I uploaded a video, but when I stream or download it from DISCO some of the sound is missing

This is likely happening because the video files you are uploading include two or more audio tracks. We often see this with with .mov video files, where the primary audio track might include a voice-over, but won’t include background music. The secondary audio track, then, might include the voice-over as well as the background music, combined.

DISCO creates an optimized .mp4 version of all .mov files for web playback. The .mp4 will only contain the primary audio track. Additional audio tracks will be not be included.

The .mov will still contain multiple audio tracks after uploading to DISCO but please note video files with multiple audio tracks will not play as expected in some media players. To ensure that all versions of your videos on DISCO include a complete audio track, you’ll want to encode the original files using a single, merged audio track prior to uploading.