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The complete tutorial for Make Professional DVD's

Comparison of non-linear edit software

Linear Video Editing Vs non-linear Video editing

Comparison of Camcorder Physical format?

CCD vs. CMOS

Comparison of  Cam Format?

Betacam is a family of half-inch professional videotape products developed by Sony from 1982 onwards. 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.

All Betacam variants from the original (plain) Betacam to Betacam SP and Digital Betacam, use the same shape cassettes, meaning vaults and other storage facilities do not have to be changed when upgrading to a new format. The cassettes come in two sizes: S and L. Betacam cameras can only load S tapes, while VTRs can play both S and L tapes. The cassette shell and case for each Betacam cassette is colored differently depending on the format, allowing for easy visual identification. There is also a mechanical key that allows a video tape recorder to tell which format has been inserted.

The format supplanted the three-quarter inch U-Matic format, which Sony had introduced in 1971. In addition to improvements in video quality, the Betacam configuration of an integrated camera/recorder led to its rapid adoption by electronic news gathering organizations.

Even though Betacam remains popular in the field and for archiving, new digital products such as the Multi Access Video Disk Recorder are leading to a phasing out of Betacam products in a studio environment.

  

MiniDV

A size comparison between video formats
Top to bottom: VHS, VHS-C, MiniDV

The "L" cassette is about 120 กม 90 กม 12 mm and can record up to 4.6 hours of video (6.9 hours in EP/LP). The better known MiniDV "S" cassettes, 65 กม 48 กม 12 mm and hold either 60 or 90 minutes of video (13 or 19.5 GB) depending on whether the video is recorded at Standard Play (SP) or Extended Play (sometimes called Long Play) (EP/LP). 80 minute tapes that use thinner tape are also available and can record 120 minutes of video in EP/LP mode. The tapes sell for as little as US$2.50 each in quantity as of 2008. DV on SP has a helical scan track width of 10 micrometres, while EP uses a track width of only 6.7 micrometres. Since the tolerances are much tighter, the recorded tape may not play back properly or at all on other devices.

A disassembled MiniDV cassette.

Software is currently available for ordinary home computers which allows users to record any sort of computer data on MiniDV cassettes using common DV decks or camcorders. Though originally intended for the consumer market as a high-quality replacement for VHS, L-size DV cassettes are largely nonexistent in the consumer market, and are generally used only in professional settings. Even in professional markets, most DV camcorders support only MiniDV, though many professional DV VTRs support both sizes of tape.

 

DVCAM

Sony's DVCAM is a professional variant of the DV standard that uses the same cassettes as DV and MiniDV, but transports the tape 50% faster. This leads to a higher track width of 15 micrometres. This variant uses the same codec as regular DV. However, the greater track width lowers the chances of dropout errors. The LP mode of consumer DV is not supported. All DVCAM recorders and cameras can play back DV material, but DVCPRO support was only recently added to some models like DSR-1800, DSR-2000, DSR-1600. DVCAM tapes (or DV tapes recorded in DVCAM mode) have their recording time reduced by one third.

Because of wider track DVCAM has the ability to do a frame accurate insert tape edit. DV will vary by a few frames on each edit compared to the preview. Another feature of DVCAM is locked audio. If several generations of copies are made on DV, the audio sync may drift. On DVCam this does not happen.[6]

DVCPRO

Panasonic specifically created the DVCPRO family for electronic news gathering (ENG) use, with better linear editing capabilities and robustness. It has an even greater track width of 18 micrometres and uses another tape type (Metal Particle instead of Metal Evaporated). Additionally, the tape has a longitudinal analog audio cue track. Audio is only available in the 16-bit/48 kHz variant, there is no EP mode, and DVCPRO always uses 4:1:1 color subsampling (even in PAL mode). Apart from that, standard DVCPRO (also known as DVCPRO25) is otherwise identical to DV at a bitstream level. However, unlike Sony, Panasonic chose to promote its DV variant for professional high-end applications.

DVCPRO50 is often described as two DV-codecs in parallel. The DVCPRO50 standard doubles the coded video bitrate from 25 Mbit/s to 50 Mbit/s, and uses 4:2:2 chroma subsampling instead of 4:1:1. DVCPRO50 was created for high-value ENG compatibility. The higher datarate cuts recording time in half (compared to DVCPRO25), but the resulting picture quality is reputed to rival Digital Betacam. BBC preferred DVCPRO50 camcorders over HDCAM cameras to film popular TV series, such as Space Race (2005) and Rome (2006).

DVCPRO HD, also known as DVCPRO100, uses four parallel codecs and a recorded video bitrate of 40-100 Mbit/s, depending on the format flavour. DVCPRO HD encodes using 4:2:2 color sampling, compared to 4:2:0 or 4:1:1 for lower-bitrate video formats. DVCPRO HD horizontally compresses recorded images to 960x720 pixels for 720p output, 1280x1080 for 1080/59.94i or 1440x1080 for 1080/50i. This horizontal compression is similar to but more significant than that of other HD formats such as HDCam, HDV, AVCHD and AVCCAM. The final DCT compression ratio of DVCPRO HD is approximately 6.7:1. To maintain compatibility with HDSDI, DVCPRO100 equipment upsamples video during playback. A camcorder using a special variable-framerate (from 4 to 60 frame/s) variant of DVCPRO HD called VariCam is also available. All these variants are backward compatible but not forward compatible. DVCPRO-HD is codified as SMPTE 370M; the DVCPRO-HD tape format is SMPTE 371M, and the MXF Op-Atom format used for DVCPRO-HD on P2 cards is SMPTE 390M.

DVCPRO cassettes are always labeled with a pair of run times, the smaller of the two being the capacity for DVCPRO50. A "M" tape can hold up to 66/33 minutes of video. The color of the lid indicates the format: DVCPRO tapes have a yellow lid, longer "L" tapes made specially for DVCPRO50 have a blue lid and DVCPRO HD tapes have a red lid. The formulation of the tape is the same, and the tapes are interchangeable between formats. The running time of each tape is 1x for DVCPRO, ½x for DVCPRO 50, ½x for DVCPRO HD EX, and ¼x for DVCPRO HD, since the tape speed changes between formats. Thus a tape made 126 minutes for DVCPRO will last approximately 32 minutes in DVCPRO HD.

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