Tips & Tricks

Two-Pass Encoding: What Is It & How Worth It?

3 min read
Two-pass encoding

A lot of new and advanced technology has blessed the world of the video industry. Multipass encoding is one of them, which has become an essential part of video encoding. Multipass encoding is the compression of a digital video multiple times to achieve the highest possible quality. Two-pass encoding is a type of multipass encoding that involves two passes through the encoding process to optimize final results better.

In contrast to single-pass encoding, two-pass encoding is more efficient in delivering the best video quality. It is because two-pass encoding allows for more thorough data optimization. The first pass collects information about the video, such as motion complexity and scene changes. The second pass applies this collected data to encode the video more efficiently and optimally.

In this blog post, we will explore the further details of two-pass encoding and why it is worth more than single-pass encoding. Let’s get started!

What is Two-Pass Encoding?

Two-pass encoding is a video encoding process in which the video is compressed twice. In this multi-pass encoding process, video data is processed in two phases. The first pass collects the data from the source video and creates a statistical summary of that video. Then, this collected data guides the second pass to optimize the final video quality.

In this video encoding strategy, the first pass helps to identify the complexity of motion and scenes in the video, which leads to achieving the target video file size. In a two-pass video encoding process, the first pass can be considered the analysis pass, and the second can be referred to as the optimization pass.

How Does Two-Pass Encoding Work?

Two-pass encoding is an effective way to reduce the size of a video file. It employs two passes to get the desired result. The main goal of two-pass video encoding is to compress a raw video file with decent quality.

The first pass is used to analyze the input data and gather statistics, such as the number of colors, frames, and motion types. Then, this information is saved as a log file to make an optimized set of encoding variables for the second pass. The final compressed video file is made in the second pass of encoding.

Since two-pass video encoding allows more control over the video output, it’s recommended for the best encoding quality.

Is 2-Pass Encoding Worth It?

The short answer is yes. Two-pass encoding always produces higher-quality results at an average video bitrate. The two-pass encoding provides a more efficient data optimization that leads to the best video quality possible. But since the process is complex and consumes time, encoding video in this way can be more costly than single-pass encoding. Moreover, two-pass video encoding is not an intelligent decision when streaming live videos. It takes more time than single-pass encoding and can cause latency issues in live streaming.

Benefits of Two-Pass Encoding

Compared to single-pass encoding, two-pass encoding has a higher chance of delivering an optimized and compressed video. With its custom, device-specific compression algorithm, this solution can retain the most intricate details while using minimal storage space. It offers a superior viewing experience across all devices without compromising quality or file size.

As a result, two-pass encoding can provide more precise control over the bitrate of the compressed video, which can lead to a smaller file size for the compressed video. Additionally, two-pass video encoding can improve the compatibility of the encoded video with a broader range of playback devices.

Drawbacks of Two-Pass Encoding

As mentioned above, two-pass encoding takes more time than single-pass, and it doesn’t work with live streaming. Other than that, it also requires a lot of computing power and may be too costly for some users. Since the process is very complex, a device compatibility issue may arise. Also, the initial hardware and start-up costs are high for two-pass video encoding.

Wrapping up

In conclusion, two-pass encoding is a crucial tool for streamers and content creators who want to maintain high video quality while still optimizing their streaming budget. It takes more time than single-pass encoding, but it can give you the best possible balance between resolution, bitrate, and overall quality of your output file.

While two-pass encoding has limitations, it remains an invaluable technology in the streaming industry and should be used whenever possible. Shortly, this encoding technology will become even more accessible and powerful.

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