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Digital VCR Formats Compared: Tabular Specifications

Table 1

Compatibility Between Formats

Analog VCRs have no compatibility between formats. Straddling two worlds, some DVRs are able to play tapes made on analog VCRs. A few DVRs are also compatible with other digital formats.

Format	Can also play
Betacam SX	Betacam Betacam SP
Digital S	SVHS (some models)
Digital 8	Plays 8mm or Hi8
DVCAM	record or play DV*
DVC PRO	DV, DVCAM
Digital Betacam	Betacam (some models) Betacam SP
D3 D5	Data recorders D3

*DV is the consumer digital video recorder format

Table 2

Digital Videotape Formats at a glance

Designation	Video	Compression	Tape size	Maker	Notes
D1	Component	not compressed	¾"	Sony
D2	Composite	not compressed	¾"	Sony/Ampex	Same tape shell as D1 but not compatible with it.
D3	Composite	not compressed	½"	Panasonic
D4					Not used; unlucky number in Japanese culture
D5	Component	not compressed	½"	Panasonic
D6	Component	compressed	¾"		Digital HDTV recorder using D1 tape
D7 (DVC PRO)	Component	compressed	1/4"	Panasonic, Ikegami, Philips	Compatible with DV and DVCAM
DCT	Component	compressed	¾"	Ampex
Betacam SX	Component	compressed	½"	Sony	Can play Betacam SP
Digital Betacam	Component	compressed	½"	Sony	Some models also play Betacam and Betacam SP
DV	Component	compressed	¼"	several	Consumer
Digital 8	Component	compressed	8mm	Sony	Consumer, can play 8mm and Hi8
Digital S (D9)	Component	compressed	½"	JVC	Some models can also play SVHS
DVCAM	Component	compressed	¼"	Sony	Compatible with DV but won't play DVC PRO and PRO 50 tapes.
DVC PRO 50	Component	compressed	1/4"	Panasonic	Can play DVCAM tapes but DVCAM can't play DVC PRO 50 tapes.

Table 3

Detailed Comparison of DVR Formats

Designation	Compression	Max Data rate in Mbps	Bits per sample	Download, upload speed	Y/R-Y/B-Y Sampling ratio	Track width in microns	Tape size	Type of tape	Max tape playing time in minutes on a mini/large cassette	Price $	Notes
D1 (Sony)	Not compressed	270	8 or 10		4:2:2:4	40	3/4U 19mm	gamma ferric oxide	94	120,000-140,000	(1) (2) (3) (8)
D2 (Sony/Ampex)	Not compressed	143	8		4:0:0	39	3/4U 19mm	Metal particle	94/208	46,000- 88,000	(4) (5)
D3 (Sony/Ampex)	Not compressed	143	8		4:0:0	20	MII ½"	Metal particle	240	50,000	(6)
D4											(7)
D5 (Panasonic)	Not compressed	170	10		4:2:2		½"	Metal evaporated	120		(3) (8) (9)
D6	Compressed				4:2:2		3/4U 19mm				(28)

D-7 (DVC PRO) (Panasonic, Ikegami, Philips)	Intraframe DCT 5:1 (I-MPEG)	25 (constant)	8	4X	4:1:1	18	¼" medium & large size cassettes	Metal particle	60/123	5,000- 20,000	(12) (13) (14)
D-9 (Digital S) (JVC)	Intraframe DCT 3.3:1	50	8	2X	4:2:2	20	VHS ½"	Metal particle (JVC VHS size tape)	124	10,000- 20,000	(18) (19) (20)
DVC PRO 50	Intraframe DCT 3.3:1	50	8		4:2:2	18	1/2"	Metal particle	30/60	10,000- 47,000
DCT (Ampex)	DCT 2:1		8			39	3/4U 19mm				(10)
Betacam SX (Sony)	Interframe 10:1 MPEG-2	18	8	4X down only	4:2:2	32	Betacam ½"	Metal particle	90/184	20,000- 50,000	(22) (23) (24) (25) (26)
Digital Betacam (Sony)	2:1	90	10	4X	4:2:2		Betacam ½"	Metal particle	60/120	33,000- 45,000	(21)
DV	Intraframe DCT 5:1 (I-MPEG)	25 (constant)	8		4:1:1	10 (SP) 6.7 (LP)	¼" 6.35mm	Metal evaporated	90/180	2,000- 4,000	(11)

Digital 8	Intraframe DCT 5:1 (I-MPEG)	25 (constant)	8		4:1:1	16.3	8mm	Metal evaporated or metal particle	60	900-1400	29
DVCAM (Sony)	Intraframe DCT 5:1 (I-MPEG)	25 (constant)	8	4X	4:1:1	15	¼" mini & large cassettes	Metal evaporated	60/240	4800- 18,000	(15) (16)
D-VHS (JVC)	Pre-compressed MPEG-2	several, up to 28.2					1/2"	VHS size tape	210 at fast speed	1000	(17)
Camcutter (Avid/Ikegami)	AVR-70		8		4:2:2		2.4 GB disk field pack	Disk based	20	20,000- 60,000	(27)

Notes:

All D designations are rack mountable and studio configurable.

All digital formats on this table sample the Y component at 13.5 MHz (although D5 is switchable to 18 MHz for HDTV)

1. Can be used in 525 (NTSC) or 625 (PAL) environments. The 4:2:2:4 sampling permits an alpha (transparency, or linear keying) channel to be recorded.
   
2. Two D1 machines can be teamed up to provide twice the picture detail.
   
3. D1 and D5 conform to CCIR-601 standard. CCIR-601 is a standard set by the International Radio Consulting Committee and formalized by SMPTE (Society of Motion Picture and Television Engineers). CCIR changed its name to ITU-R (International Telecommunications Union), so this standard is sometimes described as ITU-R BT. 601-2.
   
4. Same audio tracks and cassette shell as D1, but not compatible with D1. Same signal type as D3 but cassette not compatible.
   
5. Excellent error correction but poor interchange (ability to play tapes from another D2 machine).
   
6. Uses MII tape transport and the same tape as D5 but at ½ the speed as D5.
   
7. The number 4 means death in Japanese culture, so the manufacturers skipped this number format.
   
8. Ten (10) bit has 4 times the resolution as 8 bit, and is capable of HDTV.
   
9. Can play D3 tapes and make component signals from them.
   
10. DCT (Digital Component Technology) followed D2 and was optimized for post production. Uses DCT (Digital Cosine Transform) compression. Excellent interchange with other tapes.
    
11. Consumer format, agreed to by 60 companies. I-MPEG is MPEG with minor interfield compression; only I frames are used. Image is 720´ 480 pixels yielding a horizontal resolution of 500 lines at 54dB S/N. The heads spin at 9000 RPM (vs 1800 for analog VTRs), and the tape moves 10mm/sec., twice that of VHS and 8mm. Track width is 10 microns (vs 20 for 8mm and 58 for VHS). Audio is switchable between 16 bit with one pair of tracks or 12 bit with 2 pair of tracks. The 16 bit audio uses 48kHz (24 kHz/channel) sampling, (like DAT) or 44.1kHz, yielding an audio frequency range up to 20kHz. The 12 bit audio uses 32kHz (16 kHz/channel) sampling. During editing a new pair of audio channels is added (not erasing the original pair). Fast tape speed (SP) yields 60 minutes on a mini DV cassette; slow speed (LP) yields 90 minutes.
    
12. DVC PRO can play DV and DVCAM tapes but DV and DVCAM can't play DCV PRO tapes.. Camcorder can also accept disk recorder.
13. Color quality is reported to be equal to Betacam and Betacam SP, but not as good as digital Betacam, D1 and D5.
    
14. DVC PRO has extra analog cue track for SMPTE time code, and an analog control track for quick lockup during editing, and has 2 analog audio channels which remain audible when scanning or searching. The two digital audio channels are 16 bit, 48kHz (better than CD quality).
    
15. DVCAM can play and record DV cassettes.
    
16. Two channel audio is 16 bit, 48kHz.
    
17. No A/D encoders, or D/A decoders, like other DVRs. Does have analog in/out, but only to record/play SVHS and VHS tapes. Called a bitstream recorder because it records/plays straight data. Used to record direct satellite broadcast services data from Echostar satellite. Hitachi model works with DirecTV, USSB. Upon playback, data goes to decoder which makes audio and video.
    
18. Records and edits two or four 16 bit PCM audio tracks (depending on model) sampled at 48kHz. Also has 2 linear audio tracks and a control track to accommodate variable speed play with sound. Searches up to 32´ normal speed.
    
19. Has preread (plays a track, then records over it in one sweep of the heads) which allows A/B rolls with 2 decks instead of 3. Can record/play 150 minutes in "guardbandless" mode
    
20. Has 2 TV lines of uncompressed video which allows closed captioning to be recorded undisturbed.
    
21. Some models also play Betacam and Betacam SP.
    
22. Mbps was selected so that 2 signals (one incoming and one outgoing, or 2 outgoing) could fit on a DS-3 telephone link useful for news and networks. Also, the low data rate offers interconnection possibilities with computers.
    
23. Can play Betacam SP. Has 4 channel audio.
    
24. Various versions also play SVHS tapes
    
25. Has 4 audio channels.
    
26. Runs ½ the speed of Betacam SP, resulting in one hour recordings per tape.
    
27. Camcutter is a DIGITAL DISK RECORDER (DDR). In news situations, the advantage is that the disks can be inserted directly into a computer for editing, skipping the download time. Also, disk can record in "retroloop", erasing what was recorded 20 minutes earlier as it continuously records (waiting for an event to happen). Animators also use DDR because it easily records still frames.
    
28. Digital HDTV recorder using D1 tape.
    
29. Records on 8mm or Hi8 tape at double the normal speed. Can play 8mm/Hi cassettes but not record in those formats. Sony's D8 designation is their own and is not the same as a SMPTE D8 designation (as in D1, D2, D3...).

Table 4

Tape speeds and consumption

Format	Width (in.)	Speed (in./sec.)	Sq ft/hr
DV	¼	.85	5.4
DVC PRO	¼	1.3	8.3
DVCAM	1/4	1.27	8
Digital 8	.32	1.12	9
DIGITAL S	½	2.1	26.3
BETACAM SX	½	2.3	29
D1	¾	11.25	210.3