Video Transcoding: What Is It and How to Use It to Optimize Content

In the era of rapid development of digital technologies, video content has become an integral part of our lives. We watch movies online, communicate via video calls, learn and work remotely. However, with the growing popularity of video streaming and the variety of playback devices, the industry faced a major challenge: how to ensure high video quality and accessibility for all users, regardless of their technical capabilities and internet speed?

The solution to this problem is video transcoding – the process of converting a video stream from one format to another to adapt the content to different devices and data transmission channels. Thanks to transcoding, streaming services can deliver videos to viewers in optimal quality considering network bandwidth, and video surveillance systems can efficiently store and transmit camera footage.

In this article, we will look in detail at what video transcoding is, what problems it solves, and why this technology is critical for the modern video industry. You will learn about different types and methods of transcoding, technical aspects of codecs and formats, as well as advanced solutions in this field like Flussonic Media Server.

Contents

• What is Video Transcoding
• Types of Transcoding
• Where Video Transcoding is Used
• Technical Aspects of Video Transcoding
• Real-Time Transcoding
• Flussonic Media Server as a Transcoding Solution
• Conclusion
• Frequently Asked Questions (FAQ)

What is Video Transcoding

Video transcoding is the process of converting a digital video signal from one format to another. Simply put, it means changing the properties of a video stream, such as resolution, bitrate, codec, or container, to adapt the video to specific requirements.

It's important to understand how transcoding differs from simple encoding or decoding. Encoding is the process of compressing the original video signal using a specific codec to reduce the amount of data. Decoding is the reverse process, where the compressed video is restored for playback. Transcoding combines these two processes: first, the video is decoded from its original format, and then it is re-encoded with different parameters.

This video conversion is critical for many areas that deal with the processing and transmission of video data. In streaming, transcoding allows for the adaptation of video content to network bandwidth and user device capabilities, ensuring stable transmission without buffering. In video surveillance systems, transcoding helps optimize the volume of stored data and the load on communication channels by reducing the resolution and bitrate of video streams from cameras. When archiving video material, transcoding to newer, more efficient formats saves server space and improves compatibility with modern software.

Thus, video transcoding is a key technology that enables the efficient distribution and use of video content in various fields. Without it, many video services and applications we know today could not exist in their current form.

Types of Transcoding

Depending on the task and source data, video transcoding can be performed in different ways:

• Complete transcoding - is the full conversion of a video stream, including changes to the codec, resolution, bitrate, and other parameters. This method is applied when the video format needs to be radically changed, for example, to adapt it to new standards or platform requirements. Complete video transcoding requires significant computing resources and time but allows for videos with completely new quality.
• Partial transcoding - involves changing only some parameters of the video stream without affecting others. For example, you can reduce the resolution and bitrate of the video while maintaining the original codec and container. Or conversely - re-encode the video into a different format but leave the resolution and quality unchanged. Partial transcoding requires fewer resources and is performed faster than complete transcoding.
• Adaptive transcoding - is a special type of video conversion used in streaming. Its essence lies in creating multiple versions of the video stream with different properties (resolution, bitrate) and switching between them in real-time depending on channel bandwidth and user device capabilities. Thus, a viewer with a slow internet connection receives video in low resolution, and when the connection speed increases, the player automatically switches to a higher quality stream. Adaptive transcoding provides an optimal balance between video quality and playback stability.

Table: Comparison of Video Transcoding Types

*Average CPU utilization when transcoding Full HD (1080p) video

**Average GPU utilization when using hardware acceleration (NVENC, QSV)

***Relative transcoding speed compared to complete transcoding

****Delay between input and output video streams

The choice of one or another video transcoding type depends on the specific requirements of the project. In some cases, partial video conversion is sufficient, while in others, complete re-encoding into new formats is required. For streaming, adaptive transcoding is the gold standard, ensuring the delivery of quality video to the widest possible audience.

Where Video Transcoding is Used

Video transcoding finds application in various fields that deal with the processing and delivery of video content. Let's consider the main areas where this technology plays a key role.

• Streaming services. Broadcasting platforms like YouTube, Netflix, Twitch use transcoding to provide adaptive video streaming. The original content is transcoded into multiple versions with different resolutions and bitrates so that each viewer can receive video in optimal quality according to their internet connection speed. This ensures the accessibility of content to the widest possible audience and minimizes buffering issues.
• Video surveillance systems. In the security field, video transcoding helps optimize the recording and storage of video data from surveillance cameras. The high-quality video stream from a camera is converted into a format with lower resolution and bitrate before being sent to the server, saving disk space and reducing network load. At the same time, more important video segments (e.g., moments when the motion detector is triggered) can be stored in high resolution for later analysis.
• IPTV and OTT platforms. Digital television providers use transcoding to unify video streams from various sources (satellite channels, studios, IP cameras) and adapt them to the transmission parameters in their networks. This allows for ensuring a uniform quality standard and compatibility of content with subscriber devices (TVs, set-top boxes, mobile devices).
• Media libraries and archives. Transcoding is indispensable when working with large collections of video material. It allows for bringing diverse content into a unified storage format, saving server space through the use of efficient codecs, and ensuring the compatibility of archived footage with modern playback systems. Additionally, video transcoding makes it possible to create video versions in different quality for various purposes - for example, high resolution for editing and low resolution for preview. The application areas of video transcoding are constantly expanding with the development of technologies and the emergence of new platforms for video content consumption. The ability to flexibly and efficiently manage video stream parameters opens up enormous possibilities for infrastructure optimization and improvement of user experience in many video-related industries.

Technical Aspects of Video Transcoding

To understand the process of video transcoding, it's important to know the main technical components that underlie it. First and foremost, these are codecs - algorithms for compressing and decompressing video data. The most common codecs used today are:

• H.264/AVC - a universal codec widely used in streaming, video conferencing, and on physical media (Blu-ray). It offers high video quality at relatively low bitrate.
• H.265/HEVC - an improved codec that provides even more efficient compression than H.264. It allows for the transmission of high-resolution video (up to 8K) with lower bitrate, saving network traffic.
• AV1 - a new open-source codec developed by an alliance of leading IT companies. It surpasses H.265 in terms of compression efficiency and has the advantage of not having license fees.

The choice of codec and encoding settings (bitrate, resolution, profile) directly affects the video quality after transcoding and its size. The higher the bitrate and resolution, the better the image detail, but also the larger the file size and the load on data transmission channels. Therefore, in transcoding, it is always necessary to find an optimal balance between video quality and size, considering specific requirements.

In addition to codecs, container formats play an important role in transcoding. They define the file structure in which video, audio, and metadata (such as subtitles, information about resolution and bitrate) are stored. The most popular multimedia containers are:

• MP4 - a universal format compatible with most devices and platforms. It can contain video encoded in H.264, H.265, and other codecs.
• MKV - a flexible container with support for a wide range of codecs and advanced capabilities for storing metadata. Often used in home media collections.
• MPEG-TS - a transport stream used in digital television (IPTV, over-the-air, and cable TV) for the transmission of video, audio, and service information.

When transcoding video from one format to another (e.g., from AVI to MP4), the streams are repackaged into a new container and, if necessary, re-encoded with the selected video and audio codec.

Video transcoding is a fairly resource-intensive process, especially when working with high-resolution video or in real-time mode. It requires significant CPU computing power and can take a lot of time. To speed up transcoding, hardware accelerators (graphics processors, specialized chips) and optimized software solutions that utilize parallel processing and other techniques are employed.

Additionally, various problems can occur during the transcoding process - compression artifacts (blocking, blurring), audio-video desynchronization, format incompatibility. To solve these, advanced video processing algorithms (noise reduction, deblocking, frame rate change) and careful selection of encoding and containerization parameters are applied.

Therefore, effective video transcoding requires a deep understanding of how codecs, formats, and multimedia containers work, as well as the presence of a powerful infrastructure for processing video streams. The quality of the result and the performance of the entire system depend on the right choice of technologies and their configuration.

Real-Time Transcoding

One of the most complex and demanded applications of transcoding is real-time video processing. This process involves the immediate conversion of a video stream "on the fly," without prior recording or storage of the content.

Real-time video transcoding is used in various fields:

• Live broadcasts (streaming): online concerts, sporting events, webinars, gaming streams. The original video stream from a camera or software source is transcoded into multiple versions with different resolutions and bitrates for adaptive delivery to viewers.
• Video conferences and remote education. Signals from participants' webcams are processed in real-time to ensure compatibility with client applications and optimize connection quality.
• Cloud rendering and gaming services. Video from game servers or applications is transcoded "on the fly" to adapt it to the parameters of the user's device and transmit it over the network, allowing resource-intensive applications to run even on low-performance machines.
• Remote surveillance and monitoring. In industrial and security systems, video streams from multiple cameras are transcoded in real-time to save network traffic and adapt to the bandwidth of data transmission channels.

Real-time transcoding places very high demands on computing resources and network bandwidth. Video processing must be done with minimal delay to ensure immediate content delivery and interactivity. This requires powerful servers with multi-core processors, graphics accelerators, and high-speed network interfaces.

Software solutions for real-time transcoding use special techniques such as splitting the video stream into independent parts (chunks) and parallel processing of multiple frames simultaneously. This allows for increasing the transcoding speed and reducing delays.

To reduce the load on transcoding servers and optimize video delivery, Content Delivery Networks (CDNs) are used. These place copies of video fragments on multiple servers around the world, allowing users to receive data from the nearest node rather than from a central server. This reduces latency and increases the availability of streams.

Managing the infrastructure for real-time transcoding is a complex engineering task that requires careful resource planning, load monitoring, and fault tolerance. It is necessary to dynamically scale capacity depending on the number of viewers and adapt to peak loads. For this, virtualization, containerization, and orchestration technologies are used, which allow for quickly deploying additional transcoder instances and distributing the load between them.

Overall, real-time transcoding is one of the key technologies that enables the operation of many modern video services. Thanks to it, we can enjoy online broadcasts, work and learn remotely, and play demanding games on any device. However, behind the seeming simplicity and accessibility of these capabilities lies an enormous amount of engineering work and an extremely complex infrastructure that continues to evolve to meet the growing needs of users.

Flussonic Media Server as a Transcoding Solution

Effective video transcoding in real-time and offline processing modes requires powerful and flexible software tools. One of the market leaders in this field is Flussonic Media Server - a multifunctional platform for broadcasting video and audio.

Flussonic Media Server includes a powerful transcoder capable of processing multiple video streams simultaneously. It supports a wide range of input and output formats, codecs, and protocols, enabling its use in various scenarios of video transmission and delivery.

Key advantages of using Flussonic Media Server for transcoding:

• High performance. Thanks to its optimized architecture and support for hardware acceleration (Intel QSV, NVIDIA NVENC), Flussonic provides fast and efficient video transcoding even in high-resolution formats like 4K and 8K.
• Flexibility and scalability. Flussonic allows for flexibly configuring the transcoding parameters for each video stream and adapting them to the requirements of a specific project. The system can dynamically scale by distributing the load across multiple servers in a cluster.
• Support for adaptive bitrate. Flussonic implements adaptive streaming technology (ABR) based on HLS and MPEG-DASH protocols. This allows for automatically generating multiple versions of a video stream with different quality and switching between them depending on network bandwidth and viewer device capabilities.
• Extensive integration capabilities. Flussonic offers multiple interfaces and protocols for integration with external systems: RESTful API, WebRTC, RTMP, RTSP, HLS, UDP/RTP. This facilitates the inclusion of the transcoder into the existing infrastructure and the organization of flexible workflows for video processing.
• Advanced monitoring and management features. Flussonic is equipped with a user-friendly web interface for managing transcoding, monitoring the status of streams, and collecting statistics. It supports integration with logging and notification systems (Syslog, SNMP) and also offers tools for analyzing video quality (error checking, measuring delays and frame losses).
• Additional video editing features. In addition to basic transcoding functions, Flussonic offers advanced tools for manipulating video streams: overlay of graphics and watermarks, advertising insertion, file recording, creation of screenshots and animated previews.

Due to the combination of high performance, flexibility, and multifunctionality, Flussonic Media Server is an optimal choice for organizing video transcoding in a wide range of projects: internet broadcasting, video surveillance, IPTV, corporate communications, and remote education.

Implementing Flussonic does not require deep knowledge in video technology - the server is delivered as a ready-to-use package for Linux and has detailed documentation. If needed, users can count on fast technical support from developers and the community.

Therefore, Flussonic Media Server is a powerful and universal tool that takes on all the complexity of the video transcoding process, allowing you to focus on creating high-quality and innovative video services.

Conclusion

Video transcoding plays a central role in the development of modern media technologies and the streaming industry. Without reliable and efficient tools for converting video formats, it would be impossible to imagine the operation of most services and platforms that supply millions of users worldwide with video content daily.

The future of transcoding is closely tied to new challenges and opportunities that are opening up thanks to advancements in video technology. The development of new compression standards like VVC and AV1 promises to significantly increase the efficiency of transcoding and reduce the costs of transmitting and storing ultra-high-definition video.

The integration of artificial intelligence into transcoding processes opens up exciting prospects for automatic optimization of video quality, personalization of user experience, and creation of innovative video services. And the shift of transcoding to cloud environments will allow companies of any size to access flexible and scalable video processing infrastructure without having to invest in their own hardware and software.

Thus, video transcoding remains a cornerstone in the foundation of the modern video industry, ensuring its technological development and commercial success. Thanks to the continuous improvement of transcoding algorithms, hardware platforms, and infrastructure solutions like Flussonic Media Server, it becomes possible to create increasingly sophisticated, accessible, and attractive video services that enrich our lives and change the way we communicate, learn, and entertain ourselves.

Frequently Asked Questions (FAQ)

1. How does transcoding differ from video compression? Transcoding and video compression are related but different concepts. Video compression is the process of reducing the size of a video file by eliminating redundant information and applying compression algorithms. Transcoding includes compression as one of the steps but also involves changing the video format, its resolution, bitrate, and other parameters to adapt it to different devices and data transmission channels.
2. Is it possible to transcode video without quality loss? Theoretically, lossless transcoding is possible when using lossless compression codecs and maintaining the original video parameters (resolution, bitrate). In practice, however, transcoding is more often used precisely to reduce the size of the video file and adapt it to different conditions, which inevitably leads to some quality loss. The task is to choose optimal transcoding settings that provide an acceptable compromise between video quality and size.
3. What factors influence transcoding speed? Many factors influence the speed of video transcoding:
   • Processor performance (CPU) and availability of hardware acceleration (GPU)
   • Amount of RAM and speed of the disk system
   • Resolution and duration of the original video
   • Complexity and efficiency of the compression codecs used
   • Target parameters of transcoding (resolution, bitrate, format)
   • System load from other processes.
4. Which video codec provides the best compression? The choice of the optimal codec depends on the specific project requirements, target platforms, and available hardware resources. Today, the most efficient video codecs in terms of compression are:
   • H.265/HEVC - provides up to 50% bitrate savings compared to H.264 with comparable video quality. Widely used in streaming but requires significant computing resources for encoding and decoding.
   • AV1 - a new next-generation open-source codec developed by an alliance of leading IT companies. Surpasses H.265 in compression efficiency by 20-30% but still has limited hardware support and slow software encoding.
   • VVC (H.266) - the latest video compression standard that provides up to 50% bitrate savings compared to H.265/HEVC. It is in the active development and implementation phase.