DTV Formats and How That Relates to HDTV

RSawdey · 03-04-2005, 04:19 PM

Interesting that in that discussion of 'pixel hopping' there is hardly any mention of the framerate, except an incorrect one... they said progressive didn't have the chance to correct a hopped pixel like the second field scan of interlaced. But in actuality, the progressive display will have completely redrawn the display in that time, since it has a doubled framerate. Perception of motion has two aspects, resolving position in space and resolving moments in time. They are both important. As the speed of motion increases, the temporal res becomes more so... to control motion blur.

ja2935 · 04-19-2005, 03:36 PM

Sorry if this is going over old ground but how can a 720p picture be considered as good as a 1080i - except for fast action scenes? Surely more information (detail) can be displayed in 1080 lines rather than 720. So a fairly static scene would look sharper in 1080?

ABC chose 720p but now has lost Monday Night Football!!!!

**rbinck** · 04-19-2005, 03:47 PM

Basically if you own a 720p display, it will be better. Sort of like if you have a Ford they are better than Chevys and vice versa. Most of the temporal arguments fall apart when talking about different resolutions. They make complete sense when comparing interlaced to progressive at the same resolutions. Because of the fast motion aspects of the 720p 60fps vs 1080i 30fps overall they are considered equal.

ja2935 · 04-19-2005, 06:52 PM

The UK has not yet started HD service but from what I have read the HD format being developed is the same as in the US, ie, 720p or 1080i. This is interesting because the current standard is 625 lines so it doesn't sound to be as much an improvement as it is here.

Zman1 · 04-24-2005, 08:59 AM

I am confused about the present and future transmission of digital TV signals and how they will appear on TV's..I am still in shopping mode but rapidly coming to buying one of these HD sets..Here is what I am seeing so please comment.
1. presently more and more on my old sets I see both commercials and some shows on digital channels broadcast in letterbox fashion..a:When viewed on your 16:9 set do those images commercials and programs fill the screen ??
b: When viewed on your 4:3 HD set do you get letterbox bars or full screen with those commercials, and channels ?

2.When the switch to all digital transmission occurs how do the broadcasters intend to send out their signals ?:
a) Letterboxed in 16:9
b)Fullscreen in 4:3

The comments of those of you who actually watch standard TV on your HD sets will be most welcome.

**rbinck** · 04-24-2005, 10:56 AM

It is very confusing to many people. Partly because they can not reconize where the bars originate. They can originate at the TV station, the set top box or the TV itself.

First of all it should be stressed that HD is not part of the mandate. Also it should be stressed that 16:9 aspect ratio is also not part of the mandate. The only thing that is mandated is the change to digital transmission and there are 18 available formats that stations can choose for their particular transmissions.

There seems to be four formats that has been currently adopted by stations:
640x480p @ 60fps EDTV - 4:3
704x480p @ 60fps EDTV - 16:9
1280x720p @ 60fps HDTV - 16:9
1920x1080i @ 30fps HDTV - 16:9

My NBC affiliate for example uses the 1920x1080i @30fps for their 2-1 HD subchannel and for their two other subchannels 2-2 & 2-3 they use the 640x480p @ 60fps. Same for the CBS affiliate.

My ABC affiliate uses the 1280x720p @ 60fps for their 13-1 HD subchannel and the 640x480p @ 60fps for their other subchannels.

There is a religious station here that uses 640x480p @ 60fps EDTV 4:3 for all four of their subchannels. My STB must supply the pillarboxes for these channels.

For a while our local FOX station was using the 704x480p @ 60fps widescreen format. They eventually switched to the 1280x720p @ 60fps.

The point that should be retained is the 16:9 aspect ratio is not part of the mandate, but once a station chooses the format they are going to use, they do not vary from it. What they do is convert the original programming to fit the format they have chosen.

Most of the programming will be sent out in the 16:9 format. It will be unusual for a station to adopt any of the 4:3 formats as their standard. The exception could be independants that feel they will only be offering 4:3 SD material or secondary channels for weather, etc and cable channels/networks. Now given that the stations will choose one of the 16:9 formats for their HD subchannel, what you will get is a mix of full screen, pillarbox and letterbox video.

The commercials you refered to are shot in 16:9 with the move to 16:9 HDTV being the norm in mind. Most of the time these commercials will be shown with both pillarbox and letterbox so we end up with black bars all the way around. This is because right now when the networks switch to commercials they use the 4:3 analog feed and merge the image into the 16:9 frame rather than using the commercial in HD and cropping the center of the image for the 4:3. On some occasions we see full screen HD comercials, probably depending on the advertiser's desires and budget.

Now the shows that are shot in 16:9 will be shown full screen. If the producers of the show feel like too much of the image would be lost cropped to 4:3, they will broadcast the show in 4:3 letterboxed. Other shows are shot so that they can be cropped for the 4:3 analog broadcast.

mfabien · 04-24-2005, 11:29 AM

Quote:

Originally Posted by Zman1

I am confused about the present and future transmission of digital TV signals and how they will appear on TV's..I am still in shopping mode but rapidly coming to buying one of these HD sets..Here is what I am seeing so please comment.
1. presently more and more on my old sets I see both commercials and some shows on digital channels broadcast in letterbox fashion..a:When viewed on your 16:9 set do those images commercials and programs fill the screen ??
b: When viewed on your 4:3 HD set do you get letterbox bars or full screen with those commercials, and channels ?

2.When the switch to all digital transmission occurs how do the broadcasters intend to send out their signals ?:
a) Letterboxed in 16:9
b)Fullscreen in 4:3

The comments of those of you who actually watch standard TV on your HD sets will be most welcome.

These are non HD commercials. If you see them on a SD channel, you will get letterbox for a 16:9 screen and bars top and bottom with a 4:3 screen.

For an HDTV and an HD channel, you will have black bars top and bottom and on each side. Some programs are SD upconverted to 1080i, Discovery channel in Canada carries them frequently.

True HD is 16:9 display.

slowmo · 04-25-2005, 11:37 AM

You probably noticed the very limited commercials during the Masters were full widescreen.

I recall a few from last year's Super Bowl and this year's final four.

borromini · 04-25-2005, 02:45 PM

This year's Super Bowl showed several movie trailer commercials and all of them were in HD.

roulettewheel · 05-14-2005, 02:56 PM

Quote:

Originally Posted by RSawdey

You should configure the DVR for 1080i output, your native res.

If your STB allows for Pass-Through of the signal straight to your monitor should you select that or still set your STB to 1080i? I have mine set to Pass-Through. Both are the same, right?

mfabien · 05-14-2005, 04:55 PM

Quote:

Originally Posted by roulettewheel

If your STB allows for Pass-Through of the signal straight to your monitor should you select that or still set your STB to 1080i? I have mine set to Pass-Through. Both are the same, right?

With Pass-Through you get the TV to adjust to 720p for certain channels and 1080i for other HD channels then one more time if you select a SD channel. It is annoying.

If your TV's native resolution is 1080i, you would be better off to select Upconvert1 for Picture Format. For those with 720p native resolution, Upcovert2 is th proper choice. In both cases, when a SD channel is selected, the 480p Picture Format will come on automatically (provided 480p was also selected in setup).

RSawdey · 05-14-2005, 05:18 PM

I don't think NTSC tuners are relevant to the determination of HD-ready... it's just about DIGITAL tuners... HD-ready has none, intergrated HDTV does.

16:10 formats are meant for graphics workstations that edit HDTV... puts the working image up & still has room for a small tool pallette on screen.

All formats are converted to the native res of the TV for display. Format conversion is never perfect... the new 1080p/60 displays are the ultimate since both 720p/60 and 1080i/30 can be upconverted without dataloss. Cross conversion of 720p <-> 1080i has different issues depending on the direction it's going...

RSawdey · 05-14-2005, 05:21 PM

I don't remember which set you've got roulettewheel, but I seem to have recommended setting 1080i (must be a CRT). This causes the STB to do the format conversions. Setting 'pass thru' will have your TV do all the format conversions, which might be better or worse - you've got to try & see.

rc4man · 06-07-2005, 10:35 AM

I just regestered, but I have occasionally read comments in the forum. my major questin is...Some posters have said that they bought an LCD and the cable pictsure was not great or even good, but when they hooked up to Dish or Direct with digital signal it looked great. Do you think I need to go to Direct or Dish....Have 30 inch tube Samsung HDTV and polorid 17 inch lcd...looking to buy a 30 or 32 inch lcd and replace my Samsung....help will be appreciated. rc4man

rc4man · 06-07-2005, 10:49 AM

What is Pillow Box...retired from tv in 97, but never heard f pillow box...pibe me some help so I can stay current...rc4man

Quote:

Originally Posted by rbinck

It is very confusing to many people. Partly because they can not reconize where the bars originate. They can originate at the TV station, the set top box or the TV itself.

First of all it should be stressed that HD is not part of the mandate. Also it should be stressed that 16:9 aspect ratio is also not part of the mandate. The only thing that is mandated is the change to digital transmission and there are 18 available formats that stations can choose for their particular transmissions.

There seems to be four formats that has been currently adopted by stations:
640x480p @ 60fps EDTV - 4:3
704x480p @ 60fps EDTV - 16:9
1280x720p @ 60fps HDTV - 16:9
1920x1080i @ 30fps HDTV - 16:9

My NBC affiliate for example uses the 1920x1080i @30fps for their 2-1 HD subchannel and for their two other subchannels 2-2 & 2-3 they use the 640x480p @ 60fps. Same for the CBS affiliate.

My ABC affiliate uses the 1280x720p @ 60fps for their 13-1 HD subchannel and the 640x480p @ 60fps for their other subchannels.

There is a religious station here that uses 640x480p @ 60fps EDTV 4:3 for all four of their subchannels. My STB must supply the pillarboxes for these channels.

For a while our local FOX station was using the 704x480p @ 60fps widescreen format. They eventually switched to the 1280x720p @ 60fps.

The point that should be retained is the 16:9 aspect ratio is not part of the mandate, but once a station chooses the format they are going to use, they do not vary from it. What they do is convert the original programming to fit the format they have chosen.

Most of the programming will be sent out in the 16:9 format. It will be unusual for a station to adopt any of the 4:3 formats as their standard. The exception could be independants that feel they will only be offering 4:3 SD material or secondary channels for weather, etc and cable channels/networks. Now given that the stations will choose one of the 16:9 formats for their HD subchannel, what you will get is a mix of full screen, pillarbox and letterbox video.

The commercials you refered to are shot in 16:9 with the move to 16:9 HDTV being the norm in mind. Most of the time these commercials will be shown with both pillarbox and letterbox so we end up with black bars all the way around. This is because right now when the networks switch to commercials they use the 4:3 analog feed and merge the image into the 16:9 frame rather than using the commercial in HD and cropping the center of the image for the 4:3. On some occasions we see full screen HD comercials, probably depending on the advertiser's desires and budget.

Now the shows that are shot in 16:9 will be shown full screen. If the producers of the show feel like too much of the image would be lost cropped to 4:3, they will broadcast the show in 4:3 letterboxed. Other shows are shot so that they can be cropped for the 4:3 analog broadcast.

04-19-2005, 03:36 PM	#17
ja2935 High Definition is the definition of life. Join Date: Jul 2004 Location: Atlanta, GA Posts: 1,034	720p versus 1080i Sorry if this is going over old ground but how can a 720p picture be considered as good as a 1080i - except for fast action scenes? Surely more information (detail) can be displayed in 1080 lines rather than 720. So a fairly static scene would look sharper in 1080? ABC chose 720p but now has lost Monday Night Football!!!!

04-19-2005, 06:52 PM	#19
ja2935 High Definition is the definition of life. Join Date: Jul 2004 Location: Atlanta, GA Posts: 1,034	UK/European High Def The UK has not yet started HD service but from what I have read the HD format being developed is the same as in the US, ie, 720p or 1080i. This is interesting because the current standard is 625 lines so it doesn't sound to be as much an improvement as it is here.

04-24-2005, 10:56 AM	#21
rbinck Super Moderator Join Date: Apr 2004 Location: Houston, Texas Posts: 10,612	It is very confusing to many people. Partly because they can not reconize where the bars originate. They can originate at the TV station, the set top box or the TV itself. First of all it should be stressed that HD is not part of the mandate. Also it should be stressed that 16:9 aspect ratio is also not part of the mandate. The only thing that is mandated is the change to digital transmission and there are 18 available formats that stations can choose for their particular transmissions. There seems to be four formats that has been currently adopted by stations: 640x480p @ 60fps EDTV - 4:3 704x480p @ 60fps EDTV - 16:9 1280x720p @ 60fps HDTV - 16:9 1920x1080i @ 30fps HDTV - 16:9 My NBC affiliate for example uses the 1920x1080i @30fps for their 2-1 HD subchannel and for their two other subchannels 2-2 & 2-3 they use the 640x480p @ 60fps. Same for the CBS affiliate. My ABC affiliate uses the 1280x720p @ 60fps for their 13-1 HD subchannel and the 640x480p @ 60fps for their other subchannels. There is a religious station here that uses 640x480p @ 60fps EDTV 4:3 for all four of their subchannels. My STB must supply the pillarboxes for these channels. For a while our local FOX station was using the 704x480p @ 60fps widescreen format. They eventually switched to the 1280x720p @ 60fps. The point that should be retained is the 16:9 aspect ratio is not part of the mandate, but once a station chooses the format they are going to use, they do not vary from it. What they do is convert the original programming to fit the format they have chosen. Most of the programming will be sent out in the 16:9 format. It will be unusual for a station to adopt any of the 4:3 formats as their standard. The exception could be independants that feel they will only be offering 4:3 SD material or secondary channels for weather, etc and cable channels/networks. Now given that the stations will choose one of the 16:9 formats for their HD subchannel, what you will get is a mix of full screen, pillarbox and letterbox video. The commercials you refered to are shot in 16:9 with the move to 16:9 HDTV being the norm in mind. Most of the time these commercials will be shown with both pillarbox and letterbox so we end up with black bars all the way around. This is because right now when the networks switch to commercials they use the 4:3 analog feed and merge the image into the 16:9 frame rather than using the commercial in HD and cropping the center of the image for the 4:3. On some occasions we see full screen HD comercials, probably depending on the advertiser's desires and budget. Now the shows that are shot in 16:9 will be shown full screen. If the producers of the show feel like too much of the image would be lost cropped to 4:3, they will broadcast the show in 4:3 letterboxed. Other shows are shot so that they can be cropped for the 4:3 analog broadcast. Last edited by rbinck; 04-24-2005 at 11:02 AM.

04-25-2005, 02:45 PM	#24
borromini HT Frontiersman Join Date: Jun 2004 Location: Northern California Posts: 9,566	This year's Super Bowl showed several movie trailer commercials and all of them were in HD. __________________ "I'd rather have a bottle in front of me than a frontal lobotomy"

06-07-2005, 10:35 AM	#29
rc4man My plasma is High Def. Join Date: Jun 2005 Posts: 5	cable tv clarity on lcd screen I just regestered, but I have occasionally read comments in the forum. my major questin is...Some posters have said that they bought an LCD and the cable pictsure was not great or even good, but when they hooked up to Dish or Direct with digital signal it looked great. Do you think I need to go to Direct or Dish....Have 30 inch tube Samsung HDTV and polorid 17 inch lcd...looking to buy a 30 or 32 inch lcd and replace my Samsung....help will be appreciated. rc4man

03-04-2005, 04:19 PM	#16
RSawdey Mr. Wizard Join Date: Feb 2005 Location: Ferndale, Michigan Age: 60 Posts: 5,981	Interesting that in that discussion of 'pixel hopping' there is hardly any mention of the framerate, except an incorrect one... they said progressive didn't have the chance to correct a hopped pixel like the second field scan of interlaced. But in actuality, the progressive display will have completely redrawn the display in that time, since it has a doubled framerate. Perception of motion has two aspects, resolving position in space and resolving moments in time. They are both important. As the speed of motion increases, the temporal res becomes more so... to control motion blur.

04-19-2005, 03:47 PM	#18
rbinck Super Moderator Join Date: Apr 2004 Location: Houston, Texas Posts: 10,612	Basically if you own a 720p display, it will be better. Sort of like if you have a Ford they are better than Chevys and vice versa. Most of the temporal arguments fall apart when talking about different resolutions. They make complete sense when comparing interlaced to progressive at the same resolutions. Because of the fast motion aspects of the 720p 60fps vs 1080i 30fps overall they are considered equal.

04-24-2005, 08:59 AM	#20
Zman1 High Definition is the definition of life. Join Date: Apr 2005 Posts: 32	I am confused about the present and future transmission of digital TV signals and how they will appear on TV's..I am still in shopping mode but rapidly coming to buying one of these HD sets..Here is what I am seeing so please comment. 1. presently more and more on my old sets I see both commercials and some shows on digital channels broadcast in letterbox fashion..a:When viewed on your 16:9 set do those images commercials and programs fill the screen ?? b: When viewed on your 4:3 HD set do you get letterbox bars or full screen with those commercials, and channels ? 2.When the switch to all digital transmission occurs how do the broadcasters intend to send out their signals ?: a) Letterboxed in 16:9 b)Fullscreen in 4:3 The comments of those of you who actually watch standard TV on your HD sets will be most welcome.

04-25-2005, 11:37 AM	#23
slowmo High Definition is the definition of life. Join Date: Nov 2004 Posts: 759	You probably noticed the very limited commercials during the Masters were full widescreen. I recall a few from last year's Super Bowl and this year's final four.

05-14-2005, 05:18 PM	#27
RSawdey Mr. Wizard Join Date: Feb 2005 Location: Ferndale, Michigan Age: 60 Posts: 5,981	I don't think NTSC tuners are relevant to the determination of HD-ready... it's just about DIGITAL tuners... HD-ready has none, intergrated HDTV does. 16:10 formats are meant for graphics workstations that edit HDTV... puts the working image up & still has room for a small tool pallette on screen. All formats are converted to the native res of the TV for display. Format conversion is never perfect... the new 1080p/60 displays are the ultimate since both 720p/60 and 1080i/30 can be upconverted without dataloss. Cross conversion of 720p <-> 1080i has different issues depending on the direction it's going...

05-14-2005, 05:21 PM	#28
RSawdey Mr. Wizard Join Date: Feb 2005 Location: Ferndale, Michigan Age: 60 Posts: 5,981	I don't remember which set you've got roulettewheel, but I seem to have recommended setting 1080i (must be a CRT). This causes the STB to do the format conversions. Setting 'pass thru' will have your TV do all the format conversions, which might be better or worse - you've got to try & see.

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