The consumer world is slowly transitioning to a wireless audio ecosystem with wireless earphones or headphones being the go-to choice for people. All major flagship smartphones have gotten rid of the headphone jack too. Since Bluetooth supports wireless functionality, here we’re talking about Bluetooth codecs.
A Bluetooth codec determines how the data is transferred from your devices such as your mobile phone or laptop to your headphone or earphone through Bluetooth. Read this article to find out about Bluetooth codecs.
Before jumping into the Bluetooth codecs, let’s first understand four basic audio terminologies.
Sample Rate
- The sample rate is the number of data points present in each second in the file. It is the rate at which the frequency of an audio signal is captured or stored.
- The unit of sample rate is Hertz.
- The minimum sample rate used is 44.1 kHz and for high-resolution audio, 96kHz or more is used.
- The bigger the sample rate, the bigger is the file size.
Bit Depth
- The bit depth determines the number of bits present in each audio sample. It tells us about the resolution of the file.
- There are two-bit depth – 16 bit and 24 bit, and the high-resolution audio uses a 24-bit depth.
- More the bit depth, more is the file size.
Bit Rate
- The number of bits processed or transferred per second is known as the Bit Rate. It is measured in kbps or Mbps.
- You can calculate Bit Rate by multiplying the Sample Rate and Bit Depth.
Connectivity Range
Connectivity Range is the range over which your Bluetooth signal becomes disrupted due to the presence of other signals such as radio signals, wifi signals, or objects such as walls or people.
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Why is bluetooth codec required?
Every time whenever you listen to audio using a wireless earphone, the sound is transmitted from your device to your earphones via Bluetooth. The audio on your device is in digital form and to share it with your headsets, the digital form of audio is converted into an analogue format, and then it is transmitted to your earphones. Thus, the music that you hear through your headphones is in analogue format.
The transformation of your audio from digital to analogue happens with the help of a digital to analogue converter present in your devices.
The conversion affects the quality of your sound and hence, to maintain the quality, Bluetooth codecs are required. Bluetooth codecs are audio codec algorithms that maintain the quality of audio when it is converted from digital to analogue form.
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6 major groups of Bluetooth codecs explained
There are different types of codecs available. Let’s go through some of them.
SBC
SBC stands for Sub-Band Codec. It is the first Bluetooth codec algorithm and is required for all A2DP-enabled devices. It supports 16-bit audio files and is universally compatible. SBC is a lossy compression algorithm and it can transfer the audio at 192-320 kbps but with some data loss.
AAC
Advanced Audio Coding is a codec for lossy digital audio compression. It is better implemented on iOS devices and is supported by Android above version 8. Even though Android supports AAC, the performance of AAC is poor and unreliable in Android devices. AAC is a license-free audio standard for YouTube and Apple devices. It has high power consumption and can produce better results than SBC. AAC supports 24-bit audio files with a 250 kbps bit rate.
Qualcomm’s proprietary codecs
Qualcomm is the developer of many wireless codes which are primarily used in Android devices and has enhanced the music quality through Bluetooth. Smartphones of brands such as Microsoft, LG uses Qualcomm codecs. iOS devices do not support the Qualcomm codecs.
Here are some of Qualcomm’s key codecs.
- aptX – aptX is the lossy compression algorithm and is better than SBC. Android 4.4 or above supports aptX codec. It supports 16-bit audio files and bit rates upto 384 kbps.
- aptX HD – aptX HD is an improved version of the aptX codec. It supports 24-bit audio files with upto 576 kbps of bit rate. aptX HD is supported by Android 8 or above.
- aptX LL – aptX LL is aptX codec with low latency which delivers the audio in sync with the video or game. It supports 16-bit audio file along iwth 350 kbps of bit rate. Windows desktpo supports aptX LL. Currently, there are no smartphoes which supports aptX LL.
LDAC
LDAC is Sony’s proprietary codec and offers near to lossless audio quality. However, when encountered with interference, the audio quality is decreased. You can transmit 24-bit audio files with a bit rate of up to 990 kbps. It supports Android 8.0 or above and all Sony devices.
LC3
LC3 stands for Low Complexity Communications Codec. It is also known as the Low Energy Audio codec. LC3 was introduced at the CES 2020 trade show and is claimed to be the new default Bluetooth codec. It provides multi-stream audio that is you can listen to different audio on your left and right earbud. Major improvements have been seen in the audio quality, power consumption, and latency level in the LC3 codec.
Samsung scalable codec
Samsung developed the Samsung Scalable Codec for the Samsung Galaxy Buds.
This codec supports a wide range of bit rates. The best feature of this codec is that the bitrate is adjusted according to the Bluetooth connection in order to maintain stability. This adjustment may lead to low audio quality, however, the connection is maintained.
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