【Log警告】WARN/AudioFlinger(34): write blocked for 76 msecs
01-16 11:10:07.191: WARN/AudioFlinger(34): write blocked for 76 msecs, 31924 delayed writes, thread 0xb3f0
01-16 11:10:12.209: WARN/AudioFlinger(34): write blocked for 74 msecs, 31951 delayed writes, thread 0xb3f0
01-16 11:10:17.233: WARN/AudioFlinger(34): write blocked for 69 msecs, 31958 delayed writes, thread 0xb3f0
01-16 11:10:22.262: WARN/AudioFlinger(34): write blocked for 73 msecs, 31987 delayed writes, thread 0xb3f0
01-16 11:10:27.345: WARN/AudioFlinger(34): write blocked for 91 msecs, 32002 delayed writes, thread 0xb3f0
01-16 11:10:32.361: WARN/AudioFlinger(34): write blocked for 77 msecs, 32030 delayed writes, thread 0xb3f0
01-16 11:10:37.395: WARN/AudioFlinger(34): write blocked for 69 msecs, 32037 delayed writes, thread 0xb3f0
01-16 11:10:42.512: WARN/AudioFlinger(34): write blocked for 78 msecs, 32064 delayed writes, thread 0xb3f0
01-16 11:10:47.675: WARN/AudioFlinger(34): write blocked for 74 msecs, 32078 delayed writes, thread 0xb3f0
01-16 11:10:52.730: WARN/AudioFlinger(34): write blocked for 93 msecs, 32108 delayed writes, thread 0xb3f0
播放音频和视频log里输出以上警告,是什么原因?