57U
05-24-2004, 02:34 PM
HDTV Formats
This question comes up frequently, so here are the formats that the various television stations "broadcast". The term broadcast is in quotes because some of these channels don't broadcast at all, but they send signals to service providers.
1080i
1080i is "crisp" and may be seen as "sharper" than 720P, but 720P has other advantages, such as less bandwidth required and better PQ when lots of motion is on screen.
CBC
Radio Canada
CBS
City
CTV
Discovery
Global (Global sends 720P to BEV)
HBO
HDNet
INHD
NBC
National Geographic (Canada)
OMNI 1 & 2
PBS (Most Stations, but not all - see below)
Rogers Demo Station
Rogers Sportsnet
Showtime
Showcase
Starz
TMN & MPix
TSN (TSN may supply BEV with 720P)
UPN
WB
Any other channel not listed below as 720P is very likely to be 1080i.
All cable companies (excepting Shaw) "pass" the broadcast format directly to the STB. It may then be that you only have one output format, depending on the STB, but that's a different scenario.
StarChoice is 1080i only.
Shaw is also now 1080i only, excepting perhaps PBS. This runs contrary to all the other cable providers which do not alter the signal sent to the STB.
720P
720P saves a bit of bandwidth and is also said to be "smoother" and "better" for sports programming.
ABC
A&E
ESPN
Some PBS stations like Detroit, Buffalo, NJ, Etc
Fox, as of Mid-September 2004
Raptors
The Score
Bell ExpressVu
About 1/2 the channels are 1080i and half 720P and they are in an almost constant state of flux while BEV is messing with its transponders....
You'll notice that some PBS stations are now also using 720P for the same reason (less bandwidth), since some of them are "multicasting". I'm not sure what the US Sats do.
Broadcasting vs Original Material
An affiliate broadcaster only broadcasts in one resolution. The only exception is Global, when it's not actually broadcasting, but sending a signal to BEV as 720P.
Please remember that the broadcaster (excepting Fox for their own programming) has nothing to do with the original signal/material, which for HD tapes, is usually 1080/24P, even for ABC, which then broadcasts in 720P.
People are often concerned about the affiliate "converting" signals say from 720p to 1080i, when this doesn't necessarily happen due to the nature of the original material.
HDTV Native Formats
Please note that all current HDTVs only display in one HD format - either 1080i (CRT-based HDTVs) or a "720P type" (720P or 768P) format for most pixel-based HDTVs, as well as 1080P for newer HDTVs. All incoming HD formats are converted to this native HD format. It therefore makes little difference what the channel is broadcasting, since it will be converted by the TV. Also, most STBs have the ability (or mandatory) to change output formats.
1080P
There are now 1080P HDTVs on the market. Also note that some of the 1080P HDTVs did NOT accept 1080P input signals (early models). Some HDTVs accept 1080P signals, but have a native display format which is "lower" (usually 768P for example on many LCDs and Plasmas). There probably won't be any 1080P broadcast signals for many years due to bandwidth limitations...
Some useful ATSC links.
http://support.gateway.com/s/CsmrEltrncs/DigitalTV/Shared/2517984faq42.shtml
http://www.cdtv.ca/en/faq/#4
http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html
Please PM me if you have any comments or suggestions.
This question comes up frequently, so here are the formats that the various television stations "broadcast". The term broadcast is in quotes because some of these channels don't broadcast at all, but they send signals to service providers.
1080i
1080i is "crisp" and may be seen as "sharper" than 720P, but 720P has other advantages, such as less bandwidth required and better PQ when lots of motion is on screen.
CBC
Radio Canada
CBS
City
CTV
Discovery
Global (Global sends 720P to BEV)
HBO
HDNet
INHD
NBC
National Geographic (Canada)
OMNI 1 & 2
PBS (Most Stations, but not all - see below)
Rogers Demo Station
Rogers Sportsnet
Showtime
Showcase
Starz
TMN & MPix
TSN (TSN may supply BEV with 720P)
UPN
WB
Any other channel not listed below as 720P is very likely to be 1080i.
All cable companies (excepting Shaw) "pass" the broadcast format directly to the STB. It may then be that you only have one output format, depending on the STB, but that's a different scenario.
StarChoice is 1080i only.
Shaw is also now 1080i only, excepting perhaps PBS. This runs contrary to all the other cable providers which do not alter the signal sent to the STB.
720P
720P saves a bit of bandwidth and is also said to be "smoother" and "better" for sports programming.
ABC
A&E
ESPN
Some PBS stations like Detroit, Buffalo, NJ, Etc
Fox, as of Mid-September 2004
Raptors
The Score
Bell ExpressVu
About 1/2 the channels are 1080i and half 720P and they are in an almost constant state of flux while BEV is messing with its transponders....
You'll notice that some PBS stations are now also using 720P for the same reason (less bandwidth), since some of them are "multicasting". I'm not sure what the US Sats do.
Broadcasting vs Original Material
An affiliate broadcaster only broadcasts in one resolution. The only exception is Global, when it's not actually broadcasting, but sending a signal to BEV as 720P.
Please remember that the broadcaster (excepting Fox for their own programming) has nothing to do with the original signal/material, which for HD tapes, is usually 1080/24P, even for ABC, which then broadcasts in 720P.
People are often concerned about the affiliate "converting" signals say from 720p to 1080i, when this doesn't necessarily happen due to the nature of the original material.
HDTV Native Formats
Please note that all current HDTVs only display in one HD format - either 1080i (CRT-based HDTVs) or a "720P type" (720P or 768P) format for most pixel-based HDTVs, as well as 1080P for newer HDTVs. All incoming HD formats are converted to this native HD format. It therefore makes little difference what the channel is broadcasting, since it will be converted by the TV. Also, most STBs have the ability (or mandatory) to change output formats.
1080P
There are now 1080P HDTVs on the market. Also note that some of the 1080P HDTVs did NOT accept 1080P input signals (early models). Some HDTVs accept 1080P signals, but have a native display format which is "lower" (usually 768P for example on many LCDs and Plasmas). There probably won't be any 1080P broadcast signals for many years due to bandwidth limitations...
Some useful ATSC links.
http://support.gateway.com/s/CsmrEltrncs/DigitalTV/Shared/2517984faq42.shtml
http://www.cdtv.ca/en/faq/#4
http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html
Please PM me if you have any comments or suggestions.
