Add work-around for muxer bug where idx1 offset is from 0, not "movi"

location

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/avi/AviExtractor.java

@@ -399,6 +399,14 @@ public class AviExtractor implements Extractor {
       w("No video track found");
       w("No video track found");
       return;
       return;
     }
     }
+    if (remaining < 16) {
+      output.seekMap(new SeekMap.Unseekable(getDuration()));
+      w("Index too short");
+      return;
+    }
+    final ByteBuffer firstEntry = AviExtractor.allocate(16);
+    input.peekFully(firstEntry.array(), 0, 16);
+
     final int videoId = videoTrack.id;
     final int videoId = videoTrack.id;
     final ByteBuffer indexByteBuffer = allocate(Math.min(remaining, 64 * 1024));
     final ByteBuffer indexByteBuffer = allocate(Math.min(remaining, 64 * 1024));
     final byte[] bytes = indexByteBuffer.array();
     final byte[] bytes = indexByteBuffer.array();
@@ -466,8 +474,10 @@ public class AviExtractor implements Extractor {
       videoTrack.setKeyFrames(seekIndexes[videoId].getArray());
       videoTrack.setKeyFrames(seekIndexes[videoId].getArray());
     }
     }
 
 
+    //Work-around a bug where the offset is from the start of the file, not "movi"
+    final long seekOffset = firstEntry.getInt(8) > moviOffset ? 0L : moviOffset;
     final AviSeekMap seekMap = new AviSeekMap(videoId, videoTrack.clock.durationUs, videoTrack.chunks,
     final AviSeekMap seekMap = new AviSeekMap(videoId, videoTrack.clock.durationUs, videoTrack.chunks,
-        keyFrameOffsetsDiv2.getArray(), seekIndexes, moviOffset);
+        keyFrameOffsetsDiv2.getArray(), seekIndexes, seekOffset);
 
 
     i("Video chunks=" + videoTrack.chunks + " us=" + seekMap.getDurationUs());
     i("Video chunks=" + videoTrack.chunks + " us=" + seekMap.getDurationUs());
 
 

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/avi/AviSeekMap.java

@@ -14,10 +14,13 @@ public class AviSeekMap implements SeekMap {
   final int[] keyFrameOffsetsDiv2;
   final int[] keyFrameOffsetsDiv2;
   //Seek chunk indexes by streamId
   //Seek chunk indexes by streamId
   final int[][] seekIndexes;
   final int[][] seekIndexes;
-  final long moviOffset;
+  /**
+   * Usually the same as moviOffset, but sometimes 0 (muxer bug)
+   */
+  final long seekOffset;
 
 
   public AviSeekMap(int videoId, long usDuration, int videoChunks, int[] keyFrameOffsetsDiv2,
   public AviSeekMap(int videoId, long usDuration, int videoChunks, int[] keyFrameOffsetsDiv2,
-      UnboundedIntArray[] seekIndexes, long moviOffset) {
+      UnboundedIntArray[] seekIndexes, long seekOffset) {
     this.videoId = videoId;
     this.videoId = videoId;
     this.videoUsPerChunk = usDuration / videoChunks;
     this.videoUsPerChunk = usDuration / videoChunks;
     this.duration = usDuration;
     this.duration = usDuration;
@@ -26,7 +29,7 @@ public class AviSeekMap implements SeekMap {
     for (int i=0;i<seekIndexes.length;i++) {
     for (int i=0;i<seekIndexes.length;i++) {
       this.seekIndexes[i] = seekIndexes[i].getArray();
       this.seekIndexes[i] = seekIndexes[i].getArray();
     }
     }
-    this.moviOffset = moviOffset;
+    this.seekOffset = seekOffset;
   }
   }
 
 
   @Override
   @Override
@@ -56,7 +59,7 @@ public class AviSeekMap implements SeekMap {
   private SeekPoint getSeekPoint(int index) {
   private SeekPoint getSeekPoint(int index) {
     long offset = keyFrameOffsetsDiv2[index] * 2L;
     long offset = keyFrameOffsetsDiv2[index] * 2L;
     final long outUs = seekIndexes[videoId][index] * videoUsPerChunk;
     final long outUs = seekIndexes[videoId][index] * videoUsPerChunk;
-    final long position = offset + moviOffset;
+    final long position = offset + seekOffset;
     return new SeekPoint(outUs, position);
     return new SeekPoint(outUs, position);
   }
   }
 
 
@@ -78,7 +81,7 @@ public class AviSeekMap implements SeekMap {
   }
   }
 
 
   public void setFrames(final long position, final long timeUs, final AviTrack[] aviTracks) {
   public void setFrames(final long position, final long timeUs, final AviTrack[] aviTracks) {
-    final int index = Arrays.binarySearch(keyFrameOffsetsDiv2, (int)((position - moviOffset) / 2));
+    final int index = Arrays.binarySearch(keyFrameOffsetsDiv2, (int)((position - seekOffset) / 2));
 
 
     if (index < 0) {
     if (index < 0) {
       throw new IllegalArgumentException("Position: " + position);
       throw new IllegalArgumentException("Position: " + position);

library/extractor/src/test/java/com/google/android/exoplayer2/extractor/avi/AviSeekMapTest.java

@@ -9,7 +9,7 @@ public class AviSeekMapTest {
   @Test
   @Test
   public void setFrames_givenExactSeekPointMatch() {
   public void setFrames_givenExactSeekPointMatch() {
     final AviSeekMap aviSeekMap = DataHelper.getAviSeekMap();
     final AviSeekMap aviSeekMap = DataHelper.getAviSeekMap();
-    final long position = aviSeekMap.keyFrameOffsetsDiv2[1] * 2L + aviSeekMap.moviOffset;
+    final long position = aviSeekMap.keyFrameOffsetsDiv2[1] * 2L + aviSeekMap.seekOffset;
     final int secs = 4;
     final int secs = 4;
     final AviTrack[] aviTracks = new AviTrack[]{DataHelper.getVideoAviTrack(secs),
     final AviTrack[] aviTracks = new AviTrack[]{DataHelper.getVideoAviTrack(secs),
         DataHelper.getAudioAviTrack(secs)};
         DataHelper.getAudioAviTrack(secs)};