QLab

QLab is centered around the concept of cues, which are grouped into cue lists. A simple workspace might contain a single cue list with multiple cues, each of which plays back a single audio file. More complex workspaces may contain multiple cue lists, groups of cues, advanced timing control, and integrations with external devices. == Version history ==

The concept for QLab originated in late 2005, when Baltimore-based theater designer Chris Ashworth responded to a request from a small theatre company for audio playback solutions. The initial version of QLab utilized the Core Audio API in Mac OS X, a defining feature, which made the program exclusive to Apple computers. Ashworth advertised the beta version of QLab on a listserv for theatrical sound designers, and incorporated their feedback into version 1.0, released in September 2006. QLab 2 was released in 2009. Key features in version 2 include a revised interface; support for timecode via MIDI and LTC; automatic and manual vamping; and scripting via AppleScript, Python, and Ruby. QLab 3, released in 2013, introduced a rebuilt video system, support for Open Sound Control, and a mobile app for remote control on the iPad. Version 3.2.15, released in October 2018, is the final supported release of QLab 3. QLab 4 was released in 2016, introducing lighting control functionality. QLab 4 controls lighting devices with the industry standard DMX512 protocol, using commercially available USB-DMX adapters or networked systems via Art-Net. This version also integrates features from QCart, a previously separate program for non-linear show control and advanced programming. QLab 5 was released in 2022. This version adds features for real-time collaboration, and introduces a rebuilt video rendering system based on the Metal API. Additional features include a revised audio routing system and enhanced functionality in the "Audition" preview mode. As of September 2024, QLab 5 is the latest major version of the program. All major versions of QLab are supported by smaller releases of bugfixes and additional features. As of November 2023, QLab 4 and 5 receive these updates. == Licensing ==

QLab offers multiple tiers of licenses, reflecting the broad feature set of the program. The free version of the program includes limited audio and video playback functionality, and separate licenses are available for fully-featured audio output, video output, and lighting control. Licenses are available as a perpetual license, as a daily rental, or as a volume license for large installations. As of November 2023, licenses are only sold for QLab 5; these licenses are also honored for QLab 4 installations. Perpetual licenses can be reassigned to different computers via an automated web interface. == Features ==

Audio playback QLab allows an end-user or designer to align audio files in a sequential order. Once the audio files are inserted into the cue list, the end-user can then manipulate it by looping it, changing the amplitude or volume, and adding fades in or out. Audio cues can also be placed into groups, so that multiple files can be triggered at one moment. Object Audio With the release of QLab 5.5, Object Audio was introduced allowing the positioning of sound in the real world. By mapping outputs to specific locations on a 2d plane, users are able to easily set up spacial sound. Video playback QLab is capable of playing back multiple video formats, fully integrated with audio playback and other cues. In addition to video files, QLab can route and display video signals from cameras, through multiple supported protocols. A text editor is also available for surtitles and other applications, and video effects can be applied to any content. The video system in QLab supports advanced use cases such as projection mapping. Show control integration QLab supports MIDI bi-directionally. QLab allows MIDI signals to be sent as a cue to trigger other devices, such as digital audio consoles. The software also accepts MIDI signals as triggers for its own cues. MIDI signals can be sent to QLab from any other MIDI capable device, using a MIDI interface. In addition to MIDI control, QLab also supports MIDI timecode and linear timecode, allowing users to trigger cues in sync with external devices. Live playback A key software feature with QLab is its ease of use in live playback situations. The designer of a cue sheet can save their show file, and lock it, preventing any changes to the cues. After doing so, an untrained user can run the software in a playback situation. By default, a cue is triggered by clicking a large GO button on the screen, or by pressing the space bar. Scripting and Automation QLab supports both AppleScript and OSC, allowing QLab to control other MacOS software, or take commands from external control surfaces with the use of Companion; a piece of software designed to work with customizable control pads such as the Elgato Stream Deck. == References ==