A high-definition (HD) digital videotape format from Sony. Introduced in 1997, HDCAM came out three years after Sony launched its standard definition (SD) Digital Betacam format. Both HDCAM and Digital Betacam use the 1/2" helical scan transport technology. Compression and Specifications HDCAM uses 8-bit DCT compression and 3:1:1 sampling. HDCAM SR (Superior Resolution) came out in 2003, supporting 10 bits, MPEG-4 and 4:4:4 sampling (full color). HDCAM SR dramatically increased the bit rate from 144 to 440 Mbps, and HDCAM VTRs with a 2x mode can record two data streams simultaneously. HDCAM VTRs also typically play back Digital Betacam cassettes. See Betacam, 3:1:1 and HD formats.