EECS 1520 Lecture Notes - Lecture 4: Flac, Moving Picture Experts Group, Scalable Vector Graphics

• School: York University
• Department: Electrical Engineering and Computer Science
• Course: EECS 1520
• Professor: Steven Castellucci

Document Summary

Microphone is a transducer, converting audio (sound waves) into electrical signals. Digitizing sound involves taking samples (measurements) at a fixed rate (sampling rate) Each sample is a fixed size, called bit depth: higher bit depth means a more accurate sample. Combining bit depth + sampling rate gives a bit rate. Higher bit rate = better quality = larger file size. Range of human hearing 20 hz-20 khz: nyquist-shannon theorem recommends sampling rate approx. Cd quality audio (industry standard): 16 bits bit depth (per channel, stereo has 2 channels, 44. 1 khz sampling rate, 1. 4 mbits/sec bit rate. Uncompressed audio typically saved in . wav format. Lossless audio compression: similar to text compression techniques. Lossy audio compression: remove imperceptible sounds (using psychoacoustics models, reduce bit rate (less accurate reproduction of the original) Codecs: compression and decompression algorithms for audio (and video, port(cid:373)a(cid:374)teau (cid:894)(cid:449)ord (cid:272)o(cid:373)(cid:271)i(cid:374)atio(cid:374)(cid:895) of (cid:862)(cid:272)oder(cid:895) a(cid:374)d (cid:862)de(cid:272)oder(cid:863)or i(cid:374) this (cid:272)ase (cid:862)(cid:272)o(cid:373)pressor(cid:863) a(cid:374)d (cid:862)de(cid:272)o(cid:373)pressor(cid:863)