HDMI

High-Definition Multimedia Interface (HDMI)

High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.

History

HDMI was developed by a consortium of electronics manufacturers including Sony, Philips, Panasonic, and Toshiba. The first HDMI specification was released in December 2002, and the first consumer HDMI products hit the market in 2003. Since then, HDMI has become the standard interface for high-definition video and audio, with widespread adoption in consumer electronics.

Technical Specifications

HDMI supports several different video and audio formats, including:

• Video Formats: HDMI supports standard, enhanced, and high-definition video, as well as 3D video. It can carry video signals up to 4K resolution at 60 frames per second.
• Audio Formats: HDMI supports up to 8 channels of uncompressed digital audio at 192 kHz, and it can also carry compressed formats such as Dolby Digital and DTS.

HDMI cables come in several types, including Standard, High Speed, Premium High Speed, and Ultra High Speed, each supporting different bandwidths and features.

Versions

HDMI has undergone several revisions since its inception, each adding new features and capabilities:

• HDMI 1.0: Released in December 2002, it supported a maximum resolution of 1080p and 8-channel audio.
• HDMI 1.4: Introduced in 2009, it added support for 3D video, Ethernet over HDMI, and an audio return channel (ARC).
• HDMI 2.0: Released in 2013, it increased the maximum bandwidth to 18 Gbps, allowing for 4K video at 60 Hz.
• HDMI 2.1: Announced in 2017, it supports 48 Gbps bandwidth, enabling 8K video at 60 Hz and 4K video at 120 Hz, along with dynamic HDR and enhanced audio return channel (eARC).

Applications

HDMI is used in a wide range of consumer electronics, including:

• Televisions: Most modern TVs come equipped with multiple HDMI ports for connecting devices such as Blu-ray players, gaming consoles, and streaming devices.
• Computers: HDMI is commonly used to connect computers to monitors and projectors.
• Home Theater Systems: HDMI is used to connect audio/video receivers to TVs and speakers, providing high-quality audio and video.

Advantages

HDMI offers several advantages over older analog standards such as VGA and Component Video:

• Single Cable: HDMI carries both audio and video signals, reducing cable clutter.
• Digital Quality: HDMI transmits uncompressed digital signals, providing superior picture and sound quality.
• HDCP Support: HDMI supports High-bandwidth Digital Content Protection (HDCP), which is used to prevent unauthorized copying of digital content.

Limitations

While HDMI is widely used, it does have some limitations:

• Cable Length: HDMI cables are typically limited to lengths of 15 meters (about 50 feet) for reliable signal transmission.
• Compatibility: Older HDMI versions may not support newer features such as 4K video or HDR.

Also see

• DisplayPort
• DVI
• VGA
• Audio Return Channel
• HDCP