As I changed audio codec to aac, the problem remained. I also checked the browser console, and no error found.
Help!
Metadata:
encoder : Lavf57.25.100
Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007), yuv422p, 640x480, q=-1--1, max. 500 kb/s, 1000k fps, 1k tbn, 1000k...