[Show abstract][Hide abstract] ABSTRACT: As usual this, first quarter, edition of the Technical review is dedicated to reporting the Digital Broadcasting
Symposium (DBS) concluded in March 2015.
Over-the-air broadcasting is increasingly threatened by a lack of frequencies available to offer new and future
services, such as 4K. The ABU, together with other partners, is making efforts to secure access to broadcast spectrum to maintain plurality and access to information. Once again, DBS-2015 dedicated a session to
spectrum issues, followed by a session debating the need for spectrum in broadcasting.
The 2015 ABU Digital Broadcasting Symposium explored all the exciting prospects of high dynamic range, UHDTV and cloud technologies, for the broadcasting industry to move forward with new services, especially
in the converging world. A collection of photos and articles related to a number of the sessions is also included in this edition of Technical Review. Seventy-three speakers presented in eleven conference sessions
and thirteen workshop sessions over four days. A total of 954 participants attended the event, including 600 conference delegates. Fifty five exhibitors exhibited their products and services and reported that they
were pleased with the interactions with visitors to their booths.
This issue also carries two articles; one on the live terrestrial broadcasting of UHDTV-1 (4K) sports events and the other on OTT for all media stakeholders.
[Show abstract][Hide abstract] ABSTRACT: KBS (Korean Broadcasting System) has carried out 4K terrestrial live broadcasting of three big sports .events in 2014, the KBL (Korean Basketball League) finals, the 2014 FIFA World Cup, and the 2014 Incheon Asian Games. 4K UHD live coverage of the KBL finals was the world's first terrestrial 4K live broadcasting. This article covers from on-location live production of sports events, SFN (Single Frequency Network) transmission, as well as experimental IP transmission of uncompressed 4K video via KREONET, a national R&D network run by KISTI (Korea Institute of Science and Technology Information).
[Show abstract][Hide abstract] ABSTRACT: This 255th issue offers two technical articles contributed
by Korean Broadcasting System and Turkish Radio and
Television Corporation together with profiles of ABU
members in Vietnam.
The KBS article shares practical experiences regarding
the implementation of 4K using DVB-T2 technology and how to deliver
4K television signals to television viewers terrestrially. The article reports
the success and the potential of the service.
The TRT article describes the implementation of a building block of a
system to enhance the efficiency and effectiveness of the production of
radio programmes and broadcasting in all stages.
A report on a six-day Technical Advisory Service to the Palestine
Broadcasting Commission is included together with details of the ABU
Festival of Technology Webinars that was held over August and September.
This issue also provides reports on BroadcastAsia2013, the DAB+
Technology Workshop held in Hanoi, the Central Asia Media Forum
held in Bishkek and the 2013 Pacific Media Partnership Conference
held in Vanuatu.
In addition, our usual features, news from region, updates on digital
broadcasting and new broadcasting equipment, make up the rest.
[Show abstract][Hide abstract] ABSTRACT: Recently, 3DTV has drawn much attention as a new broadcasting service. In spite of technical advances in 3DTV broadcasting services, there are two barriers that hinder the new services from being launched for terrestrial broadcasting: the lack of available bandwidth for transmission of additional-view video via terrestrial channel and backward compatibility with the legacy 2-D HDTV services. As an alternative, a hybrid stereoscopic video coding scheme is proposed for a stereoscopic 3DTV service, where one-view video is transmitted through the legacy broadcasting systems and the other one is delivered via broadband networks to which TV terminals are connected. In this paper, the proposed hybrid stereoscopic video coding scheme incorporates an MPEG-2 codec for backward compatibility with a legacy 2-D HDTV service and an HEVC codec with inter-view prediction coding as an extension to encode additional-view video sequences with high coding efficiency. The proposed inter-view prediction coding scheme in the extended HEVC incorporates an advanced motion and disparity vector prediction (AMDVP) method for enhanced motion- and disparity-compensated coding. The experimental results demonstrate that the proposed hybrid stereoscopic video coding scheme achieves an average coding efficiency of 38.22% (32.86%) in BD-rate or 1.394 dB (1.235 dB) in BD-PSNR for the out-band (in-band) scenario.
No preview · Article · Sep 2013 · IEEE Transactions on Circuits and Systems for Video Technology
[Show abstract][Hide abstract] ABSTRACT: The sense of presence in UHDTV(Ultra High Definition TV) mainly arises from a wide field of view combined with ultra high definition resolution and an extremely fine picture quality. Therefore, UHDTV requires a resolution of 4K(3840x2160) or 8K(7680x4320) pixels. Furthermore, to provide a more vivid picture, UHDTV goes as far as a frame-rate of 120fps, a wider colour gamut and a colour-depth of 12 bits. For this reason, UHDTV necessarily results in an extremely huge amount of data. Even many experts have questioned whether the 6MHz or 8MHz bandwidth of a terrestrial TV channel offers realistic possibilities for UHDTV transmission. In Korea, the KBS(Korean Broadcasting System) carried out the world's first terrestrial 4K 30p UHDTV experimental broadcast from 9th October to 31st December 2012. The most prominent feature of this broadcasting was the use of a terrestrial TV channel. To fit the extremely high video datarate into its limited bandwidth, we exploited HEVC (High Efficiency Video Coding) compression and DVB-T2 transmission and reception systems. In this paper, we shall give an overview of KBS' 4K-UHDTV experimental broadcast and explain 4K-UHDTV content compression with an HEVC codec and the DVB-T2 system used in the trial. In addition, we shall show the result of our optimisation tests on HEVC coding of 4K 60p UHDTV.
[Show abstract][Hide abstract] ABSTRACT: New broadcasting services such as 3DTV and UHDTV are turning up and catching the public attention, because people nowadays like to have more realistic watching experience in TV. However, terrestrial broadcasters have difficulties in launching them, because new terrestrial broadcasting services necessarily need new frequency allocation. As frequency is public goods and the frequency for broadcasting is limited. To solve the lack of frequency, we designed hybrid 3DTV broadcasting technology combining terrestrial broadcasting channel and broadband network. For the hybrid 3DTV, the left view is transmitted through the terrestrial broadcasting channel and the right view is delivered using the internet. The difference of two transport networks causes inevitable receiving time delay. To synchronize the left view and the delayed right view by frame accuracy, we insert SMPTE time code into the left and right elementary streams respectively and transmit them. To verify the validity and practicality of hybrid 3DTV service, we performed live broadcasting of 'IAAF World Championships' in August 2011 via hybrid 3DTV technology.
[Show abstract][Hide abstract] ABSTRACT: A hybrid stereoscopic broadcasting service is considered a possible solution to the lack of frequency bandwidth for transmission of additional view sequences and to the backward compatibility for the existing MPEG-2 based DTV services. In this paper, a hybrid stereoscopic encoder based on MPEG-2 and HEVC is first considered where left-view sequences are encoded by MPEG-2 to provide the backward compatibility while right-view sequences are encoded by HEVC for delivery over Internet. In the hybrid stereoscopic encoder, we propose an inter-view coding scheme between the left- and right-view sequences to enhance the coding performance of HEVC for right-view sequences. Therefore, in this paper, an extension to HEVC is made with an inter-view coding scheme by having disparity based motion-compensated prediction. For this, MPEG-2 motion vectors from left-view sequences and global disparity vectors between two-view sequences are utilized. The experimental results show that the proposed hybrid stereoscopic encoder achieves average 37.75% coding gain in BDBR compared with the performance of HEVC simulcast encoding for right-view sequences.
[Show abstract][Hide abstract] ABSTRACT: In this paper, a two-stage block-mode classification scheme of H.264|MPEG-4 Part 10 AVC is presented as a pattern classification approach using SVMs in order to reduce high computational complexity of its encoders. For the block-mode classification, the feature vectors for each macroblock are formed for the SVMs with SATD and CBP values to detect the large and small block modes. From the experimental results, the proposed scheme yields 80% and 95% of the correct classification rate in average for the first and second stage, which has led to from 35% to 55% reduction in the total encoding time while maintaining negligible amounts of bit rate increases and PSNR drops for test sequences with QCIF, CIF, and 4CIF resolutions and various quantization parameter values.
[Show abstract][Hide abstract] ABSTRACT: In this paper, a low complexity encoding scheme for coarse grain scalability in Scalable Video Coding is proposed. The coarse grain scalability is a kind of SNR quality scalability in Scalable Video Coding. It utilizes the similar coding scheme with spatial scalability using inter-layer prediction and has a base layer and several enhancement layers. While CGS scalability supports video at the different quality levels, the computational complexity also dramatically increases as the number of quality levels increases. The proposed method exploits the statistics of residuals between current and reference blocks computed using the macroblock mode predicted from the previous quality layer. Since the quality between consecutive layers is significantly different, the block mode from the previous layer cannot be utilized directly. To test how efficient is some modes in the current layer, the statistical hypothesis testing for the variances of the residual sub-blocks is performed. If the variances tests for sub-block of residuals are accepted, the mode from the previous layer is regarded as the optimal in the current layer. Otherwise, one of other modes is recommended according to the result of the statistical test. The proposed method reduces the total encoding time when three CGS scalability layers are encoded up to 51%. However, the quality degradation and bit-rate increment of the each layer are negligible.
[Show abstract][Hide abstract] ABSTRACT: We introduce an efficient mode selection method in the enhancement layers of spatial scalability in the SVC encoder by selectively performing the inter-layer residual coding of the SVC. The proposed method is to make an analysis of the characteristics of integer transform coefficients for the subtracted signals for two residuals from lower and upper spatial layers. Then it selectively performs the inter-layer residual prediction coding in the spatial scalability if the SAD values of inter-layer residuals exceed adaptive threshold values. Therefore, by classifying the residuals according to the properties of integer-transform coefficients only with the SAD of inter-layer residual signals between two layers, the SVC encoder can perform the inter-layer residual coding selectively, thus significantly reducing the total encoding time with 51.2% in average while maintaining the RD performance with negligible amounts of quality degradation.
No preview · Article · Aug 2008 · Proceedings of SPIE - The International Society for Optical Engineering
[Show abstract][Hide abstract] ABSTRACT: Scalable Video Coding (SVC) can be applicable in mobile broadcasting environment due to the flexibility of spatial, temporal and quality scalability. Recently, SVC technology becomes mature rapidly but its reference SW encoder isn't optimized yet. Therefore, we have developed a real-time SW SVC encoder for broadcasting. In this paper, we show our SVC encoder that can provide two spatial layers: QVGA(320 x 240) and VGA(640 x 480). The base layer can be fully compatible with H.264/AVC. Our encoder is performing real-time operation on a normal PC by optimizing SVC algorithm.
[Show abstract][Hide abstract] ABSTRACT: In this paper, a fast intermode decision scheme which is suitable for the hierarchical B-picture structure in which much computational power is spent for combined variable block sizes and bi-predictive motion estimation is introduced. The hypothesis testing considering the characteristics of the hierarchical B-picture structure in the proposed method is performed on 16x16 and 8x8 blocks to have early termination for RD computation of all possible modes. The early termination in intermode decision is performed by comparing the pixel values of current blocks and corresponding motion-compensated blocks. When the hypothesis tests are performed, the confidence intervals to accept the null hypothesis or not are decided according to the temporal scalability levels under the consideration of properties of hierarchical B-pictures. The proposed scheme exhibits effective early termination behavior in intermode decision of temporal scalabilities and leads to a significant reduction up to 69% in computational complexity with slight increment in bit amounts. The degradation of visual quality turns out to be negligible in terms of PSNR values.
Preview · Article · Jan 2008 · Proceedings of SPIE - The International Society for Optical Engineering
[Show abstract][Hide abstract] ABSTRACT: The AVC|H.264 video coding standard adopts 4x4 integer transform on residuals between an original pixel block and its motion-compensated pixel block to make better prediction for the improvement of temporal redundancy reduction. Detecting all-zero blocks prior to integer transform in AVC|H.264 was taken into account as an important step in fast encoding process. Different from the previous approaches to early detection of all-zero blocks based on sums of absolute differences and quantization steps, this paper designed a linear classifier with additional features available before integer transform. With significant features to detect all-zero IT coefficients, the linear classifier improved detection accuracy so that skipping the integer transform process could accelerate the encoding process and minimize the encoding performance drop in PSNR values. The linear classifier is trained with large amount of training data and tested by video sequences with different characteristics. Experimental results demonstrated that through a wide range of quantization parameters and video sequences the proposed approach improved detection of all-zero blocks over the conventional approach with negligible amounts of PSNR degradation.
[Show abstract][Hide abstract] ABSTRACT: The H.264MPEG-4 Part 10 (AVC) standard incorporates an intra prediction into inter frame coding. However, this leads to excessive increase of encoding time. This paper presents a fast intra mode decision and intra prediction algorithm to reduce encoding time. Basically, the proposed algorithm designs the skip condition for candidate modes of 4times4 intra prediction to be dependent of the content types of sequences and the context of pre-encoded adjacent blocks in terms of intra prediction-related probabilities. The content and context adaptive conditional probability table for the most probable modes is generated during an I- frame coding and is exploited for the intra mode decision in the following P frames until the next I-frame. The experimental results show that the total encoding time saving can be achieved up to maximally 43.17% with negligible PSNR drop and bitrate increase compared to the joint model (JM) reference software of AVC.
[Show abstract][Hide abstract] ABSTRACT: We propose a fast inter-layer mode decision method by utilizing coding information of base layer upward its enhancement layer in scalable video coding (SVC), also called MPEG-4 part 10 Advanced Video Coding Amendment 3 or H.264 Scalable Extension (SE). In this paper, when the motion vectors from the base layer have zero motion (0, 0) in inter-layer motion prediction or the Integer Transform coefficients of the residual between current MB and the motion compensated MB by the predicted motion vectors from the base layer are all zero, the block mode of the corresponding block to be encoded in the enhancement layer is determined to be the 16*16 mode. In addition, if the predicted mode of the MB to be encoded at the enhancement layer is not equal to the 16 *16 mode, then the rate-distortion optimization is only performed on the reduced numbers of candidate modes which are same or smaller partitioned modes. Our proposed method exhibits the complexity reduction in encoding time up to 70%. Nevertheless, it shows negligible PSNR degradation and bit rate increase up to 0.2 MB and 0.71 % respectively.
[Show abstract][Hide abstract] ABSTRACT: MPEG Scalable Video Coding (SVC), which also known as H.264 Scalable Extension, makes video adaptation more flexible to meet user consumption preferences, application requirements, and also varying network conditions. An SVC bit stream consists of one or more scalable layers that form hierarchical dependency such that a layer has dependency on its lower layers. Therefore a layer cannot be decoded perfectly if all of its lower layers are not decoded a priori. In this paper, we propose layered protection, which is a partial protection scheme, for SVC bit streams by fully utilizing layer dependency characteristics of SVC. Layered protection scheme can achieve protection degree as high as that of given by protection of entire SVC bit streams (referred as total protection). Therefore it reduces complexity for protecting/unprotecting SVC bit streams. We use a modified Structural Similarity Index (SSIM) to show effectiveness of layered protection scheme in term of visual perception degradation. Our experiments show that layered protection scheme is not only effective in term of visual degradation, but also efficient in term of computational complexity. For our test videos, in average, we only need to protect 42.45% of input bit stream to achieve the same visual perception degradation as that of given by total protection (protecting 100% of input bit stream).
[Show abstract][Hide abstract] ABSTRACT: Quantization in video coding plays an important role in controlling the bitrate of compressed bitstreams to adjust with the allowed bandwidth of delivery networks and storage. Since scalable video coding (SVC) being currently standardized exhibits highly dependent coding nature not only between frames but also in the lower and higher layers, we propose a dependent quantization scheme for SVC and compare its performance in visual qualities and bitrates with the current technique in JSVM reference software. The experimental results show that the dependent quantization outperforms the current technique in JSVM reference software with 0.5 ~ 1.25 dB PSNR increment or 5 ~ 20% bits saving for the enhancement layer of SVC.
[Show abstract][Hide abstract] ABSTRACT: For video streaming, we must consider terminal and network characteristics. The scalable video coding (SVC) can represent video bitstreams in different scalable layers for flexible adaptation to terminal and network characteristics. The SVC can allow for extraction of appropriate partial bitstreams to meet specific target bitrates and spatial resolutions from an SVC bitstream with several spatial, temporal and quality scalability layers. Moreover, the extraction process is fast, so it is possible to extract the partial video streams online to cope with the delivery networks with changing characteristics such as bandwidth etc. With all the advantages of SVC, we design and implement a network-adaptive SVC streaming system to extract partial SVC bitstreams to meet the required target bitrates and spatial resolutions. We present the implementation of our SVC streaming system with experimental results.
[Show abstract][Hide abstract] ABSTRACT: High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.