diff --git a/demo/src/main/java/com/google/android/exoplayer/demo/PlayerActivity.java b/demo/src/main/java/com/google/android/exoplayer/demo/PlayerActivity.java
index dbcdd2cacc..dfc300f516 100644
--- a/demo/src/main/java/com/google/android/exoplayer/demo/PlayerActivity.java
+++ b/demo/src/main/java/com/google/android/exoplayer/demo/PlayerActivity.java
@@ -505,8 +505,7 @@ public class PlayerActivity extends Activity implements SurfaceHolder.Callback,
   }
 
   private static String buildTrackIdString(MediaFormat format) {
-    return format.trackId == MediaFormat.NO_VALUE ? ""
-        : String.format(Locale.US, " (%d)", format.trackId);
+    return format.trackId == null ? "" : " (" + format.trackId + ")";
   }
 
   private boolean onTrackItemClick(MenuItem item, int type) {
diff --git a/library/src/main/java/com/google/android/exoplayer/FrameworkSampleSource.java b/library/src/main/java/com/google/android/exoplayer/FrameworkSampleSource.java
index 23bd7ce1c6..e83738c4c1 100644
--- a/library/src/main/java/com/google/android/exoplayer/FrameworkSampleSource.java
+++ b/library/src/main/java/com/google/android/exoplayer/FrameworkSampleSource.java
@@ -315,7 +315,7 @@ public final class FrameworkSampleSource implements SampleSource, SampleSourceRe
     }
     long durationUs = format.containsKey(android.media.MediaFormat.KEY_DURATION)
         ? format.getLong(android.media.MediaFormat.KEY_DURATION) : C.UNKNOWN_TIME_US;
-    MediaFormat mediaFormat = new MediaFormat(null, MediaFormat.NO_VALUE, mimeType, MediaFormat.NO_VALUE,
+    MediaFormat mediaFormat = new MediaFormat(null, mimeType, MediaFormat.NO_VALUE,
         maxInputSize, durationUs, width, height, rotationDegrees, MediaFormat.NO_VALUE,
         channelCount, sampleRate, language, MediaFormat.OFFSET_SAMPLE_RELATIVE, initializationData,
         false, MediaFormat.NO_VALUE, MediaFormat.NO_VALUE);
diff --git a/library/src/main/java/com/google/android/exoplayer/MediaFormat.java b/library/src/main/java/com/google/android/exoplayer/MediaFormat.java
index 5c849eab9e..07fa0fd060 100644
--- a/library/src/main/java/com/google/android/exoplayer/MediaFormat.java
+++ b/library/src/main/java/com/google/android/exoplayer/MediaFormat.java
@@ -39,14 +39,10 @@ public final class MediaFormat {
    */
   public static final long OFFSET_SAMPLE_RELATIVE = Long.MAX_VALUE;
   /**
-   * An identifier for the format.
-   */
-  public final String id;
-  /**
-   * The identifier for the track represented by the format, or {@link #NO_VALUE} if unknown or not
+   * The identifier for the track represented by the format, or null if unknown or not
    * applicable.
    */
-  public final int trackId;
+  public final String trackId;
   /**
    * The mime type of the format.
    */
@@ -142,53 +138,52 @@ public final class MediaFormat {
   private int hashCode;
   private android.media.MediaFormat frameworkMediaFormat;
 
-  public static MediaFormat createVideoFormat(String id, int trackId, String mimeType, int bitrate,
+  public static MediaFormat createVideoFormat(String trackId, String mimeType, int bitrate,
       int maxInputSize, long durationUs, int width, int height, List<byte[]> initializationData) {
-    return createVideoFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+    return createVideoFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
         initializationData, NO_VALUE, NO_VALUE);
   }
 
-  public static MediaFormat createVideoFormat(String id, int trackId, String mimeType, int bitrate,
+  public static MediaFormat createVideoFormat(String trackId, String mimeType, int bitrate,
       int maxInputSize, long durationUs, int width, int height, List<byte[]> initializationData,
       int rotationDegrees, float pixelWidthHeightRatio) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
         rotationDegrees, pixelWidthHeightRatio, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE,
         initializationData, false, NO_VALUE, NO_VALUE);
   }
 
-  public static MediaFormat createAudioFormat(String id, int trackId, String mimeType, int bitrate,
+  public static MediaFormat createAudioFormat(String trackId, String mimeType, int bitrate,
       int maxInputSize, long durationUs, int channelCount, int sampleRate,
       List<byte[]> initializationData, String language) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, NO_VALUE, NO_VALUE,
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, NO_VALUE, NO_VALUE,
         NO_VALUE, NO_VALUE, channelCount, sampleRate, language, OFFSET_SAMPLE_RELATIVE,
         initializationData, false, NO_VALUE, NO_VALUE);
   }
 
-  public static MediaFormat createTextFormat(String id, int trackId, String mimeType, int bitrate,
+  public static MediaFormat createTextFormat(String trackId, String mimeType, int bitrate,
       long durationUs, String language) {
-    return createTextFormat(id, trackId, mimeType, bitrate, durationUs, language,
+    return createTextFormat(trackId, mimeType, bitrate, durationUs, language,
         OFFSET_SAMPLE_RELATIVE);
   }
 
-  public static MediaFormat createTextFormat(String id, int trackId, String mimeType, int bitrate,
+  public static MediaFormat createTextFormat(String trackId, String mimeType, int bitrate,
       long durationUs, String language, long subsampleOffsetUs) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, NO_VALUE, durationUs, NO_VALUE, NO_VALUE,
+    return new MediaFormat(trackId, mimeType, bitrate, NO_VALUE, durationUs, NO_VALUE, NO_VALUE,
         NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, language, subsampleOffsetUs, null, false, NO_VALUE,
         NO_VALUE);
   }
 
-  public static MediaFormat createFormatForMimeType(String id, int trackId, String mimeType, int bitrate,
+  public static MediaFormat createFormatForMimeType(String trackId, String mimeType, int bitrate,
       long durationUs) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, NO_VALUE, durationUs, NO_VALUE, NO_VALUE,
+    return new MediaFormat(trackId, mimeType, bitrate, NO_VALUE, durationUs, NO_VALUE, NO_VALUE,
         NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE, null, false, NO_VALUE,
         NO_VALUE);
   }
 
-  /* package */ MediaFormat(String id, int trackId, String mimeType, int bitrate, int maxInputSize,
+  /* package */ MediaFormat(String trackId, String mimeType, int bitrate, int maxInputSize,
       long durationUs, int width, int height, int rotationDegrees, float pixelWidthHeightRatio,
       int channelCount, int sampleRate, String language, long subsampleOffsetUs,
       List<byte[]> initializationData, boolean adaptive, int maxWidth, int maxHeight) {
-    this.id = id;
     this.trackId = trackId;
     this.mimeType = Assertions.checkNotEmpty(mimeType);
     this.bitrate = bitrate;
@@ -210,31 +205,31 @@ public final class MediaFormat {
   }
 
   public MediaFormat copyWithMaxInputSize(int maxInputSize) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
         rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate, language,
         subsampleOffsetUs, initializationData, adaptive, maxWidth, maxHeight);
   }
 
   public MediaFormat copyWithMaxVideoDimensions(int maxWidth, int maxHeight) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
         rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate, language,
         subsampleOffsetUs, initializationData, adaptive, maxWidth, maxHeight);
   }
 
   public MediaFormat copyWithSubsampleOffsetUs(long subsampleOffsetUs) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
         rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate, language,
         subsampleOffsetUs, initializationData, adaptive, maxWidth, maxHeight);
   }
 
   public MediaFormat copyWithDurationUs(long durationUs) {
-    return new MediaFormat(id, trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
         rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate, language,
         subsampleOffsetUs, initializationData, adaptive, maxWidth, maxHeight);
   }
 
   public MediaFormat copyAsAdaptive() {
-    return new MediaFormat(id, trackId, mimeType, NO_VALUE, NO_VALUE, durationUs, NO_VALUE, NO_VALUE,
+    return new MediaFormat(null, mimeType, NO_VALUE, NO_VALUE, durationUs, NO_VALUE, NO_VALUE,
         NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, null, OFFSET_SAMPLE_RELATIVE, null, true, maxWidth,
         maxHeight);
   }
@@ -292,7 +287,7 @@ public final class MediaFormat {
   public int hashCode() {
     if (hashCode == 0) {
       int result = 17;
-      result = 31 * result + trackId;
+      result = 31 * result + (trackId == null ? 0 : trackId.hashCode());
       result = 31 * result + (mimeType == null ? 0 : mimeType.hashCode());
       result = 31 * result + bitrate;
       result = 31 * result + maxInputSize;
diff --git a/library/src/main/java/com/google/android/exoplayer/dash/DashChunkSource.java b/library/src/main/java/com/google/android/exoplayer/dash/DashChunkSource.java
index 4f2672daab..3bb88028be 100644
--- a/library/src/main/java/com/google/android/exoplayer/dash/DashChunkSource.java
+++ b/library/src/main/java/com/google/android/exoplayer/dash/DashChunkSource.java
@@ -608,14 +608,14 @@ public class DashChunkSource implements ChunkSource, Output {
       String mediaMimeType, long durationUs) {
     switch (adaptationSetType) {
       case AdaptationSet.TYPE_VIDEO:
-        return MediaFormat.createVideoFormat(format.id, MediaFormat.NO_VALUE, mediaMimeType, format.bitrate,
+        return MediaFormat.createVideoFormat(format.id, mediaMimeType, format.bitrate,
             MediaFormat.NO_VALUE, durationUs, format.width, format.height, null);
       case AdaptationSet.TYPE_AUDIO:
-        return MediaFormat.createAudioFormat(format.id, MediaFormat.NO_VALUE, mediaMimeType, format.bitrate,
+        return MediaFormat.createAudioFormat(format.id, mediaMimeType, format.bitrate,
             MediaFormat.NO_VALUE, durationUs, format.audioChannels, format.audioSamplingRate, null,
             format.language);
       case AdaptationSet.TYPE_TEXT:
-        return MediaFormat.createTextFormat(format.id, MediaFormat.NO_VALUE, mediaMimeType, format.bitrate,
+        return MediaFormat.createTextFormat(format.id, mediaMimeType, format.bitrate,
             durationUs, format.language);
       default:
         return null;
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java b/library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java
index b7b013b5fa..8fcc147477 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/mp3/Mp3Extractor.java
@@ -332,7 +332,7 @@ public final class Mp3Extractor implements Extractor {
     if (seeker == null) {
       setupSeeker(extractorInput, headerPosition);
       extractorOutput.seekMap(seeker);
-      trackOutput.format(MediaFormat.createAudioFormat(null, MediaFormat.NO_VALUE,
+      trackOutput.format(MediaFormat.createAudioFormat(null,
           synchronizedHeader.mimeType, MediaFormat.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES,
           seeker.getDurationUs(), synchronizedHeader.channels, synchronizedHeader.sampleRate, null,
           null));
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/mp4/AtomParsers.java b/library/src/main/java/com/google/android/exoplayer/extractor/mp4/AtomParsers.java
index 4c7bff673b..29243c1c1e 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/mp4/AtomParsers.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/mp4/AtomParsers.java
@@ -387,13 +387,13 @@ import java.util.List;
         parseAudioSampleEntry(stsd, childAtomType, childStartPosition, childAtomSize, trackId,
             durationUs, language, out, i);
       } else if (childAtomType == Atom.TYPE_TTML) {
-        out.mediaFormat = MediaFormat.createTextFormat(null, trackId, MimeTypes.APPLICATION_TTML,
+        out.mediaFormat = MediaFormat.createTextFormat(Integer.toString(trackId), MimeTypes.APPLICATION_TTML,
             MediaFormat.NO_VALUE, durationUs, language);
       } else if (childAtomType == Atom.TYPE_tx3g) {
-        out.mediaFormat = MediaFormat.createTextFormat(null, trackId, MimeTypes.APPLICATION_TX3G,
+        out.mediaFormat = MediaFormat.createTextFormat(Integer.toString(trackId), MimeTypes.APPLICATION_TX3G,
             MediaFormat.NO_VALUE, durationUs, language);
       } else if (childAtomType == Atom.TYPE_stpp) {
-        out.mediaFormat = MediaFormat.createTextFormat(null, trackId, MimeTypes.APPLICATION_TTML,
+        out.mediaFormat = MediaFormat.createTextFormat(Integer.toString(trackId), MimeTypes.APPLICATION_TTML,
             MediaFormat.NO_VALUE, durationUs, language, 0 /* subsample timing is absolute */);
       }
       stsd.setPosition(childStartPosition + childAtomSize);
@@ -464,7 +464,7 @@ import java.util.List;
       return;
     }
 
-    out.mediaFormat = MediaFormat.createVideoFormat(null, trackId, mimeType, MediaFormat.NO_VALUE,
+    out.mediaFormat = MediaFormat.createVideoFormat(Integer.toString(trackId), mimeType, MediaFormat.NO_VALUE,
         MediaFormat.NO_VALUE, durationUs, width, height, initializationData, rotationDegrees,
         pixelWidthHeightRatio);
   }
@@ -653,7 +653,7 @@ import java.util.List;
       } else if ((atomType == Atom.TYPE_dtsc || atomType == Atom.TYPE_dtse
           || atomType == Atom.TYPE_dtsh || atomType == Atom.TYPE_dtsl)
           && childAtomType == Atom.TYPE_ddts) {
-        out.mediaFormat = MediaFormat.createAudioFormat(null, trackId, mimeType, MediaFormat.NO_VALUE,
+        out.mediaFormat = MediaFormat.createAudioFormat(Integer.toString(trackId), mimeType, MediaFormat.NO_VALUE,
             MediaFormat.NO_VALUE, durationUs, channelCount, sampleRate, null, language);
         return;
       }
@@ -665,7 +665,7 @@ import java.util.List;
       return;
     }
 
-    out.mediaFormat = MediaFormat.createAudioFormat(null, trackId, mimeType, MediaFormat.NO_VALUE,
+    out.mediaFormat = MediaFormat.createAudioFormat(Integer.toString(trackId), mimeType, MediaFormat.NO_VALUE,
         sampleSize, durationUs, channelCount, sampleRate,
         initializationData == null ? null : Collections.singletonList(initializationData),
         language);
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/ts/AdtsReader.java b/library/src/main/java/com/google/android/exoplayer/extractor/ts/AdtsReader.java
index 88bce4b159..ba3d69e024 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/ts/AdtsReader.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/ts/AdtsReader.java
@@ -170,7 +170,7 @@ import java.util.Collections;
       Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAacAudioSpecificConfig(
           audioSpecificConfig);
 
-      MediaFormat mediaFormat = MediaFormat.createAudioFormat(null, MediaFormat.NO_VALUE,
+      MediaFormat mediaFormat = MediaFormat.createAudioFormat(null,
           MimeTypes.AUDIO_AAC, MediaFormat.NO_VALUE, MediaFormat.NO_VALUE, C.UNKNOWN_TIME_US,
           audioParams.second, audioParams.first, Collections.singletonList(audioSpecificConfig),
           null);
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/ts/H264Reader.java b/library/src/main/java/com/google/android/exoplayer/extractor/ts/H264Reader.java
index 30c4a8bf5c..efa3a8e5a2 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/ts/H264Reader.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/ts/H264Reader.java
@@ -210,7 +210,7 @@ import java.util.List;
     SpsData parsedSpsData = CodecSpecificDataUtil.parseSpsNalUnit(bitArray);
 
     // Construct and output the format.
-    output.format(MediaFormat.createVideoFormat(null, MediaFormat.NO_VALUE, MimeTypes.VIDEO_H264,
+    output.format(MediaFormat.createVideoFormat(null, MimeTypes.VIDEO_H264,
         MediaFormat.NO_VALUE, MediaFormat.NO_VALUE, C.UNKNOWN_TIME_US, parsedSpsData.width,
         parsedSpsData.height, initializationData, MediaFormat.NO_VALUE,
         parsedSpsData.pixelWidthAspectRatio));
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/ts/H265Reader.java b/library/src/main/java/com/google/android/exoplayer/extractor/ts/H265Reader.java
index 2d3482e69a..41a1ff85a7 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/ts/H265Reader.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/ts/H265Reader.java
@@ -294,7 +294,7 @@ import java.util.Collections;
       }
     }
 
-    output.format(MediaFormat.createVideoFormat(null, MediaFormat.NO_VALUE, MimeTypes.VIDEO_H265,
+    output.format(MediaFormat.createVideoFormat(null, MimeTypes.VIDEO_H265,
         MediaFormat.NO_VALUE, MediaFormat.NO_VALUE, C.UNKNOWN_TIME_US, picWidthInLumaSamples,
         picHeightInLumaSamples, Collections.singletonList(csd), MediaFormat.NO_VALUE,
         pixelWidthHeightRatio));
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/ts/Id3Reader.java b/library/src/main/java/com/google/android/exoplayer/extractor/ts/Id3Reader.java
index 740a2e5e9a..ffbeafc295 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/ts/Id3Reader.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/ts/Id3Reader.java
@@ -35,7 +35,7 @@ import com.google.android.exoplayer.util.ParsableByteArray;
 
   public Id3Reader(TrackOutput output) {
     super(output);
-    output.format(MediaFormat.createFormatForMimeType(null, MediaFormat.NO_VALUE,
+    output.format(MediaFormat.createFormatForMimeType(null,
         MimeTypes.APPLICATION_ID3, MediaFormat.NO_VALUE, C.UNKNOWN_TIME_US));
   }
 
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/ts/MpegAudioReader.java b/library/src/main/java/com/google/android/exoplayer/extractor/ts/MpegAudioReader.java
index a9563e130a..ee8f84cfde 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/ts/MpegAudioReader.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/ts/MpegAudioReader.java
@@ -160,7 +160,7 @@ import com.google.android.exoplayer.util.ParsableByteArray;
     frameSize = header.frameSize;
     if (!hasOutputFormat) {
       frameDurationUs = (C.MICROS_PER_SECOND * header.samplesPerFrame) / header.sampleRate;
-      MediaFormat mediaFormat = MediaFormat.createAudioFormat(null, MediaFormat.NO_VALUE, header.mimeType,
+      MediaFormat mediaFormat = MediaFormat.createAudioFormat(null, header.mimeType,
           MediaFormat.NO_VALUE, MpegAudioHeader.MAX_FRAME_SIZE_BYTES, C.UNKNOWN_TIME_US,
           header.channels, header.sampleRate, null, null);
       output.format(mediaFormat);
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/ts/SeiReader.java b/library/src/main/java/com/google/android/exoplayer/extractor/ts/SeiReader.java
index b33595d64e..2aa143d44a 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/ts/SeiReader.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/ts/SeiReader.java
@@ -32,7 +32,7 @@ import com.google.android.exoplayer.util.ParsableByteArray;
 
   public SeiReader(TrackOutput output) {
     super(output);
-    output.format(MediaFormat.createTextFormat(null, MediaFormat.NO_VALUE, MimeTypes.APPLICATION_EIA608,
+    output.format(MediaFormat.createTextFormat(null, MimeTypes.APPLICATION_EIA608,
         MediaFormat.NO_VALUE, C.UNKNOWN_TIME_US, null));
   }
 
diff --git a/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java b/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java
index adcaae0741..c4b1590cd4 100644
--- a/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java
+++ b/library/src/main/java/com/google/android/exoplayer/extractor/webm/WebmExtractor.java
@@ -1229,15 +1229,15 @@ public final class WebmExtractor implements Extractor {
 
       MediaFormat format;
       // TODO: Read the name of the track from the header of the webm container and
-      // supply this as id instead of 'null'
+      // supply this as id instead of trackId?
       if (MimeTypes.isAudio(mimeType)) {
-        format = MediaFormat.createAudioFormat(null, trackId, mimeType, MediaFormat.NO_VALUE,
+        format = MediaFormat.createAudioFormat(Integer.toString(trackId), mimeType, MediaFormat.NO_VALUE,
             maxInputSize, durationUs, channelCount, sampleRate, initializationData, language);
       } else if (MimeTypes.isVideo(mimeType)) {
-        format = MediaFormat.createVideoFormat(null, trackId, mimeType, MediaFormat.NO_VALUE,
+        format = MediaFormat.createVideoFormat(Integer.toString(trackId), mimeType, MediaFormat.NO_VALUE,
             maxInputSize, durationUs, width, height, initializationData);
       } else if (MimeTypes.APPLICATION_SUBRIP.equals(mimeType)) {
-        format = MediaFormat.createTextFormat(null, trackId, mimeType, MediaFormat.NO_VALUE, durationUs,
+        format = MediaFormat.createTextFormat(Integer.toString(trackId), mimeType, MediaFormat.NO_VALUE, durationUs,
             language);
       } else {
         throw new ParserException("Unexpected MIME type.");
diff --git a/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java b/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java
index fbfba8e7e8..42ee97c74b 100644
--- a/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java
+++ b/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java
@@ -398,7 +398,7 @@ public class SmoothStreamingChunkSource implements ChunkSource,
     int mp4TrackType;
     switch (element.type) {
       case StreamElement.TYPE_VIDEO:
-        mediaFormat = MediaFormat.createVideoFormat(format.id, MediaFormat.NO_VALUE, format.mimeType,
+        mediaFormat = MediaFormat.createVideoFormat(format.id, format.mimeType,
             format.bitrate, MediaFormat.NO_VALUE, durationUs, format.width, format.height,
             Arrays.asList(csdArray));
         mp4TrackType = Track.TYPE_vide;
@@ -411,13 +411,13 @@ public class SmoothStreamingChunkSource implements ChunkSource,
           csd = Collections.singletonList(CodecSpecificDataUtil.buildAacAudioSpecificConfig(
               format.audioSamplingRate, format.audioChannels));
         }
-        mediaFormat = MediaFormat.createAudioFormat(format.id, MediaFormat.NO_VALUE, format.mimeType,
+        mediaFormat = MediaFormat.createAudioFormat(format.id, format.mimeType,
             format.bitrate, MediaFormat.NO_VALUE, durationUs, format.audioChannels,
             format.audioSamplingRate, csd, format.language);
         mp4TrackType = Track.TYPE_soun;
         break;
       case StreamElement.TYPE_TEXT:
-        mediaFormat = MediaFormat.createTextFormat(format.id, MediaFormat.NO_VALUE, format.mimeType,
+        mediaFormat = MediaFormat.createTextFormat(format.id, format.mimeType,
             format.bitrate, durationUs, format.language);
         mp4TrackType = Track.TYPE_text;
         break;
diff --git a/library/src/main/java/com/google/android/exoplayer/util/Ac3Util.java b/library/src/main/java/com/google/android/exoplayer/util/Ac3Util.java
index fd81706b30..041983fc67 100644
--- a/library/src/main/java/com/google/android/exoplayer/util/Ac3Util.java
+++ b/library/src/main/java/com/google/android/exoplayer/util/Ac3Util.java
@@ -55,7 +55,7 @@ public final class Ac3Util {
     if ((nextByte & 0x04) != 0) {
       channelCount++;
     }
-    return MediaFormat.createAudioFormat(null, trackId, MimeTypes.AUDIO_AC3, MediaFormat.NO_VALUE,
+    return MediaFormat.createAudioFormat(Integer.toString(trackId), MimeTypes.AUDIO_AC3, MediaFormat.NO_VALUE,
         MediaFormat.NO_VALUE, durationUs, channelCount, sampleRate, null, language);
   }
 
@@ -85,7 +85,7 @@ public final class Ac3Util {
     if ((nextByte & 0x01) != 0) {
       channelCount++;
     }
-    return MediaFormat.createAudioFormat(null, trackId, MimeTypes.AUDIO_EC3, MediaFormat.NO_VALUE,
+    return MediaFormat.createAudioFormat(Integer.toString(trackId), MimeTypes.AUDIO_EC3, MediaFormat.NO_VALUE,
         MediaFormat.NO_VALUE, durationUs, channelCount, sampleRate, null, language);
   }
 
@@ -117,7 +117,7 @@ public final class Ac3Util {
       data.skipBits(2); // dsurmod
     }
     boolean lfeon = data.readBit();
-    return MediaFormat.createAudioFormat(null, trackId, MimeTypes.AUDIO_AC3, MediaFormat.NO_VALUE,
+    return MediaFormat.createAudioFormat(Integer.toString(trackId), MimeTypes.AUDIO_AC3, MediaFormat.NO_VALUE,
         MediaFormat.NO_VALUE, durationUs, CHANNEL_COUNTS[acmod] + (lfeon ? 1 : 0),
         SAMPLE_RATES[fscod], null, language);
   }