The H.264/AVC standard has been extended with a Scalable Video Coding (SVC) extension to enable video transmission and decoding of partial bit streams with lower temporal or spatial resolutions or reduced fidelity while maintaining high reconstruction quality relative to the bit stream rate. SVC provides functionalities such as graceful degradation in lossy environments, bit rate, format, and power adaptation, enhancing transmission and storage applications. SVC improves coding efficiency and scalability compared to prior standards, with the ability to support temporal, spatial, and quality scalability. The paper provides an overview of the basic concepts for extending H.264/AVC towards SVC, detailing the tools for temporal, spatial, and quality scalability, and analyzing their efficiency and complexity. SVC is a highly attractive solution for modern video transmission systems, allowing adaptation to varying terminal capabilities and network conditions. The paper also discusses the history of SVC, the design concepts of H.264/AVC, and the concepts for extending H.264/AVC towards an SVC standard. The paper outlines the essential requirements for SVC, including similar coding efficiency to single-layer coding, low decoding complexity, support for temporal, spatial, and quality scalability, and backward compatibility with H.264/AVC. The paper also discusses the coding efficiency of hierarchical prediction structures for both high- and low-delay coding, showing that temporal scalability does not negatively impact coding efficiency. SVC supports spatial scalability through multilayer coding, with inter-layer prediction mechanisms to improve rate-distortion efficiency. The paper also discusses the complexity considerations of SVC, including the use of inter-layer intra-prediction and the reduction of decoder complexity through constrained inter-layer prediction. Overall, SVC provides a flexible and efficient solution for scalable video coding, enabling a wide range of applications.The H.264/AVC standard has been extended with a Scalable Video Coding (SVC) extension to enable video transmission and decoding of partial bit streams with lower temporal or spatial resolutions or reduced fidelity while maintaining high reconstruction quality relative to the bit stream rate. SVC provides functionalities such as graceful degradation in lossy environments, bit rate, format, and power adaptation, enhancing transmission and storage applications. SVC improves coding efficiency and scalability compared to prior standards, with the ability to support temporal, spatial, and quality scalability. The paper provides an overview of the basic concepts for extending H.264/AVC towards SVC, detailing the tools for temporal, spatial, and quality scalability, and analyzing their efficiency and complexity. SVC is a highly attractive solution for modern video transmission systems, allowing adaptation to varying terminal capabilities and network conditions. The paper also discusses the history of SVC, the design concepts of H.264/AVC, and the concepts for extending H.264/AVC towards an SVC standard. The paper outlines the essential requirements for SVC, including similar coding efficiency to single-layer coding, low decoding complexity, support for temporal, spatial, and quality scalability, and backward compatibility with H.264/AVC. The paper also discusses the coding efficiency of hierarchical prediction structures for both high- and low-delay coding, showing that temporal scalability does not negatively impact coding efficiency. SVC supports spatial scalability through multilayer coding, with inter-layer prediction mechanisms to improve rate-distortion efficiency. The paper also discusses the complexity considerations of SVC, including the use of inter-layer intra-prediction and the reduction of decoder complexity through constrained inter-layer prediction. Overall, SVC provides a flexible and efficient solution for scalable video coding, enabling a wide range of applications.