Audio Visual Digitization Hardware and Software
Digitization is the process of converting information into a digital format. In this format, information is organized into discrete units (0 or 1) of data called bits that can be separately addressed in multiple-bit groups called bytes (8 bits). This is the binary data that computers and many devices can process.
Audio and video digitization uses one of many analog-to-digital conversion processes in which a continuously variable (analog) signal is changed, without altering its essential content, into a multi-level (digital) signal. The process of sampling measures the amplitude (signal strength) of an analog wavefront (imaginary surface representing corresponding points of a wave that vibrate simultaneously) evenly spaced time markers and represents the samples as numerical values for input as digital data.
The digitization process can be broken down into four main operations:
- Rendering analog signals
- Converting analog signal to digital information
- Capturing digital data stream
- Editing and exporting digital files
Rendering analog signals
It is important to use high performance equipment to render analog signals in its original format. We use a variety of vintage equipment to play audio visual material in their original format.
- For open reel audio tapes, we use Technics RS-1500 US Reel To Reel Tape Deck Recorder
- For audio cassette tapes, we use Tascam 202 MK IV Audio Cassette Recorder / Player
- For VHS videos tapes, we use Panasonic PV-7662 Metal Head VHS Video Deck
- For U-Matic video tapes, we use Sony VO-9850 U-matic Videocassette Recorder
- For Mini DVs, we use Canon Vixia HV40 High-Definition Mini–DV Camcorder
Converting analog signals to digital information
Analog signals are processed by an electronic device called analog-digital converter, or digitizer. This device takes analog signals as input, formats the data into a serial bit stream as its output. Its input ports are connected to analog signal rendering devices such as a video player through cables such as RCA cables. Its output ports are connected to a computer through cables, such as an Apple Firewire.
- For digitizing audio, we use FIREWIRE Solo recording interface M-AUDIO
- For digitizing video, we use Canopus ADVC110 Bi-Directional Analog-to-Digital Convertor
Capturing digital data stream
As the analog-digital converter outputting data stream in real time, a software must capture the digital bit stream like a digital recorder. Depending on the size, quality, and format of the original material, we use a few software to record the digital data.
- For audio with narrow dynamic range and unified speed, we use a simple software Amadues Pro
- For audio with wider dynamic range, varied speed, we use a more robust software Adobe Audition
- For short videos in common video format, we use Apple Final Cut Pro
- For longer videos in not so common format, we use Adobe Premiere Pro
Editing and encoding digital files
The final step in digitization process is the editing and encoding digital files for intended purposes. Depending on the quality of the original materials, some need very little editing, others need much more. Depending on the quality of the output format, some can be batch rendered quickly, others need sophisticated settings adjusted meticulously and monitored carefully.
- For editing audio and video files, we use the common media post production software such as Adobe Creative Suite.
- For easy compression, we use Handbrake
- For more demanding encoding, we use Adobe Media Encoder
Digitizing audio visual archives is not a static task. It is a parallel development with the development of digitizing hardware, software, and industrial standards. Computer science, electronic engineering, data science, library science are rapidly advancing fields of studies. With the advancement in these fields, the audiovisual digitization process is in a constant evolution.