4X3,letterbox or 16X9

[wxndave]

Hi All,

I have been in discussion with others about what screen format broadcasters should transmit.   I am interested in what this group thinks about this.

1. Should broadcasters always transmit upconverted 4X3 on their HD stream when HD is not available?  

2. Should they toggle the stream between 16X9 and 4X3?

3. Should the broadcaster try to make a 4X3 fill more of the 16X9 screen?

4.  Should shows that are taped in 16X9 be aired on the NTSC channel as 4X3 full screen with the sides cut off or Letterbox?

Thanks
Dave

[Joseph S]

A) All shows should be shown in their native Aspect Ratio. If people want stuff stretched, they can do so with their TV and not subject everyone to the distortion.
B) All shows available on the network ATSC feed either 4:3 or 16:9 should be shown from the ATSC feed instead of the local inferior upconvert
C) The local broadcaster should learn to flip the switch on time, every time instead of planning new schemes to distort the picture
D) All networks should have DVHS and equivalents in place to timeshift HD programming if need be.

[Snard]

...
D) All networks should have DVHS and equivalents in place to timeshift HD programming if need be.

Considering that I have an equivalent device at home, that I am renting from Time Warner for about $7/month (the SA8300HD in my signature),  the local stations have no excuse not to have such devices like this on hand. (I realize that a professional grade DVR is a bit more expensive than an 8300HD, but if the consumer grade ones have gotten this cheap, the pro grade ones have to be cheaper too.)

[beeper]

Hi All,

I have been in discussion with others about what screen format broadcasters should transmit.   I am interested in what this group thinks about this.

Thanks
Dave

Standards are already in place regarding aspect ratio. I doubt there will be any change from what is now being used.

Broadcasters and hardware manufacturers had to address compatibility issues and that many people will still be using 4X3 screens for years to come, as well as
existing 4X3 source being rebroadcast in the future.

Your tuner should have a "set by program" setting that will automatically give a
picture that is the correct aspect ratio depending on the source aspect ratio, without distortion.

Depending on  the viewer's screen type (16X9 or 4X3 ), other aspect ratio or
zoom settings on the tuner could be selected to meet the viewer's hardware or viewing preference.

Broadcasters should never crop a 4X3 source to fill a 16X9 screen. That must be left up to the final viewer to decide. The top of peoples heads are already cut off above the eyebrows in close ups with current taping and editing trends.

NTSC should remain unchanged. Since most viewers will be using a 4X3 screen, any 16X9 source should be zoomed and cropped to fill the screen as it is now.

beeper

[GBK]

all shows should be produced using Widescreen format (doesn't have to be HD - although I would prefer it as Hd- if the production is meant to be 'cheap') however it is easier to format that content for 4x3 tv by either broadcasting a native ATSC which will fill the 4x3 picture and the person won't know that there is extra stuff or letterboxing it for 4x3 that way people that have 16x9 tv won't have to deal with distorting the picture in any way so that the content fills their screen.

Letterboxing would be better for 4x3 because it would speed the adoption of tv's that can handle the native resolution of HD programs.  just my 2c.

[picopir8]

I agree with the ealier post that all shows should be broadcast in their native format.  The user can then stretch,chop, or do whatever they want.  If the stations upconvert SD programs and broadcast in a 16:9 format then SD and 4:3 HD sets end up having black bars all around the picture (top/bottom and sides).  Even if the tuner allows you to zoom such pictures, they end up looking like crap compared to simply broadcasting in 4:3.  And lets face is SD sets are not going away anytime soon.  Many people, schools, small businesses, etc. do not have the money to replace perfectly good TVs.  Also a lot of people dont care about HD.  They just want to watch TV.  Even people who get HDTVs will likely only get one or two. Yet the average household has a lot more TVs.  So SD sets will have higher penetration for probably another 10 years after they stop selling SD sets.  Consequently, broadcasters need to accomodate all of us with SD sets, otherwise they will hear a lot of complaints about small pictures in the center of 4:3 screens.

[beeper]

9

all shows should be produced using Widescreen format.

The original question of the thread was regarding broadcasting format, not production format.
Obviously, producing 16X9 programming will become a standard.

Fortunately (or unfortunately) programming will continue to exist and be broadcast in both formats.

Nonpassive viewers will have to adjust their hardware to their liking.
Everyone else will have to settle for whatever the broadcasting standards are.

Examples.

Watching Leno in 16X9 is a complete waste of the wider aspect ratio because
nobody is missing a thing worth seeing compared to the 4X3 format.
(Currently most camera shots still center a 4X3 aspect ratio so that both formats
can continue to coexist.) In other words, a 16X9 aspect ratio in many cases can not be used to its full extent. Anyone veiwing Leno in 4X3 would still want the picture to fill their screen, not a smaller image 16X9 on a 4X3 screen.  

The March madness basketball that was broadcast on 58 is another example.

This is where 16X9 is great, but still needs to be customized to viewer preference.
The camera work generally showed a shot that included the audience 20 rows up. I prefered using cinema zoom to take away the audience and provide a larger image of the players.  The camera work was correct, in that it allowed me to do this while others may have wanted to see the audience and could choose not to zoom.

The bottom line is that the the final viewer should be able to select whatever
aspect ratio/zoom settings suits them, their equipment and more importantly,
the type of programming being viewed.

beeper

[GBK]

that is exactly my point it doesn't cost much more to produce a show in 16x9 format but then you have the extra picture data so that people with 16x9 tv's don't have to stretch it so they can fill their screen.  it's easier to crop the extra image to keep the 4x3 people happy.

but I completely agree with keeping the image in native format. no prestreching Ntsc garbage if it's in 4x3 now leave it don't zoom, stretch or otherwise mess with the image unless you can guarantee the results to be superior to what the person at home can do.

However I stand by my original idea.  It is completely idiotic to treat the symptoms of the problem instead of addressing it outright.

[wxndave]

This discussion was started by someone I work with.  He feels that most of the local   stations are not airing content correctly.  I will pick WTMJ as an example.  He feels that  when they air the local news or other non HD show, they should encode the signal as 4X3.  This would tell your equipment that  it is a 4X3 show much like ch24.  They would then only encode 16X9 when a HD produced program airs like Leno.  

So what do you as a view want to happen when there isn't HD programming?

Dave

[GBK]

well I don't know what the capabilities are for the HD equipment but as I understand the moment when you up convert to HD which is what channel 4 does that is what forces the 16x9 to be sent.. 18 is the same way they basically lock the aspect ratio. On the other hand PBS HD they're aspect ratio's remain open so even if it's HD you can still zoom crop etc.  that might be a choice or it might be forced by the equipment they use.  this question should be possed to Jimboy and Sean to answer.

[beeper]

This discussion was started by someone I work with.  He feels that most of the local   stations are not airing content correctly.  I will pick WTMJ as an example.  He feels that  when they air the local news or other non HD show, they should encode the signal as 4X3.  This would tell your equipment that  it is a 4X3 show much like ch24.  They would then only encode 16X9 when a HD produced program airs like Leno.  

So what do you as a view want to happen when there isn't HD programming?

Dave

Ask your co-worker what he has selected for the aspect ratio setting available in his receiver.

The signal has a code that will tell your receiver the correct aspect ratio.
If he selects "set by program" it should detect either a 16X9 or 4x3 source and show an undistorted pictuce depending on the type of broadcast.

If he has selected any other aspect ratio setting, the picture may be distorted
in one of the formats.

beeper

[foxeng]

ATSC protocol states that a non 480i signal be sent in 16:9. If the station wishes to use side curtains to keep any 4:3 material in OAR on this non 480i stream, that is just fine. If a station wishes to stretch the 4:3 to fill the 16:9, that is acceptable in the protocol as well. The protocol also allows for aspect ratio changes from 480i to non 480i, but there is no flag in the protocol to alert the display that the stream is 16:9 but format 4:3 or format for 16:9. it is either 16:9 for non 480i or 4:3 or 16:9 for 480i/p content.

[Joseph S]

If a station wishes to stretch the 4:3 to fill the 16:9, that is acceptable in the protocol as well.

It may be in the protocol, but it is anything but acceptable to people with one eye and a visual cortex. Neither are the atrocious full width white lines of garbage on Fox  ATSC 4:3 broadcasts acceptable.

[tazman]

ATSC protocol states that a non 480i signal be sent in 16:9. If the station wishes to use side curtains to keep any 4:3 material in OAR on this non 480i stream, that is just fine. If a station wishes to stretch the 4:3 to fill the 16:9, that is acceptable in the protocol as well. The protocol also allows for aspect ratio changes from 480i to non 480i, but there is no flag in the protocol to alert the display that the stream is 16:9 but format 4:3 or format for 16:9. it is either 16:9 for non 480i or 4:3 or 16:9 for 480i/p content.

What about the widescreen SD or ED PBS feeds or programming that are not carried on the PBS HD channel?  I guess I do not understand all the technical aspects of this.  All I know is that there have been compaints here about our local PBS stations not passing through the SD/ED PBS widescreen programming on our non HD channel.  I've checked this for myself by going directly to the PBS feeds on AMC-3 and found the same program running concurently on satellite in SD widescreen whose quality was very impresive and only to have 4x3 letter boxed on our local OTA PBS channel.  Rather disapointing.

[Jimboy]

Ideally in a perfect world...... :eek:

Two things need to happen.

Broadcasters would send the Active Format Description Data based on the outgoing video format and receiver's would be made to act upon it accordingly.
(Details from ATSC 53c below)  

This typically affects those people with 4:3 aspect ratio sets.  Upon receiving 16:9 video the 4:3 display would show letterboxed video.  When the 4:3 display receives 4:3 content the video would fill the screen.

Stations would need to switch (yes, that ugly word again) the AFD based on the outgoing video format. For the most part that should be easy. Upconvert=4:3.
Network=16:9.  But there are times when Network ATSC is 4:3. So now the Network needs to do their part in sending the correct data at the correct times.

I believe use of the AFD is optional since receivers default to the aspect ratio of the format being sent anyway. I was told last year (October) that this was a "in the future" option that receiver makers were going to add to products.
 
So to answer Dave's co-workers original question.  The content is being aired correctly - but - the two items above need to happen in order for a 4:3 display to show it properly.  (automatically)

Check this out! Page 2. (ATSC newsletter from 2002)
http://www.atsc.org/news_information/newsletter/ATSC_Newsletter-9.pdf

Also. Page 3 of this one. http://www.atsc.org/news_information/papers/2003_comments_fcc/ATSC_Comments_MB_03-151.pdf

This one makes the most sense...
http://www.tvtechnology.com/features/Tech-Corner/f-rh-aspect-ratio.shtml


5.2.4 Active Format Description Data
Active Format Description (AFD) should be included in video user data whenever the rectangular picture area containing useful information does not extend to the full height or width of the coded frame. AFD data may also be included in user data when the rectangular picture area containing useful information extends to the full height and width of the coded frame.
The AFD shall be carried in the user data of the video Elementary Stream. After each sequence start (and repeat sequence start) the default aspect ratio of the area of interest shall be that signalled by the sequence header and sequence display extension parameters. After introduction, an AFD shall remain in effect until the next sequence start or until another AFD is introduced. Receivers should interpret the absence of AFD in a sequence start to mean the active
format is the same as the coded frame, corresponding to AFD value '1000' (see Table A12).
Note: AFD as defined here is identical to that specified in ETSI TR 101 154 V1.4.1 [A17], and is reprinted here with permission.
ATSC Digital Television Standard, Revision C (Annex A) 21 May 2004

5.2.4.1 AFD Syntax
Table A11 describes the syntax of the Active Format Description.
Table A11 Active Format Description Syntax
Syntax No. of Bits Format
user_data_start_code 32 bslbf
afd_identifier 32 bslbf
zero 1 '0'
active_format_flag 1 bslbf
reserved 6 '00 0001'
if (active_format_flag == 1) {
reserved 4 '1111'
active_format 4 bslbf
}
5.2.4.2 5.2.4.2 AFD Semantics
afd_identifier – A 32-bit field that identifies that the syntax of the user data is Active Format Description. Its value is 0x44544731.
active_format_flag – A 1 bit flag. A value of '1' indicates that an active format is described in this data structure.
active_format – A 4 bit field describing the "area of interest" in terms of its aspect ratio within the coded frame as defined in ISO/IEC 13818-2 [A7].
The active_format is used by the decoder in conjunction with the "source aspect ratio." The source aspect ratio is derived from the "display aspect ratio" (DAR) signaled in the aspect_ratio_information, the horizontal_size, vertical_size, and display_horizontal_size and display_vertical_size if present (see ISO/IEC 13818-2 [A7]):
• If sequence_display_extension() is not present, source aspect ratio = DAR
• If sequence_display_extension() is present, source aspect ratio =
DAR display_horizontal_size vertical_size
display_vertical_size horizontal_size
× ×
The combination of source aspect ratio and active_format allows the decoder to identify whether the "area of interest" is the whole of the frame (e.g. source aspect ratio 16:9, active_format 16:9 center), a letterbox within the frame (e.g. source aspect ratio 4:3, active_format 16:9 center), or a "pillarbox" within the frame (e.g. source aspect ratio 16:9, active_format 4:3 center).
Table A12 defines the coding of active_format.
ATSC Digital Television Standard, Revision C (Annex A) 21 May 2004
38
Table A12 Active Format
active_format Aspect Ratio of the "Area of Interest"
'0000' – '0001' reserved
'0010' box 16:9 (top)
'0011' box 14:9 (top)
'0100' box > 16:9 (center)
'0101' – '0111' reserved
'1000' Active format is the same as the coded frame
'1001' 4:3 (center)
'1010' 16:9 (center)
'1011' 14:9 (center)
'1100' reserved
'1101' 4:3 (with shoot & protect 14:9 center)
'1110' 16:9 (with shoot & protect 14:9 center)
'1111' 16:9 (with shoot & protect 4:3 center)
Illustrations of the various values of active_format may be found in [A19]. Users are strongly encouraged to consult this reference.

5.2.4.3 Recommended Receiver Response to AFD
Receiving device designers are strongly encouraged to study the Recommended Receiver Reaction to Aspect Ratio Signaling [A19] and to design implementations conformant to its recommendations. In several instances, a variety of design choices are possible when processing a given AFD value for display and the recommendation identifies one preferred method.

5.2.5 Relationship Between Bar Data and AFD (Informative)
Any combination of Active Format Description and bar data may be present in video user data (either, neither, or both). Note that AFD data may not always exactly match bar data because AFD only deals with 4:3, 14:9, and 16:9 aspect ratios while bar data can accurately represent nearly any aspect ratio. Whenever bar data is present, it should be assumed to be exact.
ATSC Digital Television Standard, Revision C (Annex B) 21 May 2004
Annex B: