äänikoodaus

Äänikoodaus, also known as audio coding, refers to the process of converting analog audio signals into a digital format or compressing digital audio data for efficient storage and transmission. This conversion is essential for modern digital audio technologies, from music playback on smartphones to high-definition broadcasting and streaming services.

The first step in äänikoodaus is typically analog-to-digital conversion (ADC). An analog audio signal, which is continuous, is sampled at regular intervals. The amplitude of the signal at each sample point is then quantized, meaning it is assigned a discrete numerical value. The frequency of these samples and the number of bits used for quantization determine the fidelity of the digital audio. Higher sampling rates and more bits per sample result in a more accurate representation of the original sound but also produce larger file sizes.

Following digitization, audio data can be further processed using äänikoodaus techniques to reduce its size. This is achieved through compression. Lossless compression algorithms reduce file size without discarding any audio information, meaning the original signal can be perfectly reconstructed. Examples include FLAC and ALAC. Lossy compression, on the other hand, achieves greater size reduction by selectively removing audio information that is less perceptible to the human ear. MP3 and AAC are common examples of lossy audio codecs. The choice between lossless and lossy compression depends on the balance required between file size and audio quality.