Added an ICY header workaround for unseekable MP3 streams.

Issue:google#6537
PiperOrigin-RevId: 275477266

RELEASENOTES.md

@@ -93,6 +93,11 @@
   fragment) ([#6470](https://github.com/google/ExoPlayer/issues/6470)).
 * Add `MediaPeriod.isLoading` to improve `Player.isLoading` state.
 * Make show and hide player controls accessible for TalkBack in `PlayerView`.
+* Add workaround to avoid truncating MP3 live streams with ICY metadata and
+  introductions that have a seeking header
+  ([#6537](https://github.com/google/ExoPlayer/issues/6537),
+  [#6315](https://github.com/google/ExoPlayer/issues/6315) and
+  [#5658](https://github.com/google/ExoPlayer/issues/5658)).
 * Pass the codec output `MediaFormat` to `VideoFrameMetadataListener`.
 
 ### 2.10.6 (2019-10-17) ###

library/core/src/main/java/com/google/android/exoplayer2/extractor/SeekMap.java

@@ -25,7 +25,7 @@
 public interface SeekMap {
 
   /** A {@link SeekMap} that does not support seeking. */
-  final class Unseekable implements SeekMap {
+  class Unseekable implements SeekMap {
 
     private final long durationUs;
     private final SeekPoints startSeekPoints;

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/ConstantBitrateSeeker.java

@@ -22,8 +22,7 @@
 /**
  * MP3 seeker that doesn't rely on metadata and seeks assuming the source has a constant bitrate.
  */
-/* package */ final class ConstantBitrateSeeker extends ConstantBitrateSeekMap
-    implements Mp3Extractor.Seeker {
+/* package */ final class ConstantBitrateSeeker extends ConstantBitrateSeekMap implements Seeker {
 
   /**
    * @param inputLength The length of the stream in bytes, or {@link C#LENGTH_UNSET} if unknown.

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/MlltSeeker.java

@@ -22,7 +22,7 @@
 import com.google.android.exoplayer2.util.Util;
 
 /** MP3 seeker that uses metadata from an {@link MlltFrame}. */
-/* package */ final class MlltSeeker implements Mp3Extractor.Seeker {
+/* package */ final class MlltSeeker implements Seeker {
 
   /**
    * Returns an {@link MlltSeeker} for seeking in the stream.

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/Mp3Extractor.java

@@ -28,8 +28,8 @@
 import com.google.android.exoplayer2.extractor.Id3Peeker;
 import com.google.android.exoplayer2.extractor.MpegAudioHeader;
 import com.google.android.exoplayer2.extractor.PositionHolder;
-import com.google.android.exoplayer2.extractor.SeekMap;
 import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.extractor.mp3.Seeker.UnseekableSeeker;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.metadata.id3.Id3Decoder;
 import com.google.android.exoplayer2.metadata.id3.Id3Decoder.FramePredicate;
@@ -113,7 +113,8 @@ public final class Mp3Extractor implements Extractor {
   private int synchronizedHeaderData;
 
   private Metadata metadata;
-  private Seeker seeker;
+  @Nullable private Seeker seeker;
+  private boolean disableSeeking;
   private long basisTimeUs;
   private long samplesRead;
   private long firstSamplePosition;
@@ -187,14 +188,19 @@ public int read(ExtractorInput input, PositionHolder seekPosition)
       // takes priority as it can provide greater precision.
       Seeker seekFrameSeeker = maybeReadSeekFrame(input);
       Seeker metadataSeeker = maybeHandleSeekMetadata(metadata, input.getPosition());
-      if (metadataSeeker != null) {
-        seeker = metadataSeeker;
-      } else if (seekFrameSeeker != null) {
-        seeker = seekFrameSeeker;
-      }
-      if (seeker == null
-          || (!seeker.isSeekable() && (flags & FLAG_ENABLE_CONSTANT_BITRATE_SEEKING) != 0)) {
-        seeker = getConstantBitrateSeeker(input);
+
+      if (disableSeeking) {
+        seeker = new UnseekableSeeker();
+      } else {
+        if (metadataSeeker != null) {
+          seeker = metadataSeeker;
+        } else if (seekFrameSeeker != null) {
+          seeker = seekFrameSeeker;
+        }
+        if (seeker == null
+            || (!seeker.isSeekable() && (flags & FLAG_ENABLE_CONSTANT_BITRATE_SEEKING) != 0)) {
+          seeker = getConstantBitrateSeeker(input);
+        }
       }
       extractorOutput.seekMap(seeker);
       trackOutput.format(
@@ -225,6 +231,15 @@ public int read(ExtractorInput input, PositionHolder seekPosition)
     return readSample(input);
   }
 
+  /**
+   * Disables the extractor from being able to seek through the media.
+   *
+   * <p>Please note that this needs to be called before {@link #read}.
+   */
+  public void disableSeeking() {
+    disableSeeking = true;
+  }
+
   // Internal methods.
 
   private int readSample(ExtractorInput extractorInput) throws IOException, InterruptedException {
@@ -463,26 +478,5 @@ private static MlltSeeker maybeHandleSeekMetadata(Metadata metadata, long firstF
     return null;
   }
 
-  /**
-   * {@link SeekMap} that provides the end position of audio data and also allows mapping from
-   * position (byte offset) back to time, which can be used to work out the new sample basis
-   * timestamp after seeking and resynchronization.
-   */
-  /* package */ interface Seeker extends SeekMap {
-
-    /**
-     * Maps a position (byte offset) to a corresponding sample timestamp.
-     *
-     * @param position A seek position (byte offset) relative to the start of the stream.
-     * @return The corresponding timestamp of the next sample to be read, in microseconds.
-     */
-    long getTimeUs(long position);
-
-    /**
-     * Returns the position (byte offset) in the stream that is immediately after audio data, or
-     * {@link C#POSITION_UNSET} if not known.
-     */
-    long getDataEndPosition();
-  }
 
 }

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/Seeker.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.extractor.mp3;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.extractor.SeekMap;
+
+/**
+ * {@link SeekMap} that provides the end position of audio data and also allows mapping from
+ * position (byte offset) back to time, which can be used to work out the new sample basis timestamp
+ * after seeking and resynchronization.
+ */
+/* package */ interface Seeker extends SeekMap {
+
+  /**
+   * Maps a position (byte offset) to a corresponding sample timestamp.
+   *
+   * @param position A seek position (byte offset) relative to the start of the stream.
+   * @return The corresponding timestamp of the next sample to be read, in microseconds.
+   */
+  long getTimeUs(long position);
+
+  /**
+   * Returns the position (byte offset) in the stream that is immediately after audio data, or
+   * {@link C#POSITION_UNSET} if not known.
+   */
+  long getDataEndPosition();
+
+  /** A {@link Seeker} that does not support seeking through audio data. */
+  /* package */ class UnseekableSeeker extends SeekMap.Unseekable implements Seeker {
+
+    public UnseekableSeeker() {
+      super(/* durationUs= */ C.TIME_UNSET);
+    }
+
+    @Override
+    public long getTimeUs(long position) {
+      return 0;
+    }
+
+    @Override
+    public long getDataEndPosition() {
+      // Position unset as we do not know the data end position. Note that returning 0 doesn't work.
+      return C.POSITION_UNSET;
+    }
+  }
+}

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/VbriSeeker.java

@@ -23,10 +23,8 @@
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 
-/**
- * MP3 seeker that uses metadata from a VBRI header.
- */
-/* package */ final class VbriSeeker implements Mp3Extractor.Seeker {
+/** MP3 seeker that uses metadata from a VBRI header. */
+/* package */ final class VbriSeeker implements Seeker {
 
   private static final String TAG = "VbriSeeker";
 

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp3/XingSeeker.java

@@ -24,10 +24,8 @@
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 
-/**
- * MP3 seeker that uses metadata from a Xing header.
- */
-/* package */ final class XingSeeker implements Mp3Extractor.Seeker {
+/** MP3 seeker that uses metadata from a Xing header. */
+/* package */ final class XingSeeker implements Seeker {
 
   private static final String TAG = "XingSeeker";
 

library/core/src/main/java/com/google/android/exoplayer2/source/ProgressiveMediaPeriod.java

@@ -34,6 +34,7 @@
 import com.google.android.exoplayer2.extractor.SeekMap.SeekPoints;
 import com.google.android.exoplayer2.extractor.SeekMap.Unseekable;
 import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.extractor.mp3.Mp3Extractor;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.metadata.icy.IcyHeaders;
 import com.google.android.exoplayer2.source.MediaSourceEventListener.EventDispatcher;
@@ -985,6 +986,12 @@ public void load() throws IOException, InterruptedException {
           }
           input = new DefaultExtractorInput(extractorDataSource, position, length);
           Extractor extractor = extractorHolder.selectExtractor(input, extractorOutput, uri);
+
+          // MP3 live streams commonly have seekable metadata, despite being unseekable.
+          if (icyHeaders != null && extractor instanceof Mp3Extractor) {
+            ((Mp3Extractor) extractor).disableSeeking();
+          }
+
           if (pendingExtractorSeek) {
             extractor.seek(position, seekTimeUs);
             pendingExtractorSeek = false;