No. 1 2 3
Profile
PD PD PD
Mandatory/Optional in Spec(note1)
Mandatory
320x240 320X180 416x240
Picture Aspect Ratio (Nominal)
4x3 16x9 16x9
320 320 416
240 192 240
320 320 416
240 180 240
Cropping
No No No
Aspect Ratio
1.00 1.00 1.00
1.333 1.667 1.733
Picture Aspect Ratio - Active 1.333 1.778 1.733
Display width (sq. pixels, w/o overscan)
320 320 416
Display width Max (sq. pixels, w/ overscan)
320 320 416
Frame rates
Progressive / interlace
Progressive Progressive Progressive
Black Padding
Inactive frame areas shall be filled with visible black (RGB=16, 16, 16)
Luma (Y') 16-235 visible (not clipped, 1 - 255 valid)
BT.709-5, , chroma +/-128 (clipped; i.e. no negative RGB coefficients)
Recommended practice topicsResolution (Nominal)
Horizontal Encoded Frame Size - N/16 - 1
=
pic_width_in_mbs_minus1
Vertical Encoded Frame Size - N/16 - 1 =
pic_height_in_map_units_minus1
Active Picture Width (Max) Active Picture Height (Max)
Center
picture, AVC
crop set to
active area
Center picture
in 180 line
area, AVC
crop set to
active area
Center
picture, AVC
crop set to
active area
Overscan Flag = 1?
Sample Aspect Ratio - aspect_ratio_idc
(sar_width, sar_height - if necessary)
Aspect Ratio - Container ["picture" del]
11.99p,
14.99p,
23.976p, 25p,
29.97p
11.99p,
14.99p,
23.976p, 25p,
29.97p
11.99p,
14.99p,
23.976p, 25p,
29.97p
Quantization range[2]
Color space [3]
Content not interlace filtered, intended for deinterlacers and progressive display (device should flicker filter if direct to interlaced CRT). Encoding 3:2 pulldown not recommended.
50Hz
Interlaced temporal sub-sampling, filtering
Gamma curve, render intent, display
adaptation maritx_coefficients=1, i.e. BT.601 and BT.709 gamma. Video balanced on standard gamma 2.2 studio monitor and viewing conditions, devices shall provide gamma compensation (e.g. 2.5 - 3.0 for
small screens and bright viewing, 1.8 - 2.0 for home theater)
Devices shall decode 50Hz picture formats allowed above. Devices shall display 50Hz formats if equipped with internal displays. Devices shall output at 50 Hz or higher, if equipped with compatible
video outputs, e.g. SCART, HDMI, VGA, etc. Format conversion from 25/50Hz to 60Hz outputs is optional for devices.
[1] e.g. NTSC, PAL, anamorphic, sq, … [2] e.g. 16-235, 0-255, +/-128, …
[3] e.g. Rec 601, 709; negative coefficients
(note1)
Mandatory: Mandatory for all devices to
support for each corresponding Profile.
Optional: Optional for all devices to
support for each corresponding Profile.
4 5 6 7 8 9
SD SD SD SD SD
Mandatory
480x360 640x480 864x480 704x480 720x480
4x3 4x3 16x9 4x3 16x9 4x3
480 640 864 704 704 720
360 480 480 480 480 480
480 640 864 704 704 704
360 480 480 480 480 480
No No No No No Yes
1.00 1.00 1.00 0.91 1.21 0.91
1.333 1.333 1.800 1.333 1.778 1.364
1.333 1.333 1.800 1.333 1.778 1.333
480 640 864 640 853 640
480 640 864 640 853 655
Progressive Progressive Progressive Both Both Both
Inactive frame areas shall be filled with visible black (RGB=16, 16, 16)
Luma (Y') 16-235 visible (not clipped, 1 - 255 valid)
BT.709-5, , chroma +/-128 (clipped; i.e. no negative RGB coefficients)
Center picture,
AVC crop set
to active area
Center picture,
AVC crop set
to active area
Center picture,
AVC crop set
to active area
Center
picture,
AVC crop
set to
active area
Center
picture,
AVC crop
set to
active area
Center
picture,
AVC crop
set to
active area
11.99p,
14.99p,
23.976p, 25p,
29.97p
11.99p,
14.99p,
23.976p, 25p,
29.97p
11.99p,
14.99p,
23.976p, 25p
23.976p,
29.97i 23.976p, 29.97i 23.976p, 29.97i
Content not interlace filtered, intended for deinterlacers and progressive display (device should flicker filter if direct to interlaced CRT). Encoding 3:2 pulldown not recommended.
maritx_coefficients=1, i.e. BT.601 and BT.709 gamma. Video balanced on standard gamma 2.2 studio monitor and viewing conditions, devices shall provide gamma compensation (e.g. 2.5 - 3.0 for
small screens and bright viewing, 1.8 - 2.0 for home theater)
Devices shall decode 50Hz picture formats allowed above. Devices shall display 50Hz formats if equipped with internal displays. Devices shall output at 50 Hz or higher, if equipped with compatible
video outputs, e.g. SCART, HDMI, VGA, etc. Format conversion from 25/50Hz to 60Hz outputs is optional for devices.
10 11 12 13 14
SD HD HD HD HD
Mandatory
720x480 1280X720 960X720 1440X1080 1920X1080
16x9 16x9 4x3 4x3 16x9
720 1280 960 1440 1920
480 720 720 1088 1088
704 1280 960 1440 1920
480 720 720 1080 1080
Yes No No No No
1.21 1.00 1.00 1.00 1.00
1.818 1.778 1.333 1.324 1.765
1.778 1.778 1.333 1.333 1.778
853 1280 960 1440 1920
873 1280 960 1440 1920
Both Progressive Progressive Both Both
Inactive frame areas shall be filled with visible black (RGB=16, 16, 16)
Luma (Y') 16-235 visible (not clipped, 1 - 255 valid)
BT.709-5, , chroma +/-128 (clipped; i.e. no negative RGB coefficients)
Center
picture,
AVC crop
set to
active area
Center picture,
AVC crop set
to active area
Center picture,
AVC crop set
to active area
Center
picture in
1080 line
area, AVC
crop set to
active area
Center
picture in
1080 line
area, AVC
crop set to
active area
23.976p,
29.97i 23.976p, 25p,
29.97p, 50p,
59.94p
23.976p, 25p,
29.97p, 50p,
59.94p
23.976p,
25p,
29.97p,
50p, 25i,
29.97i
23.976p,
25p,
29.97p,
50p, 25i,29.97i
Content not interlace filtered, intended for deinterlacers and progressive display (device should flicker filter if direct to interlaced CRT). Encoding 3:2 pulldown not recommended.
maritx_coefficients=1, i.e. BT.601 and BT.709 gamma. Video balanced on standard gamma 2.2 studio monitor and viewing conditions, devices shall provide gamma compensation (e.g. 2.5 - 3.0 for
small screens and bright viewing, 1.8 - 2.0 for home theater)
Devices shall decode 50Hz picture formats allowed above. Devices shall display 50Hz formats if equipped with internal displays. Devices shall output at 50 Hz or higher, if equipped with compatible
No. 1
Proponent Example
Profile HD
Mandatory/Optional in Spec(note1)
Resolution
1920x1080
1920
1080
Cropping
Overscan
Aspect RatioPicture Aspect Ratio - Container
Picture Aspect Ratio - Active 1.85, 2.35 etc
Frame rates
23.976
50Hz
Progressive / interlace
Mandatory
Horizontal Encoded Size -
pic_width_in_mbs_minus1
1920
pic_width_in_mbs_minus1: 119
Vertical Encoded Size -
pic_height_in_map_units_minus1 1088 pic_height_in_map_units_minus1:
PLACEHOLDER TB CLEANED BY 67
MOVING TO SEPARATE PROFILES
AND MOVING BELOW
Display Width
Display Height
Crop 8 bottom lines using AVC
cropping parameter.
frame_crop_bottom_offset : 4
No
Sample Aspect Ratio - aspect_ratio_idc
(sar_width, sar_height - if necessary) 1:1 aspect_ratio_idc: 1
16:9
Progressive
Black Padding
Req 709
Recommended practice topicsInterlaced temporal sub-sampling, filtering
Send coordinates of active picture
using private data stream
Quantization range[2]
16-235, 0-253 legal range as
defined in Rec 601 and 709
Color space [3]
Gamma curve, render intent, display
adaptation
[1] e.g. NTSC, PAL, anamorphic, sq, … [2] e.g. 16-235, 0-255, +/-128, …
[3] e.g. Rec 601, 709; negative coefficients
(note1)
Mandatory: Mandatory for all devices to
support for each corresponding Profile.
Optional: Optional for all devices to
support for each corresponding Profile.
2 3 Microsoft
ALL ALL
720, 1280, 1920, 720 PD 320
480, 720, 1080, 576 PD 240
1:1, 10:11, 40:33, 4:3
4:3, 16:9
29.97, 23.976 plus 25 for 50Hz
Both Both
Sony Toshiba Panasonic
720x480 , 1280x720,
1920x1080, plus 720x576 for
50Hz
PD 320x240, 416x240, SD
640x480, 720x480NTSC,
864x480, HD 1280x720,
1440x1080, 1920x1080
Optional for devices to crop
L+R to 704 with overscan flag
in AVC elementary stream
AVC cropping parameters
specified in stream and ISO
Track size equals decoder
output size e.g. 1080 or 704,
not 1088 or 720 encoded size
1:1, 10:11, 40:33, 4:3, plus
12:11, 16:11 for 50Hz
1.33, 1.78, 1.85, 2.35
Encoded frame 4:3 , 16:9
14.99, 23.976, 25, 29.97, 50,
59.94
Send coordinates of active
picture
using private data stream
OK, but encode AVC cropping
parameters of actual picture
area
16-235, 0-253 legal range as
defined in Rec 601 and 709 16-235, 0-253 visible range,
not clipped, as defined in Rec
601 and 709
Req 601 for PD, SD, Req 709
for HD Req 601 for PD, SD; Req 709
for HD, negative RGB OK
Optimized for progressive
display, default AVC 4:2:0
subsample locations
Encoded with studio monitor
gamma. Display correction
applied by device (e.g. 2.4 for
computer or hand held, 1.5 for
home theater)
4 5 6 7 Paramount Paramount
PD SD HD PD
Mandatory
320, 416
240
320x192 for 320x180
No
1:1 1:1
4:3, 16:9 4:3, 16:9 4:3, 16:9
4:3, 16:9
29.97
Optional Optional
Progressive Both Both Progressive
Toshiba
Panasonic SamsungNBCU
Nokia
320x240,
320x180 640x480, 720x480
720x576
1280x720
1920x1080 320x240, 416x240
Cropping
limited to the
size of the
active picture
area
Cropping
limited to the
size of the
active picture
area
Cropping
limited to
the size of
the active
picture
area
1:1, 10:11,
40:33, 4:3,
plus 12:11,
16:11 for
50Hz
1:1, 10:11,
40:33, 4:3,
plus 12:11,
16:11 for
50Hz
1.33, 1.78,
1.85, 2.35,
2.40
1.33, 1.78,
1.85, 2.35,
2.40
1.33,
1.78,
1.85,
2.35, 2.40
23.976, 25,
29.97, 50,
59.94
23.976, 25,
29.97, 50,
59.94
23.976,
29.97, 25,
30
Send coordinates of active picture
Req 709 Req 601 Req 709
Rec 709 or Rec 601
Optional Optional
Padding is
acceptable in
addition to
cropping as
limited in Item
7
Padding is
acceptable in
addition to
cropping as
limited in Item
7
16-235 legal range as defined in
Rec 601 16-235, 0-253
legal range as
defined in Rec
601 and 709
16-235, 0-253
legal range as
defined in Rec
601 and 709
16-235, 0-
253 legal
range as
defined in
Rec 601
and 709
Notes to Discuss:
•
[MS] Attempting to pre-correct for limited devices at encoding (e.g. vertical resolution filtering to prevent “CRT flicker”, encoding letterbox bars, encoded pulldown, etc.) usually compromises high end devices (progressive displays, 120Hz, motion interpolation, automatic PAR adaptation, etc.)
•
[MS] Might recommend safe areas based on device cropping to 4:3
•
[MS] Clarification of “exact scan” pixel dimensions to avoid unnecessary scaling (e.g. 704 or 720 = 4:3? = 16:9 anamorphic?) Display intent must be specified explicitly using correct SAR in h.264
•
[SPE] Proposes a new MP4 box for optional frame crop.
•
Crop box parameters shall be constant through an entire track
•
Crop box must exist in every sync sample for random access.
•
Luma crop parameters must be a multiple of 2 to compensate for 4:2:0 subsampling of chroma pixels.
•
Top and Bottom luma crop parameters are limited to a multiple of 4 to compensate for field based presentations in 4:2:0.
•
Composition objects such as subtitles require positioning methods to coordinate with frame cropping. This is not included in the scope of this box and must be defined elsewhere.
•
[MS] Vertical coding size can be any number of lines up to defined maximum number.
•
[MS] Some of current internet streaming distributed contents are encoded with respect to aspect ratio of the source video.
•
PC software platforms are capable of handling as it is done today
•
CE platforms may not be capable of handling flexible sized videoformat
•
Limited guaranteed video format supported in LSI
•
Increase in testing –can not guarantee every combination
•
[SPE] Define active video window in MP4 file format as DECE unique user data
•
[SPE] Contents are encoded with embedded black lines as done today (for non-internet streaming contents)
•
[SPE] PC software uses MP4 file format to crop the embedded black lines as post process before displaying the contents.
•
[SPE] CE platform displays/outputs with black lines –may optionally crop the black lines.
[MS] Attempting to pre-correct for limited devices at encoding (e.g. vertical resolution filtering to prevent “CRT flicker”, encoding letterbox bars, encoded pulldown, etc.) usually compromises high end devices (progressive displays, 120Hz, motion interpolation, automatic PAR adaptation, etc.)
[MS] Clarification of “exact scan” pixel dimensions to avoid unnecessary scaling (e.g. 704 or 720 = 4:3? = 16:9 anamorphic?) Display intent must be specified explicitly using correct SAR in h.264
Luma crop parameters must be a multiple of 2 to compensate for 4:2:0 subsampling of chroma pixels.
Top and Bottom luma crop parameters are limited to a multiple of 4 to compensate for field based presentations in 4:2:0.
Composition objects such as subtitles require positioning methods to coordinate with frame cropping. This is not included in the scope of this box and must be defined elsewhere.
[MS] Vertical coding size can be any number of lines up to defined maximum number.
[MS] Some of current internet streaming distributed contents are encoded with respect to aspect ratio of the source video.
[SPE] Contents are encoded with embedded black lines as done today (for non-internet streaming contents)
[SPE] PC software uses MP4 file format to crop the embedded black lines as post process before displaying the contents.
[SPE] CE platform displays/outputs with black lines –may optionally crop the black lines.
[MS] Attempting to pre-correct for limited devices at encoding (e.g. vertical resolution filtering to prevent “CRT flicker”, encoding letterbox bars, encoded pulldown, etc.) usually compromises high end devices (progressive displays, 120Hz, motion interpolation, automatic PAR adaptation, etc.)
[MS] Clarification of “exact scan” pixel dimensions to avoid unnecessary scaling (e.g. 704 or 720 = 4:3? = 16:9 anamorphic?) Display intent must be specified explicitly using correct SAR in h.264
Composition objects such as subtitles require positioning methods to coordinate with frame cropping. This is not included in the scope of this box and must be defined elsewhere.
[MS] Attempting to pre-correct for limited devices at encoding (e.g. vertical resolution filtering to prevent “CRT flicker”, encoding letterbox bars, encoded pulldown, etc.) usually compromises high end devices (progressive displays, 120Hz, motion interpolation, automatic PAR adaptation, etc.)
Pixel Aspect Ratio
Rec.601 Digital Rec.601 Digital
720×576
59:54:00 12:11
704×576
352×288 118:81 16:11
720×480
10:11
704×480
352×240 40:33:00
Video System
Picture Dimension
s
Pixel Aspect Ratio (Decimal)
Standard
(4:3) PAL
(e.g. 576i)
Widescreen (16:9) PAL
Standard
(4:3)
NTSC
(e.g. 480i)
Widescreen (16:9) NTSC
Sample Pixel Aspect Ratio
Pixel aspect ratio (often abbreviated PAR) is a mathematical ratio that describes how the width of pixels in a digital image compares to their height.
Most digital imaging systems describe an image as a grid of very small but nonetheless square pixels. However, some imaging systems, especially those which must maintain compatibility with Standard-definition television motion pictures, define an image as a grid of rectangular pixels in which the width of the pixel is slightly different from that of its height. Pixel Aspect Ratio
describes this difference.
Use of Pixel Aspect Ratio mostly involves pictures pertaining to standard-definition television and some other exceptional cases. Most other imaging systems, including those which comply with SMPTE standards and practices, use square pixels. Pixel aspect ratios of common video formats
Pixel Aspect Ratio values for common standard-definition video formats are listed below. Note that for each video format, three different types of Pixel Aspect Ratio values are listed:
Rec.601, a Rec.601-compliant value, which is considered the real Pixel Aspect Ratio of standard-definition video of that type. (Read Explanation)
Digital, which is roughly equivalent to Rec.601 and is more suitable to use in Digital Video Editing software. (Read Explanation)
Picture Aspect Ratio - Active Picture
TV - 1.33 (4:3), 1.78 (16:9)
Movies – 1.33 (4:3), 1.85, 2.35, 2.40 Common aspect ratios:
1.33 (4:3 TV), 1.78 (16:9 TV), 1.85 2.0, 2.33, 2.4(film), 16:9 anamorphic 708x483 SMPTE D1 display aperture
704x480 ATSC 4:3? 720x480 DVD 4:3?
The aspect ratio of an image is its width divided by its height. Aspect ratios are mathematically expressed as x :y (pronounced
"x-to-y") and x×y (pronounced "x-by-y"). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1[1]. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras, previously only commonly seen in professional cameras, 16:9[2][3]. Other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used in photography as well.
Converting formats of unequal ratios is done by either cropping the original image to the receiving format's aspect ratio
(zooming), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, or by distorting the image to fill the receiving format's ratio. Cinematographic aspect ratios are usually denoted as a decimal fraction width to unit height, while videographic aspect ratios are usually denoted by ratios of whole numbers.
Resolution
The display resolution of a digital television or display typically refers to the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays.
Televisions are of the following resolutions:
SDTV: 480i (NTSC, 720×480 split into two 240-line fields) SDTV: 576i (PAL, 720×576 split into two 288-line fields) EDTV: 480p (NTSC, 720×480)
EDTV: 576p (PAL, 720×576) HDTV: 720p (1280×720)
HDTV: 1080i (1280×1080, 1440×1080, or 1920×1080 split into two 540-line fields) HDTV: 1080p (1920×1080 progressive scan)
Computers have higher resolutions. Currently, 1024×768 is regarded as an acceptable default. As of July, 2002, 1024×768 Extended Graphics Array was the most common display resolution.[1][2] Many web sites and multimedia products were re- designed from the previous 800×600 format to the higher 1024×768-optimized layout. The validity of this method of gathering statistics is diminishing, however, as LCD monitors have only one native display resolution - the highest available on that particular monitor. When users select a lower resolution, the lower resolution is reported to the statistics gathering website. This is useful if you want to know what resolution the user is seeing (which most web designers want to know), but it does not tell you the highest resolution the monitor is capable of displaying. Nevertheless, the actual number of pixels in front of the user has not changed. Instead, interpolation in the monitor causes the picture to become fuzzy as it attempts to display an image of the wrong resolution by scaling it.
The availability of inexpensive LCD monitors has made the 5:4 aspect ratio resolution of 1280×1024 more popular for desktop usage. Many computer users including CAD users, graphic artists and video game players run their computers at 1600×1200 resolution (UXGA, Ultra-eXtended) or higher if they have the necessary equipment. Other recently available resolutions include oversize aspects like 1400×1050 SXGA+ and wide aspects like 1280×720 WXGA, 1680×1050 WSXGA+, and 1920×1200 WUXGA. A new HD resolution of 2560×1600 WQXGA has been released mainly in 30" LCD monitors. Special monitors for medical diagnostic work are using 3280×2048 WQSXGA, which is the current maximum resolution available in a single monitor. The most common computer display resolutions are as follows:[
Overscan
Overscan is extra image area around the four edges of a video image that is not normally seen by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube (CRT).
Early televisions varied in their displayable area because of manufacturing tolerance problems. There were also effects from the early design limitations of linear power supplies, whose DC voltage was not regulated as well as in later switching-type power supplies. This would cause the image to shrink when AC power 'browned out', as well as a process called blooming, where the image size increased slightly when a brighter overall picture was displayed. Because of this, TV producers could not be certain where the visible edges of the image would be. In order to cope with this, they defined three areas:[1]
Title safe: An area visible by all reasonably maintained sets, where text was certain not to be cut off.
Action safe: A larger area that represented where a "perfect" set (with high precision to allow less overscanning) would cut the image off.
Overscan: The full image area to the electronic edge of the signal.
A significant number of people would still see some of the Overscan area, so while nothing important to a scene could be placed there, it also had to be kept free of microphones, stage hands, and other distractions. Studio monitors and camera viewfinders can be set to show this area, so that producers and directors can make certain it is clear. When activated, this mode is called underscan.[2]
Analog to digital resolution issues 720 vs. 702 or 704
PAL - 702 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (702 can be either).
NTSC - 704 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (704 can be either).
625 / 525 or 576 / 480
In broadcasting, analogue systems count the lines not used for the visible picture, whereas the digital systems only bother to encode (and compress) content that may contain something to see.
The 625 (PAL) and 525 (NTSC) line areas therefore contain even more to overscan, which can be seen when vertical hold is lost and the picture rolls.[citation needed]
A large part of the vertical overscan available in analogue only, known as the vertical blanking interval, can be used for older forms of analogue datacasting such as Teletext services (like Ceefex and subtitling in the UK). The equivalent service on Digital television does not employ overscan and instead often uses MHEG.[citation needed]
Horizontally, the difference between 702/704 and 720 is referred to as nominal analogue blanking. 480 vs 486
The 525-line system originally contained 486 lines of picture, not 480.
Digital foundations to most storage and transmission systems since the early 1990s have meant that analogue NTSC has only been expected to have 480 lines of picture.[citation needed]
How this affects the interpretation of "the 4:3 ratio" as equal to 704x480 or 704x486 is unclear, but the VGA standard of 640x480 has had a large impact.[citation needed]
CRT legacy. New model 1:1 sample to pixel (but reality usually involves scaling). Need to explicitly state SAR in video.
“Hypothetical reference display”.
Black Padding
Horizontal Subsampling
4:2:0, 4:1:1, 1440h, etc.
Sample aspect ratio is changed from the norm. See anamorphic Squeeze, subsample the horizontal to match aspect ratio of non-square pixels.
Quantization range
e.g. 16-235, 0-255, +/-128
Color space
Rec 601, 709; negative coefficients
50 Hz
Professional conversion tools exist but results are just okay Input by SPE
Consider building a progressive frame, then output converted interlace frame
Standardizing on 24p and 60i for as line standards allows content to be used globally on modern equipment (external displays) Input by Microsoft
Restrict 50Hz Contents
Allow 50Hz Content and devices in 50Hz Regions (Both Contents & Devices Regionally optional) Allow 50Hz Content Worldwide with a Warning (Contents Regionally optional, Devices mandatory) Playback of 25i content on 60Hz interfaces/displays
Gamma curve, render intent, display adaptation
Frame rates
15.00p, 23.97p, 25.00i, 29.97i/p, 50.00p, 59.97i/p (1000/1001 video rates)
Any frame rate is OK on a self contained device with decoupled refresh or multisync; but NTSC, PAL, HDMI, etc. video connections have limited frame rate options.
Typically, STB can output 24Hz to new displays, or 30i to old (3:2 pulldown)
Typically STB can output 24Hz with 3:2 or +4% to 50/60 Hz displays; problem is 25i content to 60Hz only displays. Devices can insert pulldown
Setup, color space, 3:2 pulldown, deinterlace, crop, p/s, letterbox, pillarbox, tiltscan, cylindrical stretch
Output signal limitations: e.g. 1280x720 may require 1366x720, etc. connection to allow “Overscan” cropping and 1:1 sample to pixel mapping (without scaling and filtering)
Progressive or Interlacing
Interlaced temporal sub-sampling, filtering
Gamma curve, render intent, display adaptation
Picture Aspect Ratio - Active Picture
TV - 1.33 (4:3), 1.78 (16:9)
Movies – 1.33 (4:3), 1.85, 2.35, 2.40 Common aspect ratios:
1.33 (4:3 TV), 1.78 (16:9 TV), 1.85 2.0, 2.33, 2.4(film), 16:9 anamorphic 708x483 SMPTE D1 display aperture
704x480 ATSC 4:3? 720x480 DVD 4:3?
The aspect ratio of an image is its width divided by its height. Aspect ratios are mathematically expressed as x :y (pronounced
"x-to-y") and x×y (pronounced "x-by-y"). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1[1]. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras, previously only commonly seen in professional cameras, 16:9[2][3]. Other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used in photography as well.
Converting formats of unequal ratios is done by either cropping the original image to the receiving format's aspect ratio
(zooming), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, or by distorting the image to fill the receiving format's ratio. Cinematographic aspect ratios are usually denoted as a decimal fraction width to unit height, while videographic aspect ratios are usually denoted by ratios of whole numbers.
Resolution
The display resolution of a digital television or display typically refers to the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays.
Televisions are of the following resolutions:
SDTV: 480i (NTSC, 720×480 split into two 240-line fields) SDTV: 576i (PAL, 720×576 split into two 288-line fields) EDTV: 480p (NTSC, 720×480)
EDTV: 576p (PAL, 720×576) HDTV: 720p (1280×720)
HDTV: 1080i (1280×1080, 1440×1080, or 1920×1080 split into two 540-line fields) HDTV: 1080p (1920×1080 progressive scan)
Computers have higher resolutions. Currently, 1024×768 is regarded as an acceptable default. As of July, 2002, 1024×768 Extended Graphics Array was the most common display resolution.[1][2] Many web sites and multimedia products were re- designed from the previous 800×600 format to the higher 1024×768-optimized layout. The validity of this method of gathering statistics is diminishing, however, as LCD monitors have only one native display resolution - the highest available on that particular monitor. When users select a lower resolution, the lower resolution is reported to the statistics gathering website. This is useful if you want to know what resolution the user is seeing (which most web designers want to know), but it does not tell you the highest resolution the monitor is capable of displaying. Nevertheless, the actual number of pixels in front of the user has not changed. Instead, interpolation in the monitor causes the picture to become fuzzy as it attempts to display an image of the wrong resolution by scaling it.
The availability of inexpensive LCD monitors has made the 5:4 aspect ratio resolution of 1280×1024 more popular for desktop usage. Many computer users including CAD users, graphic artists and video game players run their computers at 1600×1200 resolution (UXGA, Ultra-eXtended) or higher if they have the necessary equipment. Other recently available resolutions include oversize aspects like 1400×1050 SXGA+ and wide aspects like 1280×720 WXGA, 1680×1050 WSXGA+, and 1920×1200 WUXGA. A new HD resolution of 2560×1600 WQXGA has been released mainly in 30" LCD monitors. Special monitors for medical diagnostic work are using 3280×2048 WQSXGA, which is the current maximum resolution available in a single monitor. The most common computer display resolutions are as follows:[
Overscan
Overscan is extra image area around the four edges of a video image that is not normally seen by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube (CRT).
Early televisions varied in their displayable area because of manufacturing tolerance problems. There were also effects from the early design limitations of linear power supplies, whose DC voltage was not regulated as well as in later switching-type power supplies. This would cause the image to shrink when AC power 'browned out', as well as a process called blooming, where the image size increased slightly when a brighter overall picture was displayed. Because of this, TV producers could not be certain where the visible edges of the image would be. In order to cope with this, they defined three areas:[1]
Title safe: An area visible by all reasonably maintained sets, where text was certain not to be cut off.
Action safe: A larger area that represented where a "perfect" set (with high precision to allow less overscanning) would cut the image off.
Overscan: The full image area to the electronic edge of the signal.
A significant number of people would still see some of the Overscan area, so while nothing important to a scene could be placed there, it also had to be kept free of microphones, stage hands, and other distractions. Studio monitors and camera viewfinders can be set to show this area, so that producers and directors can make certain it is clear. When activated, this mode is called underscan.[2]
Analog to digital resolution issues 720 vs. 702 or 704
PAL - 702 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (702 can be either).
NTSC - 704 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (704 can be either).
625 / 525 or 576 / 480
In broadcasting, analogue systems count the lines not used for the visible picture, whereas the digital systems only bother to encode (and compress) content that may contain something to see.
The 625 (PAL) and 525 (NTSC) line areas therefore contain even more to overscan, which can be seen when vertical hold is lost and the picture rolls.[citation needed]
A large part of the vertical overscan available in analogue only, known as the vertical blanking interval, can be used for older forms of analogue datacasting such as Teletext services (like Ceefex and subtitling in the UK). The equivalent service on Digital television does not employ overscan and instead often uses MHEG.[citation needed]
Horizontally, the difference between 702/704 and 720 is referred to as nominal analogue blanking. 480 vs 486
The 525-line system originally contained 486 lines of picture, not 480.
Digital foundations to most storage and transmission systems since the early 1990s have meant that analogue NTSC has only been expected to have 480 lines of picture.[citation needed]
How this affects the interpretation of "the 4:3 ratio" as equal to 704x480 or 704x486 is unclear, but the VGA standard of 640x480 has had a large impact.[citation needed]
CRT legacy. New model 1:1 sample to pixel (but reality usually involves scaling). Need to explicitly state SAR in video.
“Hypothetical reference display”.
Black Padding
Horizontal Subsampling
4:2:0, 4:1:1, 1440h, etc.
Sample aspect ratio is changed from the norm. See anamorphic Squeeze, subsample the horizontal to match aspect ratio of non-square pixels.
Quantization range
e.g. 16-235, 0-255, +/-128
Color space
Rec 601, 709; negative coefficients
50 Hz
Professional conversion tools exist but results are just okay Input by SPE
Consider building a progressive frame, then output converted interlace frame
Standardizing on 24p and 60i for as line standards allows content to be used globally on modern equipment (external displays) Input by Microsoft
Restrict 50Hz Contents
Allow 50Hz Content and devices in 50Hz Regions (Both Contents & Devices Regionally optional) Allow 50Hz Content Worldwide with a Warning (Contents Regionally optional, Devices mandatory) Playback of 25i content on 60Hz interfaces/displays
Gamma curve, render intent, display adaptation
Frame rates
15.00p, 23.97p, 25.00i, 29.97i/p, 50.00p, 59.97i/p (1000/1001 video rates)
Any frame rate is OK on a self contained device with decoupled refresh or multisync; but NTSC, PAL, HDMI, etc. video connections have limited frame rate options.
Typically, STB can output 24Hz to new displays, or 30i to old (3:2 pulldown)
Typically STB can output 24Hz with 3:2 or +4% to 50/60 Hz displays; problem is 25i content to 60Hz only displays. Devices can insert pulldown
Setup, color space, 3:2 pulldown, deinterlace, crop, p/s, letterbox, pillarbox, tiltscan, cylindrical stretch
Output signal limitations: e.g. 1280x720 may require 1366x720, etc. connection to allow “Overscan” cropping and 1:1 sample to pixel mapping (without scaling and filtering)
Progressive or Interlacing
Interlaced temporal sub-sampling, filtering
Gamma curve, render intent, display adaptation
Picture Aspect Ratio - Active Picture
TV - 1.33 (4:3), 1.78 (16:9)
Movies – 1.33 (4:3), 1.85, 2.35, 2.40 Common aspect ratios:
1.33 (4:3 TV), 1.78 (16:9 TV), 1.85 2.0, 2.33, 2.4(film), 16:9 anamorphic 708x483 SMPTE D1 display aperture
704x480 ATSC 4:3? 720x480 DVD 4:3?
The aspect ratio of an image is its width divided by its height. Aspect ratios are mathematically expressed as x :y (pronounced
"x-to-y") and x×y (pronounced "x-by-y"). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1[1]. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras, previously only commonly seen in professional cameras, 16:9[2][3]. Other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used in photography as well.
Converting formats of unequal ratios is done by either cropping the original image to the receiving format's aspect ratio
(zooming), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, or by distorting the image to fill the receiving format's ratio. Cinematographic aspect ratios are usually denoted as a decimal fraction width to unit height, while videographic aspect ratios are usually denoted by ratios of whole numbers.
Resolution
The display resolution of a digital television or display typically refers to the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays.
Televisions are of the following resolutions:
SDTV: 480i (NTSC, 720×480 split into two 240-line fields) SDTV: 576i (PAL, 720×576 split into two 288-line fields) EDTV: 480p (NTSC, 720×480)
EDTV: 576p (PAL, 720×576) HDTV: 720p (1280×720)
HDTV: 1080i (1280×1080, 1440×1080, or 1920×1080 split into two 540-line fields) HDTV: 1080p (1920×1080 progressive scan)
Computers have higher resolutions. Currently, 1024×768 is regarded as an acceptable default. As of July, 2002, 1024×768 Extended Graphics Array was the most common display resolution.[1][2] Many web sites and multimedia products were re- designed from the previous 800×600 format to the higher 1024×768-optimized layout. The validity of this method of gathering statistics is diminishing, however, as LCD monitors have only one native display resolution - the highest available on that particular monitor. When users select a lower resolution, the lower resolution is reported to the statistics gathering website. This is useful if you want to know what resolution the user is seeing (which most web designers want to know), but it does not tell you the highest resolution the monitor is capable of displaying. Nevertheless, the actual number of pixels in front of the user has not changed. Instead, interpolation in the monitor causes the picture to become fuzzy as it attempts to display an image of the wrong resolution by scaling it.
The availability of inexpensive LCD monitors has made the 5:4 aspect ratio resolution of 1280×1024 more popular for desktop usage. Many computer users including CAD users, graphic artists and video game players run their computers at 1600×1200 resolution (UXGA, Ultra-eXtended) or higher if they have the necessary equipment. Other recently available resolutions include oversize aspects like 1400×1050 SXGA+ and wide aspects like 1280×720 WXGA, 1680×1050 WSXGA+, and 1920×1200 WUXGA. A new HD resolution of 2560×1600 WQXGA has been released mainly in 30" LCD monitors. Special monitors for medical diagnostic work are using 3280×2048 WQSXGA, which is the current maximum resolution available in a single monitor. The most common computer display resolutions are as follows:[
Overscan
Overscan is extra image area around the four edges of a video image that is not normally seen by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube (CRT).
Early televisions varied in their displayable area because of manufacturing tolerance problems. There were also effects from the early design limitations of linear power supplies, whose DC voltage was not regulated as well as in later switching-type power supplies. This would cause the image to shrink when AC power 'browned out', as well as a process called blooming, where the image size increased slightly when a brighter overall picture was displayed. Because of this, TV producers could not be certain where the visible edges of the image would be. In order to cope with this, they defined three areas:[1]
Title safe: An area visible by all reasonably maintained sets, where text was certain not to be cut off.
Action safe: A larger area that represented where a "perfect" set (with high precision to allow less overscanning) would cut the image off.
Overscan: The full image area to the electronic edge of the signal.
A significant number of people would still see some of the Overscan area, so while nothing important to a scene could be placed there, it also had to be kept free of microphones, stage hands, and other distractions. Studio monitors and camera viewfinders can be set to show this area, so that producers and directors can make certain it is clear. When activated, this mode is called underscan.[2]
Analog to digital resolution issues 720 vs. 702 or 704
PAL - 702 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (702 can be either).
NTSC - 704 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (704 can be either).
625 / 525 or 576 / 480
In broadcasting, analogue systems count the lines not used for the visible picture, whereas the digital systems only bother to encode (and compress) content that may contain something to see.
The 625 (PAL) and 525 (NTSC) line areas therefore contain even more to overscan, which can be seen when vertical hold is lost and the picture rolls.[citation needed]
A large part of the vertical overscan available in analogue only, known as the vertical blanking interval, can be used for older forms of analogue datacasting such as Teletext services (like Ceefex and subtitling in the UK). The equivalent service on Digital television does not employ overscan and instead often uses MHEG.[citation needed]
Horizontally, the difference between 702/704 and 720 is referred to as nominal analogue blanking. 480 vs 486
The 525-line system originally contained 486 lines of picture, not 480.
Digital foundations to most storage and transmission systems since the early 1990s have meant that analogue NTSC has only been expected to have 480 lines of picture.[citation needed]
How this affects the interpretation of "the 4:3 ratio" as equal to 704x480 or 704x486 is unclear, but the VGA standard of 640x480 has had a large impact.[citation needed]
CRT legacy. New model 1:1 sample to pixel (but reality usually involves scaling). Need to explicitly state SAR in video.
“Hypothetical reference display”.
Black Padding
Horizontal Subsampling
4:2:0, 4:1:1, 1440h, etc.
Sample aspect ratio is changed from the norm. See anamorphic Squeeze, subsample the horizontal to match aspect ratio of non-square pixels.
Quantization range
e.g. 16-235, 0-255, +/-128
Color space
Rec 601, 709; negative coefficients
50 Hz
Professional conversion tools exist but results are just okay Input by SPE
Consider building a progressive frame, then output converted interlace frame
Standardizing on 24p and 60i for as line standards allows content to be used globally on modern equipment (external displays) Input by Microsoft
Restrict 50Hz Contents
Allow 50Hz Content and devices in 50Hz Regions (Both Contents & Devices Regionally optional) Allow 50Hz Content Worldwide with a Warning (Contents Regionally optional, Devices mandatory) Playback of 25i content on 60Hz interfaces/displays
Gamma curve, render intent, display adaptation
Frame rates
15.00p, 23.97p, 25.00i, 29.97i/p, 50.00p, 59.97i/p (1000/1001 video rates)
Any frame rate is OK on a self contained device with decoupled refresh or multisync; but NTSC, PAL, HDMI, etc. video connections have limited frame rate options.
Typically, STB can output 24Hz to new displays, or 30i to old (3:2 pulldown)
Typically STB can output 24Hz with 3:2 or +4% to 50/60 Hz displays; problem is 25i content to 60Hz only displays. Devices can insert pulldown
Setup, color space, 3:2 pulldown, deinterlace, crop, p/s, letterbox, pillarbox, tiltscan, cylindrical stretch
Output signal limitations: e.g. 1280x720 may require 1366x720, etc. connection to allow “Overscan” cropping and 1:1 sample to pixel mapping (without scaling and filtering)
Progressive or Interlacing
Interlaced temporal sub-sampling, filtering
Gamma curve, render intent, display adaptation
Picture Aspect Ratio - Active Picture
TV - 1.33 (4:3), 1.78 (16:9)
Movies – 1.33 (4:3), 1.85, 2.35, 2.40 Common aspect ratios:
1.33 (4:3 TV), 1.78 (16:9 TV), 1.85 2.0, 2.33, 2.4(film), 16:9 anamorphic 708x483 SMPTE D1 display aperture
704x480 ATSC 4:3? 720x480 DVD 4:3?
The aspect ratio of an image is its width divided by its height. Aspect ratios are mathematically expressed as x :y (pronounced
"x-to-y") and x×y (pronounced "x-by-y"). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1[1]. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras, previously only commonly seen in professional cameras, 16:9[2][3]. Other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used in photography as well.
Converting formats of unequal ratios is done by either cropping the original image to the receiving format's aspect ratio
(zooming), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, or by distorting the image to fill the receiving format's ratio. Cinematographic aspect ratios are usually denoted as a decimal fraction width to unit height, while videographic aspect ratios are usually denoted by ratios of whole numbers.
Resolution
The display resolution of a digital television or display typically refers to the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays.
Televisions are of the following resolutions:
SDTV: 480i (NTSC, 720×480 split into two 240-line fields) SDTV: 576i (PAL, 720×576 split into two 288-line fields) EDTV: 480p (NTSC, 720×480)
EDTV: 576p (PAL, 720×576) HDTV: 720p (1280×720)
HDTV: 1080i (1280×1080, 1440×1080, or 1920×1080 split into two 540-line fields) HDTV: 1080p (1920×1080 progressive scan)
Computers have higher resolutions. Currently, 1024×768 is regarded as an acceptable default. As of July, 2002, 1024×768 Extended Graphics Array was the most common display resolution.[1][2] Many web sites and multimedia products were re- designed from the previous 800×600 format to the higher 1024×768-optimized layout. The validity of this method of gathering statistics is diminishing, however, as LCD monitors have only one native display resolution - the highest available on that particular monitor. When users select a lower resolution, the lower resolution is reported to the statistics gathering website. This is useful if you want to know what resolution the user is seeing (which most web designers want to know), but it does not tell you the highest resolution the monitor is capable of displaying. Nevertheless, the actual number of pixels in front of the user has not changed. Instead, interpolation in the monitor causes the picture to become fuzzy as it attempts to display an image of the wrong resolution by scaling it.
The availability of inexpensive LCD monitors has made the 5:4 aspect ratio resolution of 1280×1024 more popular for desktop usage. Many computer users including CAD users, graphic artists and video game players run their computers at 1600×1200 resolution (UXGA, Ultra-eXtended) or higher if they have the necessary equipment. Other recently available resolutions include oversize aspects like 1400×1050 SXGA+ and wide aspects like 1280×720 WXGA, 1680×1050 WSXGA+, and 1920×1200 WUXGA. A new HD resolution of 2560×1600 WQXGA has been released mainly in 30" LCD monitors. Special monitors for medical diagnostic work are using 3280×2048 WQSXGA, which is the current maximum resolution available in a single monitor. The most common computer display resolutions are as follows:[
Overscan
Overscan is extra image area around the four edges of a video image that is not normally seen by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube (CRT).
Early televisions varied in their displayable area because of manufacturing tolerance problems. There were also effects from the early design limitations of linear power supplies, whose DC voltage was not regulated as well as in later switching-type power supplies. This would cause the image to shrink when AC power 'browned out', as well as a process called blooming, where the image size increased slightly when a brighter overall picture was displayed. Because of this, TV producers could not be certain where the visible edges of the image would be. In order to cope with this, they defined three areas:[1]
Title safe: An area visible by all reasonably maintained sets, where text was certain not to be cut off.
Action safe: A larger area that represented where a "perfect" set (with high precision to allow less overscanning) would cut the image off.
Overscan: The full image area to the electronic edge of the signal.
A significant number of people would still see some of the Overscan area, so while nothing important to a scene could be placed there, it also had to be kept free of microphones, stage hands, and other distractions. Studio monitors and camera viewfinders can be set to show this area, so that producers and directors can make certain it is clear. When activated, this mode is called underscan.[2]
Analog to digital resolution issues 720 vs. 702 or 704
PAL - 702 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (702 can be either).
NTSC - 704 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (704 can be either).
625 / 525 or 576 / 480
In broadcasting, analogue systems count the lines not used for the visible picture, whereas the digital systems only bother to encode (and compress) content that may contain something to see.
The 625 (PAL) and 525 (NTSC) line areas therefore contain even more to overscan, which can be seen when vertical hold is lost and the picture rolls.[citation needed]
A large part of the vertical overscan available in analogue only, known as the vertical blanking interval, can be used for older forms of analogue datacasting such as Teletext services (like Ceefex and subtitling in the UK). The equivalent service on Digital television does not employ overscan and instead often uses MHEG.[citation needed]
Horizontally, the difference between 702/704 and 720 is referred to as nominal analogue blanking. 480 vs 486
The 525-line system originally contained 486 lines of picture, not 480.
Digital foundations to most storage and transmission systems since the early 1990s have meant that analogue NTSC has only been expected to have 480 lines of picture.[citation needed]
How this affects the interpretation of "the 4:3 ratio" as equal to 704x480 or 704x486 is unclear, but the VGA standard of 640x480 has had a large impact.[citation needed]
CRT legacy. New model 1:1 sample to pixel (but reality usually involves scaling). Need to explicitly state SAR in video.
“Hypothetical reference display”.
Black Padding
Horizontal Subsampling
4:2:0, 4:1:1, 1440h, etc.
Sample aspect ratio is changed from the norm. See anamorphic Squeeze, subsample the horizontal to match aspect ratio of non-square pixels.
Quantization range
e.g. 16-235, 0-255, +/-128
Color space
Rec 601, 709; negative coefficients
50 Hz
Professional conversion tools exist but results are just okay Input by SPE
Consider building a progressive frame, then output converted interlace frame
Standardizing on 24p and 60i for as line standards allows content to be used globally on modern equipment (external displays) Input by Microsoft
Restrict 50Hz Contents
Allow 50Hz Content and devices in 50Hz Regions (Both Contents & Devices Regionally optional) Allow 50Hz Content Worldwide with a Warning (Contents Regionally optional, Devices mandatory) Playback of 25i content on 60Hz interfaces/displays
Gamma curve, render intent, display adaptation
Frame rates
15.00p, 23.97p, 25.00i, 29.97i/p, 50.00p, 59.97i/p (1000/1001 video rates)
Any frame rate is OK on a self contained device with decoupled refresh or multisync; but NTSC, PAL, HDMI, etc. video connections have limited frame rate options.
Typically, STB can output 24Hz to new displays, or 30i to old (3:2 pulldown)
Typically STB can output 24Hz with 3:2 or +4% to 50/60 Hz displays; problem is 25i content to 60Hz only displays. Devices can insert pulldown
Setup, color space, 3:2 pulldown, deinterlace, crop, p/s, letterbox, pillarbox, tiltscan, cylindrical stretch
Output signal limitations: e.g. 1280x720 may require 1366x720, etc. connection to allow “Overscan” cropping and 1:1 sample to pixel mapping (without scaling and filtering)
Progressive or Interlacing
Interlaced temporal sub-sampling, filtering
Gamma curve, render intent, display adaptation
Picture Aspect Ratio - Active Picture
TV - 1.33 (4:3), 1.78 (16:9)
Movies – 1.33 (4:3), 1.85, 2.35, 2.40 Common aspect ratios:
1.33 (4:3 TV), 1.78 (16:9 TV), 1.85 2.0, 2.33, 2.4(film), 16:9 anamorphic 708x483 SMPTE D1 display aperture
704x480 ATSC 4:3? 720x480 DVD 4:3?
The aspect ratio of an image is its width divided by its height. Aspect ratios are mathematically expressed as x :y (pronounced
"x-to-y") and x×y (pronounced "x-by-y"). The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1[1]. Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. Other cinema and video aspect ratios exist, but are used infrequently. In still camera photography, the most common aspect ratios are 4:3, 3:2, and more recently being found in consumer cameras, previously only commonly seen in professional cameras, 16:9[2][3]. Other aspect ratios, such as 5:4, 6:7, and 1:1 (square format), are used in photography as well.
Converting formats of unequal ratios is done by either cropping the original image to the receiving format's aspect ratio
(zooming), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, or by distorting the image to fill the receiving format's ratio. Cinematographic aspect ratios are usually denoted as a decimal fraction width to unit height, while videographic aspect ratios are usually denoted by ratios of whole numbers.
Resolution
The display resolution of a digital television or display typically refers to the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays.
Televisions are of the following resolutions:
SDTV: 480i (NTSC, 720×480 split into two 240-line fields) SDTV: 576i (PAL, 720×576 split into two 288-line fields) EDTV: 480p (NTSC, 720×480)
EDTV: 576p (PAL, 720×576) HDTV: 720p (1280×720)
HDTV: 1080i (1280×1080, 1440×1080, or 1920×1080 split into two 540-line fields) HDTV: 1080p (1920×1080 progressive scan)
Computers have higher resolutions. Currently, 1024×768 is regarded as an acceptable default. As of July, 2002, 1024×768 Extended Graphics Array was the most common display resolution.[1][2] Many web sites and multimedia products were re- designed from the previous 800×600 format to the higher 1024×768-optimized layout. The validity of this method of gathering statistics is diminishing, however, as LCD monitors have only one native display resolution - the highest available on that particular monitor. When users select a lower resolution, the lower resolution is reported to the statistics gathering website. This is useful if you want to know what resolution the user is seeing (which most web designers want to know), but it does not tell you the highest resolution the monitor is capable of displaying. Nevertheless, the actual number of pixels in front of the user has not changed. Instead, interpolation in the monitor causes the picture to become fuzzy as it attempts to display an image of the wrong resolution by scaling it.
The availability of inexpensive LCD monitors has made the 5:4 aspect ratio resolution of 1280×1024 more popular for desktop usage. Many computer users including CAD users, graphic artists and video game players run their computers at 1600×1200 resolution (UXGA, Ultra-eXtended) or higher if they have the necessary equipment. Other recently available resolutions include oversize aspects like 1400×1050 SXGA+ and wide aspects like 1280×720 WXGA, 1680×1050 WSXGA+, and 1920×1200 WUXGA. A new HD resolution of 2560×1600 WQXGA has been released mainly in 30" LCD monitors. Special monitors for medical diagnostic work are using 3280×2048 WQSXGA, which is the current maximum resolution available in a single monitor. The most common computer display resolutions are as follows:[
Overscan
Overscan is extra image area around the four edges of a video image that is not normally seen by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube (CRT).
Early televisions varied in their displayable area because of manufacturing tolerance problems. There were also effects from the early design limitations of linear power supplies, whose DC voltage was not regulated as well as in later switching-type power supplies. This would cause the image to shrink when AC power 'browned out', as well as a process called blooming, where the image size increased slightly when a brighter overall picture was displayed. Because of this, TV producers could not be certain where the visible edges of the image would be. In order to cope with this, they defined three areas:[1]
Title safe: An area visible by all reasonably maintained sets, where text was certain not to be cut off.
Action safe: A larger area that represented where a "perfect" set (with high precision to allow less overscanning) would cut the image off.
Overscan: The full image area to the electronic edge of the signal.
A significant number of people would still see some of the Overscan area, so while nothing important to a scene could be placed there, it also had to be kept free of microphones, stage hands, and other distractions. Studio monitors and camera viewfinders can be set to show this area, so that producers and directors can make certain it is clear. When activated, this mode is called underscan.[2]
Analog to digital resolution issues 720 vs. 702 or 704
PAL - 702 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (702 can be either).
NTSC - 704 is the width of analogue, not digital; the definition of what is 4:3, and what is 16:9, derives from here (704 can be either).
625 / 525 or 576 / 480
In broadcasting, analogue systems count the lines not used for the visible picture, whereas the digital systems only bother to encode (and compress) content that may contain something to see.
The 625 (PAL) and 525 (NTSC) line areas therefore contain even more to overscan, which can be seen when vertical hold is lost and the picture rolls.[citation needed]
A large part of the vertical overscan available in analogue only, known as the vertical blanking interval, can be used for older forms of analogue datacasting such as Teletext services (like Ceefex and subtitling in the UK). The equivalent service on Digital television does not employ overscan and instead often uses MHEG.[citation needed]
Horizontally, the difference between 702/704 and 720 is referred to as nominal analogue blanking. 480 vs 486
The 525-line system originally contained 486 lines of picture, not 480.
Digital foundations to most storage and transmission systems since the early 1990s have meant that analogue NTSC has only been expected to have 480 lines of picture.[citation needed]
How this affects the interpretation of "the 4:3 ratio" as equal to 704x480 or 704x486 is unclear, but the VGA standard of 640x480 has had a large impact.[citation needed]
CRT legacy. New model 1:1 sample to pixel (but reality usually involves scaling). Need to explicitly state SAR in video.
“Hypothetical reference display”.
Black Padding
Horizontal Subsampling
4:2:0, 4:1:1, 1440h, etc.
Sample aspect ratio is changed from the norm. See anamorphic Squeeze, subsample the horizontal to match aspect ratio of non-square pixels.
Quantization range
e.g. 16-235, 0-255, +/-128
Color space
Rec 601, 709; negative coefficients
50 Hz
Professional conversion tools exist but results are just okay Input by SPE
Consider building a progressive frame, then output converted interlace frame
Standardizing on 24p and 60i for as line standards allows content to be used globally on modern equipment (external displays) Input by Microsoft
Restrict 50Hz Contents
Allow 50Hz Content and devices in 50Hz Regions (Both Contents & Devices Regionally optional) Allow 50Hz Content Worldwide with a Warning (Contents Regionally optional, Devices mandatory) Playback of 25i content on 60Hz interfaces/displays
Gamma curve, render intent, display adaptation
Frame rates
15.00p, 23.97p, 25.00i, 29.97i/p, 50.00p, 59.97i/p (1000/1001 video rates)
Any frame rate is OK on a self contained device with decoupled refresh or multisync; but NTSC, PAL, HDMI, etc. video connections have limited frame rate options.
Typically, STB can output 24Hz to new displays, or 30i to old (3:2 pulldown)
Typically STB can output 24Hz with 3:2 or +4% to 50/60 Hz displays; problem is 25i content to 60Hz only displays. Devices can insert pulldown
Setup, color space, 3:2 pulldown, deinterlace, crop, p/s, letterbox, pillarbox, tiltscan, cylindrical stretch
Output signal limitations: e.g. 1280x720 may require 1366x720, etc. connection to allow “Overscan” cropping and 1:1 sample to pixel mapping (without scaling and filtering)
