What Is HD Format?
High-definition video (HD video) is a video with high resolution and high audiovisual quality. HD has no standardized meaning, but is generally considered as a video with more than 480 vertical scan lines (in the US) or 576 vertical scan lines (in Europe).
Most HD video formats provide either 720 or 1080 vertical scan lines. Common formats include Blu-ray, AVC-Intra, AVCHD, D-5 HD, and DivX Plus HD.
In this article:
- SD vs HD Video Formats
- Types of High Definition Video Formats
SD vs HD Video Formats
Standard definition (SD) and high definition (HD) are two types of video formats. Both types allow users to view video content online, and are used by content creators or website owners to stream video. Popular video platforms like Amazon Prime, Netflix, and YouTube support both SD and HD video.
The main difference between SD and HD is quality:
- HD video provides higher quality and clarity of image and sound, and higher image resolution. However, it requires higher bandwidth to stream to end users.
- SD video provides lower quality, but is cheaper and faster to stream, and can be used on older devices or in environments with limited Internet bandwidth and connectivity, or for users with limited data plans.
History of SD and HD
From the mid-20th century through the 1990s, SD was the standard for audiovisual content in the US and the rest of the world. SD media improved significantly over time, as both broadcast and cable television technology improved. Video formats improved over time and moved from 480 to 576 vertical scan lines, enabling improved resolution and clarity. Although these were considered standard, some countries used different resolutions for video content.
HDTV first appeared on the market in 1993, intended as a way to improve on existing SD television. It included transmission systems with better aspect ratios, additional lines and the ability to deliver higher-quality signals. Additional improvements included new video compression technologies, which allowed HDTV content to be transmitted over the available bandwidth.
Today, almost all televisions and audiovisual equipment supports HD. SD devices started to disappear from the market in the early 2020s. However, SD is still widely supported on the Internet for the benefit of users with lower-end devices or limited bandwidth.
HD formats rely on advanced codecs. Learn more in our guide to video codecs
Types of High Definition Video Formats
Blu-ray is a successor to the DVD optical disc format, used for storing large amounts of high-definition video data. Developed by a collaboration of companies, including Hitachi, Panasonic, Samsung, LG, Sony, Sharp, and more, it became the standard format for HD video content.
The name refers to the blue laser that reads and writes to the disc. The 405 nm-wavelength laser has a sharper focus than DVD’s red laser, allowing the format to store data. Phase change technology allows repeated writing to disc. Blu-ray has 36 Mbps data streams enabling HD video recording.
Panasonic’s AVC-Intra codec provides production-grade video at high bitrates, supporting high-resolution video recording. It is compliant with H.264/MPEG-4 AVC, but it is unclear whether Panasonic follows the SMPTE RP 2027-2007 specification. Designed for professionals who need to store video data for archiving and editing, AVC-Intra defines an edit-friendly 10-bit, intra-frame compression. It outperforms older HDV formats and enables the codec to retain high-quality videos in small storage space.
The Advanced Video Coding High Definition (AVCHD) file format enables the recording and playing of high-definition digital video. It uses H.264/MPEG-4 AVC video compression to support various resolutions, Dolby AC-3 audio compression, and uncompressed pulse-code modulation (PCM) audio. It also supports 5.1 surround and stereo.
AVCHD offers many intuitive features for improved media presentation, such as menus and subtitles, similar to DVD. It allows users to prepare slide shows from sequences of AVC frames. Certain camcorders use subtitles as timestamps when recording. The file’s MPEG transport stream stores multiplexed streams as binary files.
4. D-5 HD
Panasonic’s D-5 video format is a 10-bit uncompressed professional digital video system. It uses the same tapes as the D-3 format. It is possible to retrofit D-5 definition decks to record HD video. This conversion does not support error correction because it requires the tape’s entire bandwidth for recording.
D-5 HD records video using D-5 videotapes and 4:1 intra-frame compression. It supports the various line standards at different field rates, including 1035 and 1080. It also supports multiple PCM audio channels.
5. DivX Plus HD
The DivX Plus HD file type is the default DivX format for HD video. It includes high-definition video based on the H.264/MPEG-4 AVC standard, and Advanced Audio Coding (AAC) surround sound, packaged in a Matroska container. The files leverage Matroska support for multiple chapters, languages, subtitles, and other features.
HDCAM is an HD digital recording cassette implementation of Digital Betacam. It uses 8-bit DCT-compressed recording, with downsampled resolutions compatible with 1080i (and more PsF modes in newer models). HDCAM records videos with rectangular pixels, allowing the upsampling of stored content from 1440X1080 to 1920X1080. It has a recorded video bitrate of 144 Mbit per second.
HD-DVD is an obsolete, high-capacity optical disc that originally sought to replace the standard DVD format. An HD-DVD disc can store 15-30GB, compared to a standard DVD’s 4.7-8.5 GB. Double-layer HD-DVDs can store 48 hours of standard video content or eight hours of HDTV content. It has a fast data transfer rate (36 Mbps) to support TV transmissions.
HD-DVD builds on NEC and Toshiba’s Advanced Optical Disc (AOD) technology and stores data in microscopic pits. It reads the pits with a blue laser, and the video player reads the sensor data as a digital signal.
The HDV format supports HD video on DV cassettes. Initially developed by JVC, Sony Sharp, and Canon also support HDV. HDV encodes video and audio data digitally with lossy interframe compression, using H.262/MPEG-2 video compression and MPEG-1 audio compression for stereo. HDV devices record the multiplexed, compressed video and audio on a magnetic cassette tape and allow computer file-based storage.
HDV has a constant data rate for video and audio, which can cause bitrate issues in highly detailed videos. While low for video, the same bitrate is high for audio, making it lossless. The two main HDV versions are 720p (HDV1), preferred by JVC, and 1080i (HDV2), used by Canon and Sony.