What is HDTV and what you need to get it

What is HDTV? Just the biggest advancement in TV technology since color replaced black and white.

The advantage of HDTV over SDTV

• Color: HDTV provides vivid color — including a wide range of hues — without any bleeding at the edges.
• Clarity and detail: HDTV has over five times the resolution of regular TV, so the sharpness of HDTV is dramatically better.
  • You can see details like the specks of colors in an actor’s eyes, or the individual sweat drops on a football player’s face.
• Wide screen: HDTV uses a 16:9 wide-screen format, the same format used in movie theaters. Current TVs use a 4:3 (NTSC) image, which forces a wide image into a narrow space and cuts pictures off.
  
• Dolby Digital 5.1 surround sound: All HDTV programming can provide 5.1 Dolby Digital surround sound — just like true theater sound.
  • Note: Availability depends on the broadcaster.

HD vs. SD TV

Feature	HD	SD (NTSC)
Signal	Digital	Analog
Sound	AC-3 digital audio (also called SPDIF) that can be distributed to 6 separate channels. Includes: Dolby Pro Logic Dolby Digital Digital Theater Systems (DTS) THX DVD-Audio Super Audio CD (SACD)	2-Channel stereo via audio signal
Horizontal line display	1080i (interlaced) or 720p (progressive) (Refer to your TV manual for information regarding 1080i and 720p.)	480i (interlaced) (Most standard TVs have 525 horizontal screen lines.)
Pixels	Up to 2 million (small, square) per image	Up to 210,000 (rectangular) per image
Aspect ratio	16:9	4:3

Learn more about HD service or see pricing and packages for your area.

The Comcast HD advantage: Choices

With Comcast HD, you can watch more than 1,000 programs in HD on your channel lineup and through Xfinity On Demand. Comcast HD choices include:

• New release movies (pay movies).
• Free movies.
• Top network shows.
• Cable shows from FX, MTV, Food Network, AMC, The History Channel, and more.
• Broadcast programming from ABC, CBS, FOX, and more.
• Cable programming from A&E, HGTV, ESPN, and more.
• Premium movies and shows from Showtime, Starz, HBO, EPIX and more.
• Music performances.

Look for specific HD channels in your area.

• Enter your address and click Submit.
• For the Select a package type drop-down menu, select High Definition.
  

Get the programming schedule for your HD channels.

• Enter your ZIP code and select your location.
• Check that the channel lineup in the box matches your channel lineup.
• Click OK to view your listings.
• When your listings appear, go to the Filters menu bar and click the gray HD button.

What you need to watch in HD

• HDTV
  • HD is a specific kind of digital signal format that requires a special television. Today's HD televisions come in two forms:
    • HD–ready TVs have the HD receiver or decoder built-in.
    • HD–capable TVs need an additional external receiver or decoder to receive digital broadcasts.
• HD TV Box
  • HD is different than digital cable.
    • Digital cable works with the cable already wired to your television, so it doesn’t require a special type of TV but it does need an HD-enabled TV Box (like an HD–DVR or HD TV Box).
    • We'll provide this box for an additional monthly fee. Contact us to order.
• HD service
  • HD service is available for all our Xfinity TV packages.

What to know when you watch TV with an HD connection

• If you have an HD connection (such as HDMI or component cabling), you might be able to watch SD TV channels.
  • They will still be in SD mode. 
  • See how to identify video, internet, and voice connection types to learn more.
• If you have an HD TV Box, HD TV, and an HD subscription, make sure your TV and TV Box are connected with an HD connection (such as HDMI or component cabling).
  • If your HD TV and TV Box are connected with any other cable type, your HD channels will only come in SD mode.
• If you do not have a subscription for HD service, you aren’t able to access HD channels. It doesn’t matter if you have a TV Box and/or an HD TV.
• If you’re watching a DVD on an HD TV set, it will not be true HD.
  • The DVD format was developed before HDTV, so it doesn’t use HD technology.
  • One difference is that DVDs can be viewed in the 16:9 aspect ratio on an HD TV set.

Learn more about HD from Comcast and find out what’s on this month.

Have questions?

See HD programming FAQs to learn more.

Additional information

Visit our Online Support Center to find common solutions.

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Need additional support? Ask Xfinity Assistant.