Crash in frameencoder when AUDelimiter is turned on

[Former user]

[ This problem is fixed in the default branch, this issue is just for record purpose.]

When the AccessUnitDelimiter option is turned on, the frameencoder will crash when generate the AUDelimiter because the bitstream is not set in the entropyencoder.

The fix is at commit 47e6a51 in default branch

[Former user]

The fix is at commit 47e6a51