"Digital Media Primer" Yue-Ling Wong, Copyright (c)2013 by Pearson Education, Inc. All rights reserved.

Chapter 6 Fundamentals of Digital Video Part 3 Digital Video Standards

In this lecture, you will learn: Video standards for: standard definition digital video high definition digital video digital televisions YUV color model Picture format notation

Digital Video Standards Standard definition High definition Digital Television

The Term DV Common simple abbreviation for digital video DV compression and DV format: specific types of digital video compression and format respectively In this textbook DV refers to the specific types of digital video DV is NOT used to abbreviate digital video

Standard Definition DV25 Format Pixel Dimensions 720  480 (NTSC) Frame Aspect Ratio 4:3 16:9 Pixel Aspect Ratio 0.9 1.2 Data Rate Total (video + audio + control information): 3.6 megabytes per second (MB/s), i.e. about 4.6 minutes of video per gigabyte of storage space Video data only: 25 megabits per second (Mbps); compressed at a fixed rate of 5 :1 Color Sampling Method YUV 4:1:1 Audio Setting Sampling rate and bit depth: Two options: 48 kHz, 16-bit 32 kHz, 12-bit

Standard Definition DV25 Format widescreen format Pixel Dimensions 720  480 (NTSC) Frame Aspect Ratio 4:3 16:9 Pixel Aspect Ratio 0.9 1.2 Data Rate Total (video + audio + control information): 3.6 megabytes per second (MB/s), i.e. about 4.6 minutes of video per gigabyte of storage space Video data only: 25 megabits per second (Mbps); compressed at a fixed rate of 5 :1 Color Sampling Method YUV 4:1:1 Audio Setting Sampling rate and bit depth: Two options: 48 kHz, 16-bit 32 kHz, 12-bit

Standard Definition DV25 Format Pixel Dimensions 720  480 (NTSC) Frame Aspect Ration 4:3 16:9 Pixel Aspect Ratio 0.9 1.2 Data Rate Total (video + audio + control information): 3.6 megabytes per second (MB/s), i.e. about 4.6 minutes of video per gigabyte of storage space Video data only: 25 megabits per second (Mbps); compressed at a fixed rate of 5 :1 Color Sampling Method YUV 4:1:1 Audio Setting Sampling rate and bit depth: Two options: 48 kHz, 16-bit 32 kHz, 12-bit

YUV A luminance-chrominance color model A color model that digital video uses to represent the color of each pixel Y: luminance (brightness) component U: a chrominance (color or hue) component V : a chrominance (color or hue) component

Advantages Using YUV over RGB The human eye is more sensitive to changes of the luminance than it is to chrominance changes. Thus, with YUV, we can assign fewer bits to store the chrominance components. Fewer bits means smaller file size.

Loss of Color Information Some chrominance data are discarded in order to reduce bits. Chroma subsampling or color subsampling

The Three Numbers in YUV Ratio of numbers of samples of Y : U : V for each group of 4 pixels 4:4:4 4:2:2 4:2:0 4:1:1

YUV 4:4:4 YUV No. of samples of Y for each group of 4 pixels No. of samples of U for each group of 4 pixels No. of samples of V for each group of 4 pixels Total no. of YUV samples of for each group of 4 pixels Saving in storage 4:4:4 4 4+4+4=12 None (no compression, i.e., no subsampling)

Used in Digital Betacam, DVCPRO HD, AVC-Intra YUV 4:2:2 YUV No. of samples of Y for each group of 4 pixels No. of samples of U for each group of 4 pixels No. of samples of V for each group of 4 pixels Total no. of YUV samples of for each group of 4 pixels Saving in storage 4:2:2 4 2 4+2+2=8 Reduced 4 samples out of 12 samples, i.e. 33% compression Used in Digital Betacam, DVCPRO HD, AVC-Intra

Used in HDV, AVCHD, AVC-Intra, MPEG-1, DVD MPEG-2, PAL DV YUV 4:2:0 YUV No. of samples of Y for each group of 4 pixels No. of samples of U for each group of 4 pixels No. of samples of V for each group of 4 pixels Total no. of YUV samples of for each group of 4 pixels Saving in storage 4:2:0 4 2 4+2+0=6 Reduced 6 samples out of 12 samples, i.e. 50% compression Used in HDV, AVCHD, AVC-Intra, MPEG-1, DVD MPEG-2, PAL DV

YUV 4:1:1 Used in NTSC DV YUV No. of samples of Y for each group of 4 pixels No. of samples of U for each group of 4 pixels No. of samples of V for each group of 4 pixels Total no. of YUV samples of for each group of 4 pixels Saving in storage 4:2:0 4 1 4+1+1=6 Reduced 6 samples out of 12 samples, i.e. 50% compression Used in NTSC DV

High Definition Common high definition video formats: HDV DVCPro HD AVCHD AVC-Intra Different video cameras support different high def. format The name of the supported format is printed on the body of the video camera

HDV

AVCHD

DVCPRO HD

Commalities Among High Definition Specifications Frame aspect ratio: 16:9 Picture formats: 1080 and/or 720 interlace and/or progress For 1080, possible frame sizes: 1440  1080 (pixel aspect ratio: 1.333) 1920  1080 (pixel aspect ratio: 1.0) For 720, possible frame sizes: 960  720 (pixel aspect ratio: 1.333) 1280  720 (pixel aspect ratio: 1.0) Color sampling methods: 4:2:0 4:2:2

High Definition HDV Format Picture Format 720/25p, 720/30p, 720/50p, 720/60p 1080/50i 1080/60i Pixel Dimensions 1280  720 1440  1080 Frame Aspect Ration 16:9 Pixel Aspect Ratio 1.0 1.33 Data Rate Video data only: approx. 19 Mbps approx. 25 Mbps Color Sampling Method YUV 4:2:0 Audio Setting Sampling rate and bit depth: 48 kHz 16-bit Bit rate after compression: 384 kbps

Picture Format Notation 1080 / 60 i "i": interlaced "p": progressive frame/field frequency frame height

Frame Size (Resolution) Comparison between Standard Definition and High Definition By viewing frame size

Frame Size (Resolution) Comparison between Standard Definition and High Definition By pixel dimensions

Frame Size (Resolution) Comparison between Standard Definition and High Definition A frame from a 1080i video

Frame Size (Resolution) Comparison between Standard Definition and High Definition Same frame as 720p

Same frame as standard definition DV wide-screen (16:9) Frame Size (Resolution) Comparison between Standard Definition and High Definition Same frame as standard definition DV wide-screen (16:9)

Same frame as standard definition DV standard 4:3 Frame Size (Resolution) Comparison between Standard Definition and High Definition Same frame as standard definition DV standard 4:3

Digital Television (DTV) Signals of DTV are broadcast and transmitted digitally Need a digital TV set to watch

Digital Television (DTV) Standard definition 704  480, 16:9 and 4:3, progressive and interlaced 640  480, 4:3, progressive and interlaced High definition 1920  1080, 16:9, progressive and interlaced 1280  720, 16:9, progressive and interlaced MPEG-2

Review Questions Note to instructor: Depending on your preference, you may want to go over the review questions at the end of this lecture as an instant review or at the beginning of next lecture to refresh students' memory of this lecture.

Review Question Chroma subsampling reduces the storage of pixel information by assigning fewer bits to store the ___ components. RGB luminance chrominance C

Review Question The format of chroma subsampling is designated with three numbers separated by colons (for example, 4:2:2) to represent ___. the ratio of red : green : blue the ratio of the luminance to the two chrominance components the ratio of the numbers of three different types of pixels hours : minutes : seconds B

Review Question True/False: 720  480 is the only frame size of NTSC standard definition digital video. True

Review Question The two possible pixel aspect ratios of the standard definition NTSC digital video format are ___ and ___. 0.9 1.0 1.2 1.333 1.67 A and C

Review Question The pixel aspect ratio of the widescreen format of the standard definition NTSC digital video is ___. 4:3 16:9 0.9 1.2 D

Review Question The frame aspect ratio of the widescreen format of the standard definition NTSC digital video is ___. 4:3 16:9 0.9 1.2 B

Review Question Standard definition DV camcorders support audio of ___. 32 kHz 44.1 kHz 48 kHz A and C

Review Question True/False: The signals of digital television are broadcast or transmitted digitally. True

Review Question True/False: The frame aspect ratio of HDTV formats is 16:9. True

Review Question HDTV is in ___ format. MPEG-1 MPEG-2 MPEG-3 MPEG-4 QuickTime AVI B

Review Question The frame size for NTSC standard definition DV is ___ pixels, and ___ pixels for the PAL system. 720  480; 720  480 720  576; 720  576 720  480; 720  576 720  576; 720  480 C

Review Question High definition video camcorders are available to record 720p and 1080i formats. The number in the format name--720 or 1080--designates the ___. data rate of the video width (in pixels) of the frame size height (in pixels) of the frame size ppi of the video none of the above; they are model numbers of different companies C

Review Question High definition video camcorders are available to record 720p and 1080i formats. The letters "p" and "i" in each format name stand for ___ and ___ respectively. pixels; inches professional; intermediate progressive; interlaced pixels per inch; inches per pixel C

Review Question True/False: The frame aspect ratio of all high definition video formats is 16:9. True

Review Question The two possible frame sizes of the 1080 format are ___ and ___. 1440  1080 1920  1080 1080  1440 1080  1920 A and B

Review Question The two possible frame sizes of the 720 format are ___ and ___. 960  720 1280  720 720 960 720 1280 A and B

Review Question The two possible pixel aspect ratios of the high definition video formats are ___ and ___. 0.9 1.0 1.2 1.333 1.67 B and D

Review Question The two possible color sampling methods of the common high definition video formats are ___ and ___. 4:4:4 4:2:2 4:2:0 4:1:1 B and C