NullPointerException in TsExtractor

[clhols]

With some of my streams I get the following NullPointerException with r2.0.4:

E/LoadTask: Unexpected exception loading stream
    java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.exoplayer2.extractor.ts.ElementaryStreamReader.init(com.google.android.exoplayer2.extractor.ExtractorOutput, com.google.android.exoplayer2.extractor.ts.ElementaryStreamReader$TrackIdGenerator)' on a null object reference
        at com.google.android.exoplayer2.extractor.ts.TsExtractor$PmtReader.consume(TsExtractor.java:470)
        at com.google.android.exoplayer2.extractor.ts.TsExtractor.read(TsExtractor.java:242)
        at com.google.android.exoplayer2.source.hls.HlsMediaChunk.load(HlsMediaChunk.java:180)
        at com.google.android.exoplayer2.upstream.Loader$LoadTask.run(Loader.java:295)

It happens because streamReaderFactory.createStreamReader in TxExtractor returns null in the following snippet:

pesPayloadReader = streamReaderFactory.createStreamReader(streamType, esInfo);
pesPayloadReader.init(output, new TrackIdGenerator(trackId, MAX_PID_PLUS_ONE));

The reason why createStreamReader returns null is because the flag FLAG_IGNORE_H264_STREAM in DefaultStreamReaderFactory is set. The reason why that flag is set is due to the following lines in HlsChunkSource:

// Sometimes AAC and H264 streams are declared in TS chunks even though they don't really
// exist. If we know from the codec attribute that they don't exist, then we can
// explicitly ignore them even if they're declared.
if (!MimeTypes.AUDIO_AAC.equals(MimeTypes.getAudioMediaMimeType(codecs))) {
  esReaderFactoryFlags |= DefaultStreamReaderFactory.FLAG_IGNORE_AAC_STREAM;
}
**if (!MimeTypes.VIDEO_H264.equals(MimeTypes.getVideoMediaMimeType(codecs))) {
  esReaderFactoryFlags |= DefaultStreamReaderFactory.FLAG_IGNORE_H264_STREAM;
}**

After debugging this I see that the "codecs" variable only contains the audio codec mp4a.40.2. Other streams that doesn't have this issue lists both the video and audio codecs.

So I looked into the TS data and it is:

GET /session/b40d3704-ba06-11e6-8abc-90b11c442bb3/zfynsx/c/9/5/1/c_283_95119f3b0523409cbf735f15b01ec35b/11_17.m3u8 HTTP/1.1

HTTP/1.1 200 OK
Content-Length: 645
Cache-Control: no-cache
Connection: Keep-Alive
Date: Sun, 04 Dec 2016 09:47:43 GMT
Content-Type: application/x-mpegURL

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=6190800,CODECS="mp4a.40.2"
tv11.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=4320800,CODECS="mp4a.40.2"
tv12.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2820400,CODECS="mp4a.40.2"
tv13.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1720364,CODECS="mp4a.40.2"
tv14.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1170400,CODECS="mp4a.40.2"
tv15.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=620364,CODECS="mp4a.40.2"
tv16.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=290400,CODECS="mp4a.40.2"
tv17.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=61600,CODECS="mp4a.40.2"
tv18.m3u8

And when a stream is chosen, the you get this:

GET /session/b40d3704-ba06-11e6-8abc-90b11c442bb3/zfynsx/c/9/5/1/c_283_95119f3b0523409cbf735f15b01ec35b/tv15.m3u8 HTTP/1.1

HTTP/1.1 200 OK
Content-Length: 581
Cache-Control: no-cache
Connection: Keep-Alive
Date: Sun, 04 Dec 2016 09:47:43 GMT
Content-Type: application/x-mpegURL

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:12
#EXT-X-MEDIA-SEQUENCE:275842
#EXT-X-DISCONTINUITY-SEQUENCE:1
#EXTINF:12.000,
tv15_20161204T094540_275842.ts
#EXTINF:12.000,
tv15_20161204T094552_275843.ts
#EXTINF:12.000,
tv15_20161204T094604_275844.ts
#EXTINF:12.000,
tv15_20161204T094616_275845.ts
#EXTINF:12.000,
tv15_20161204T094628_275846.ts
#EXTINF:12.000,
tv15_20161204T094640_275847.ts
#EXTINF:12.000,
tv15_20161204T094652_275848.ts
#EXTINF:12.000,
tv15_20161204T094704_275849.ts
#EXTINF:12.000,
tv15_20161204T094716_275850.ts
#EXTINF:12.000,
tv15_20161204T094728_275851.ts


GET /session/b40d3704-ba06-11e6-8abc-90b11c442bb3/zfynsx/c/9/5/1/c_283_95119f3b0523409cbf735f15b01ec35b/tv15_20161204T094704_275849.ts HTTP/1.1

HTTP/1.1 200 OK
Content-Length: 1812320
Cache-Control: no-cache
Connection: Keep-Alive
Date: Sun, 04 Dec 2016 09:47:44 GMT
Content-Type: video/MP2T

So there is video in the stream.
I then tried to remove esReaderFactoryFlags |= DefaultStreamReaderFactory.FLAG_IGNORE_H264_STREAM in HlsChunkSource and then both video and audio plays just fine.

[ojw28]

Already fixed in dev-v2: b2222f8

[clhols]

Ok, but dev-v2 is still unable to play the video part of the stream. So what has replaced DefaultStreamReaderFactory.FLAG_IGNORE_H264_STREAM in dev-v2?

[ojw28]

If there's video in this stream then the HLS master playlist is in violation of the spec. From the HLS spec:

If an EXT-X-STREAM-INF tag or EXT-X-I-FRAME-STREAM-INF tag contains the CODECS attribute, the attribute value MUST include every media format [RFC6381] present in any Media Segment in any of the Renditions specified by the Variant Stream.

In your master playlist CODECS="mp4a.40.2" is indicating that only audio is present. The video codec needs to be listed there too. If the video codec were listed, we'd play the video part of the stream correctly.

[clhols]

Ok, I can't change the playlist, so I will have to fork the library and remove FLAG_IGNORE_H264_STREAM. Thanks for looking into it.