Dig Deeper - Type Definitions

Audio

• AI - Artificial Intelligence algorithms can effectively remove background noise (hiss, hum, wind) from audio recordings, significantly improving clarity. They can also enhance audio quality by adjusting levels, equalization, and compression, often surpassing the capabilities of traditional manual editing. In addition, AI algorithms can repair damaged or degraded audio recordings, restoring clarity and filling in missing parts. This is invaluable for preserving historical recordings and archival material
• AM - AM radio, short for Amplitude Modulation, is a method of broadcasting radio signals where the amplitude (strength) of the carrier wave is varied to encode the audio information. While it may not sound as good as FM, its long range and simple technology make it a persistent and valuable broadcasting method
• Azimuth Adjustment - The alignment of the tape heads in relation to the tape's motion (crucial for ensuring optimal playback quality), achieved by physically adjusting the angle of the playback head of a cassette tape player
• bit - This refers to the bit depth of the audio signal, which indicates the number of bits used to represent each audio sample in a digital audio file. 16-bit audio is the standard bit depth for CD-quality, 24-bit audio increases the dynamic range and provides more headroom for audio processing
• De-Click - Removing transient noises, pops or clicks that can occur in a recording
• De-Clip - Removing a form of distortion that occurs when the amplitude of an audio signal exceeds the maximum level that can be accurately captured or played back, causing the waveform to flatten at the peaks. This results in a loss of dynamic range and can produce harsh, unpleasant sounds
• De-Crackle - Removing distortion that produces a series of short, sharp, and often harsh sounds, which can occur in audio recordings due to various issues such as degradation of vinyl records, digital artefacts, or environmental noise
• De-Hum - The process of removing a steady, continuous sound with a frequency commonly associated with electrical interference, faulty equipment, equipment noise or grounding issues. This hum often manifests as a low-frequency sound, commonly around 50 or 60Hz, which is associated with the electrical power supply
• De-Noise - Elimination of unwanted background noise from an audio signal. This noise can be anything from hums and hisses, to clicks, pops, wind noise, or room ambiance that detracts from the clarity and quality of the desired audio signal
• Dynamic Range Expansion - Increases the dynamic range of an audio signal. Dynamic range is the difference between the softest and loudest parts of a sound. In practical terms, expanding the dynamic range means enhancing the perceived difference between quiet and loud sounds (comes in two types, downward and upward)
• EQ - Equalisation is a process used to adjust the balance of different frequency components within an audio signal. This technique can be used to enhance or attenuate specific frequencies in a sound, which can greatly affect its tonal quality and overall character
• Fixed Dropouts - Repairing interruptions in the audio signal that create gaps or breaks in the sound found during audio playback or recording, where there is a sudden loss of sound. This can result from various factors, including faulty cables, connectors, or components in the recording gear as well as glitches in the recording software or drivers on a computer
• Flutter Reduction - An attempt to fix undesirable variation in pitch or amplitude that can occur in audio recordings, particularly with tape-based systems that are usually the result of imperfections in the tape itself. It is characterised by rapid fluctuations that can create a wavering, unstable sound, which can be distracting to listeners
• FM - FM radio broadcasts sound using frequency modulation, offering superior sound quality and noise immunity compared to AM's amplitude modulation, which is more susceptible to interference. In addition, FM broadcasts are in stereo (this is achieved using a technique called multiplex transmission)
• Generation Tape - The "generation" refers to the number of times an audio signal has been copied. It's about the lineage of the recording, not a specific tape format like cassette or reel-to-reel. Beyond three generations, the quality loss becomes significant, making further copies largely undesirable for most listeners
• Hiss Reduction - An attempt to to minimise or eliminate unwanted high-frequency sound that can be heard in quiet passages of audio, usually caused by the inherent noise of recording equipment, electrical interference, or the characteristics of certain microphones. Analogue tapes, can introduce noise due to imperfections in the tape material
• kHz - This refers to the sampling rate used for digital audio, specifically, it means the audio is sampled this many times per second. Human hearing ranges up to around 20kHz, so sampling at 44.1kHz (twice that upper limit) allows for the accurate representation of audio frequencies within the audible range, while also accounting for filter roll-off and other factors. Higher sampling rates, such as 96kHz, can provide improved audio quality by allowing for more detail and fidelity in the recording, this is especially important for nuanced audio elements, such as high-frequency sounds, that might be lost at lower sampling rates like 44.1kHz
• Lossy - A type of audio compression that reduces the file size by permanently removing certain data from the audio signal. This process is designed to eliminate sounds that are less likely to be perceived by the human ear, resulting in a smaller file size while aiming to maintain a suitable level of audio quality. Common lossy audio formats include MP3, AAC, and OGG Vorbis
• Master Tape - The original, highest-quality recording. It is the tape from which all subsequent copies (generation tapes/cassettes, digital transfers, etc.) are made. Any imperfections in the Master Tape will be replicated in all subsequent copies
• Matrix - The method of combining or processing of multiple audio sources to improve the range, depth, sound quality and spatial representation of a recording
• Merge - The merging together of two or more sources (or two or more versions of the same source) to produce a more complete and/or a better listening experience
• Normalised - The process that adjusts the amplitude of an audio signal so that it reaches a target level. It is important to note that normalisation does not enhance the dynamic range or quality of the audio, it simply adjusts the levels
• Original - A recording that has not been altered (for Bootlegs, this means that a recording has not been altered after it was ripped from the Bootleg CD, it does not account for changes to the source material)
• Phase Correction - The process of aligning the phase of different audio signals to ensure that they combine effectively, avoiding issues such as cancellation or reinforcement of certain frequencies to achieve a balanced and natural sound, especially in recordings where clarity and detail are essential
• Pitch Correction - Adjusting the tone or pitch of the audio recording to ensure that the notes or sounds are at the accurate pitch they were meant to be. This technique is particularly useful for correcting slight pitch inaccuracies that can occur during recording, especially with live performances
• Raw - An audio rip straight from the source with no post-production processing, editing, or mixing
• Remaster - The process of taking an existing audio recording and improving its sound quality using modern techniques. It's not just about boosting the volume; it's a much more nuanced process aimed at enhancing the listening experience while preserving the originals artistic intent
• Restoration - The goal of restoration is to improve the quality of a degraded audio recording, bringing it closer to its original intended sound. This involves repairing or minimizing various forms of damage and imperfections that accumulate over time, or due to poor initial recording techniques
• Spectral De-Noise - An audio processing technique that reduces noise by analysing the frequency spectrum of the audio signal. Unlike time-domain noise reduction which operates on the amplitude of the signal over time, spectral de-noising focuses on the frequency components. It works by identifying frequencies that predominantly contain noise and attenuating or removing them, leaving the desired audio signal relatively intact
• Speed Correction - Adjusting the playback speed of an audio recording so that it matches the original tempo at which it was recorded. This can be necessary for various reasons, such as correcting for variations in tape speed during recording, compensating for changes in playback systems, or adjusting audio for synchronisation with video or other audio tracks
• Wow Reduction - An attempt to minimise or eliminate variations in pitch caused by inconsistencies in the rotational speed of the playback machineries speed (this affects both analogue tape and vinyl records)
• YouTube - Sourced via YouTube. Downloading audio from YouTube, even if you aim for the highest quality available, ALWAYS results in a lossy format, primarily because of the encoding processes YouTube (and most other streaming services) use.

Video

• 4k - A video resolution that has approximately four times the number of pixels as 1080p (Full HD) video. 4K video provides a sharper, more detailed image with more vibrant colours and greater clarity compared to 1080p
• AI - Artificial Intelligence can upscale video resolution, improve clarity, reduce noise and artefacts, and stabilize shaky footage. It can also enhance colour grading and dynamic range, improving the overall visual quality. AI-powered tools are emerging that can automatically edit videos, including selecting the best shots, adding transitions, and generating subtitles. This significantly reduces the time and effort required for video production
• Comparison - A side by side comparison usually showing differences in video and/or audio
• Compilation - A compilation of multiple sources of video and/or audio
• Deinterlacing - The process of converting interlaced video into a non-interlaced or progressive form. Interlaced video, which is commonly used in traditional television broadcasting, consists of two fields per frame, one field containing the odd-numbered lines and the other containing the even-numbered lines. This method was developed to reduce flicker and improve display stability on older CRT televisions. Interlaced video can lead to visual artefacts, particularly when viewed on progressive scan displays, such as computer monitors and modern televisions. These artefacts may include jagged edges, motion blur, or flickering, especially during fast-moving scenes
• Denoising - The process of reducing or eliminating noise from a video sequence. Noise in video appears as unwanted variations in pixel colour and brightness, often making the image look grainy, speckled, or otherwise visually unpleasant. This noise can be introduced at various stages, from the camera sensor itself (sensor noise) to compression artefacts during encoding and transmission
• Flicker Reduction - A technique used to minimise the perceptible flickering that can occur when projecting or viewing film. This flickering can be caused by various factors, including the frame rate of the film, the projection speed, and the way the film is illuminated
• Frame Rate Adjustment - Changing the playback speed to ensure compatibility, improve viewing quality, and maintain the artistic integrity of the original motion. Frame rate is a critical factor that affects the visual quality, motion smoothness, and overall feel of a video or film
• Interpolation - A technique for filling in gaps or enhancing content, typically using digital technology. This technique involves creating additional frames between existing frames to increase the frame rate or make motion appear smoother. It is often used in video editing and post-production processes to enhance the visual flow of a film
• Silent - A video (normally an 8mm film) which was shot without audio and is presented with audio
• Sound Sync - A video which had either no audio or a poor quality audio which is synchronised with either audio from that actual gig or the closest possible match
• Stabilising - This refers to the process of correcting the shakiness or jitter that often occurs in films, particularly those that were shot by hand or in less than ideal conditions. This can happen due to a variety of factors, including camera movement, uneven hand-holding, or problems with the film itself
• Upscale - The process of increasing the resolution of a video or film to a higher format than it was originally created in. This is typically used to improve the visual quality of lower-resolution content, such as DVD or standard-definition video, when it is displayed on higher-resolution devices, such as 4K or 8K televisions
• Vimeo/YouTube - Sourced via either Vimeo or YouTube