Generally speaking, if the necessary tool software quicktime is not installed, or the cracked version (there are many problems in this respect), there will be inexplicable problems such as unsynchronized sound and picture, mute and no sound.

In addition to changing the version, the emergency plan is to save the audio and video output as the most conventional MPEG format video file (the default setting). If the audio and video are synchronized, use the format factory to convert it into AVI format video. If it still doesn't work, you can only replace the new version of audio and video.