In January 2016, Apple shocked the world by removing the headphone jack from the iPhone 7 smartphone, and at the same time, they launched its first generation Airpods, which became the most innovative gadget in the world. This Apple move had changed the way of listening for the music lovers and market. Also, other brands have started removing the headphone jack from the smartphone, forcing music lovers to turn to wireless Bluetooth earphones.
It is a bit challenging to choose the right wireless earphone, and we often see the technical specifications such as Battery capacity, Speaker drivers, water protection, Bluetooth version, and wireless range, but few of us know about the Bluetooth code.
If you wondered about the Bluetooth Codes or if you don’t know about the Bluetooth Codes yet, so don’t worry about it. Today in this article we are going to know about Bluetooth codec technology and its types.
So with no further ado, let’s get started!
Before we dive into the information, you need to understand the basic of Bluetooth Codec:
Sample rate (Hz): The sample rate or sampling frequency determines the average number of samples of audio obtained per second. The sampling rate calculates in Hz, which stands for Hertz or samples per second. For instance, 48 kHz is 48,000 samples per second.
A sound sample is simply a number that represents the measured value of an acoustic wave at a certain point in time.
Bit-depth: Bit-depth means the number of bits of information saved for each audio sample. For example, a CD uses 16 bits per sample, but high-resolution files extend this to 24-bit, such as a and DVD-Audio, Blu-ray Disc. Higher bit rates affect the bit rate and file size.
Bit rate (kbps): Bitrate is represented in kbps or Mbps, which transfers an amount of data into audio per second. A higher bitrate usually means better sound quality.
0.001 bit per second = 1 Megabit per second (one bit per thousand seconds)
1,000 bit per second = 1 Kilobit per second (one kilobit or one thousand bits per second)
1,000,000 bit per second = 1 megabit per second (one megabit or one million bits per second)
1,000,000,000 bit per second = 1 gigabit per second (one gigabit or one billion bits per second)
Types of audio files format
The uncompressed audio format, as the name implies, is a format that does not use compression. This means that all the data is available, although there is a risk of large file sizes. WAV audio files are an example of uncompressed audio files.
The lossless compressed audio format stores data in less space without losing information. We can recreate the original uncompressed data from the compressed version. This type of audio format comprises an uncompressed audio format that encodes sound and silence with a certain number of bits per unit of time. Encoding an uncompressed minute of total silence creates a file of the same size as encoding the uncompressed minute of music. However, in a lossless compressed format, music takes up smaller files than the uncompressed format, and silence takes up brief space.
The lossy audio format lets you further reduce the file size by taking out some audio information and simplifying the data. This certainly degrades the sound quality, but various methods are used, primarily using psychoacoustics, to take out the parts of the sound that has the lowest degree impact on perceived quality and minimize the amount of audible sound added in the process.
What is Bluetooth Codec?
Depending on the software, the codec will determine how Bluetooth is transmitted from the root device to your earphone. It encodes and decodes the top-level audio data into a specific format. Better yet, it delivers a high-accuracy signal with a specified bit-rate.
Now it is time to understand are types of Bluetooth codes used in wireless Bluetooth earphones.
SBC (Low-complexity sub-band codec):
The SBC, or Low Complexity Subband Codec, is an audio subband codec designated by the Bluetooth Special Interest Group (SIG) for the Advanced Audio Distribution Profile (A2DP). Subband coding (SBC) is any form of transformation coding that typically uses the Fast Fourier Transform to divide the signal into several frequency bands, each of which is encoded independently. This decomposition is often the first step in data compression of audio and video signals.
AAC (Advanced audio coding):
As compared to the SBC (Low-complexity sub-band codec), AAC (Advanced audio coding) delivers better sound quality, and this most commonly used Bluetooth codec that found in truly wireless earbuds nowadays.
AAC (Advanced Audio Coding ) is an advanced audio coding standard application for lossy digital audio compression. This is also a YouTube license-free standard and is Apple’s recommended transfer mode. If your smartphone supports the AAC codec, then you will get the benefit of higher coding efficiency for stationary signals. With the AAC codec, Android smartphones perform much pain as compared to Apple’s iPhones. This is not surprising that Android does not handle AAC properly.
Qualcomm aptX series
Qualcomm is the leading owner and developer of the processors, which are used in the smartphone, we are familiar with Qualcomm’s processors, and most of the brands like Xiaomi, Oppo, Vivo, Oneplus, LG, and Microsoft use them in the smartphones. Qualcomm also develops advanced wireless codec algorithms, which enhance the quality of music heard via Bluetooth.
Today, Qualcomm’s proprietary codecs, aptX, aptX LL, and aptX HD, often get pleasant words for wireless headphones. Although only aptX LL supports a latency of lower than 40 milliseconds. Android’s wireless capability is inconsistent looking at what source device you are using.
Sony has its own proprietary Bluetooth codec LDAC. Variable bit rate is a defining feature that transfers the data up to 3 times as compared to SBC. It can hold the sampling rate and bit depth at 96kHz/24bit (up to 990kbps). LDAC is suitable for all Sony devices and Android 8.0 Oreo and above.
Samsung Scalable Codec
Samsung has announced Scalable Codec along with the Samsung Galaxy Buds developed with AKG. It prioritizes stability by constantly adjusting the streaming speed, so listeners are less likely to experience disconnections and dropouts. It is like how LC3 audio manages packet loss, both of which actively adjust the bit rate to signal strength to reduce audio stutter. Samsung Scalable Codec is only compatible with Samsung devices.