dan9999
04-21-2009, 08:29 PM
HDTV FAQ: What is HDMI?
Digital Home Canada
Friday, 30 January 2009
Everyday thousands of people visit the Digital Forum looking for information about High definition television (HDTV) and everyday we try to help our readers out by answering frequently asked questions.
In this HDTV FAQ article we examine a common question about high definition television – What is HDMI? In addition, we discuss how much to spend on an HDMI cable and the HDMI v1.3 standard.
The High-Definition Multi-media Interface (HDMI) is an industry-supported, uncompressed, all-digital audio/video interface with 5 Gbps of available bandwidth. Simply speaking, HDMI is a digital cable connection used to transmit video and audio signals from your cable set top box, DVD player or satellite receiver to your high definition television.
HDMI has the capacity to support existing enhanced and high-definition video formats including 480p, 720p, 1080i, and even 1080p as well as standard definition formats such as NTSC or PAL.
HDTV televisions sold in North America today have at least one HDMI input while most most have at least three or four inputs. Multiple HDMI inputs are becoming increasingly important since HDTV owners are increasingly likely to hook up multiple devices such as a DVD player, cable set top box, satellite receiver, or next generation video game console via the HDMI connection.
Benefits
There are three main benefits for using HDMI over traditional analog connections.
* Improved Sound and Video Quality - HDMI transmits uncompressed digital audio and video thereby producing the highest quality video image and sound quality.
* Reduction of cable clutter - One HDMI connection replaces 3 video connections for high definition video and 6 audio connections for high-resolution audio.
* Cost - A good quality 6 foot HDMI cable can be purchased for $20 versus up to hundreds for good quality analog cables.
HDMI is backwards-compatible with the single-link Digital Visual Interface (DVI) commonly found on older HD televisions and set top devices through the use of a suitable adapter or cable, but the audio and remote control features of HDMI will not be available.
How much should I spend on an HDMI cable?
A second common question we receive about HDMI is how much should readers spend on an HDMI cable?
In the marketplace today, a 6 foot HDMI cables can range in price from $15 Canadian to $200 Canadian.
In a test conducted last year Digital Home connected a Blu-ray player and High End DVD player to a 1080p projector using three different HDMI cables. The six foot HDMI cables, which ranged in price from $20 and $200, were from Acoustic Research, Monster and the third was a well constructed house brand from a major retailer.
We viewed hours of HD programming, DVD’s and Blu-ray movies using the same equipment but different cables on a 100” screen. We were unable to determine any difference in picture quality. Of the three cables, we choose the Acoustic Research, which was a few dollars more than the house brand HDMI cable, simply because it seemed to have the most rugged construction.
The only concern that we have about HDMI cables on the market today is their length. HDMI cables specifications are designed to use standard copper cable construction with certain levels of required performance and are expected to perform flawlessly in cables up to 50 feet in length. Beyond 50 feet we don't recommend HDMI cables.
With shorter lengths, our advice is to look for a rugged relatively inexpensive HDMI cable and avoid wasting your money on the overpriced HDMI cables being pushed by big box retailers.
What is HDMI V1.3?
Beginning early in 2008, most though not all, new televisions, A/V receivers, and home theatre components began supporting a new standard called HDMI V1.3 which promises higher speeds, higher resolutions and support for new lossless audio standards.
In 2009, virtually every set should support HDMI 1.3 but be sure to check the specifications of any new HDTV just to sure.
The HDMI 1.3 specification includes the following features not found in previous versions:
Higher speed: HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices, such as higher resolutions, Deep Color and high frame rates. In addition, built into the HDMI 1.3 specification is the technical foundation that will let future versions of HDMI reach significantly higher speeds.
Deep Color: HDMI 1.3 supports 30-bit, 36-bit and 48-bit (RGB or YCbCr) color depths, up from the 24-bit depths in previous versions of the HDMI specification.
* Lets HDTVs and other displays go from million of colors to billions of colors.
* Eliminates on-screen color banding, for smooth tonal transitions and subtle gradations between colors.
* Enables increased contrast ratio
* Can represent many times more shades of gray between black and white
* At 30-bit pixel depth, a four times improvement would be the minimum, and the typical improvement would be eight times or more.
Broader color space: HDMI 1.3 removes all limits on color selection
* Next-generation “xvYCC” color space supports 1.8 times as many colors as existing HDTV signals
* Lets HDTVs display colors more accurately
* Enables displays with natural, vivid colors
New mini connector: With small portable devices such as HD camcorders and still cameras demanding seamless connectivity to HDTVs, HDMI 1.3 offers a new, smaller form factor connector option (see below).
Lip Sync: Because consumer electronics devices are using increasingly complex digital signal processing to enhance the clarity and detail of the content, synchronization of video and audio in user devices has become a greater challenge and could potentially require complex end-user adjustments. HDMI 1.3 incorporates an automatic video/audio synching capability that allows devices to perform this synchronization automatically with total accuracy.
New lossless audio formats: In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and all currently-available compressed formats (such as Dolby Digital and DTS), HDMI 1.3 adds additional support for new, lossless compressed digital audio formats Dolby TrueHD and DTS-HD.
Digital Home Canada
Friday, 30 January 2009
Everyday thousands of people visit the Digital Forum looking for information about High definition television (HDTV) and everyday we try to help our readers out by answering frequently asked questions.
In this HDTV FAQ article we examine a common question about high definition television – What is HDMI? In addition, we discuss how much to spend on an HDMI cable and the HDMI v1.3 standard.
The High-Definition Multi-media Interface (HDMI) is an industry-supported, uncompressed, all-digital audio/video interface with 5 Gbps of available bandwidth. Simply speaking, HDMI is a digital cable connection used to transmit video and audio signals from your cable set top box, DVD player or satellite receiver to your high definition television.
HDMI has the capacity to support existing enhanced and high-definition video formats including 480p, 720p, 1080i, and even 1080p as well as standard definition formats such as NTSC or PAL.
HDTV televisions sold in North America today have at least one HDMI input while most most have at least three or four inputs. Multiple HDMI inputs are becoming increasingly important since HDTV owners are increasingly likely to hook up multiple devices such as a DVD player, cable set top box, satellite receiver, or next generation video game console via the HDMI connection.
Benefits
There are three main benefits for using HDMI over traditional analog connections.
* Improved Sound and Video Quality - HDMI transmits uncompressed digital audio and video thereby producing the highest quality video image and sound quality.
* Reduction of cable clutter - One HDMI connection replaces 3 video connections for high definition video and 6 audio connections for high-resolution audio.
* Cost - A good quality 6 foot HDMI cable can be purchased for $20 versus up to hundreds for good quality analog cables.
HDMI is backwards-compatible with the single-link Digital Visual Interface (DVI) commonly found on older HD televisions and set top devices through the use of a suitable adapter or cable, but the audio and remote control features of HDMI will not be available.
How much should I spend on an HDMI cable?
A second common question we receive about HDMI is how much should readers spend on an HDMI cable?
In the marketplace today, a 6 foot HDMI cables can range in price from $15 Canadian to $200 Canadian.
In a test conducted last year Digital Home connected a Blu-ray player and High End DVD player to a 1080p projector using three different HDMI cables. The six foot HDMI cables, which ranged in price from $20 and $200, were from Acoustic Research, Monster and the third was a well constructed house brand from a major retailer.
We viewed hours of HD programming, DVD’s and Blu-ray movies using the same equipment but different cables on a 100” screen. We were unable to determine any difference in picture quality. Of the three cables, we choose the Acoustic Research, which was a few dollars more than the house brand HDMI cable, simply because it seemed to have the most rugged construction.
The only concern that we have about HDMI cables on the market today is their length. HDMI cables specifications are designed to use standard copper cable construction with certain levels of required performance and are expected to perform flawlessly in cables up to 50 feet in length. Beyond 50 feet we don't recommend HDMI cables.
With shorter lengths, our advice is to look for a rugged relatively inexpensive HDMI cable and avoid wasting your money on the overpriced HDMI cables being pushed by big box retailers.
What is HDMI V1.3?
Beginning early in 2008, most though not all, new televisions, A/V receivers, and home theatre components began supporting a new standard called HDMI V1.3 which promises higher speeds, higher resolutions and support for new lossless audio standards.
In 2009, virtually every set should support HDMI 1.3 but be sure to check the specifications of any new HDTV just to sure.
The HDMI 1.3 specification includes the following features not found in previous versions:
Higher speed: HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices, such as higher resolutions, Deep Color and high frame rates. In addition, built into the HDMI 1.3 specification is the technical foundation that will let future versions of HDMI reach significantly higher speeds.
Deep Color: HDMI 1.3 supports 30-bit, 36-bit and 48-bit (RGB or YCbCr) color depths, up from the 24-bit depths in previous versions of the HDMI specification.
* Lets HDTVs and other displays go from million of colors to billions of colors.
* Eliminates on-screen color banding, for smooth tonal transitions and subtle gradations between colors.
* Enables increased contrast ratio
* Can represent many times more shades of gray between black and white
* At 30-bit pixel depth, a four times improvement would be the minimum, and the typical improvement would be eight times or more.
Broader color space: HDMI 1.3 removes all limits on color selection
* Next-generation “xvYCC” color space supports 1.8 times as many colors as existing HDTV signals
* Lets HDTVs display colors more accurately
* Enables displays with natural, vivid colors
New mini connector: With small portable devices such as HD camcorders and still cameras demanding seamless connectivity to HDTVs, HDMI 1.3 offers a new, smaller form factor connector option (see below).
Lip Sync: Because consumer electronics devices are using increasingly complex digital signal processing to enhance the clarity and detail of the content, synchronization of video and audio in user devices has become a greater challenge and could potentially require complex end-user adjustments. HDMI 1.3 incorporates an automatic video/audio synching capability that allows devices to perform this synchronization automatically with total accuracy.
New lossless audio formats: In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and all currently-available compressed formats (such as Dolby Digital and DTS), HDMI 1.3 adds additional support for new, lossless compressed digital audio formats Dolby TrueHD and DTS-HD.