Align Decoder(Audio|Video)Renderer decoder re-use logic

- Fix DecoderAudioRenderer to re-init codec if the DRM session changes.
- Add canKeepCodec to DecoderVideoRenderer. Previously it was assumed
  that the decoder could be re-used, but this will not be true in all
  cases for FfmpegVideoRenderer.

Issue: #7079
PiperOrigin-RevId: 309935278

Author: ojw28

extensions/av1/src/main/java/com/google/android/exoplayer2/ext/av1/Libgav1VideoRenderer.java

@@ -162,4 +162,9 @@ protected void setDecoderOutputMode(@C.VideoOutputMode int outputMode) {
       decoder.setOutputMode(outputMode);
     }
   }
+
+  @Override
+  protected boolean canKeepCodec(Format oldFormat, Format newFormat) {
+    return true;
+  }
 }

extensions/ffmpeg/src/main/java/com/google/android/exoplayer2/ext/ffmpeg/FfmpegLibrary.java

@@ -56,7 +56,8 @@ public static boolean isAvailable() {
   }
 
   /** Returns the version of the underlying library if available, or null otherwise. */
-  public static @Nullable String getVersion() {
+  @Nullable
+  public static String getVersion() {
     return isAvailable() ? ffmpegGetVersion() : null;
   }
 
@@ -69,7 +70,7 @@ public static boolean supportsFormat(String mimeType) {
     if (!isAvailable()) {
       return false;
     }
-    String codecName = getCodecName(mimeType);
+    @Nullable String codecName = getCodecName(mimeType);
     if (codecName == null) {
       return false;
     }
@@ -84,7 +85,8 @@ public static boolean supportsFormat(String mimeType) {
    * Returns the name of the FFmpeg decoder that could be used to decode the format, or {@code null}
    * if it's unsupported.
    */
-  /* package */ static @Nullable String getCodecName(String mimeType) {
+  @Nullable
+  /* package */ static String getCodecName(String mimeType) {
     switch (mimeType) {
       case MimeTypes.AUDIO_AAC:
         return "aac";

extensions/ffmpeg/src/main/java/com/google/android/exoplayer2/ext/ffmpeg/FfmpegVideoRenderer.java

@@ -24,6 +24,7 @@
 import com.google.android.exoplayer2.decoder.Decoder;
 import com.google.android.exoplayer2.drm.ExoMediaCrypto;
 import com.google.android.exoplayer2.util.TraceUtil;
+import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.DecoderVideoRenderer;
 import com.google.android.exoplayer2.video.VideoDecoderInputBuffer;
 import com.google.android.exoplayer2.video.VideoDecoderOutputBuffer;
@@ -113,4 +114,9 @@ protected void setDecoderOutputMode(@C.VideoOutputMode int outputMode) {
     }
     */
   }
+
+  @Override
+  protected boolean canKeepCodec(Format oldFormat, Format newFormat) {
+    return Util.areEqual(oldFormat.sampleMimeType, newFormat.sampleMimeType);
+  }
 }

extensions/vp9/src/main/java/com/google/android/exoplayer2/ext/vp9/LibvpxVideoRenderer.java

@@ -168,4 +168,9 @@ protected void setDecoderOutputMode(@C.VideoOutputMode int outputMode) {
       decoder.setOutputMode(outputMode);
     }
   }
+
+  @Override
+  protected boolean canKeepCodec(Format oldFormat, Format newFormat) {
+    return true;
+  }
 }

library/core/src/main/java/com/google/android/exoplayer2/audio/DecoderAudioRenderer.java

@@ -323,7 +323,7 @@ protected void onAudioTrackSkipSilenceEnabledChanged(boolean skipSilenceEnabled)
    *
    * @param oldFormat The previous format.
    * @param newFormat The new format.
-   * @return True if the existing decoder can be kept.
+   * @return Whether the existing decoder can be kept.
    */
   protected boolean canKeepCodec(Format oldFormat, Format newFormat) {
     return false;
@@ -643,7 +643,9 @@ private void onInputFormatChanged(FormatHolder formatHolder) throws ExoPlaybackE
     Format oldFormat = inputFormat;
     inputFormat = newFormat;
 
-    if (!canKeepCodec(oldFormat, inputFormat)) {
+    if (decoder == null) {
+      maybeInitDecoder();
+    } else if (sourceDrmSession != decoderDrmSession || !canKeepCodec(oldFormat, inputFormat)) {
       if (decoderReceivedBuffers) {
         // Signal end of stream and wait for any final output buffers before re-initialization.
         decoderReinitializationState = REINITIALIZATION_STATE_SIGNAL_END_OF_STREAM;
@@ -657,7 +659,6 @@ private void onInputFormatChanged(FormatHolder formatHolder) throws ExoPlaybackE
 
     encoderDelay = inputFormat.encoderDelay;
     encoderPadding = inputFormat.encoderPadding;
-
     eventDispatcher.inputFormatChanged(inputFormat);
   }
 

library/core/src/main/java/com/google/android/exoplayer2/video/DecoderVideoRenderer.java

@@ -379,9 +379,12 @@ protected void onInputFormatChanged(FormatHolder formatHolder) throws ExoPlaybac
     waitingForFirstSampleInFormat = true;
     Format newFormat = Assertions.checkNotNull(formatHolder.format);
     setSourceDrmSession(formatHolder.drmSession);
+    Format oldFormat = inputFormat;
     inputFormat = newFormat;
 
-    if (sourceDrmSession != decoderDrmSession) {
+    if (decoder == null) {
+      maybeInitDecoder();
+    } else if (sourceDrmSession != decoderDrmSession || !canKeepCodec(oldFormat, inputFormat)) {
       if (decoderReceivedBuffers) {
         // Signal end of stream and wait for any final output buffers before re-initialization.
         decoderReinitializationState = REINITIALIZATION_STATE_SIGNAL_END_OF_STREAM;
@@ -640,6 +643,17 @@ protected final void setOutputBufferRenderer(
    */
   protected abstract void setDecoderOutputMode(@C.VideoOutputMode int outputMode);
 
+  /**
+   * Returns whether the existing decoder can be kept for a new format.
+   *
+   * @param oldFormat The previous format.
+   * @param newFormat The new format.
+   * @return Whether the existing decoder can be kept.
+   */
+  protected boolean canKeepCodec(Format oldFormat, Format newFormat) {
+    return false;
+  }
+
   // Internal methods.
 
   private void setSourceDrmSession(@Nullable DrmSession session) {