Betacam

Betacam and Betacam SP Original Betacam format The original Betacam format was launched on August 7, 1982, as a relatively inexpensive cassette based physical format. It is an analog component video signal format, storing the luminance (Y), in one track and the chrominance, on another, as alternating segments of the R-Y and B-Y components performing Compressed Time Division Multiplex, or CTDM. This splitting of channels allows higher quality recording with 300 lines of horizontal luminance resolution and 120 lines of chrominance resolution. Image quality is significantly improved compared to domestic Betamax and the professional U-Matic formats. The original Betacam cassettes, loaded with ferric-oxide tape, were identical in overall design and size (15.1 × 9.5 × 2.5 cm) to consumer-grade Betamax, introduced by Sony in 1975. Betacam cassettes could be used in a Betamax VCR; likewise, a blank Betamax tape would work on a Betacam deck. However, in later years, Sony discouraged this practice, suggesting that the internal tape transport of Betamax cassette was not well suited to the faster tape transport of Betacam. In particular, the guide rollers tend to be noisy. Although there is a superficial similarity between Betamax and Betacam in that they use the same tape cassette, they are incompatible formats. Betamax records relatively low-resolution video using a heterodyne color recording system and only two recording heads, while Betacam uses four heads to record in component format, at a much higher linear tape speed of compared with Betamax's , resulting in much higher video and audio quality. A typical L-750 length Betamax cassette that yielded about 3 hours of recording time on a Betamax VCR at its B-II Speed (NTSC), or on PAL, only provided 30 minutes' record time on a Betacam VCR or camcorder. Another common point between Betamax and Betacam is the placement of the stereo linear audio tracks. Betacam was initially introduced as a camera line along with a docking companion VTR and a standalone video cassette player. The first cameras were the BVP-3, which utilized three Saticon tubes, the BVP-30, which utilized three Plumbicon tubes, and the BVP-1, which used a single tri-stripe SMF (Saticon Mixed Field) Trinicon tube. These three cameras could be operated standalone or with their docking companion VTR, the BVV-1 (quickly superseded by the BVV-1A), to form the BVW-1 (BVW-1A) integrated camcorder. Those decks were record-only. The only transport controls on the deck were eject and rewind. The docked camera's VTR button started and paused the tape recorder. Later, the Betacam SP docking decks had full transport controls (except a record button) but tapes could not be played back except in the camera's viewfinder in black-and-white only. Sony then came out with the playback adapter, the VA-500, a separate portable unit that connected via a multi-pin cable and had a composite video out jack for color playback. At first, color playback required the studio source deck, the BVW-10, which could not record, only play back. It was primarily designed as a feeder deck for A/B roll edit systems, usually for editing to a one-inch Type C or three-quarter-inch U-matic cassette edit master tape. There was also the BVW-20 field playback deck, which was a portable unit with DC power and a handle, that was used to verify color playback of tapes in the field. Unlike the BVW-10, it did not have a built-in time base corrector (TBC). With the popular success of the Betacam system as a news acquisition format, the line was soon extended to include the BVW-15 studio player and the BVW-40 studio edit recorder. The BVW-15 added dynamic tracking, which enabled clear still frame and jog playback, something the BVW-10 could not deliver. The BVW-40 enabled, for the first time, editing to a Betacam master, and if set up and wired correctly, true component video editing. It was also possible to do machine-to-machine editing between a BVW-10 or 15 and BVW-40 without an edit controller—a single serial cable between the units was all that was required to control the player from the recorder to perform simple assemble and insert editing. Additionally, there were two field models introduced, the BVW-25 field recorder, and the BVW-21 play-only portable field deck. At its introduction, many insisted that Betacam remained inferior to the bulkier one-inch type C and B videotapes, the standard broadcast production formats of the late 1970s to mid-1990s. Additionally, the maximum record time for both the cameras and studio recorders was only half an hour, a severe limitation in television production. There was also the limitation that high-quality recording was only possible if the original component signals were available, as they were in a Betacam camcorder. If the recording started as composite video, re-converting it to component for recording and then eventually back to composite for broadcast caused a drop in quality compared to recording component video directly. Betacam SP Betacam SP (commonly referred to as Beta SP) was released in 1986 in Japan before being released internationally the following year. It increased horizontal resolution to 340 lines. While the quality improvement of the format itself was minor, the improvement to the VTRs was significant, particularly in quality and features. In addition to the existing cassette, a larger cassette (25.3 × 14.4 × 2.5 cm) It supersedes both Betacam and Betacam SP, while costing significantly less than the first, 100% uncompressed D1 format, although in practice, they continued to coexist for practical and economical reasons. S tapes are available with up to 40 minutes running time, and L tapes with up to 124 minutes. The Digital Betacam format records 2.34:1 DCT-compressed digital component video signal at 10-bit YUV 4:2:2 sampling in NTSC (720×486) or PAL (720×576) resolutions at a bitrate of 90 Mbit/s plus four channels of uncompressed 48 kHz / 20 bit PCM-encoded digital audio. A fifth analog audio track is available for cueing, and a linear timecode track is also used on the tape. It was a popular digital video cassette format for broadcast television use. It uses a head drum 81 mm in diameter that rotates at 5400 RPM for NTSC video. The video heads in the drum read helical tracks 24 microns wide. Audio is also recorded on the helical tracks. The compression algorithm used by Digital Betacam is proprietary. Another key element which aided adoption was Sony's implementation of the SDI coaxial digital connection on Digital Betacam decks. Facilities could begin using digital signals on their existing coaxial wiring without having to commit to an expensive re-installation. Digibeta-L.jpg|The front of a Digital Betacam L cassette Sony DVW-A500 of China TV 20150912.jpg|A Sony DVW-A500 editing Digital Betacam VTR on display Sony DVW-A510P of DR 20111102a.jpg|A Sony DVW-A510P playback Digital Betacam VTR TV-Videocamera2.jpg|A DigiBeta camcorder used outside Betacam SX Betacam SX is a digital version of Betacam SP introduced in 1996, positioned as a cheaper alternative to Digital Betacam. It stores video using MPEG-2 4:2:2 Profile@ML compression, along with four channels of 48 kHz 16 bit PCM audio. All Betacam SX equipment is compatible with Betacam SP tapes. S tapes have a recording time up to 62 minutes, and L tapes up to 194 minutes. The Betacam SX system was very successful with newsgathering operations, which had a legacy of Betacam and Betacam SP tapes. Some Betacam SX decks, such as the DNW-A75 or DNW-A50, can natively play and work from the analog tapes interchangeably, because they contain both analog and digital playback heads. Betacam SX uses MPEG-2 4:2:2P@ML compression, compliant with CCIR 601,) feature that allows marking of each scene for fast scanning of the tape, looking at recorded marks on each single cassette, and showing the markers to the operator. The cameras themselves are generally considered by most sound recordists to be quite noisy in operation, possibly because the amount of computer processing power, and subsequent generated heat leads to cooling fans being used to keep the camera at a reasonable temperature. Betacam SX tape shells are bright yellow, but SX recordings may also be found recorded on analogue Betacam SP cassettes. Of course if such a Betacam SP tape with SX recording is inserted into a Betacam SP player, no picture or sound will appear. The helical scan head drum is 81 mm in diameter. The video tracks read by the video heads in the drum, are 32 microns wide, the drum rotates at 5400 RPM for NTSC video. The video heads have a 15.25 degree azimuth. Betasx-S.jpg|The front of a small Betacam SX cassette Sony_Betacam_SX_Side_View.jpg|A left side view of a Betacam SX camcorder Sony_Betacam_SX_01.jpg|A right side view of a Betacam SX camcorder MPEG IMX MPEG IMX also known as D-10, is a 2000 development of the Digital Betacam format. Digital video compression uses H.262/MPEG-2 Part 2 encoding at a higher bitrate than Betacam SX: 30 Mbit/s (6:1 compression), 40 Mbit/s (4:1 compression) or 50 Mbit/s (3.3:1 compression). Unlike most other MPEG-2 implementations, IMX uses intraframe compression. Additionally, IMX ensures that each frame has the same exact size in bytes to simplify recording onto video tape. Video recorded in the IMX format is compliant with CCIR 601 specification, with eight channels of audio and timecode track. It lacks an analog audio (cue) track as the Digital Betacam, but will read it as channel 7 if used for playback. This format has been standardized in SMPTE 365M and SMPTE 356M as "MPEG D10 Streaming". With its IMX VTRs, Sony introduced some new technologies including SDTI and e-VTR. SDTI allows for audio, video, timecode, and remote control functions to be transported by a single coaxial cable, while e-VTR technology extends this by allowing the same data to be transported over IP by way of an Ethernet interface on the VTR itself. All IMX VTRs can natively playback Betacam SX tapes, and some, such as the MSW-M2000P/1 are capable of playing back Digital Betacam cassettes as well as analog Betacam and Betacam SP cassettes, but they can only record to their native IMX cassettes. S tapes are available with up to 60 minutes capacity, and L tapes hold up to 184 minutes. These values are for 525/60 decks, but will extend in 625/50. A 184-minute tape will record for, as the label itself specifies, 220 minutes. IMX machines feature the same good shot mark function of the Betacam SX. MPEG IMX cassettes are a muted green. This format uses a helical scan head drum 80 mm in diameter. The video tracks read by the video heads in the drum, are 22 microns wide. The video heads have a 15.25 degree azimuth. 4:2:2 Chroma subsampling is used, and the drum rotates at 5400 RPM for NTSC video. Due to the use of an MPEG format, video is recorded with 8-bit samples (8-bit color). The XDCAM format, unveiled in 2003, allows recording of MPEG IMX video in MXF container onto Professional Disc. HDCAM/HDCAM SR HDCAM, introduced in 1997, was the first HD format available in Betacam form-factor, using an 8-bit DCT compressed 3:1:1 recording, in 1080i-compatible downsampled resolution of 1440×1080, and adding 24p and 23.976 PsF modes to later models. The HDCAM codec uses non-square pixels and as such the recorded 1440×1080 content is upsampled to 1920×1080 on playback. The recorded video bitrate is 144 Mbit/s. There are four channels of AES/EBU 20-bit/48 kHz digital audio. It was used for some of Sony's cinema-targeted CineAlta range of products (newer CineAlta devices use flash storage). HDCAM SR, introduced in 2003, uses a higher particle density tape and is capable of recording in 10 bits 4:2:2 or 4:4:4 RGB with a bitrate of 440 Mbit/s. The "SR" stands for "Superior Resolution". The increased bitrate (over HDCAM) allows HDCAM SR to capture much more of the full bandwidth of the HD-SDI signal (1920×1080). Some HDCAM SR VTRs can also use a 2× mode with an even higher bitrate of 880 Mbit/s, allowing for a 4:4:4 RGB stream at a lower compression. HDCAM SR uses the new MPEG-4 Part 2 Studio Profile for compression, and expands the number of audio channels up to 12 at 48 kHz/24 bit. HDCAM SR was used commonly for HDTV television production. 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. Sony branded HDCAM cassettes are black with an orange lid, and HDCAM SR cassettes 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. File:Hdcam.jpg|An HDCAM small cassette File:Sony BCT-40SR 20060616.jpg|An HDCAM SR small cassette File:Sony HDW-F900 of ETTV at Shiow Meei Industrial booth 20201101.jpg|A Sony HDW-F900 CineAlta HDCAM camcorder == See also ==