High definition entertainment doesn’t have to be rocket science, but it is important to be educated about the facts. Check out our hi-def dictionary, so you too can be an HD expert and impress your friends.

Questions about a topic, or know a term that should be added to the list? Let us know.

Table of Contents

Terms/Definitions

Blu-ray Disc (BD)

Blu-ray Disc is a high definition video disc format that supersedes DVD. Blu-ray has a resolution of 1920×1080 (aka 1080p), compared to 720×480 on DVD. It also has storage capacity of up to 50GB in its current state, compared to 9GB on DVD. This allows for better quality high definition video unattainable via any other medium.

See a graphical comparison of DVD, 720p and 1080p resolution.

BD-Live (a.k.a. Profile 2.0)

Profile 2.0 of the Blu-ray specification brought internet connectivity and online interactions to Blu-ray players and discs. The realm of implementations and possibilities are broad, but the most common elements introduced include firmware updates and patches, downloadable and streaming video, live director commentary events, and other community-based features.

Blu-ray 3D

Blu-ray 3D is an evolution of the 2D Blu-ray Disc standard. Blu-ray 3D, if you wish to take advantage of it, will require a special 3D capable display, player, glasses and A/V equipment, including cables. How does Blu-ray 3D work? It takes both the left and right eye images and encodes them both onto the disc, and lets the 3D disc player and 3D display decide how to decode and present the content, using the many different types of 3D display-methods available. This keeps the technology future-proof, in case newer methods of viewing 3D become available, and keeps it completely backwards compatible on standard 2D Blu-ray Disc players, by just showing one side.

DTS-HD Master Audio, Dolby TrueHD, (L)PCM

These are all lossless high definition audio formats. What does that mean? Well, before I explain, let’s talk about what kind of audio you are generally used to hearing. Via DVD, or over cable, audio is always compressed. That’s generally called “lossy” compression as there is always information lost, removed or modified during compression.

With lossless audio codecs on Blu-ray, what you hear should be essentially no different from the studio’s master audio mix, given you have appropriate speakers and equipment. LPCM offers the full uncompressed audio track, but it has a high constant bit-rate, so it is usually not very efficient. On DVD, DTS tended to be the better choice for audio over Dolby, but on Blu-ray all three formats should have no audible difference.

Film Grain

Film grain is a natural and inherent texture to all imagery shot on film. The look of film grain can vary greatly depending on a lot of factors, and sometimes is intentionally manipulated by the creators of the film to achieve a certain look or feel. Film grain is more apparent now than in previous home-media because of the low quality encoding used in those formats, which was not able to reproduce fine detail such as grain.

Reference

The best of the best. Something to aspire to. Could be a subjective term.

Reference Audio Volume / Surround Sound Calibration

Commonly 0.0dB on your amplifier/receiver, this is the same sound level standard that all film audio (and other professional mixes) are mixed and played back. Theater audio reference level is 85dB (-20dBFS), for which audio peaks should reach 105dB. At home, reference level is about 75dB. To properly calibrate your speakers, you should measure the pink noise (usually available in your receiver) and adjust all speaker levels to 75dB (-30dBFS) using an SPL meter. While it is not feasible for most home environments, with good equipment capable of reproducing great dynamic range and a large acoustically treated room, reference audio level is great to push your gear and get immersed in your favorite films, the way they were meant to be heard.

Encoding

The process of getting a film onto a disc. This includes compression.

DNR (Digital Noise Reduction)

A process applied to a film’s image during the transfer to a home video format. Meant to remove film grain from the image, it often has the unfortunate side effect of scrubbing away detail and resulting in waxy, over-smooth and unnatural imagery.

Example of DNR grain-removal and resulting issues on Predator Blu-ray.

EE (Edge Enhancement)

An artificial sharpening process applied to a film’s image during the transfer to a home video format. This, like DNR, often has unwanted and distracting side effects, like creating “halos”– thick white outlines around images and elements on screen.

Black Levels / Shadow Detail

Black level refers to how truly dark the “blacks” of the image are. Washed out greys are not good, and don’t provide proper contrast. Shadow detail is the ability to discern important details in darker scenes of an image.

LFE

“Low Frequency Effects,” more commonly known as bass. This is the section of the sound-track– the low-end– which you’d normally hear from your subwoofer. The oompf and booms of the audio.

Aspect Ratio

The width of the image divided by the height gives you the aspect ratio. Example: 16×9, or widescreen HDTV. 16 divided by 9 is 1.78. So the width of the image is 1.78 times larger than the height. So the aspect ratio would be 1.78:1. The aspect ratio has a lot to do with the “feel” of a film. A wider aspect ratio like 2.35:1 is something you associate with a very “epic” or “cinematic” film.

See a graphical comparison of aspect ratios.

OAR

Original Aspect Ratio. The way it was originally created and intended by the director, and shown in theaters. Pretty straightforward, right? The reason it sometimes needs to be specified is because of the trend to cut down the picture because of a fear of “black bars.” This is why you used to see markings like “full-screen,” which thankfully died with DVD, as almost all Blu-ray discs are OAR.

1.78:1 / 1.85:1

Commonly referred to as 16×9 or 16:9, 1.78:1 is the standard consumer aspect ratio for HDTV. It was created as a compromise as it is the general average of the most commonly used aspect ratios such as 4:3 or 2.35:1 cinemascope. 1.85:1 on the other hand is a slightly shorter aspect ratio, so you would get slivers of black bars on the top and bottom of a 16:9 display.

2.35:1 / 2.39:1 / 2.40:1

The most commonly used cinema aspect ratio for most feature films. This is generally the widescreen aspect ratio most are used to seeing in movies.

Region Code

The Region Code is a bit of metadata encoded onto each Blu-ray Disc which identifies if are compatible and playable with the players typically sold in that part of the world.

• Region A/1: North America, Central America, South America, Japan, North Korea, South Korea, Taiwan, Hong Kong and Southeast Asia.
• Region B/2: Europe, Greenland, French territories, Middle East, Africa, Australia and New Zealand.
• Region C/3: India, Nepal, Mainland China, Russia, Central and South Asia.