Digital Audio for Nerds

Everything you need to know about digital audio for everyday!

Dennis "@the_metalgamer" Fink

02 April 2016

at "Spark-Up: Creative Madness" by C3L

Table of Contents

• Samplerate & Bit Depth
• Filetypes

Samplerate

• Continous signal to discrete signal

Samplerate

• Measured in Hertz
• Common samplerates:
  • 44.1 kHz (44100 Hz)
  • 48 kHz (48000 Hz)
  • 96 kHz (96000 Hz)

Alias Effect

• Nyquist-Shannon sampling theorem
  • Samplingrate must be 2x highest frequence

Bit Depth

• Number of bits per sample
• Common bit depths:
  • 16bit
  • 24bit

Why?

• With higher samplerate & bit depth, higher quality
• Not needed for everyday listening
• But for audio engineering
• Archival

File formats

• Different types:
  • Uncompressed
    • WAV
  • Compressed:
    • Lossless:
      • FLAC
    • Lossy:
      • MP3
      • Ogg Vorbis

FLAC

• Asymmetric
• Different steps (examples):
  • Inter-Channel Decorrelation
  • Modeling
  • Residual Coding

Lossy Formats

• Psychoacoustics
  • Remove frequencies people can't hear

What to use?

• FLAC for archival
• OggVorbis with VBR 320kb/s (oggenc -b 320)