util;
 import androidx.media3.decoder.CryptoConfig;
 import androidx.media3.decoder.DecoderException;
@@ -36,6 +37,7 @@ import androidx.media3.exoplayer.audio.DecoderAudioRenderer;
 import java.util.Objects;
 
 /** Decodes and renders audio using the native IAMF decoder. */
+@UnstableApi
 public class LibiamfAudioRenderer extends DecoderAudioRenderer<IamfDecoder> {
   private final Context context;
 

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/DefaultRenderersFactory.java

@@ -547,6 +547,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
       // The extension is present, but instantiation failed.
       throw new IllegalStateException("Error instantiating FFmpeg extension", e);
     }
+
     try {
       // Full class names used for constructor args so the LINT rule triggers if any of them move.
       Class<?> clazz = Class.forName("androidx.media3.decoder.iamf.LibiamfAudioRenderer");
@@ -559,6 +560,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
       Renderer renderer =
           (Renderer) constructor.newInstance(context, eventHandler, eventListener, audioSink);
       out.add(extensionRendererIndex++, renderer);
+      Log.i(TAG, "Loaded LibiamfAudioRenderer.");
     } catch (ClassNotFoundException e) {
       // Expected if the app was built without the extension.
     } catch (Exception e) {