Audio and Video Series: Audio Basics Part 2
Introduction to sound
time domain masking
Masking that occurs between temporarily adjacent sounds.
temporary masking
audio encoding
encoding process
coded process
audio file format
Audio File Format ( wiki ): The format of the file that contains the audio data.
Format Classification
Lossless formats: such as WAV, FLAC, APE, ALAC, WavPack (WV)
Lossy formats: such as MP3, AAC, Ogg Vorbis, Opus
performance comparison
Latency Comparison
delay compare
Efficiency Comparison
efficiency comparison
AAC encoding
AAC (wiki): Advanced Audio Coding, a proprietary audio coding standard for lossy digital audio compression based on MPEG-2, which appeared in 1997.
AAC exhibits better sound quality than MP3 and is intended to replace the MP3 format.
usual format
AAC LC : (low complexity) low complexity specification
AAC HE V1 : (high efficiency) AAC LC + SBR (Spectral Band Replication)
AAC HE V2 : AAC LC + SBR + PS (parametric stereo)
ac profile
data exchange format
ADIF : (Audio Data Interchange Format) Audio Data Interchange Format, can only be decoded from scratch, commonly used in disk files.
ADTS : (Audio Data Transport Stream) audio transport stream format, each frame has a sync word, which can be decoded at any position in the audio stream for data transmission.
