MediaCodec NullPointException

[feaoes]

机型：坚果pro2
Android系统：7.1.1
使用版本：1.0.4
问题：
当结束录屏的时候，出现MediaCodec为空的情况

09-05 15:10:28.099 17703-18406/? E/AndroidRuntime: FATAL EXCEPTION: Thread-31
Process: com.swmofang.student, PID: 17703
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaCodec.signalEndOfInputStream()' on a null object reference
at com.laifeng.sopcastsdk.screen.ScreenRecordEncoder.stop(ScreenRecordEncoder.java:86)
at com.laifeng.sopcastsdk.controller.video.ScreenVideoController.stop(ScreenVideoController.java:65)
at com.laifeng.sopcastsdk.controller.StreamController$2.process(StreamController.java:81)
at com.laifeng.sopcastsdk.utils.SopCastUtils$1.run(SopCastUtils.java:27)
at java.lang.Thread.run(Thread.java:761)