AVC vs. HEVC: Which codec is better for high-quality video streaming?

In video streaming, two codecs AVC (H.264) and HEVC (H.265) play important roles in how we watch and share videos. AVC has been a popular choice for years, known for delivering good quality while keeping file sizes manageable. It's widely used in everything from online streaming to DVDs. However, as more people want to watch videos in higher resolutions like 4K and even 8K, HEVC steps in as the newer option, it offers better compression, meaning it can deliver the same quality as AVC but with smaller file sizes about 50% smaller! This makes it ideal for high-definition content.

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What are AVC (H.264) and HEVC (H.265)?

AVC (also called H.264) and HEVC (also called H.265 – the newer, younger version of H.264) are standards for compressing videos used in digital recording and distribution. AVC and HEVC are both algorithms used for reducing the file size of video content while maintaining high quality, making it easier to store and transmit data across various platforms.

So, what exactly is “compression” and why do we need H.264 or H.265? The answer lies in the sheer size of raw video data generated during production.  

Still confused? Let’s break it down with a quick calculation:  

Let’s take Full HD video with a resolution of 1920 x 1080, 32 bits per pixel (8 bits per channel for R, G, B, and an alpha channel), at 60 frames per second.

Bits per frame: 1920 * 1080 * 32 = 66,355,200 bits

Bits per second (at 60 fps): 66,355,200 * 60 = 3,998,131,200 bits

File size for 10 seconds of footage at 60 fps: 3,998,131,200 * 10 = 39,981,312,000 bits = 4,997,664,000 bytes, or approximately 4,746.1 MB (~4.7 GB).

That’s almost 4.8 GB for just 10 seconds of footage, without considering the audio. Such file sizes aren’t practical for online streaming, irrespective of your network bandwidth.

To tackle this problem, we compress our footage using software or hardware codecs, which perform the mathematical operations outlined by compression standards. This process enables us to attain an appropriate quality-to-size ratio before sending content to viewers in small, easy-to-handle segments.

Compression is an important step for both on-demand and live streaming. It ensures that viewers enjoy a smooth experience without overwhelming bandwidth limitations. Now, let’s explore the two most prominent compression methods: AVC and HEVC.

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What is AVC (H.264)?

Advanced Video Coding (AVC), also known as H.264, is a video compression standard developed in the year 2003. AVC is the most universally used codec. It works well on various devices, from smartphones to high-end broadcasting equipment, suitable for applications like online streaming, broadcast TV, video conferencing, and surveillance.

Despite the introduction of newer codecs like H.265 and AV1, AVC remains relevant due to its balance of compression efficiency and video quality. Many streaming services and broadcasting networks continue to rely on H.264, ensuring its continued prominence in the industry.

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H.264 has seen several versions since its initial release. The main ones are:

• Baseline profile: Designed for low-complexity applications, like video conferencing. ‍
• Main profile: Offers better compression and quality, suitable for standard-definition broadcast. ‍
• High profile: Provides the best quality and is commonly used for Blu-ray discs and HD broadcasts. ‍
• High ten profile: An extension that supports 10-bit color depth, improving color representation. ‍
• High 422 profile: Supports 4:2:2 chroma subsampling, often used in professional video editing.

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How Does AVC (H.264) Work?

First, each video frame is segmented into a grid of pixel blocks, referred to as macroblocks. Areas with less detail are larger, set at 16x16 matrix, while regions with more detail can be resized to 8x8 or 4x4 matrices.

Next, the codec identifies similarities among macroblocks in two ways:

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1. Within the same frame: It utilizes the similarities in brightness (luminance) and color (chrominance) of macroblocks, addressing spatial redundancy.
2. Across previous or neighboring frames: It uses motion vectors to estimate how objects move on the screen, which tackles temporal redundancy by comparing the current frame with earlier and later frames.

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These identified similarities are then grouped for compression. As a result, the data between keyframes is significantly reduced, leading to a smaller overall video file size.

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Strengths of AVC (H.264)

1. High compression efficiency: AVC can reduce the bitrate needed for a given level of visual quality by about 50% without losing any quality. AVC also supports adaptive streaming, adjusting video quality based on internet speed to ensure smooth playback. This allows for longer playback time on devices with limited storage. ‍
2. Broad compatibility: The codec is broadly compatible, functioning smoothly across different platforms like Windows, macOS, iOS, and Android. It is also usable on a wide range of devices, from basic smartphones to professional cameras. Moreover, AVC is supported by major editing and playback software, which simplifies easy video for users. ‍
3. Global standard: As an established standard, AVC benefits from extensive resources, including plenty of tutorials and forums available for learning and troubleshooting.  

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Limitations of AVC (H.264)

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1. Encoding time and power consumption: AVC encoding comes with some notable challenges. Longer encoding times can be a drawback for projects that need a quick turnaround. Increased power consumption can also affect battery life on mobile devices during playback or recording. Additionally, lower-end devices may struggle with dropped frames and reduced playback quality due to the computational load.
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2. Efficiency for high resolutions: AVC’s efficiency can fall short of 4K and higher resolutions. As video quality increases, AVC often requires higher bit rates to maintain quality, leading to larger file sizes. This can be a concern for media companies, as larger files increase storage costs and can be less suitable for bandwidth-limited scenarios.
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3. Higher latency: Latency can be a problem for AVC in real-time applications. The complexity of its encoding and decoding processes may introduce delays, which can hinder live streaming or video conferencing. Additionally, variable network conditions can lead to buffering issues, negatively impacting the user experience.
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4. Licensing and futureproofing: While AVC’s licensing fees are generally lower than HEVC’s, there are still costs associated with commercial use. The licensing process can be complex, which may lead to unexpected expenses. Furthermore, as video technology evolves, AVC may struggle to meet the demands of newer, more efficient codecs, putting content providers at risk of obsolescence.

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Developer tips for AVC (H.264)

Keep your AVC projects efficient and user-friendly. Prioritize compatibility to reach a wider audience by ensuring your videos work on various devices. Test your encoding settings to find the right balance between quality and performance. Finally, always monitor user experience to identify and resolve any playback issues quickly.

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1. Prioritize compatibility: Use AVC in applications where broad compatibility is essential. It works well across many devices and platforms, including older hardware, ensuring users can access content without issues. This makes AVC a reliable choice for content aimed at a diverse audience. Plus, its widespread support helps avoid problems related to playback and user experience.
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2. Focus on real-time performance: Implement AVC for real-time applications like video conferencing and live streaming. Low latency and quick processing are crucial for a smooth user experience in these scenarios. By prioritizing AVC, developers can enhance the quality of real-time interactions and ensure that users enjoy seamless communication. This approach also helps in minimizing delays that can disrupt conversations or streams.
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3. Optimize encoding settings: Adjust encoding parameters such as bitrate and keyframe intervals to balance quality and performance. Each use case may require different settings to ensure smooth playback without compromising visual quality. By fine-tuning these parameters, developers can achieve optimal results tailored to specific needs. This flexibility allows for better performance, especially in varying network conditions.
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4. Utilize hardware acceleration: Use hardware encoders and decoders, such as Intel Quick Sync Video or NVIDIA NVENC. These tools offload processing from the CPU, which can significantly improve performance and reduce latency. Utilizing hardware acceleration also helps maintain high-quality video without overloading system resources. This is particularly useful in resource-intensive applications, ensuring a smoother experience for users.

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What is HEVC (H.265)?

HEVC, or High-Efficiency Video Coding, is also known as H.265. This video compression standard, developed as part of the MPEG-H project, was first released in 2013. It offers better compression than its predecessor, H.264, allowing for higher-quality video at lower bit rates. This means you can stream higher resolutions with the same visual quality while using less data.

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How does HEVC (H.265) work?

H.265 uses Coding Tree Units (CTUs) instead of traditional macroblocks. While it still operates with pixel grids, the difference lies in the flexibility of block sizes available for encoding. The smallest block size is 4x4, but it can go up to 64x64.  

This allows for better handling of high resolutions, enabling efficient encoding by using fewer bits for large areas with little detail and focusing more on regions with intricate details, which is especially beneficial for dynamic scenes.

HEVC also improves how it predicts moving objects by employing spatial and temporal prediction techniques, including Merge Mode and Advanced Motion Vector Prediction. Additionally, it features enhanced deblocking filters and sample adaptive offset filtering for superior image quality.

However, these advanced capabilities mean that HEVC demands more powerful hardware compared to AVC. Encoding videos takes longer, but the result is a reduction in file size and bandwidth usage by about 50% for the same visual quality. As resolutions increase to 4K, 6K, and even 8K, the efficiency gains become even more significant, making HEVC well-suited for high-quality streaming on the internet.

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Strengths of HEVC (H.265)

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1. Improved compression efficiency:

HEVC is designed to deliver better compression than its predecessor, H.264. It achieves up to 50% reduction in file size while maintaining the same quality. This is especially important for streaming high-resolution videos, where bandwidth is a concern. Users can enjoy high-quality content without using excessive data.

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2. Support for higher resolutions:

HEVC supports higher video resolutions like 4K and 8K. As video quality demands increase, this codec can handle larger file sizes efficiently. This makes it suitable for modern applications such as ultra-HD streaming and broadcasting. Viewers benefit from sharper and clearer images.

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3. Advanced prediction techniques:

HEVC uses advanced prediction methods to improve video quality. It employs spatial and temporal prediction to better handle motion and changes in the scene. This means that moving objects appear smoother, reducing blurriness during fast action. These techniques enhance the overall viewing experience.

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4. Better image quality:

With features like improved deblocking filters and sample adaptive offset filtering, HEVC ensures superior image quality. These enhancements reduce artifacts and improve the clarity of the picture. Viewers can expect richer colors and finer details, making videos look more vibrant and lifelike. This results in a more enjoyable viewing experience.

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Limitations of HEVC (H.265)

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1. Higher Hardware requirements:

HEVC demands more powerful hardware than older codecs like H.264. This can be a challenge for users with older devices, as they may struggle to play HEVC content smoothly. As a result, some users might experience lag or buffering during playback. Upgrading hardware can be necessary for optimal performance.

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2. Longer encoding times:

Encoding videos with HEVC takes more time compared to H.264. The advanced compression techniques require additional processing power, leading to longer wait times for rendering. This can be inconvenient for projects needing quick turnaround times. Users may need to plan for these extended encoding durations.

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3. Licensing costs:

HEVC comes with licensing fees that can add to production costs. While these fees are generally lower than those for other advanced codecs, they still present a financial consideration for content creators. Understanding the licensing agreements can be complicated, potentially leading to unexpected expenses. This may deter some users from adopting HEVC.

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4. Limited software support:

Not all software supports HEVC, which can create compatibility issues. Users may encounter problems when trying to edit or play HEVC files on older applications. This can limit the codec’s usability in certain environments, especially for those relying on specific tools. Ensuring proper software support is essential for seamless workflow.

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Comparing AVC (H.264) and HEVC (H.265) codecs:

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Case Study: Streaming Optimization for a Sports Streaming Platform

A sports streaming platform was facing challenges in delivering high-quality live streams for international events, especially in regions with varying internet speeds. They needed to balance video quality and bandwidth efficiency to ensure a seamless viewing experience for both low- and high-bandwidth users.

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Problem:

• Initial setup: The platform initially used AVC (H.264) encoding for all their streams. ‍
• Issue: Viewers in high-bandwidth regions received lower-quality streams due to AVC’s higher bitrate requirements, while viewers in low-bandwidth regions experienced buffering and latency issues.

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Solution:

The platform tested HEVC (H.265) encoding, leveraging its better compression capabilities for higher resolutions at lower bitrates. By switching to HEVC for high-definition streams and using AVC for lower-quality fallback streams, they optimized the user experience.

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Results:

• Reduction in Bandwidth Usage: The shift to HEVC reduced bandwidth usage by 40% for 1080p streams. ‍
• Improved Viewer Experience: Buffering incidents dropped by 20% in regions with lower internet speeds. ‍
• Scalability: The platform was able to stream 4K content more efficiently, improving their offerings for high-end viewers while maintaining smooth playback for low-bandwidth users.

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Conclusion

In the discussion of AVC vs. HEVC, choosing the right video codec can significantly impact your streaming experience. Your videos can be delivered using H.264 for broad compatibility and solid compression. For 4K and 8K quality with smaller file sizes, H.265 is the way to go.

At FastPix, we make it easy to enhance your video content and provide great experiences for your audience. With FastPix’s Video API, you can easily integrate AVC and HEVC into your projects, ensuring accelerated uploads and user satisfaction through adaptive bitrate streaming. Focus on quality and efficiency with Fastpix’s solutions. Sign up today for free!