FAQ

Differences between H.264 vs H.265

H.264 and H.265 are two popular dvr video compression standards that are widely used for streaming, broadcasting and recording. They both have advantages and disadvantages, depending on the application and the quality requirements. In this blog post, we will compare and contrast some of the main differences between H.265 and H.264.

H.265, also known as High Efficiency Video Coding (HEVC), is the successor of H.264, also known as Advanced Video Coding (AVC). H.265 was developed to provide better compression efficiency and higher video quality than H.264. H.265 can achieve up to 50% bitrate reduction compared to H.264, while maintaining the same perceptual quality. This means that H.265 can deliver higher resolution and smoother video with less bandwidth and storage space.

H.264, on the other hand, is more compatible and widely supported than H.265. H.264 is the dominant video compression standard for online streaming platforms, such as YouTube and Netflix, as well as for Blu-ray discs and digital cameras. H.264 has a simpler encoding and decoding process than H.265, which makes it faster and less computationally intensive. However, H.264 also requires more bitrate to achieve the same quality as H.265, which can result in larger file sizes and more network congestion.

Key technical differences between H.265 and H.264

– Block size: H.265 uses a variable block size of up to 64×64 pixels, while H.264 uses a fixed block size of 16×16 pixels. This allows H.265 to adapt to different levels of detail and motion in the video, resulting in more efficient compression.

– Prediction modes: H.265 hevc has more prediction modes than H.264, which enable it to exploit spatial and temporal redundancy in the video more effectively. For example, H.265 hevc has intra prediction modes that can predict a block from its neighboring blocks within the same frame, as well as inter prediction modes that can predict a block from its corresponding blocks in previous or future frames.

– Parallel processing: H.265 supports parallel processing at multiple levels, such as tiles, slices and wavefront parallel processing (WPP). This enables H.265 to divide the video into independent segments that can be encoded or decoded simultaneously by multiple processors or cores, improving the speed and scalability of the codec.

– Bit depth: H.265 supports up to 12 bits per color channel, while H.264 supports up to 10 bits per color channel. This means that H.265 can encode more colors and shades than H.264, enhancing the dynamic range and color accuracy of the video.

In conclusion, H.265 and H.264 are both powerful video compression standards that have their own strengths and weaknesses. The choice between them depends on various factors, such as the application scenario, the quality requirements, the device compatibility and the processing power available.

What is a Digital Video Recorder –DVR?

A Digital Video Recorder (DVR) records video to local storage devices, most commonly a hard drive.  DVR can record analog video sources on-site or capture video from a digital source. DVRs can be connected to analog cameras via coaxial cables, enabling them to be accessed remotely.  DVRs offer enhanced functionality like the ability to search recordings for events, or sort by time and date. DVRs can be configured to automatically replace older footage once storage becomes full.

DVR Hardware Features

• Mountable in a server rack
• Can include multiple source inputs (coaxial/optical)
• External monitor output
• I/O connection for tilt pan zoom (PTZ) camera
• Event notification from security devices
• Notification for connectivity issues

DVR Software Features

• Image capture by the user or triggered by an event
• Set resolution of recording by the user or by an event
• H.264 Video compression for higher resolution at lower bandwidth
• Video analytics such as dwell time, the direction of movement, and motion tracking
• Alarm, event, and time search functions
• Multi-channel audio recordings
• Archived footage

DVRs are limited to the physical number of input channels and are not upgradable.  This makes them best suited for small businesses or home security systems.  Network Video Recording (NVR) is a cloud-based video surveillance recording solution that can be upgraded at any time.  Analog limitations mean DVR record is much lower quality than a network solution and also the video is always stored locally versus in the cloud.

Digital Video Recorders (DVR) advantages include:

• Analog systems are low cost and not technical
• Simple to operate
• Low data consumption since data is stored locally

Digital Video Recorders (DVR) disadvantages include:

• Lower resolutions, frame rates compared to network recording
• Requires local wiring and connectivity
• Installation can be complex with multiple cameras and locations
• Separate power supply required
• Not suitable for use with IP camera
• Only some models are capable of recording audio

With the cost of storage and cloud-based services coming down, NVRs have replaced analog DVRs for today’s security surveillance systems.