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Blu-ray Audio Codecs Explained

If you need Blu-ray audio codecs explained, you are becoming a real audio tech geek. But, don’t worry, it’s a compliment, not a putdown. Understanding how audio and media devices work is rapidly becoming vital information as technology continues to grow at a phenomenal rate.

Do you already know what codecs are?

If so, understanding Blue-ray codecs can help you to enhance the quality and capabilities of your home theater system, especially if you are using Dolby Digital, Dolby True, or Dolby Atmos. So, what are Blu-ray codecs, and how do audio codecs work?

What Are Blu-ray Audio Codecs?

Blu-ray Audio Codecs

The definition of an audio codec is a program or device that converts analog audio signals into digital audio signals for transmission or storage.

By performing this process, the size and bandwidth of the files are compressed. However, the audio quality remains high. Furthermore, there are specific Blu-ray codecs to convert files into supported formats. We will discuss them throughout this guide.

Understanding Audio Encoding and Decoding

Before we go any further in the technicalities of codecs, we need to cover the basics. We need to understand the difference between audio encoding and decoding. Most of the confusion in regards to this subject is that your everyday Blu-ray user doesn’t understand audio formats. And why would they?

Audio encoding is the process used to store audio on Blu-ray discs, which can be saved in several audio formats that are used to compress the audio onto the disk. In regards to these formats, if Blu-ray doesn’t support them, you will not be able to play the disk.

Surely you have inserted a Blu-ray disk before, only to find you cannot play the movie. That’s because of the encoding format issues. You can see the supported formats on your Blu-ray box.

What is audio decoding?

Audio decoding is a different process entirely. This is the function that processes the Blu-ray disc data and plays it through your amp and speakers. This process was almost always performed by the amp and speakers. But in this day and age, it can be done by the media player. Or, in this case, your Blu-ray player.

The decoding process will split the audio from your Blu-ray disc into multiple audio channels and send it to the speakers. Encoding and decoding might seem like two heads on the same coin, but they are different.

However, there are lots of different encoding and decoding types. We need to explore the Blu-ray audio format types to see the bigger picture.

Blu-ray Audio Formats Guide

Let’s get down to business and get these Blu-ray audio codecs explained in greater detail. What are the different types of codecs that a Blu-ray player supports? There are seven main Blu-ray codecs, although some more have been created recently. The important thing to remember is that three of those codecs are mandatory, while the other four are optional.

When the Ultra-HD Blu-ray specifications were recently made available, two more codecs were added. These are Dolby Atmos and DTS:X. Because these are new codecs, the vast majority of new players do not support these.

Although one way around that is to use an AV receiver, you must always check the supported audio formats of your Blu-ray player. So, let’s check out the nine common Blu-ray codecs…

1 – Linear PCM – Mandatory Codec Format

This codec is sometimes referred to as LPCM or just PCM. These are the standard codec formats for both CD and DVD players, which are also used as standard Blu-ray audio codec. In terms of audio quality, this is the best one.

This format is uncompressed audio that offers the best quality sound. However, the file size is usually quite big and takes up lots of storage space.

This type of codec supports eight audio channels, so it’s perfect for 7.1 surround sound systems. But it’s usually a staple in 5.1 stereo surround sound systems. 24-bit sample rates are supported by this codec. But it’s common for LPCM audio will be 16-bit, so you can maximize storage space.

High audio quality, max storage space…

This is a very popular codec because you get high-quality audio that matches both Dolby TrueHD and DTS HD-Master Audio. It’s important to mention that the lossless HD versions probably come from higher resolution masters. In theory, they can be compressed, so they use less storage.

If you are using an LPCM 5.1 surround sound system, you can use HDMI for stereo transfer with coaxial digital connections. LPCM is the mandatory codecs that offer the highest sound quality, but takes up the most storage space.

2 – Dolby Digital – Mandatory Blu-ray Codecs

Dolby Digital goes by many different names. The most common are Dolby 2.0, Dolby AC-3, and DD 5.1. This type has more names than Daenerys Targaryen but won’t burn down your entire city.

Dolby Digital does have some limitations because it uses six channels. This means that 5.1 surround sound systems are its ceiling. However, the maximum sample rate covered by this type is 48kHz.

This format compresses the audio to save disk space. Therefore, some audio info is lost along the way, slightly affecting sound quality. This is the standard codec you will find on a DVD. And you can also send this audio via HDMI or digital/coaxial cables, very similar to LPCM formats. Dolby Digital is a generic name given to most 5.1 encoding systems.

3 – DTS Surround Sound – Mandatory Blu-Ray Codecs

DTS Surround Sound is another mandatory Blu-ray codec that is essentially a DTS version of Dolby Digital formats. This format is also referred to as DTS 5.1. This type is limited to six channels and uses compression to make the file much smaller on the disc. DTS is different from Dolby Digital, as it supports a higher bitrate of 1500kb/s compared to 640kb/s bit rates.

However, this type is not limited to 5.1 sound systems. It can support some 6.1 sound systems, known as DTS-ES. The extra rear channel is part of the DTS 5.1 sound info, but will only activate when an extra rear speaker is added.

The debate between Dolby DTS and DTS sound quality is always heated. There is a noticeable difference between the two, but your personal preference will have to decide on the best option.

4 – Dolby Digital Plus – Optional Blu-ray Format

Dolby Digital Plus is also commonly known as E-AC-3 or DD+ and is an extension of Dolby Digital. It supports 7.1 sound Blu-ray discs. However, this can be problematic as most Blu-ray movies are 5.1. The sound quality is decent because this format has a maximum bitrate of 6Mbits/s. Putting this into context, the maximum bitrate of Blu-ray discs is 1.7Mbits/s.

The sample rate is 48kHz, which is the same as the lossy compression with Dolby Digital. This means you will lose some audio quality on compression, but not too much.

DD+ also doesn’t support coaxial and digital cable. But if you do use them, it will automatically switch to standard Dolby Digital. You will need an HDMI connection to use this format unless your player comes with multiple analog audio channels.

5 – DTS-HD Hi-Res Audio – Optional Blu-ray Codecs

When we need Blu-ray audio codecs explained, we cannot overlook this DTS-HD Hi-Res Audio format. This codec is usually referred to as DTS 5.1 but can be configured to work with 7.1 channel sound systems.

This format has a bitrate of 6Mbits/s, which makes it much better than DTS 5.1. This is still a lossy format that will lose some audio quality and resolution during compression.

The connections are the same as Dolby Digital. Coaxial and optical connections are not supported, and if used, the format will switch to DTS 5.1. You can use HDMI 1.3 connections, or higher, unless your player can decode the signal as LPCM.

6 – Dolby TrueHD – Optional Blue-ray Format

Dolby Digital

Dolby TrueHD is one of the most unique Blu-ray formats. This is a lossless format that not only compresses the audio but will also make a copy of the original audio file. This ensures you get the best of both worlds. You can enjoy the best audio performance while also getting a compressed copy saved on the disc.

The audio in this format has a greater dynamic range than DD+ or DD 5.1 formats. This ensures you will hear more of the high and low-end frequencies that create a fuller and rounder sound. You can push the boat out with this format. It supports 7.1 sound Blu-ray systems and can support up to 14 channels.

Similar to Dolby Digital Plus…

The 7.1 audio format supports 24-bit/96kHz resolution, while the 5.1 format supports 24-bit/192kHz resolution. The maximum bitrate of this format is a massive 18Mbits/s. This means you will need HDMI connections to transfer these codecs.

If you do need to send this signal through an HDMI connection, you will need an AV receiver with Dolby TrueHD decoding functions. You will also need at least an HDMI 1.3 model.

7 – DTS-HD Master Audio – Optional Codec

The best way to describe this codec would be a lossless audio version of DTS. If you are fortunate enough to buy a Blu-ray disc with this format, you have the bit-to-bit copy of the movie studio’s master tapes.

The lossless sound of this on a Blu-ray disk will be in either the DTS version, the Dolby TrueHD version, or both. The main problem you will encounter is your Blu-ray player probably doesn’t support this format type. So you won’t be able to watch it.

This format has the highest bitrate of all, with 24.5 Mbits/s on a Blu-ray disc. If you are using eight channels, this will run at 24-bit/96kHz, which is the same as Dolby.

8 – Dolby Atmos – Optional Blu-ray Codecs

Dolby Atmos is one of the new types of codec that I mentioned earlier. This optional codec showcases object-based soundtracks for the first time. Because the format is so new, we are only starting to see this appear on the latest Blu-ray disc releases.

This format is great for movie-makers who want to add sounds to the channel-based audio. Furthermore, it allows you to create the ultimate 3D experience where you can move sounds in different directions.

Just remember that you will need at least two height speakers and an AV receiver that can use bitstream to send the signals from your Blu-ray player. You will be happy to know that this format is backward-compatible with older Blu-ray models. But you will need at least an HDMI 1.4 connection to make it happen.

9 – DTS:X – Optional Blue-ray Format

This DST:X format is also object-based. It is similar to Dolby Atmos and might be supported by the latest Blu-ray disc releases. But it is widely supported by DTS-HD Master Audio. You will need an AV receiver that supports this codec and height speakers. But it can work on existing 5.1 and 7.1 speaker systems.

Check out the 5 best Blu-ray players…

To help you get started on enjoying Blu-ray discs, here are some great Blu-ray players for your consideration.

Best Blu-ray Audio Codecs Explained – Final Thoughts

Now you’ve had Blu-ray codecs explained in the best possible way, what did we learn? You now know the differences in the multitude of Blu-ray codec formats. This will give you the insight you need to make the correct purchase based on what you are trying to achieve with your home theater system.

Codecs seem extremely confusing and technical at first. But they are essentially a method to convert analog audio to digital formats to play or store. Just make sure you check the supported codecs on your potential Blu-ray player purchase to ensure you have the format option you need or think you will need in the future.

Until next time, enjoy the show.

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