DV stands for Digital Video.
The video format is the result of the cooperation between about 60 electronics giants such as Sony, Panasonic, JVC, Canon, and Sharp, among others.
It is a tape format released in 1996. Before the advent of HD video, DV was popularly used for consumer and professional video production.
DV is also a codec as will be explained below.
The variants of the DV format are MiniDV, DVCAM, and DVCPRO.
- 1 DV Advantage
- 2 Democratization of Video Production
- 3 Main Features of DV
- 4 Audio
- 5 DV Resolution
- 6 DV Format Variants
- 7 Digital8
- 8 DVCPRO50
- 9 DV Loses its Popularity
Before the arrival of DV, particularly mini-DV, analog formats like Video8 and Hi-8 were popular. The main drawback was they suffered quality loss (known as generation loss) each time video is copied or duplicated.
Lossless Video Quality
With DV generation loss is not a problem. You can capture DV in lossless quality through a Firewire (IEEE1394)connection.
Digital video carries pure data and not analog signals. Data can be replicated during the transmission process without any quality loss through a digital pathway.
For this to happen, tapes must be copied from one piece of digital equipment to another.
For example, you can get lossless video quality if you copy a mini-DV tape from a camcorder to a blank tape in a mini-DV player. You can edit DV footage on a computer and then copy the edited version back to a tape in a mini-DV camcorder without any quality loss.
You can also compress it (with quality loss) to other formats like DVD or VCD.
Democratization of Video Production
DV opened the way for consumers and professionals to produce high-quality video at relatively lower costs.
DV’s picture and sound quality rivaled that of the broadcast-standard Betacam SP.
DV also used to be the best format for computer video editing, compared to formats like DVD camcorder’s MPEG-2.
Interchangeable Tape Format
A standout advantage of DV is that you can use the DV tape on equipment by any manufacturer. For example, you can play back a Panasonic mini-DV tape on a Sony mini-DV player.
Main Features of DV
The DV codec is also known as DV-25 or DV-25 codec. This is the codec that got the whole DV revolution going.
Compresssion ratio is 5:1. It employs the 4:1:1 chroma sub-sampling scheme for NTSC. For PAL it is 4:2:0.
This strikes a good balance between picture quality and compression size for standard-definition video.
The DV codec uses an intra-frame compression which is DCT (Discrete Cosine Transform)-based. Such compression is also used for M-JPEG.
The intra-frame compression makes video easier to edit as every frame is compressed separately without having to rely on the preceding frame.
DV Tape Speed and Data Rate
As provided by the IEC 61834 standard, DV tape speed is at a constant rate of 18.8mm/second which results in a data rate of 25 Mbps.
DV Color Quality
As mentioned, DV excels when it comes to color quality compared to its analog counterparts.
DV allocates 1.5MHZ bandwidth for color. This is twice the amount of the color bandwidth of VHS.
Also, DV splits color into 2 signal components – the brightness (luminance – Y) signal and the color (chrominance or C) signals.
In this way more color signal data is possible and this enhances picture quality.
DV Signal-to-Noise Ratio
DV has a signal-to-noise ratio of 54db. VHS has about 42db.
The higher the ratio, the superior the picture quality.
DV provides digital audio in PCM mode. The same process is used for audio CD and Digital Audio Tape (DAT).
DV supports 2 audio channels at 48kHz (16 bits) or 4 audio channels at 32kHz (12 bits).
The 16-bit mode produces CD-quality audio. The 12-bit mode produces 2 pairs of left and right audio channels.
DV comes with an error correction system that minimizes tape dropouts which you’ll see in the form of brief white specks.
At Standard Definition (SD) DV video footage is recorded at a resolution of 720 x 480 at 29.97 frames/sec for NTSC and 720 x 576 at 25 frames/sec for PAL.
The horizontal resolution of standard DV is around 500 lines. With 3 CCD pro DV cameras, you get more lines.
VHS and Video8 can manage only around half the amount at about 240 lines. Hi-8 and S-VHS were the superior formats providing 400 lines of resolution.
DV Format Variants
Below are the variants of the DV format. The number behind each DV subformat denotes the bitrate in Mbps.
DV or DV25
The DV format was originally intended for the consumer market because of its affordable cost and high quality.
First-generation DV equipment centered around the mini-DV tape. Later equipment we hybrid in nature – compatible with standard DV tape and mini-DV tapes.
Digital8 tape format is different in size from the DV tape format. However, Digital8 uses DV encoding. You can enjoy all the benefits of DV with Digital8, including Firewire video capture.
Learn more about the Digital8 format.
This is Sony’s proprietary DV format meant for the industrial and professional market.
Read more about DVCAM.
DVCPRO (D7) or DVCPRO25
This DV format was developed by Panasonic and BTS/Philips. It is meant for the professional and broadcast markets.
It was popularly used in the electronic newsgathering (ENG) field.
Read more about DVCPRO.
This variation of DVCPRO records twice the amount of data compared to DVCPRO. It can be used for standard-definition and high-definition video recording.
Learn more about DVCPRO50.
DVCPRO-HD or DVCPRO100
This DV variant records in 1080i and 720p resolutions. The data rate is twice that of DVCPRO50.
The differences between the above DV variants center around video track width, tape speed, and tape type (metal particle of metal evaporated).
Learn more about DVCPRO-HD.
Apart from outputting digital video as mentioned earlier, DV can also output analog video. What this means is, if you don’t have a Firewire connection in your computer, you can use analog connections like S-Video and RCA to play back or capture video.
The DV format uses the L-size tape which measures 120x90x12mm. The recording duration is 2 hours.
The popular mini-DV format uses S-size cassettes measuring 65x48x12 mm. The recording time is an hour.
The track format is of the helical scan format. The two recording modes are SP (Standard Play) and LP (Long Play).
In LP mode you can record 1.5 times longer. Sony’s DVCAM doesn’t record in LP mode, however.
Standard Play uses a track width of 10 microns and Long Play uses 6.7 microns.
DV tapes can also be used for computer data storage. An hour of tape can store 13GB of data at a data rate of 3.6Mb/second.
DV Loses its Popularity
DV which once provided quality and editing advantages over other analog video formats didn’t reign long.
It had competition from DVD camcorders (ease of use but not quality), hard drive camcorders, and the emerging HD formats.