H.265, also known as HEVC (High Efficiency Video Coding), is a video compression standard developed as a successor to H.264/AVC. Its primary goal is to deliver similar or even better video quality at half the bit rate of H.264, thus offering significant improvements in compression efficiency. Here’s a detailed overview of H.265:
Design Purpose: H.265 was developed to address the increasing demand for higher resolution video (like 4K and 8K) while using less bandwidth. This makes it particularly suitable for streaming high-definition videos over the internet.
Compression Techniques:
- Larger Block StructuresUnlike H.264, which uses a macroblock structure up to 16×16 pixels, H.265 uses Coding Tree Units (CTUs) that can be as large as 64×64 pixels. This allows for better efficiency in representing larger regions of similar data.
- Improved Intra PredictionH.265 offers 33 directional modes for intra prediction, compared to the 9 in H.264, providing better prediction accuracy.
- Parallel ProcessingH.265 is designed to utilize parallel processing techniques, making encoding and decoding processes more efficient on modern multi-core processors.
- Improved Motion Vector Prediction and PrecisionThis aids in better inter prediction.
- Entropy CodingH.265 uses only CABAC (Context Adaptive Binary Arithmetic Coding) for entropy coding, which is more efficient than CAVLC used in H.264.
Profiles and Levels: Like its predecessor, H.265 defines several profiles catering to different classes of applications, and levels that set maximum parameters for those profiles.
Network Adaptability: H.265 provides better error recovery features, making it more resilient in environments with packet loss, such as streaming over the internet.
Applications: H.265 is increasingly being adopted for:
- Streaming services (especially for 4K and 8K content)
- Broadcast
- Video storage solutions
- Video conferencing
Licensing: Licensing for H.265 has been more complex than H.264 due to multiple patent pools and licensors. This has been a factor in the adoption rate of H.265 in certain scenarios.
Competition and Alternatives: Other codecs, such as AV1, aim to provide similar or better compression efficiencies as H.265 without the associated patent royalty costs. AV1 is being promoted as a royalty-free alternative, gaining traction, especially in web-based streaming.
In summary, H.265/HEVC represents a significant advancement in video codec technology, offering superior compression efficiency, especially for high-resolution videos. Its adoption rate, however, has been influenced by licensing complexities and the emergence of alternative codecs.
Key terms in plain language
Open a term for a concise explanation of language used on this page.
Bandwidth
The amount of data a connection can carry in a given time, usually measured in Mbps or Gbps. More bandwidth supports more users, devices, and simultaneous applications.
Cloud Computing
Computing resources—such as applications, servers, storage, or databases—delivered from remote infrastructure and scaled as requirements change.
Infrastructure as a Service (IaaS)
Cloud-based servers, storage, and networking that customers configure and manage without owning the underlying data-center hardware.
Software as a Service (SaaS)
Software accessed as an online service instead of being installed and maintained entirely on the customer’s own computers or servers.
Disaster Recovery (DRaaS)
A plan and service for restoring applications, data, and operations after an outage or disruption. DRaaS provides recovery infrastructure through a managed cloud service.
Identity and Access Management (IAM)
The systems and policies that determine who a user is, what resources they may access, and how that access is authenticated and reviewed.