DVI cable 101
Oct-2005
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DVI cable 101
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Oct-2005
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There are 3 different types of DVI connectors:
1. DVI-D (digital)
2. DVI-A (Analog)
3. DVI-I (Integrated Digital/Analog)
| 1. DVI-D - Pure Digital Video only In the PC world, all video cards initially produce a digital video signal, which is then converted into analog at the VGA port. The analog signal travels to the PC CRT monitor and is re-converted back into a digital signal finally. The original digital signal is degraded as it goes through many steps of convertion. DVI-D eliminates the many steps of analog conversion process and retains
the signal in it's original quality between the source and the display.
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| 2. DVI-A - Analog Signal
DVI-A format is used to carry a digital DVI signal to an analog display
which incorperates a DVI-A connector instead of a VGA port. The 4 pins carry the analog signal. There are no pins to carry any digital signal. This format is practically obsolete. |
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| 3 DVI-I - Digital & Analog Combo
DVI-I combines DVI-D and DVI-A signal in one single cable. The connector has all the digital sigal pins plus 4 analog video pins. But DON'T just go out to buy this cable becasue it takes care both digital
and analog world. Some digital LCD/Plasma/Projector displays only comes
with DVI-D connector. In other words, the 4 analog pin will be in the
way conncting the DVI-I cable to a DVI-D connector of your display. |
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Confuse the DVI cable further, each DVI format comes in Single-link and Dual-link.
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Male
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DVI-D Single-link
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Single-Link uses one TMDS (transition minimized differential signaling) to transmit signal. A Single-link LCD can display a resolution of 1920 x 1080 (HDTV standard). |
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DVI-D Dual-link
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DVI-I Single-link
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A dual-link uses 2 TMDS to transmit signal. A Dual-link can
display a resolution of 2560 x 1600. But you need a dual-link video card ($1,500) and a Dual-link monitor ( Apple's 30" Cinema Display $3,000) to display such high resolution. |
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DVI-I Dual-link
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| Single and dual link has nothing to do with quality A dual link cables is not better than a single link cables. A single link cable is 100% as good as a dual link cable for normal single-link equipment which covers about 99.5% of current equipment, including LCD/Plasma/Projector. There is no need to spend extra on something we don't need. Besides there is no need to waste resources further. |
HDMI cable - the future
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HDMI developments
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Comments
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v1.0
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video only
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HDMI is able to tranmit 5Gbps.
HDTV requires 2.2Gbps. The remaining 2.8Gbps will then be spared to take care digital audio and any future gadgets. |
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v1.1
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video and audio
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v1.2
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support 1-bit audio
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HDMI cable
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HDMI can transmit both digital audio and video
over one cable, replacing many messy cables hanging behind the AV components.
HDMI is essentially a cable that carries DVI style video and iLink style audio (version 2 carries 8 channel audio). HDMI is capable of running over longer cable lengths than DVI. But your AV receiver must have the HDMI interface to pick up both the digital video adn the audio stream. |
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HDMI receiver setup
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HDMI-DVI connector
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HDMI handle both digital video and audio, and DVI only handles
digital video. With an adapter, a DVI device (DVD player) can be connected to an HDMI device, and transmit the digital video only. The audio signal would rely on the traditional methods such as analog RCA outputs or an optical digital output. (During the transition period, lot of clients will rely on HDMI-DVI converter to connect their existing DVI DVD to the the latest HDMI enabled LCD/Plasma.) |
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HDMI-DVI adapter
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HDMI-DVI adapter performance the same function as the HDMI-DVI connector without the cable. |
DVI & HDMI issue
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Issues
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Comments
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Nov-05
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There is lip-sync problem if we connect HDMI video to display directly and audio to receiver for surround output. | |