The supported video file format extensions on the camera roll
#include <camera/camera_api.h>
typedef enum {
CAMERA_ROLL_VIDEO_FMT_DEFAULT = 0,
CAMERA_ROLL_VIDEO_FMT_MP4
} camera_roll_video_fmt_t;
These extensions are used only to generate filenames. The actual formatting of the video data is the responsibility of the application writing to the file.