HDCAM-SR
HDCAM videotape
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| Media type | Magnetic tape |
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| Usage | Video production |
HDCAM, introduced in 1997, is a high-definition video digital recording videocassette version of digital Betacam, using an 8-bit discrete cosine transform (DCT) compressed 3:1:1 recording, in 1080i-compatible down-sampled resolution of 1440×1080, and adding 24p and 23.976 progressive segmented frame (PsF) 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 bit rate is 144 Mbit/s. Audio is also similar, with four channels of AES3 20-bit, 48 kHz digital audio.
Like Betacam, HDCAM tapes are produced in small and large cassette sizes; the small cassette uses the same form factor as the original Betamax.
The main competitor to HDCAM is the DVCPRO HD format offered by Panasonic. It uses a similar compression scheme and bit rates ranging from 40 Mbit/s to 100 Mbit/s depending on frame rate.
HDCAM is standardized as SMPTE 367M, also known as SMPTE D-11.
SMPTE 367M, also known as SMPTE D-11, is the SMPTE standard for HDCAM. The standard specifies compression of high-definition digital video. D11 source picture rates can be 24, 24/1.001, 25 or 30/1.001 frames per second progressive scan, or 50 or 60/1.001 fields per second interlaced; compression yields output bit rates ranging from 112 to 140 Mbit/s. Each D11 source frame is composed of a luminance channel at 1920 x 1080 pixels and a chrominance channel at 960 x 1080 pixels. During compression, each frame's luminance channel is subsampled at 1440 x 1080, while the chrominance channel is subsampled at 480 x 1080.
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