Improving Quality of Video Networking

Transcription

1 Improving Quality of Video Networking Mohammad Ghanbari LFIEEE School of Computer Science and Electronic Engineering University of Essex, UK December 17-19, 2018

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3 Improving video networking quality Improving Video Compression Techniques Improving Channel Rate Allocation Improving Video Resolution Improving Video Generation and Display tools

4 Standard codecs ITU-T Standard H.261 (Version 1) H.261 (Version 2) H.263 H.263+ H Joint ITU-T/MPEG Standards H.262/MPEG-2 H.264/MPEG-4 AVC H.264/SVC H.265/HEVC MPEG Standard MPEG-1 MPEG-4 (Version 1) MPEG-4 (Version 2) AV1 - VVC

5 Early video codecs H.261 (1989) Network: Circuit switch, Channel rate: 1-30 Telephone channels (64-2 Mbit/s) Video resolution: CIF (360 pixels x 288 lines x 30 Frame/s) H.263 (1993) Wireless (3G) Channel rate: 20 Kbit/s Video resolution: QSIF (180 pixels x 144 lines x 10 Frames/s) H.263+, H.263++: advanced versions with more error resiliency

6 MPEG-1 (1991) Media: Storage on CD Roms (680 Mbytes) Data rate: 1 Mbit/s Video resolution: SIF (320 pixels x 288 lines x 25 frames/s) MPEG-2/H.262 (1993) Network: Broadcast: Digital terrestrial (DTT), Satellite (DVBs), as well as ATM network Channel rate: 2-3 Mbit/s The first codec in digital video transmission Video resolution: SD (720 pixels x 576 lines x 25 frames/s) H.262-SVC: includes scalable coding (Temporal, Spatial, SNR) for Error resiliency over ATM networks

7 Advanced video coding H.264/AVC (2003) Network: All (4G, DTT, DVBs, IP) Data rate: 20 Kbit/s (QSIF video) to 3-5 Mbit/s for HD Video Resolution: QSIF (180 x 90 x 10) (1920x1080x25) Compression efficiency: twice better than MPEG-2/H.262 Replacing MPEG-2 in broadcast Replacing H.263 in Video over Wireless Highly error resilient H.264/SVC: scalable coding (temporal, Spatial, SNR) The main tool in video streaming today

8 New Generation of codecs H.265/HEVC (2013) Network: soon to replace H.264/AVC Data rate:2-30 Mbit/s Compression efficiency : 40% better than H.264/AVC Video resolution: HD to UHD (3960 x 2160 x50)= 4Kvideo AV1 (2016) Open source advanced video coding to replace H.265/HEVC 20% more efficient than H.265/HEVC VVC (2017) Versatile video coding Network: All kind, mainly for video streaming

9 A Typical Video Over IP For better quality of video over IP sufficient channel rate should be allocated

10 TCP-Friendly Rate Control (TFRC) Existing solutions, including the standard TCP-Friendly Rate Control (TFRC) equation-based congestion controller, are prone to fluctuations in their sending rate and may respond only when packet loss has already occurred. This is a major problem, because both fluctuations and packet loss affect the end-user s perception of the delivered video.

11 Use of Fuzzy for congestion control

12 Type-II = A series of Type-I

13 Fuzzy Type-I / TCP (TFRC)

14 FLC2/FLC1

15 FLC2/FLC1 (Quality)

16 Video Quality with Fuzzy-I Flow Control

17 Video Quality with Fuzzy-II Flow control

18 Evolving Digital Media: Need for High Bit Rates 1-24 Gbps 500 Mbps Gbps 250 Mbs - 6 Gbps 250 Mbps Gbps 200 Mbps - 3 Gbps 20 Mbps Gbps 5-25 Mbps More 8K 4K 2 SHD 4K 2K 2 2K HD 2 HDTV HDV UHDTV Stereo 4K (future) SHD (Quad HD) Digital Cinema Stereo HD HDTV Consumer HD

19 Why More Resolution is Better? More resolution allows closer viewing of larger images Closer viewing of larger image increases viewing angle Increased viewing angle produces stronger emotional response UHDTV(8K) 7680 HDTV (2K) Picture Height 30º 3840 SHD (4K) 0.75 Picture Height 100º 60º 1.5 Picture Height

20 How to improve video quality further? So far we have improved video delivery through: More efficient video compression technique Better bandwidth allocation Higher picture resolution How can we improve it further? In fact efficient compression means, more video channels, OR better quality for the same number of channels Statistics indicate Higher resolution video only has 20% added value on satisfaction But look at the next pictures!

21 How does a normal TV in a stadium look like?

22 We like to see it like this! ( What is added value for this picture?)

23 Display parameters defining video quality Luminance Contrast Colour In CRT 0.1 < Lum <100 nits In LCD < Lum < 1000 nits HSV But Colour remains the same as BT. 709 standard

24 Luminance range of CRT vs LCD

25 Scene of objects with various light intensity

26 Opto-Electric/Eletro-Optic Transfer functions in Normal TV At display: Electro- Optic Transfer Function: EOTF At the camera: Opto- Electric Transfer Function: OETF System Transfer Function= Opto-Optic Transfer Function= OOTF

27 Comparison between BT.709 /BT.2020

28 Human Visual Colour (HSV) Response IDEAL LCD CRT

29 Colour Gamut in BT.709 & BT 2020+HDR

30 Opto-Optical Transfer Function (OOTF) = Systems transfer function System transfer function for CRT OOTF SDR = OETF 709 EOTF 709 System transfer function for LCD OOTF SDR = OETF 709 EOTF 1880 System transfer function for HDR OOTF HDR = OETF PQ EOTF PQ

31 Perceptual Quantizer

32 Metadata

33 O/E Transfer functions Display mapping

34 Hybrid Log-Gamma (HLG)

35 Comparison between OETF of PQ/HLG

36 Dolby vision HDR ITU-R BT.2020 colour diagram 12 bit Perceptual Quantizer (PQ) Adaptive (frame by frame) metadata (can also be static) Is not free Applications: UHD-HDR on Blue-Ray & Streaming With 12 bits it can produce 10,000 nits, but in practice is about 4,000 nits Supporters: 4k-HDR manufacturers; LG, TCL, Vizio

37 Hybrid Logarithmic Gamma HDR Hybrid Logarithmic Gamma (HLG) quantizer ITU-BT 2020 Colour diagram 10 bit resolution BBC and NHK Joint work Compatible to SDR (EOTF is similar to SDR up to 100 nits) (note: new LCDs also use BT.2020 colour, specially UHD-TV) No metadata

38 Other standards HDR10 ITU-R BT bit colour PQ Fixed Metadata Supported by: Dell LG Samsung Sharp Sony و Vizio, Microsoft and Sony HDR10+ ITU-R BT.2020 Could be more than 10 bits PQ Metadata change fr/fr Supported by Samsung and Amazon (free)

39 Single Layer Directly Standard Dynamic Range = SL-HDR1 Also called advanced HDR It sends SDR + supplement Enhancement Information for HDR (supported by H.264 and H.265) Easy compatibility with SDR Also supported by ETSI in 2016 Supporters: STMicroelectronics, Philips, CableLabs & Technicolour research Centre (France)

40 Transmission of Quality Scalable HDR

41 Transmission of SL-HDR1

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43 4K-HDR Trial via Satellite 10 bit 4k-video HOTBIRD (13 East) Frequency: MHz Horizontal polarization Symbol rate: DVB-S2, 8PSK, FEC 5/6 HEVC encoding at 30 Mbit/s 2 Samsung receivers with 1000 nits (HDR and SDR)

44 Added Value Expected satisfaction from one TV format to another? Black & White to Colour TV (High) SD to HD (medium) HD to UHD (medium) HD to HD-HDR is higher than HD to UHD HD to UHD-HDR (high)

45 Which HDR format? All 4 formats are under study by the standard groups Dolby vision: Will be most used in Blue-rays HDR10 HLG Most likely to be used in North America Most likely to be used in Europe and Asia SL-HDR1 Most likely to be used as format convertors

46 Sunset

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51 The End