Dolby markets EAC3 as “Dolby Digital Plus”. The surround channels enable producers to create a sensation of sound from any direction surrounding the listener.ĭolby upgraded AC3 with EAC3. Related: AdTech Predictions for 2023 – The Experts Speak!ĭolby Digital supports up to 5.1 channels – left, right, center, left surround, right surround, and a low-frequency enhancement channel. Dolby Digital is almost synonymous with “surround sound” in cinema, home theaters, and broadcast. Dolby uses the market name “Dolby Digital” for AC3. Music and audio on the Internet, personal audio devices digital broadcasting (radio and TV)ĪC3 is an audio codec from Dolby. Widely available AAC is supported by most web browsers and consumer audio devices OEMs and end-user software vendors (eg., media players) need to pay royalties to patent holders Sampling rates supported (kHz)ĩ6 kbps or above for 48 kHz stereo supports arbitrary bit rates Some of the variants are AAC LC (Low Complexity), AAC Main, AAC LD (Low Delay), and HE-AAC (High Efficiency). It also has various variants intended for different use-cases and applications. It supports a broader range of sampling rates, bit rates, and numbers of channels. Another way of looking at this is that AAC gives superior audio quality than MP3 at the same bit rate.ĪAC is much more versatile than MP3.

AAC features several improvements and new coding techniques that enable significant bit rate improvements over MP3 at the same audio quality.

AAC is an abbreviation for Advanced Audio Coding. ISO standardized AAC in MPEG-2 and MPEG-4 as the successor to MP3. Music and audio on the Internet, personal audio devices Widely available MP3 is supported by almost all web browsers and consumer audio devices Stereo 5.1 is supported only in MPEG-2 for bit rates less than 32 kHz Sampling rates supported (kHz)ģ2, 44.1, 48 (MPEG-1) 16, 22.05, 24 (MPEG-2)ġ28 kbps or above for 48 kHz stereo supports up to 320 kbps As a result, they are not useful for all kinds of audio. But these sampling rates discard a good amount of human audible frequencies (i.e., above 8, 11.025, and 12 kHz respectively). MPEG-2 (Part 3) included an extension to MP3 that supported lower sampling rates (16, 22.05, 24 kHz) and channels up to 5.1. MP3 was standardized by ISO as MPEG-1 Audio Layer III in 1993. MP3 ushered in the digital audio revolution in the ‘90s. MP3 is the most well-known audio codec by far and almost synonymous with digital audio in the popular imagination. Let’s now jump right in and take a look at the characteristics of some popular codecs. The lower the bit rate, the lower the size of the encoded audio and the network bandwidth requirement. Most often, the bit rate is a tunable parameter during encoding.īit rate is important because it has a direct impact on the size of the encoded file (in storage applications) and the network bandwidth needed for audio transmission (in streaming and broadcast applications). Bit rate is expressed in units of kbps (kilobits per second). The bit rate of a codec refers to the (average) number of bits it uses to encode one second of raw audio. Bit RateĪ note on “bit rate” before we start. If not, do check my article on the basics of digital audio here. This article assumes that you have an understanding of the common terms related to digital audio like frequency, sampling rate, and channels.

If you’ve been wondering what exactly is the difference between MP3, AAC, AC3, WAV, WMA, and Opus, then this article is for you. In particular, I will focus on the aspects that are most relevant from a user’s perspective (and not from an algorithm perspective). In this article, I will discuss and compare the key features of some popular audio codecs.

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