Why the image disappears but you can hear the sound?

The Core of The Problem

This situation is similar to problem "Sound is missing while the image is normal". The codec for encoding the video is missing. The solution is quite similar to the forward situation. Use a video converter to convert your video file to QuickTime format.

Convert Video to QuickTime Format on Mac OS X

Step 1, Download and install QuickTime video converter

You can download it for free here:

• Intel Version
• Power PC Version

To install it, simply mount the .dmg archive by double-clicking it, and copy the application to your applications folder (or wherever you want).

Step 2, Load video files

Click the "Add Files" button to add video files to the program. This QuickTime video converter for Mac supports drag and dropping. It also supports batch conversion, so you can import and convert several multimedia files at a time.

Step 3, Select output format

Use the “format” on the bottom of the window to control the output format. Click on the toggle to the right of the "Format" label to expand the panel. Select "MOV - QuickTime (.mov)" as the output format.

Step 4, Change QuickTime Video and audio Settings

Click on the “Setting” button to expand “Setting” panel.

You can change the Resolution, Encoder, Bit rate and Frame rate of the QuickTime video and Sample Rate, Channels, Encoder and Bit Rate of the QuickTime Audio. The size of the QuickTime file depends a lot on these settings.

Step 5, Select output directory

Expand the "Output" panel. Use the "Browse" button to select an output directory.

Step 6, Click “Convert” to convert Video to QuickTime files on Mac.