RTSP: app crash because of duplicated header from ip-camera

[ArtRoman]

There is non-catchable app chash when opening RTSP link from ip camera because of duplicated RTSP key "framerate".

java.lang.IllegalArgumentException: Multiple entries with same key: framerate=25 and framerate=0S
  at com.google.common.collect.RegularImmutableMap.createHashTable(RegularImmutableMap.java:104)
  at com.google.common.collect.RegularImmutableMap.create(RegularImmutableMap.java:74)
  at com.google.common.collect.ImmutableMap$Builder.build(ImmutableMap.java:339)
  at com.google.android.exoplayer2.source.rtsp.MediaDescription$Builder.build(MediaDescription.java:198)
  at com.google.android.exoplayer2.source.rtsp.SessionDescriptionParser.addMediaDescriptionToSession(SessionDescriptionParser.java:201)
  at com.google.android.exoplayer2.source.rtsp.SessionDescriptionParser.parse(SessionDescriptionParser.java:186)
  at com.google.android.exoplayer2.source.rtsp.RtspClient$MessageListener.onRtspMessageReceived(RtspClient.java:384)
  at com.google.android.exoplayer2.source.rtsp.RtspMessageChannel$Receiver.lambda$handleRtspMessage$0$RtspMessageChannel$Receiver(RtspMessageChannel.java:291)
  at com.google.android.exoplayer2.source.rtsp.-$$Lambda$RtspMessageChannel$Receiver$HitD0FATwe-gLFkoSjlAUnzETfA.run(-.java:-1:-1)
  at android.os.Handler.handleCallback(Handler.java:755)
  at android.os.Handler.dispatchMessage(Handler.java:95)
  at android.os.Looper.loop(Looper.java:154)
  at android.os.HandlerThread.run(HandlerThread.java:61)

Corresponding RTSP response is:

RTSP/1.0 200 OK
Content-Type: application/sdp
Server: H264DVR 1.0
Cseq: 1
Content-Base: rtsp://192.168.1.11:554/user=admin&password=&channel=1&stream=0.sdp/
Cache-Control: private
x-Accept-Retransmit: our-retransmit
x-Accept-Dynamic-Rate: 1
Content-Length: 412

v=0
o=- 38990265062388 38990265062388 IN IP4 192.168.1.11
s=RTSP Session
c=IN IP4 192.168.1.11
t=0 0
a=control:*
a=range:npt=0-
m=video 0 RTP/AVP 96
a=rtpmap:96 H264/90000 
a=range:npt=0-
a=framerate:0S
a=fmtp:96 profile-level-id=4d0029; packetization-mode=1; sprop-parameter-sets=J00AKY1uBQBboQAAAwABAAADADKE,KO4Fcg==
a=framerate:25
a=control:trackID=3
m=audio 0 RTP/AVP 8
a=control:trackID=4

Player initialization:

val streamUrl = "rtsp://192.168.1.11:554/user=admin&password=&channel=1&stream=0.sdp"
val mediaSource = RtspMediaSource.Factory().createMediaSource(MediaItem.fromUri(streamUrl))

val player = SimpleExoPlayer.Builder(context).build()
player.repeatMode = Player.REPEAT_MODE_OFF
player.setVideoTextureView(ipcamVideoView)
player.setMediaSource(mediaSource)
player.prepare()
player.play()

Stream URL is not public available. I can do nothing with the camera, I couldn't find option to remove duplicated header.
Is there any way to filter RTSP headers before creating MediaDescription? Maybe any other suggestions to avoid crash?

One of ExoPlayer forks with RTSP support works quite good with this stream.

• ExoPlayer 2.14.0
• Android 7.1.2
• TinkerBoard S

[claincly]

The SDP does look off, no? Setting frame rate to 0S and 25. I'll add the code to make the error surface a bit better. However, it wouldn't change the overall behaviour, because the semantics of this problem is also unclear: do you keep (for the same key) the first value, or the last, or some one in between? In your case, it probably makes more sense to keep "25", but there's no clear cut.

The fail is easy to fix, change the usage of the ImmutableMap.Builder here to use a regular Map,

ExoPlayer/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/MediaDescription.java

Line 109 in 9be5ece

private final ImmutableMap.Builder<String, String> attributesBuilder;

And change this line

ExoPlayer/library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/MediaDescription.java

Line 198 in 9be5ece

ImmutableMap<String, String> attributes = attributesBuilder.build();

to something like

ImmutableMap<String, String> attributes = ImmutableMap.copyOf(yourMap);

[ArtRoman]

the semantics of this problem is also unclear: do you keep (for the same key) the first value, or the last, or some one in between?

I expect HashMap-like behaviour: new value with the same key replaces the previous one, so the last header value is kept.

However, it wouldn't change the overall behaviour

Library shouldn't crash app because of uncatched exception. I can't validate all headers of any stream. Error should be handled via error listener, player should stop playing media.

The fail is easy to fix

I will try later to add submodule with modifications instead of library dependency.