Implementation and evaluation of A/153 ATSC mobile DTV standard

Transcription

1 EE 5359 Implementation and evaluation of A/153 ATSC mobile DTV standard Sriniveditha Shivakkumaran ( ) Under the guidance of Dr.Rao

2 What is ATSC? Advanced Television Systems Committee, Inc., is an international organization which develops standards for digital television. ATSC coordinates television standards among various communications media. [1]

3 A/153 : ATSC mobile DTV standard Developed to support various services. Defines the technical specifications to provide new services to mobile and handheld devices using DTV transmissions. Services include real-time interactive services and file-based content download. [1]

4 Parts of A/153 standard [1] The A/153 ATSC mobile DTV standard consists of eight parts Part 1 - Mobile/Handheld Digital Television System Part 2 - RF/Transmission Part 3 - Service multiplex and Transport subsystem Part 4 - Announcement Part 5 - Application Framework Part 6 - Service Protection Part 7 - AVC and SVC Video System Part 8 - HE AAC Audio System

5 AVC and SVC video system characteristics Possible video inputs Standardized video input formats [2]

6 Video standards SMPTE (Society of Motion Picture and Television Engineers) 274M Specifies representation of uncompressed highdefinition television. Image format is 1920x1080 pixels with progressive and interlaced scanning. SMPTE 296M defines systems with an image size of 1280x720 pixels and progressive scanning. ITU-R BT standardizes the format of high-definition television with 16:9 aspect ratio. Number of samples per digital active line is 720 and 483 active lines.

7 Video processing before AVC compression [3] 1080i formats - Out of 1920 pixels per line of video, 24 pixels each on the left side of the image and the right side of the image are cropped. Resulting 1872 pixels by 1080 line image is de-interlaced to 416 pixels by 240 lines before compression. 720p formats - Out of 1280 pixels per line of video, 16 pixels each on the left side and right side of the image are cropped. Resulting 1248 pixels by 720 line image is de-interlaced to 416 pixels by 240 lines before compression. Standard definition formats with 16 : 9 Aspect Ratio - Of the 720 pixels per line, 8 pixels each on the left side and right side of the image are cropped. Resulting image has 704 pixels per line. The 704 pixel by 480 line image is de-interlaced to 416 pixels by 240 lines prior to compression.

8 Video processing before AVC compression [3] Standard definition formats with 4:3 Aspect Ratio -Since the M/H video system can encode only 16:9 video formats, 4:3 SD video must be converted to a 16:9 video format before compression. It is converted to a high definition format and the 16:9 frame is converted to 416 pixels by 240 lines.

9 Image resize i formats p formats i and 480p formats

10 H.264 coding standard H.264 is developed for multimedia applications. High compression efficiency In this project, H.264 is used for encoding the video bitstream in the ATSC broadcast system.

11 Block diagram of H.264 Encoder [11]

12 4x4 Integer transform Context-based adaptive variable length coding (CAVLC) and Context-based adaptive binary arithmetic coding (CABAC) entropy coding -Match symbol to code. - CAVLC and CABAC for quantized coefficients. - To read the residual data (quantized transform coefficients), zig-zag scan (interlaced) or alternate scan (noninterlaced or field) is used. - For coding the residual data, a more sophisticated method called CAVLC is employed. Also, CABAC is employed in Main and High profiles, CABAC has more coding efficiency but higher complexity compared to CAVLC.

13 Deblocking filter - H.264 employs a deblocking filter to reduce the blocking artifacts in the block boundaries. - It stops the propagation of accumulated coded noise. The filter is applied after the inverse transform (before reconstructing and storing the macroblock for future predictions) and in the decoder (before reconstructing and displaying the macroblocks).

14 H.264 intra prediction modes

15 During intra prediction, the encoder derives a predicted block based on its prediction with previously decoded samples. The predicted block is then subtracted from the current block and then encoded. There are a total of nine prediction modes for each 4x4 luma block, four prediction modes for each 16x16 luma block and four modes for each chroma block.

16 Block diagram of H.264 decoder [18]

17 H.264 decoder Includes all the control information such as picture or slice type, macroblock types and subtypes, reference frames index, motion vectors, loop filter control, as well as coded data comprising of quantized transform coefficients. The decoder works similar to the local decoder at the encoder; a simplified description is as follows. - After entropy (CABAC or CAVLC) decoding, the transform coefficients are inverse scanned and inverse quantized prior to being inverse transformed.

18 H.264 decoder - To the resulting blocks of residual signal, an appropriate prediction signal (intra or motion compensated inter) is added. - The reconstructed video frames undergo deblock filtering prior to being stored for future use for prediction. -The frames at the output of deblocking filter may need to undergo reordering prior to display.

19 H.264 profiles [12]

20 Common coding parts for the Profiles I slice (Intra-coded slice) : the coded slice by using prediction only from decoded samples within the same slice P slice (Predictive-coded slice) : the coded slice by using inter prediction from previously-decoded reference pictures, using at most one motion vector and reference index to predict the sample values of each block CAVLC (Context-based Adaptive Variable Length Coding) for entropy coding

21 Coding parts for Baseline Profile Common parts : I slice, P slice, CAVLC FMO Flexible macroblock order : macroblocks may not necessarily be in the scan order. The map assigns macroblocks to a slice group ASO Arbitrary slice order : the macroblock address of the first macroblock of a slice of a picture may be smaller than the macroblock address of the first macroblock of some other preceding slice of the same coded picture RS Redundant slice : This slice belongs to the redundant coded data obtained by same or different coding rate, in comparison with previous coded data of same slice

22 Coding parts for Main Profile Common parts : I slice, P slice, CAVLC B slice (Bi-directionally predictive-coded slice) : the coded slice by using inter prediction from previously-decoded reference pictures. Weighted prediction : scaling operation by applying a weighting factor to the samples of motion-compensated prediction data in P or B slice CABAC (Context-based Adaptive Binary Arithmetic Coding) for entropy coding

23 Sub-blocks of a macroblock [15] Motion Estimation sizes in H.264 A MB can be partitioned into smaller block sizes 4 cases for 16 x 16 MB, 4 cases for 8 x 8 Sub-MB Large partition size : homogeneous areas, small : detailed areas

24 Performance results Tempete (CIF) sequence

25 MSE SSIM Tempete (CIF) sequence 400 Bitrate vs. MSE 1 Bitrate vs. SSIM

26 PSNR (db) Performance results Bus (CIF) sequence 55 Bitrate vs. PSNR (db)

27 MSE SSIM Bus (CIF) sequence 350 Bitrate vs. MSE 1 Bitrate vs. SSIM

28 PSNR (db) Performance results Coastguard (CIF) sequence 55 Bitrate vs. PSNR(dB)

29 MSE SSIM Coastguard (CIF) sequence 250 Bitrate vs. MSE 1 Bitrate vs. SSIM

30 PSNR (db) Performance results Waterfall (CIF) sequence 55 Bitrate vs. PSNR (db)

31 MSE SSIM Waterfall (CIF) sequence 200 Bitrate vs. MSE 1 Bitrate vs. SSIM

32 PSNR(dB) Performance results Foreman (QCIF) sequence 55 Bitrate vs. PSNR

33 MSE SSIM Foreman (QCIF) sequence 300 Bitrate vs. MSE 1 Bitrate vs. SSIM

34 PSNR(dB) Performance results Akiyo (QCIF) sequence 55 Bitrate vs. PSNR(dB)

35 MSE SSIM Akiyo (QCIF) sequence 180 Bitrate vs. MSE 1 Bitrate vs. SSIM

36 PSNR(dB) Performance results Claire (QCIF) sequence 55 Bitrate vs. PSNR (db)

37 MSE SSIM Claire (QCIF) sequence 140 Bitrate vs. MSE 1.02 Bitrate vs. SSIM

38 PSNR(dB) Performance results News (QCIF) sequence 55 Bitrate vs. PSNR(dB)

39 MSE SSIM News (QCIF) sequence 350 Bitrate vs. MSE 1 Bitrate vs. SSIM

40 PSNR(dB) Performance results Harbour (HD) sequence

41 MSE SSIM Harbour (HD) sequence

42 PSNR(dB) Performance results Blue sky (HD) sequence

43 MSE SSIM Blue sky (HD) sequence

44 PSNR(dB) Performance results Mobile (HD) sequence

45 MSE SSIM Mobile (HD) sequence

46 REFERENCES [1] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 1 Mobile/Handheld Digital Television System, Doc. A/153 Part 1:2009, Advanced Television Systems Committee, Washington, D.C., 15 October [2] ATSC: ATSC Digital Television Standard, Part 4 MPEG- 2 Video System Characteristics, Doc. A/53 Part 4:2009, Advanced Television Systems Committee, Washington, D.C., 7 August [3] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 7 AVC and SVC Video System Characteristics, Doc. A/153 Part 7:2009, Advanced Television Systems Committee, Washington, D.C., 15 October [4] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 2 RF/Transmission System Characteristics, Doc. A/153 Part 2:2009, Advanced Television Systems Committee, Washington, D.C., 15 October *5+ ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 3 Service Multiplex and Transport Subsystem Characteristics, Doc. A/153 Part 3:2009, Advanced Television Systems Committee, Washington, D.C., 15 October 2009.

47 REFERENCES [6] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 4 Announcement, Doc. A/153 Part 4:2009, Advanced Television Systems Committee, Washington, D.C., 15 October [7] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 5 Presentation Framework, Doc. A/153 Part 5:2009, Advanced Television Systems Committee, Washington, D.C., 15 October [8] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 6 Service Protection, Doc. A/153 Part 6:2009, Advanced Television Systems Committee, Washington, D.C., 15 October [9] ATSC: ATSC Mobile/Handheld Digital Television Standard, Part 8 HE AAC Audio System Characteristics, Doc. A/153 Part 8:2009, Advanced Television Systems Committee, Washington, D.C., 15 October [10] G.A.Davidson et al, "ATSC video and audio coding", Proc. IEEE, vol. 94, pp , Jan.2006 [11] A. Puri, X. Chen and A. Luthra, Video coding using the H.264/MPEG-4 AVC compression standard, Signal Processing: Image Communication, vol. 19, pp , Oct. 2004

48 REFERENCES *12+ S.K.Kwon, A.Tamhankar and K.R.Rao, Overview of H.264 / MPEG-4 Part 10 J. Visual Communication and Image Representation, Vol 17, pp , April *13+T.Wiegand, et al Overview of the H.264/AVC video coding standard, IEEE Trans. on Circuits and Systems for Video Technology, Vol.13, pp , July *14+ T. Wiegand and G. J. Sullivan, The H.264 video coding standard, IEEE Signal Processing Magazine, vol. 24, pp , March 2007 *15+ A. Ravi and K.R. Rao, Performance analysis and comparison of the Dirac video codec with H.264 / MPEG-4 Part 10 AVC, IJWMIP. (under review) *16+ A. Puri, X. Chen and A. Luthra, Video coding using the H.264/MPEG-4 AVC compression standard, Signal Processing: Image Communication, vol. 19, pp , Oct [17] H.264 AVC JM software: [18] A/153 ATSC mobile DTV standard :

49 ACRONYMS AAC Advanced Audio Coding AES Advanced Encryption Standard AT ATSC Time ATSC Advanced Television Systems Committee ATSC-M/H ATSC Mobile/Handheld Standard AVC Advanced Video Coding (ITU-T H.264 ISO/IEC ) BSD/A Broadcast Service Distribution/Adaptation Center BSM BCAST Subscription Management CIT-MH Cell Information Table for ATSC-M/H CRC Cyclic Redundancy Check DNS Domain Name System DRM Digital Rights Management DVB Digital Video Broadcasting FEC Forward Error Correction HE AAC High Efficiency Advanced Audio Coding HE AAC v2 High Efficiency Advanced Audio Coding version 2 LTKM Long-Term Key Message

50 ACRONYMS M/H Mobile/pedestrian/handheld MHE M/H Encapsulation MPEG Moving Picture Experts Group N Number of columns in RS Frame payload NTP Network Time Protocol PEK Program Encryption Key RTP Real-time Transport Protocol SDP Session Description Protocol SEK Service Encryption Key SG (Electronic) Service Guide SLT-MH Service Labeling Table for ATSC-M/H STKM Short-Term Key Message SVC Scalable Video Coding (Annex G of ITU-T rec. H.264 ISO/IEC ) SVG Scalable Vector Graphics TCP Transmission Control Protocol TEK Traffic Encryption Key TPC Transmission parameter channel