What Is H.264 Format?
H.264 is a video compression standard and format that uses advanced compression techniques to deliver high-quality video at low bit rates. It is part of the MPEG-4 standard and is also known as MPEG-4 Part 10, Advanced Video Coding (AVC). It is a popular format for delivering high-quality video content over the internet and for storing video in memory-limited devices such as mobile phones, digital cameras, and security cameras.
H.264 provides support for a range of resolutions and frame rates, making it suitable for a variety of applications including internet video streaming, digital television broadcasting, and video conferencing. The H.264 format is widely used because of its ability to deliver good video quality at low bit rates and its compatibility with a range of devices and platforms.
This is part of a series of articles about video optimization
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How Does H.264 Work?
H.264 can compress video data using advanced techniques such as inter-frame compression and predictive coding. The compression process removes redundant information from consecutive video frames and represents the remaining data in a highly efficient form. This compressed data is then decompressed and decoded for playback, producing an output that closely resembles the original video.
H.264 uses inter-frame compression, which compares information between multiple frames to find similarities, reducing the amount of data needed to be stored or transmitted. Predictive coding uses information from previous frames to predict the content of future frames, further reducing the amount of data required. These and other advanced techniques enable H.264 to deliver high-quality video at low bit rates.
Benefits of Using H.264 for Video Encoding
H.264 offers a range of benefits for video encoding, including:
- Low bandwidth usage: H.264 provides good video quality at low bit rates, making it a cost-effective solution for delivering video content over the internet, especially in areas with limited bandwidth.
- High-resolution monitoring: H.264 supports a wide range of resolutions, making it suitable for high-resolution video monitoring applications such as security cameras, drones, and other surveillance systems.
- Low storage demands: H.264’s efficient compression enables video to be stored in smaller file sizes, reducing the storage demands of video-intensive applications.
- Vendor-agnostic solution: H.264 is an open and widely adopted video compression standard, which makes it a vendor-agnostic solution that can be used with a wide range of devices and platforms.
H.264 vs. H.265 for Video Encoding
H.264 and H.265 are two of the most widely used video compression standards for video encoding. They are used to reduce the size of a video file while maintaining its quality, making it easier to store, transmit and stream video content.
H.265, also known as HEVC (High Efficiency Video Coding), was introduced in 2013 as a successor to H.264. It provides better compression efficiency compared to H.264, meaning that it can encode video at a similar quality with a lower bitrate. This makes H.265 a better choice for applications where bandwidth or storage is limited. For example, H.265 is especially useful for encoding 4K and 8K ultra-high definition video, as it can reduce the file size of these videos by half compared to H.264.
In terms of quality, both H.264 and H.265 can provide high-quality video, but H.265 offers a noticeable improvement in terms of compression efficiency. This means that H.265 can maintain high-quality video even at lower bitrates, making it suitable for applications where bandwidth is limited.
One drawback of H.265 is that it requires more processing power compared to H.264 for encoding and decoding. This means that H.265 may not be suitable for devices with limited processing power, such as older smartphones and computers. Additionally, the licensing costs for H.265 can be higher compared to H.264.
In terms of compatibility, H.264 is more widely supported compared to H.265, as it has been in use for longer and is supported by a wider range of devices. However, H.265 is slowly becoming more widely supported as more devices adopt it.
9 Best Practices for H.264 Video Encoding
Here are some best practices for H.264 video encoding:
- Bitrate: Choose the appropriate bitrate based on the desired output quality and the target audience’s bandwidth. A higher bitrate results in better video quality, but requires more bandwidth to stream.
- Profile: Choose the right H.264 profile based on the intended use case. For example, if the video is meant to be streamed over the internet, choose the Baseline profile, which is the most widely supported profile for online video.
- Resolution: Choose an appropriate resolution that balances quality and file size. For example, if the target audience has limited bandwidth, it may be better to encode the video at a lower resolution.
- Keyframe Interval: Set the keyframe interval to an appropriate value based on the content of the video. A keyframe is a complete image in the video stream, and the keyframe interval determines how often a keyframe is inserted. A smaller keyframe interval results in better compression efficiency, but requires more processing power to decode.
- B-frames: Enable the use of B-frames, which are inter-predicted frames that can help improve compression efficiency.
- Adaptive Bitrate Streaming: Use adaptive bitrate streaming to dynamically adjust the bitrate of the video based on the viewer’s bandwidth. This ensures that the viewer receives the best quality video possible given their connection speed.
- Deinterlacing: Deinterlace interlaced video to produce progressive video. Interlaced video can result in artifacts when displayed on progressive displays.
- Video Filter: Use video filters to improve the quality of the video. For example, use de-noise filters to reduce noise in the video, or use sharpening filters to enhance the sharpness of the image.
- Testing: Test the encoded video on a variety of devices and networks to ensure that the video is of sufficient quality and can be played back seamlessly.