Restrict Decoder generic exception type to extend DecoderException

This is useful for merging the FFmpeg video support pull request,
since it allows a Decoder base class implementation to catch
DecoderException rather than forcing it to catch Exception (i.e.,
everything). Note that unfortunately, Java doesn't allow catching
of a generic type (i.e., you cannot "catch (E e)") due to type
erasure.

PiperOrigin-RevId: 311300719

library/core/src/main/java/com/google/android/exoplayer2/decoder/Decoder.java

@@ -24,7 +24,7 @@ import androidx.annotation.Nullable;
  * @param <O> The type of buffer output from the decoder.
  * @param <E> The type of exception thrown from the decoder.
  */
-public interface Decoder<I, O, E extends Exception> {
+public interface Decoder<I, O, E extends DecoderException> {
 
   /**
    * Returns the name of the decoder.

library/core/src/main/java/com/google/android/exoplayer2/decoder/DecoderException.java

@@ -15,20 +15,36 @@
  */
 package com.google.android.exoplayer2.decoder;
 
+import androidx.annotation.Nullable;
+
 /** Thrown when a {@link Decoder} error occurs. */
 public class DecoderException extends Exception {
 
-  /** @param message The detail message for this exception. */
+  /**
+   * Creates an instance.
+   *
+   * @param message The detail message for this exception.
+   */
   public DecoderException(String message) {
     super(message);
   }
 
   /**
+   * Creates an instance.
+   *
+   * @param cause The cause of this exception, or {@code null}.
+   */
+  public DecoderException(@Nullable Throwable cause) {
+    super(cause);
+  }
+
+  /**
+   * Creates an instance.
+   *
    * @param message The detail message for this exception.
-   * @param cause the cause (which is saved for later retrieval by the {@link #getCause()} method).
-   *     A <tt>null</tt> value is permitted, and indicates that the cause is nonexistent or unknown.
+   * @param cause The cause of this exception, or {@code null}.
    */
-  public DecoderException(String message, Throwable cause) {
+  public DecoderException(String message, @Nullable Throwable cause) {
     super(message, cause);
   }
 }

library/core/src/main/java/com/google/android/exoplayer2/decoder/SimpleDecoder.java

@@ -27,7 +27,7 @@ import java.util.ArrayDeque;
  */
 @SuppressWarnings("UngroupedOverloads")
 public abstract class SimpleDecoder<
-        I extends DecoderInputBuffer, O extends OutputBuffer, E extends Exception>
+        I extends DecoderInputBuffer, O extends OutputBuffer, E extends DecoderException>
     implements Decoder<I, O, E> {
 
   private final Thread decodeThread;

library/core/src/main/java/com/google/android/exoplayer2/text/SubtitleDecoderException.java

@@ -15,10 +15,11 @@
  */
 package com.google.android.exoplayer2.text;
 
-/**
- * Thrown when an error occurs decoding subtitle data.
- */
-public class SubtitleDecoderException extends Exception {
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.decoder.DecoderException;
+
+/** Thrown when an error occurs decoding subtitle data. */
+public class SubtitleDecoderException extends DecoderException {
 
   /**
    * @param message The detail message for this exception.
@@ -27,17 +28,16 @@ public class SubtitleDecoderException extends Exception {
     super(message);
   }
 
-  /** @param cause The cause of this exception. */
-  public SubtitleDecoderException(Exception cause) {
+  /** @param cause The cause of this exception, or {@code null}. */
+  public SubtitleDecoderException(@Nullable Throwable cause) {
     super(cause);
   }
 
   /**
    * @param message The detail message for this exception.
-   * @param cause The cause of this exception.
+   * @param cause The cause of this exception, or {@code null}.
    */
-  public SubtitleDecoderException(String message, Throwable cause) {
+  public SubtitleDecoderException(String message, @Nullable Throwable cause) {
     super(message, cause);
   }
-
 }