Android SDK sample doesn't display data channel messages from C SDK. How can I display them?

[agrexgh]

Brief

I'd like to use both C SDK and Android SDK,
but this combination has a problem with data channel communication.
As the title says, Android sample doesn't display data channel messages from C SDK sample.
How can I display them?

The version of code

• amazon-kinesis-video-streams-webrtc-sdk-android
  4d1b0ed8dac338c0a8dddfda923a0b176cc50fb8

• amazon-kinesis-video-streams-webrtc-sdk-c
  08e4d294a7466f42033a7aaeacf2521f519749f7 applied the patch below.
  This patch makes C SDK sample to echo back the received data channel messages and show result of sending them.

diff --git a/samples/Common.c b/samples/Common.c
index f1c9f961a..368bd88cb 100644
--- a/samples/Common.c
+++ b/samples/Common.c
@@ -21,6 +21,9 @@ VOID onDataChannelMessage(UINT64 customData, PRtcDataChannel pDataChannel, BOOL
     } else {
         DLOGI("DataChannel String Message: %.*s\n", pMessageLen, pMessage);
     }
+
+    STATUS ret = dataChannelSend(pDataChannel, isBinary, pMessage, pMessageLen);
+    DLOGW("ret = %d", ret);
 }

 VOID onDataChannel(UINT64 customData, PRtcDataChannel pRtcDataChannel)

How to reproduce this issue

1. Launch both sdk samples and connect them to same channel.
2. From Android sample, send a data channel message.

Expected behavior

At 2, Android sample display the data channel message just like the one Android sample sent on the heads-up notification.

Actual behavior

At 2, Android app DOESNOT display them.

Supplement

• I can't tell which SDK sample has the problem.
• With Android SDK sample and JS SDK sample, there is no problem.
  Android sample shows the data channel messages from JS SDK sample on the heads-up notification.

[agrexgh]

I tried
C SDK sample (0be097904010bb53cca44fd6453c2da953ead4d9), which sends data channel message when the C sample receives data channel messages,
and Android SDK sample (4d1b0ed8dac338c0a8dddfda923a0b176cc50fb8) pairs,
but unfortunately Android SDK sample seems not to receive data from C SDK sample.

I'll try to investigate this issue,
but someone, could you give me some help?

[agrexgh]

Android SDK sample creates Data Channel only to send messages, but not this is not to receive messages
(I don't know why but onMessage() method is no op).

And C SDK sample sends and receives messages with this data channel,
but messages sent from C SDK sample is ignored by Android SDK sample.

By the way JS SDK sample is very similar to this.

Do you have any progress on this issue?
And, does this issue occur on iOS SDK?

[sirknightj]

I ran the sample just now. Using Android Master, and C viewer.

As you can see from the screenshot below, data channel messages are shown.

.

However, with C Master and Android viewer, that's when the data channel messages are not displayed.