HDCAM, introduced in 1997, is an High-definition video

High-definition video

High-definition video or HD video refers to any video system of higher resolution than standard-definition video, and most commonly involves display resolutions of 1,280×720 pixels or 1,920×1,080 pixels...

 digital recording

Digital recording

In digital recording, digital audio and digital video is directly recorded to a storage device as a stream of discrete numbers, representing the changes in air pressure for audio and chroma and luminance values for video through time, thus making an abstract template for the original sound or...

 videocassette version of Digital Betacam

Betacam

Betacam is family of half-inch professional videocassette products developed by Sony in 1982. In colloquial use, "Betacam" singly is often used to refer to a Betacam camcorder, a Betacam tape, a Betacam video recorder or the format itself....

, using an 8-bit DCT

Discrete cosine transform

A discrete cosine transform expresses a sequence of finitely many data points in terms of a sum of cosine functions oscillating at different frequencies. DCTs are important to numerous applications in science and engineering, from lossy compression of audio and images A discrete cosine transform...

 compressed 3:1:1 recording, in 1080i

1080i

1080i is the shorthand name for a high-definition television mode. The i means interlaced video; 1080i differs from 1080p, in which the p stands for progressive scan. The term 1080i assumes a widescreen aspect ratio of 16:9, implying a frame size of 1920×1080 pixels...

-compatible downsampled resolution of 1440×1080, and adding 24p

24p

In video technology, 24p refers to a video format that operates at 24 frames per second frame rate with progressive scanning . Originally, 24p was used in the non-linear editing of film-originated material...

 and 23.976 PsF

Progressive segmented Frame

Progressive segmented Frame is a scheme designed to acquire, store, modify, and distribute progressive-scan video using interlaced equipment and media....

 modes to later models. The HDCAM codec uses rectangular pixels and as such the recorded 1440×1080 content is upsampled to 1920×1080 on playback. The recorded video bitrate is 144 Mbit/s. Audio is also similar, with 4 channels of AES3 20-bit/48 kHz digital audio

Digital audio

Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...

.

Like Betacam, HDCAM tapes are produced in small and large cassette sizes; the small cassette uses the same form factor as the original Betamax

Betamax

Betamax was a consumer-level analog videocassette magnetic tape recording format developed by Sony, released on May 10, 1975. The cassettes contain -wide videotape in a design similar to the earlier, professional wide, U-matic format...

.

The main competitor to HDCAM is DVCPRO HD format offered by Panasonic. It uses a similar compression scheme and bitrates ranging from 40 Mbit/s to 100 Mbit/s depending on frame rate.

HDCAM SR

HDCAM SR was introduced in 2003 and standardised in SMPTE 409M-2005. It uses a higher particle density tape and is capable of recording in 10 bits 4:2:2 or 4:4:4 RGB with a video bitrate of 440 Mbit/s, and a total data rate of approx. 600 Mbit/s. The increased bitrate (over HDCAM) allows HDCAM SR to capture much more of the full bandwidth of the HDSDI signal (1920×1080). Some HDCAM SR VTRs can also use a 2x mode with an even higher video bitrate of 880 Mbit/s, allowing for a single 4:4:4 stream at a lower compression or two 4:2:2 video streams simultaneously. HDCAM SR uses MPEG-4 Part 2

MPEG-4 Part 2

MPEG-4 Part 2, MPEG-4 Visual is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standards. It is a discrete cosine transform compression standard, similar to previous standards such as MPEG-1 and MPEG-2...

Simple Studio Profile for compression, and expands the number of audio channels up to 12 at 48 kHz/24-bit.

There are 12 channels of audio recorded uncompressed at 24bit 48 kHz sampling. Each channel is capable of recording AES3 non-audio data.

HDCAM SR is used commonly for HDTV television production. As of 2007, many prime-time network television shows use HDCAM SR as a master recording medium.

Some HDCAM VTRs play back older Betacam variants, for example, the Sony SRW-5500 HDCAM SR recorder, plays back and records HDCAM and HDCAM SR tapes and with optional hardware also plays and upconverts Digital Betacam tapes to HD format. Tape lengths are the same as for Digital Betacam, up to 40 minutes for S and 124 minutes for L tapes. In 24p mode the runtime increases to 50 and 155 minutes, respectively.

HDCAM tapes are black with an orange lid, and HDCAM SR tapes black with a cyan lid.

440 Mbit/s mode is known as SQ, and 880 Mbit/s mode is known as HQ, and this mode has recently become available in studio models (e.g. SRW-5800) as well as portable models previously available. In 2008 the SRW-5800 will give the "HQ" 4:4:4 option.

Sony has also announced a higher compression mode called "SR Lite".
As with the 440 and 880 mode, SR Lite utilizes the MPEG-4 Part 2 Simple Studio Profile but decreases the bitrate down to 220 Mbit/s for 60i and 183 Mbit/s for 50i.
SR Lite is locked at 4:2:2 color sampling but still maintains at 10 bit pixel depth.
It also allows for 50 and 60p at the cost of a doubled data rate (440 Mbit/s for 60p).