The camera feature utilizes browser APIs, and different browsers support different sets of formats in which they can encode the captured video stream. Unfortunately, not every browser support MP4 as a target container format. If you use uploadcare-widget (jQuery widget), you can use the UPLOADCARE_VIDEO_PREFERRED_MIME_TYPES setting to force using MP4 in browsers that support it:
UPLOADCARE_VIDEO_PREFERRED_MIME_TYPES = "video/mp4";
The new uploader (Blocks 0.40.0) doesn’t have this setting yet.
If you’d like to disable the camera tab, you can use the following settings to specify a list of available upload sources:
uploadcare-widget:
blocks: