Update DataSource extension documentation

Also upgrade the RTMP extension to use an inner class
for its factory.

PiperOrigin-RevId: 381469114

extensions/cronet/README.md

@@ -20,36 +20,27 @@ Alternatively, you can clone the ExoPlayer repository and depend on the module
 locally. Instructions for doing this can be found in ExoPlayer's
 [top level README][].
 
-Note that by default, the extension will use the Cronet implementation in
-Google Play Services. If you prefer, it's also possible to embed the Cronet
-implementation directly into your application. See below for more details.
+By default, the extension will use the Cronet implementation in Google Play
+Services. If you prefer, it's also possible to embed the Cronet implementation
+directly into your application. See below for more details.
 
 [top level README]: https://github.com/google/ExoPlayer/blob/release-v2/README.md
 
 ## Using the extension ##
 
 ExoPlayer requests data through `DataSource` instances. These instances are
-either instantiated and injected from application code, or obtained from
-instances of `DataSource.Factory` that are instantiated and injected from
-application code.
+obtained from instances of `DataSource.Factory`, which are instantiated and
+injected from application code.
 
 If your application only needs to play http(s) content, using the Cronet
-extension is as simple as updating any `DataSource`s and `DataSource.Factory`
-instantiations in your application code to use `CronetDataSource` and
-`CronetDataSourceFactory` respectively. If your application also needs to play
-non-http(s) content such as local files, use
-```
-new DefaultDataSource(
-    ...
-    new CronetDataSource(...) /* baseDataSource argument */);
-```
-and
+extension is as simple as updating `DataSource.Factory` instantiations in your
+application code to use `CronetDataSource.Factory`. If your application also
+needs to play non-http(s) content such as local files, use:
 ```
 new DefaultDataSourceFactory(
     ...
-    new CronetDataSourceFactory(...) /* baseDataSourceFactory argument */);
+    /* baseDataSourceFactory= */ new CronetDataSource.Factory(...) );
 ```
-respectively.
 
 ## Choosing between Google Play Services Cronet and Cronet Embedded ##
 

extensions/okhttp/README.md

@@ -34,27 +34,18 @@ locally. Instructions for doing this can be found in ExoPlayer's
 ## Using the extension ##
 
 ExoPlayer requests data through `DataSource` instances. These instances are
-either instantiated and injected from application code, or obtained from
-instances of `DataSource.Factory` that are instantiated and injected from
-application code.
+obtained from instances of `DataSource.Factory`, which are instantiated and
+injected from application code.
 
 If your application only needs to play http(s) content, using the OkHttp
-extension is as simple as updating any `DataSource`s and `DataSource.Factory`
-instantiations in your application code to use `OkHttpDataSource` and
-`OkHttpDataSourceFactory` respectively. If your application also needs to play
-non-http(s) content such as local files, use
-```
-new DefaultDataSource(
-    ...
-    new OkHttpDataSource(...) /* baseDataSource argument */);
-```
-and
+extension is as simple as updating any `DataSource.Factory` instantiations in
+your application code to use `OkHttpDataSource.Factory`. If your application
+also needs to play non-http(s) content such as local files, use:
 ```
 new DefaultDataSourceFactory(
     ...
-    new OkHttpDataSourceFactory(...) /* baseDataSourceFactory argument */);
+    /* baseDataSourceFactory= */ new OkHttpDataSource.Factory(...));
 ```
-respectively.
 
 ## Links ##
 

extensions/rtmp/README.md

@@ -35,18 +35,17 @@ locally. Instructions for doing this can be found in ExoPlayer's
 ## Using the extension ##
 
 ExoPlayer requests data through `DataSource` instances. These instances are
-either instantiated and injected from application code, or obtained from
-instances of `DataSource.Factory` that are instantiated and injected from
-application code.
+obtained from instances of `DataSource.Factory`, which are instantiated and
+injected from application code.
 
 `DefaultDataSource` will automatically use the RTMP extension whenever it's
 available. Hence if your application is using `DefaultDataSource` or
 `DefaultDataSourceFactory`, adding support for RTMP streams is as simple as
 adding a dependency to the RTMP extension as described above. No changes to your
 application code are required. Alternatively, if you know that your application
-doesn't need to handle any other protocols, you can update any `DataSource`s and
+doesn't need to handle any other protocols, you can update any
 `DataSource.Factory` instantiations in your application code to use
-`RtmpDataSource` and `RtmpDataSourceFactory` directly.
+`RtmpDataSource.Factory` directly.
 
 ## Links ##
 

extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSource.java

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.upstream.BaseDataSource;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.TransferListener;
 import java.io.IOException;
 import net.butterflytv.rtmp_client.RtmpClient;
 import net.butterflytv.rtmp_client.RtmpClient.RtmpIOException;
@@ -35,6 +36,36 @@ public final class RtmpDataSource extends BaseDataSource {
     ExoPlayerLibraryInfo.registerModule("goog.exo.rtmp");
   }
 
+  /** {@link DataSource.Factory} for {@link RtmpDataSource} instances. */
+  public static final class Factory implements DataSource.Factory {
+
+    @Nullable private TransferListener transferListener;
+
+    /**
+     * Sets the {@link TransferListener} that will be used.
+     *
+     * <p>The default is {@code null}.
+     *
+     * <p>See {@link DataSource#addTransferListener(TransferListener)}.
+     *
+     * @param transferListener The listener that will be used.
+     * @return This factory.
+     */
+    public Factory setTransferListener(@Nullable TransferListener transferListener) {
+      this.transferListener = transferListener;
+      return this;
+    }
+
+    @Override
+    public RtmpDataSource createDataSource() {
+      RtmpDataSource dataSource = new RtmpDataSource();
+      if (transferListener != null) {
+        dataSource.addTransferListener(transferListener);
+      }
+      return dataSource;
+    }
+  }
+
   @Nullable private RtmpClient rtmpClient;
   @Nullable private Uri uri;
 

extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSourceFactory.java

@@ -17,10 +17,10 @@ package com.google.android.exoplayer2.ext.rtmp;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.upstream.DataSource;
-import com.google.android.exoplayer2.upstream.HttpDataSource.Factory;
 import com.google.android.exoplayer2.upstream.TransferListener;
 
-/** A {@link Factory} that produces {@link RtmpDataSource}. */
+/** @deprecated Use {@link RtmpDataSource.Factory} instead. */
+@Deprecated
 public final class RtmpDataSourceFactory implements DataSource.Factory {
 
   @Nullable private final TransferListener listener;