A Comprehensive Study: H.264 vs H.265 Compression in Embedded Vision

Embedded vision systems require video compression to reduce bandwidth, storage, and power requirements. Two leading compression standards are H.264 and H.265. H.264 as they provide adequate efficiency and broad compatibility. H.265 is its successor, providing nearly double the compression at comparable fidelity.

Selecting an appropriate compression standard is essential to build cost-effective, optimized embedded vision applications that conform to bandwidth, storage, power, and hardware limitations. With codecs H.264 as the current industry standard and H.265 as the future standard, which is best for your application?

Overview of H.264

H.264 standard was released in 2003 as MPEG-4 Part 10 or AVC (Advanced Video Coding). It is a popular and widely used video compression technology. The Video Coding Experts Group and Moving Picture Experts Group collaborated on the standard. The H.264 codec is used across various streaming sources and achieves significantly reduced bitrate compared to its forerunner.

It achieves improved compression efficiency over prior standards through more complex encoding algorithms. Specific techniques include:

• Intra-frame prediction within frames.
• Inter-frame prediction across frames.
• Multiple block sizes for motion compensation.
• Efficient entropy coding methods like context-adaptive binary arithmetic coding (CABAC).

Since it uses advanced algorithms, like inter-prediction and spatial intra-prediction, the macroblocks comprise a 16×16 pixel sample, which can be divided into sub-macro blocks.

Encoders can trade computational complexity, compression rate, and visual quality. The result is video bitrates 30-50% lower than MPEG-2 and H.262 standards.

Pros of H.264

Here are some pros of H.264:

• Superior image quality with a reduced bitrate

H.264 offers enhanced image quality, particularly compared to earlier standards and even at lower bitrates. Advanced encoding reduces bandwidth and storage by 30–50% while maintaining visual integrity. Thus, it works well in limited space or transmission scenarios.

• Efficient and small

The newly implemented compression algorithms in H.264 exhibit remarkable efficiency. While utilizing lower bitrates, H.264 video files are more space-efficient and exhibit fewer visible anomalies. It enables embedded platforms to optimize resource utilization when limited.

• Low latency video

H.264 offers fast response times and fewer delays during encoding/decoding steps. It makes it well-suited for real-time video applications requiring fluid streaming and interactivity.

• High-resolution monitoring

The standard supports a wide range of resolutions up to 4K. It allows high-quality video monitoring across embedded devices with H.264 acceleration built-in.

Cons of H.264

Here are some cons associated with H.264:

• Greater processing power needed

Enhanced efficacy does necessitate an increase in processing capacity. Enhanced entropy coding and advanced prediction between frames incur additional costs during encoding and decoding. Strong hardware acceleration may be inadequate for devices to process high-definition H.264 video.

• Complex configuration

The numerous adjustable parameters in H.264 contribute to its adaptability and complexity. Proper configuration requires deep analysis and tuning expertise to balance tradeoffs of speed, space, etc. This refining effort is multiplied for video applications with multiple streams.

Overview of H.265

High-Efficiency Video Coding (HEVC), or H.265, is the subsequent iteration of the H.264 video encoding standard. H.265 was formulated by the Joint Collaborative Team on Video Coding (JCT-VC) and debuted in 2013. This consortium comprised professionals from the same standards organizations that developed H.264.

To advance video compression technology, H.265 substantially enhances encoding efficiency in comparison to H.264 by implementing several significant enhancements:

• Structure of multi-type tree coding with adaptable block partitions for improved prediction
• Accuracy of advanced motion vector prediction to the quarter-pixel level
• Context-adaptive entropy coding that analyses the probability distribution of symbols
• Support for higher bit depths up to 14-bits and 4:0:0 chroma subsampling

H.265 utilizes Coding Tree Units (CTUs) for image processing, and it uses a complete range of blocks going all the way from 64×64 to 4×4, resulting in efficient compression. It reduces storage and bandwidth requirements by approximately 50% compared to H.264 for equivalent video quality.

Pros of H.265

Here are the pros of H.265 standards:

• More efficient compression

Building upon the algorithms of H.264, H.265 significantly increases compression efficiency. By achieving an equivalent level of video quality at a 50% lower bitrate, the resulting file sizes and storage requirements are reduced by approximately half. This is crucial for applications with limited capacity and a minimum resolution.

• Higher resolution and frame rate support

H.265, in contrast to H.264, limited to 4K resolution and 60 FPS, can handle next-generation video specifications, including 8K video at 300 FPS. Enhanced compression tools ensure that quality is not compromised despite increased pixels and frames.

• Improved motion tracking and reduced errors

Video quality is enhanced even at low bitrates through more complex segments/transforms and improved motion data prediction. H.265 sees fewer distracting compression artifacts around moving objects. Additionally, image blurring is reduced in comparison to H.264.

Cons of H.265

Here are some cons associated with H.265:

• More complex codec

Due to the increased complexity, the decoding algorithms for H.265 are considerably more computationally intensive than those for H.264. Even capable multicore CPUs may be affected by high-resolution H.265 playback without dedicated hardware acceleration. So, the adoption of embedded devices with limited power budgets is complicated.

• Compatibility issues

While many modern platforms and browsers now support H.265, legacy software and hardware that have not been upgraded to support the new standard continue to present backward compatibility issues. A seamless end-to-end workflow necessitates vigilant monitoring of the capabilities of the client device.

Comparison of H.264 vs. H.265

Metrics	H.264	H.265
Compression Efficiency	Reasonable (30-50% better than older standards)	~50% more efficient than H.264
Bandwidth Utilization	Higher bitrates required	Lower bitrates, ~50% less bandwidth needed
Storage Needs	Larger video file sizes	~50% smaller video files
Max Support Resolution	Up to 4K at 60fps	Up to 8K at 300fps
Color Depth Support	Up to 8-bit	Up to 14-bit
Hardware Costs	Wide availability of acceleration chips	Less support currently, growing over time
Hardware Requirements	Reasonable processing needed	Significantly higher processing requirements
Power Consumption	Lower power encoding/decoding	Higher CPU utilization impacts power budget
Embedded Vision Suitability	Good for low-mid resolution applications	Better suited for high resolution embedded vision use cases
Compatibility	Supported widely on most platforms	Some backwards compatibility issues with legacy systems

A Comparison Between H.265 And H.264

H.265 showcases better performance in compression efficiency enhancements as compared to H.264, allowing video of equivalent quality encoded at 50% lower bitrates. On the other hand, H.264 has an added advantage as it maintains superior support for legacy devices. When power consumption or hardware cost are limitations for embedded vision applications, but a high resolution or frame rate is desired, H.265 can be preferred. However, H.264 may be more suitable if comprehensive device compatibility is of higher priority.

Get the best compression standards for your application with e-con systems!

When selecting video compression for an embedded vision platform, precise application requirements must be considered regarding bandwidth, resolution, compatibility, power, and hardware capabilities.

To meet various embedded requirements, e-con systems provide camera modules that support both codecs, including GMSL and USB alternatives for H.264 streaming and specialized infrared solutions that utilize H.265.

Our camera solutions with H.264 standards

• e-CAM83_USB – 4K Microsoft Teams compliant HDR USB H.264 Camera
• Hyperyon® – 2MP Sony STARVIS IMX290 Ultra Low-light USB camera (Color)
• STURDeCAM81_CUOAGX – IP67 4K GMSL2 Camera for NVIDIA® Jetson AGX Orin™/ AGX Xavier™
• See3CAM_CU84 – 4K AR0830 USB 3.2 Gen 1 Camera (Color)

Our camera solutions with H.265 standards

• RouteCAM_CU20 – Sony® Starvis™ IMX462 Full HD GigE Camera
• RouteCAM_CU22_IP67 – Full HD Sony Starvis 2 IMX662 Lowlight GigE HDR Camera

 Are you looking forward to implementing the right compression standard for your application? Write to e-con system experts at camerasolutions@e-consystems.com, and our experts will get back to you within 1-2 business days with the perfect solution to meet your needs. Besides, you can visit our camera selector page to review our entire range of cameras supporting all kinds of compression formats.