Tae-jun Jung

A new timing model design for MPEG Media Transport (MMT)

During the recent years, broadcasting services and mobile services have started converging and it is expected that this trend will continue with other services. In order to deploy efficient solutions for the transport of MPEG media in an interoperable fashion, especially given the recent increased demand of multimedia delivery in the heterogeneous network environment, MPEG has launched a new standardization work item, called MPEG Media Transport (MMT) since the middle of 2010. In this paper, we propose an appropriate timing model for MPEG Media Transport (MMT) to support media synchronization in MMT system based media service.

A client-driven media synchronization mechanism for RTP packet-based video streaming

AbstractMedia synchronization is used to correctly playback a video stream with its associated audio. To support synchronization between video and audio streams transported over IP networks, an RTP/RTCP protocol suite is usually employed. In conventional server-driven media synchronization, the server needs to periodically transmit an RTCP sender report (SR) packet to provide the client with a UTC time in NTP format corresponding to the RTP timestamp carried by each RTP packet. In this paper, we propose a precise client-driven media synchronization mechanism for an RTP packet-based multimedia streaming service. In the proposed method, the server does not need to send any RTCP SR packets for synchronization. Instead, the client device derives the precise normal play time (NPT) for each video and audio stream from the received RTP packets containing an RTP timestamp. Simulations show that the proposed client-driven synchronization method can provide accurate media synchronization without employing an RTCP SR packet and accordingly reduce the initial synchronization delay, the processing complexity at the client device, the number of required user datagram protocol ports, and the amount of control traffic injected into the network.

An efficient delay-constrained ARQ scheme for MMT packet-based real-time video streaming over IP networks

The MPEG has recently Querydeveloped a new standard, MPEG media transport (MMT), for the next-generation hybrid media delivery service over IP networks considering the emerging convergence of digital broadcast and broadband services. On account of the heterogeneous characteristics of broadcast and broadband networks, MMT provides an efficient delivery timing model to enable inter-network synchronization, measure various kinds of transmission delays and jitters caused by the transmission delay, and re-adjust the timing relationship between the MMT packets to ensure synchronized playback. By exploiting the delivery timing model, it is possible to accurately estimate the round-trip time (RTT) experienced during MMT packet transmission. Based on the measured RTT, we propose an efficient delay-constrained automatic repeat request (ARQ) scheme, which is applicable to MMT packet-based real-time video streaming service over IP networks. In the proposed ARQ scheme, the receiver buffer fullness at the time of packet loss detection is used to compute the arrival deadline, which is the maximum allowed time for completing the requesting and retransmitting of the lost MMT packet. Simulation results demonstrate that the proposed delay-constrained ARQ scheme can not only provide reliable error recovery, but it also achieves significant bandwidth savings by reducing the number of wastefully retransmitted packets that arrive at the receiver side and exceed the allowed arrival deadline.

Error-resilient surveillance video transmission based on a practical joint source-channel distortion computing model

In recent years, IP (Internet Protocol)-based video surveillance has widely been useful for post-event analysis and assisting the work of privacy protection and public safety. To support high-quality IP video surveillance, error-resilience techniques are important for surveillance system design, because video has more stringent requirements than general video transmission for packet loss, latency, and jitter. The optimal FEC (forward error correction) code rate decision is a crucial procedure to determine the optimal source and channel coding rates to minimize the overall picture distortion when transporting video packets over packet loss channels. The conventional FEC code rate decision schemes using an analytical source-coding distortion model and a channel-induced distortion model are usually complex and typically employ the process of model parameter training, which involves potentially high computational complexity and implementation cost. To avoid the complex modeling procedure, we propose a simple but accurate joint source-channel distortion model to estimate the channel-loss threshold set for optimal FEC code rate decision. Since the proposed model is expressed as a simple closed form and has a small number of scene-dependent model parameters, a video sender of the surveillance system using the model can be easily implemented. For training the scene-dependent model parameters in real time, we propose a practical test-run procedure. This method accelerates the test-run while maintaining its accuracy for training the scene-dependent model parameters. Using the proposed simple model and practical test-run method, the video sender can find the optimal code rate for on-the-fly joint source-channel coding whenever there is a change in the packet-loss condition in the channel. Simulations show that the proposed method can accurately estimate the channel loss threshold set, resulting in an optimal FEC code rate with low computational complexity.

Overview on MPEG MMT Technology and Its Application to Hybrid Media Delivery over Heterogeneous Networks

The MPEG has recently developed a new standard, MPEG Media Transport MMT, for the next-generation hybrid media delivery service over IP networks considering the emerging convergence of digital broadcast and broadband services. MMT is intended to overcome the current limitations of available standards for media streaming by providing a streaming format that is transport- and file-format-friendly, cross-layer optimized between the video and transport layers, error-resilient for MPEG streams, and convertible between transport mechanisms and content adaptation to different networks. In this paper, we overview on the MPEG MMT technology and describe its application to hybrid media delivery over heterogeneous networks.

An Efficient DPB Design Scheme for Scalable Multi-view Video Coding Using GPB Mechanism

본 논문에서는 효율적인 스케일러블 다시점 비디오 부호화를 수행하기 위해 필요한 참조화면 재순서화, 마킹 프로세스, 참조픽처 리스트 구성을 포함하는 DPB (Decoded Picture Buffer) 작동을 위한 새로운 설계 방법을 제안한다. 다양한 실험 결과를 통해서 제안된 방법에 의해 스케일러블 다시점 비디오 부호화에 있어서 개선된 압축효율을 얻을 수 있고 BD-Rate 및 BD-PSNR 측면에서 향상된 비디오 화질을 얻을 수 있음을 확인한다.

A practical FEC code rate decision scheme based on joint source-channel distortion model

We propose a practical FEC code rate decision scheme based on joint source-channel distortion model. The conventional FEC code rate decision schemes using analytical source coding distortion model and channel-induced distortion model are usually complex, and typically employ the process of model parameter training which involves potentially high computational complexity and implementation cost. Since the proposed joint model is expressed as a simple closed form and has a small number of scene dependent model parameters, a video sender using the model can be easily implemented. It is shown by simulations that the proposed method can accurately estimate the optimal FEC code rate with low computational complexity.

Joint source-channel distortion model for optimal FEC code rate decision

The optimal FEC code rate decision is a crucial procedure to determine the optimal source and channel coding rates to minimize the overall picture distortion when transporting video packets over packet loss channels. To avoid the complex modeling procedure, we propose a simple but accurate joint source-channel distortion model to estimate channel loss threshold set for optimal FEC code rate decision.

Design and Performance Analysis of Exclusive-OR Based FEC Coding System for Error Resilient SVC Video Transmission

In this paper, we design and analyze performance of Exclusive-OR based FEC (Forward error correction) system to deploy SVC video transmission service over packet-loss prone IP network. In the designed system, we adopt standard compliant Exclusive-OR based FEC scheme and apply it to be appropriate to the hierarchical layer structure of SVC video. To verify the performance of the designed Exclusive-OR based FEC system for SVC video transmission, we employ NIST-NET based transport simulator. By the SVC video transmission using the NIST-NET based simulator, we confirm the error resilient transmission performance of the designed Exclusive-OR based FEC system.

Efficient Motion Prediction Architecture and Design of DPB for Scalable Multi-view Video Coding

In this paper, we propose an efficient motion prediction architecture and DPB design mechanism for scalable multi-view video coding which is implemented by integrating SVC and MVC coding algorithms. In the proposed motion prediction architecture, we employ pictures associated with other views as a candidate for reference picture for improved motion prediction performance. By the proposed prediction architecture, we could enormously reduce the size of compressed video data. When performing scalable multi-view video coding, an integrated DPB design mechanism is also proposed. It is shown by various simulations that the proposed motion prediction architecture for scalable multi-view video coding can result in reduced data size in the compressed bitstream.