Audio Info2
Here is some audio info I put together while doing some training with audio production and video (scoring). Maybe it will come in handy for one of you out there.
*I did not write all of this on my own, some was pulled from internet resources while putting all of this together. I cited sources as noted, but there are some that I could not find again.
Audio Production and Scoring:
What is it?
A film score is the background music in a film, generally specially written for the film and often used to heighten emotions provoked by the imagery on the screen or by the dialogue.
In many instances, film scores are performed by orchestras, which vary in size from a small chamber ensemble to a large ensemble, often including a choir. The orchestra is either a studio orchestra, employed by the studio, or a performing orchestra such as the London Symphony Orchestra. However, TV, video games, and films with even smaller budgets, often utilize sampling technology to re-create the sound of an orchestra. This is generally much cheaper, although most film-makers try to avoid this.
Some films use popular music as the primary musical component, but an orchestral score is more often preferred. An orchestral score can be much more closely adapted to a film while popular music is based upon a strong and repetitive rhythm that is inflexible and cannot be easily adapted to a scene. Popular genres of music also tend to date quickly as styles rapidly evolve while orchestral music tends to age much more gracefully. Instead, popular music may be included for special occasions where more attention must be diverted to the music. In these cases, songs are usually not written specifically for the film (see soundtrack).
How is is done?
After the film has been shot (or has completed some shooting), the composer is shown an unpolished “rough cut” of the film (or of the scenes partially finished), and talks to the director about what sort of music (styles, themes, etc.) should be used — this process is called “spotting.” Sometimes the director will have added “temp music”: already published pieces that are similar to what the director wants.Once a composer has the film, he/she will then work on creating the score.
Fundamentals
resource: http://www.tvhandbook.com/support/pdf_files/audio/Chapter8_1.pdf.
Characteristics of the Human Receiver because of the extreme importance of matching the conversion system performance to the most
sensitive human listener, the most relevant information related to the hearing process will be
reviewed briefly. First, the limits of audibility will be considered.
Limits of Audibility
For the normal listener, the ear is most sensitive to frequencies between 2000 and 5000 Hz at the threshold of hearing. Sensitivity drops for frequencies above and below this region such that by 200 Hz and 15 kHz, it is approximately 20 dB lower [11]. In addition, detection of a 20-kHz pure tone is possible for some people at high levels (>80 dB sound pressure level, SPL, [12] or >100dB SPL [13]). Despite this possibility, some experiments reveal that even highly trained listeners cannot discriminate between conditions of 16- and 20-kHz low-pass cutoff frequencies on program material containing considerable energy at and above 20 kHz [12, 14]. This result supports studies done as early as 1931, which established that a band from 40 Hz to 15 kHz is sufficient to reproduce music without an audible change in the reproduction. Nevertheless, more recent work examining the low-frequency limits for reproduction suggests that the presence of frequencies below the cutoff of the audible range (20 Hz) can contribute to a more lifelike sound quality [15]. Thus, for an ideal audio system, a generous choice of bandwidth might be 1 Hz to 20 kHz, and an acceptable bandspread would be 20 Hz to 15 kHz.
Dynamic-Range Requirements for Audio Reproduction
To establish the dynamic range required for signal playback in the ideal system, a number of facts must be considered. The ear’s effective dynamic range is 100 dB or more [11]. However, for subjectively noise-free reproduction of music in a quiet environment it has been suggested that approximately 118 dB of dynamic range is required to provide a listener with the maximum peak SPL and an undetectable noise spectrum [16]. This criterion was based partly on measurements of peak instantaneous sound levels of acoustical musical instruments (e.g., orchestral peaks registered 113-dB SPL, normal-miked percussion 122-dB SPL, and close-miked percussion 120- to.
Fundamentals of Digital Audio 8-15
139-dB SPL), as well as electronic instruments (which could deliver 128-dB SPL and higher). At the low end, an average threshold for white-noise detection in a home and studio environment was 4-dB SPL measured over a 20-kHz bandwidth, even in rooms with broadband noise levels of 50-dB SPL. This numerically unlikely feat was explained by two facts. First, a narrowband of frequencies around 4.5 kHz was probably responsible for the detection of this signal because that band was not masked by high-level, low-frequency sounds. Second, sound localization of the test noise at the loudspeaker aids the detection process [16]. On the basis of these limited studies, an ideal system must provide for playback somewhere from 100 dB to nearly 120 dB of dynamic range to fulfill the dual requirements of capturing the range of program-material dynamics and matching the ear’s range.
Audio Production Types:
MIDI vs Audio
MIDI is Musical Instrument Digital Interface
MIDI is a way to play sound files and minimize on storage space. MIDI transmits information and communicates the commands about how to play certain sounds and when. There is in fact, no audio signal when working with MIDI; only in the end workflow for sound output.
MIDI devices are the mediator between sound sources and a computer.
MIDI files are practically just code translating to the computer which note and sound to play and when to play it. (O’s, 1’s). For this reason, they take up minimal amount of space and they can be transfered from one source to another very easily, pending both points share the same audio sources.
Recorded Sound
The three most popular audio (recorded sound) formats are AU (audio format), WAV (waveform audio) and AIFF or AIF (Audio Interchange File Format). .EA is another common format, used specifically for the Web. They allow decent compression and decent sound quality.
Many formats allow for 8 and 16-bit resolution. With smaller resolution (such as 8-bit) the file size is smaller, but the quality of sound isn’t as good.
16-bit is CD quality, but recommend working in 24-bit.
Compressed formats:
MP3- MP3 is an acronym for MPEG-1 or MPEG-2 audio layer 3. MP3 is the file extension for MPEGaudio layer 3. Layer 3 is one of three coding schemes (layer 1, layer 2 and layer 3) for the compression of audio signals. Layer 3 uses perceptual audio coding and psychoacoustic compression to remove all superfluous information (more specifically, the redundant and irrelevant parts of a sound signal. The stuff the human ear doesn’t hear anyway). …
www.ucla.cyberstuff.net/glossary_digital_media.htm
AAC-Advanced Audio Coding (AAC), also known as MPEG-2 Part 7, and also MPEG- 4 Part 3 in a slightly modified form, is a digital audio encoding and lossy compression format. AAC was designed as an improved-performance codec relative to MP3 (which was specified in MPEG-1) and MPEG-2 Part 3 (which is also known as “MPEG-2 Audio” or ISO/IEC 13818-3).
AAC was promoted as the successor to MP3 for audio coding at medium to high bit rates.
