Audio bit depth Audio
In digital audio using pulse code modulation (PCM), the bit depth is the number of bits in each sample of information and corresponds to the direct resolution of each sample.
Some examples of bit depths include Compact Disc Digital Audio, which uses 16 bits per sample and can support up to 24 bits per sample of DVD-Audio and Blu-ray Disc.
In a basic implementation, bit depth fluctuations mainly affect the following noise levels: Quantization error: thus signal-to-noise ratio (SNR) and dynamic range. However, it mitigates these effects without changing the dithering, noise shape, and oversampling bit depth. Bit depth also affects bit rate and file size.
Bit depth is a digital signal that only makes sense for PCM. The non-PCM format, like the lossy compression format, does not have an associated bit depth. [to]
Binary representation
A PCM signal is a set of digital audio samples that contain data that provides the information you need. Reconstructed original analog signal. Each sample is a signal of the signal at a particular amplitude point, and the samples are evenly spaced in time. Amplitude is the only information explicitly stored in the sample and is usually stored as one of the following: Binary number encoded as integer or floating point Fixed number of digits – The bit depth of the sample, also known as word length or size word of mouth.
Resolution indicates the number of discrete values that can be represented in the analog value range. The resolution of the binary integers increases as the length of the word increases exponentially. Adding 1 bit doubles the resolution and adding 2 bits doubles the resolution. The number of possible values that can be represented by an integer bit depth can be calculated using. 2 n, where n bit depth. [1] Therefore, the resolution of a 16-bit system is 65,536 (2 16) possible values.
The entire PCM audio data is normally stored as follows: Two’s complement format for signature numbers. [2]
Many audio file formats and Digital Audio Workstations (DAWs) now support the PCM format with samples represented by floating point numbers. [3] [4] [5] [6] Both WAV and AIFF file formats support floating point rendering. [7] [8] Unlike integers, where the bit pattern is a unique set of bits, floating-point numbers consist of separate fields whose mathematical relationships form a number. The most common standard is IEEE 754, which consists of three fields. Sign bit This is whether the number is positive or negative, exponent, and mantissa. This is raised by the exponent. The mantissa is represented as a binary fraction based on two IEEE-based floating point formats. [9]
Quantization
Bit depth is the quantization error of the reconstructed signal at the maximum level determined by the signal-to-noise ratio (SNR). Bit depth is limited by frequency response, which does not affect sample rate.
Quantization error introduced in analog-to-digital conversion (ADC) as modeled quantization noise. This is the rounding error between the analog input voltage to the ADC and the digitized value of the output. The noise depends on the non-linear signal.
8-bit binary ann (149-inch decimal), highlighted LSB
If the quantization error is the least significant bit (LSB) and the signal has a uniform distribution that covers all quantization levels, the signal-to-quantization noise ratio (SQNR) can be calculated. Scriptstyle {pm frac {1} { 2}}
mathrm {SQNR} = 20log_ {10} （2 ^ {Q}） 約 6.02cdot Q mathrm {dB} 、！
Where Q is the number of quantization bits and the result is measured as follows: Decibel (dB). [10] [11]
Therefore, 16-bit digital audio has a theoretical maximum CD SNR of 96 dB, and professional 24-bit digital audio has a maximum SNR of 144 dB. As of 2011, digital audio conversion technology is limited to an SNR of approximately 123 dB [12] [13] [14] (effectively 21-bit) IC design due to the actual limit. [b] Still, this closely resembles the human performance of the auditory system.
