Does Eco-Friendly Streaming or Green Streaming Truly Exist?

Understanding the Sustainability Quotient of Live 'Retranscoding'

In the realm of "media tech sustainability," the impact of various streaming techniques on the environment becomes a significant factor. Live retranscoding, essentially a method of real-time conversion of a video stream from one format or bitrate to another, is one such technique. This method enables compatibility across a range of devices and network conditions, enhancing viewer experience. However, the sustainability implications of live retranscoding and its designation as a "green streaming" method warrant critical consideration.

In the streaming ecosystem, "just-in-time" transcoding is frequently celebrated as an efficient feature, with companies advocating eco-friendly operations (like Broadpeak, Synamedia Quortex) incorporating this into their 'Serverless' solutions. The principle behind "just-in-time" transcoding is the existence of a ready-to-broadcast source file, which the publisher (influenced by the transcoding provider) might decide to retranscode, often for specific reasons such as incorporating a Digital Rights Management (DRM) that can easily be bypassed. It's important to note that real-time transcoding is less energy-efficient and could be applied to content previously transcoded into the final output format, a practice common in reruns.

Evaluating the Carbon Footprint of Live Retranscoding

Analyzing the energy expenditure associated with live retranscoding brings us face-to-face with several sustainability challenges. This process demands dedicated hardware or cloud-based servers for managing the computational workload, which leads to considerable energy usage. Also, the heat generated through live retranscoding often calls for cooling systems, further contributing to energy consumption.

Moreover, the process of live retranscoding can amplify network traffic. As multiple versions of identical content are created to cater to diverse devices and connection speeds, the data transmission across the internet increases. This elevates energy usage in data centers and network equipment, further underscoring the need for sustainability-focused "autoscaling" policies, a consideration often overlooked by cloud vendors like AWS.

In addition, it's crucial to acknowledge the e-waste generated by hardware employed for live retranscoding. As technology evolves and hardware elements become obsolete, they are frequently discarded, intensifying the mounting issue of electronic waste.

The Necessity of Just-in-time Transcoding: A Sustainable Perspective

From a sustainability perspective, one could argue that just-in-time transcoding might be an unnecessary and wasteful practice. For instance, for free-to-air content, just-in-time transcoding might not be necessary at all. Most devices support the HLS (HTTP Live Streaming) standard, albeit not in its latest version. Given the widespread adoption of HLS as a streaming protocol, compatibility issues are reduced, eliminating the need for real-time transcoding of content into various formats or codecs. Opting for a single standard like HLS can simplify streaming while diminishing the energy and computational resources needed for transcoding.

On the other hand, just-in-time transcoding could be essential for DRM (Digital Rights Management)-protected streams, as different devices might not support the same DRM systems. Various devices and platforms might use different DRM technologies, including Widevine, PlayReady, or FairPlay. To ensure compatibility while maintaining content protection, real-time transcoding may be needed to meet the unique DRM demands of each device or platform. Despite being energy-consuming, this process guarantees that content remains protected and accessible across a broad spectrum of devices.

Balancing Energy Efficiency and Device Compatibility: The Role of Codecs

In the quest for sustainability, identifying an energy-efficient codec that also ensures extensive device compatibility is crucial. The H.264 codec, also known as AVC (Advanced Video Coding), currently fits this role. H.264 provides high video quality at relatively low bitrates and has been an industry standard for several years. This codec enjoys extensive support from various devices, including smartphones, tablets, computers, and smart TVs.

Newer codecs such as H.265 (HEVC) and AV1 offer superior compression efficiency, which could translate into energy savings during content distribution and playback. However, these codecs might not be as widely supported by devices, particularly older ones. Additionally, encoding with these codecs can be more computationally demanding, potentially leading to increased energy consumption compared to H.264.

Energy Consumption: Comparing AV1 and H264 Encoding

The energy consumption associated with video encoding is directly related to the specific codec and encoding settings used. AV1, a more advanced and efficient video codec than H.264, delivers superior video quality at lower bitrates. However, this improved compression efficiency comes at the expense of greater computational complexity during encoding.

While exact figures of energy consumption difference between AV1 and H.264 encoding can be challenging to provide, it's generally accepted that AV1 encoding demands significantly more computational resources than H.264 encoding. Depending on the specific encoding settings, AV1 might consume anywhere from 5 to 20 times the computational resources required by H.264 to encode the same video content.

This surge in computational requirements translates into higher energy consumption during the encoding process. However, the efficient compression by AV1 leading to smaller file sizes and lower streaming bandwidth requirements can offset some of this increased energy consumption during distribution and playback.

Debunking the 'Serverless' Myth: A Sustainability Angle

"Serverless" is more than a marketing term. It represents a concrete concept and architectural approach in cloud computing. Serverless computing enables developers to run applications without the need to manage the underlying infrastructure. In a serverless architecture, cloud service providers dynamically allocate resources and handle infrastructure management tasks, including server provisioning, scaling, and maintenance.

Despite its name, servers are still present in "serverless" computing, but the responsibility for managing them falls on the cloud provider. This model typically operates on a pay-as-you-go basis, where users are billed based on actual compute resource consumption rather than pre-allocated capacity.

Serverless architectures generally rely on Functions as a Service (FaaS) platforms such as AWS Lambda, Google Cloud Functions, or Microsoft Azure Functions. These platforms allow developers to write and deploy individual functions triggered by specific events or requests. This approach enables greater flexibility, faster development, and potential cost optimization (when used on-demand), as resources are consumed only when the functions are executed.

Assessing the Viability of Serverless for 24/7 Streaming Operations

While serverless computing offers numerous benefits, such as scalability, accelerated development, and reduced infrastructure management, its suitability for 24/7 operations like TV channels is questionable, particularly regarding cost and energy consumption.

The pay-as-you-go model of serverless architectures can be cost-effective for intermittent or variable workloads. However, for continuous 24/7 operations, the costs can quickly add up due to the consistent use of compute resources. In such scenarios, traditional server-based architectures or virtual machines with fixed pricing models might be more cost-effective.

In terms of energy consumption, the on-demand nature of serverless computing can lead to more efficient resource utilization for variable workloads, but this advantage diminishes for 24/7 operations. In fact, dedicated servers or virtual machines optimized for continuous workloads may consume less energy overall.



Another sustainability consideration is the amount of e-waste produced by rapidly outdated hardware used in serverless operations. This factor contributes significantly to the environmental impact of these technologies.

Media Tech Sustainability: A Call for Real Green Solutions, Not Greenwashing

Considering the factors above, it's clear that live retranscoding, just-in-time transcoding, and serverless operations cannot be dubbed as green streaming. Rather than greenwashing existing practices, 'green labels', the industry should strive for genuine media tech sustainability. This sustainability includes exploring more sustainable alternatives such as longer hardware support (eg.: 5-year warranty), adaptive bitrate streaming storage for reruns and other 'live-like' broadcasts (VOD2Live), efficient video codecs, and edge caching. These technologies can help to reduce energy consumption, network traffic, and e-waste, while still delivering a high-quality streaming experience for viewers.

Indeed, the 'greenest' TV channel may be one that utilizes the most energy-efficient CPU for transcoding, and avoids retranscoding assets that have already been transcoded. These practices are seldom found in services claiming to be 'green'. Therefore, achieving media tech sustainability requires more than PR battles and greenwashing - it demands a commitment to developing and implementing truly green technologies.

For that reason, the TV channel demoed below is likely 'greener' than most initiatives currently labeled as 'green' in the streaming industry (especially for companies advertising their "green" focus at all trade shows worldwide, often involving 10 or more people traveling). Not only does it utilize the most energy-efficient CPU for transcoding, but it also avoids retranscoding assets that have already been transcoded and actual transcoding is performed with solar overcapacity, sometimes with computers more than 10 years old (H.264 CPU encoding started in 2003). This sets it apart from many advertised green services that fail to implement either of these practices.

Article written by
Sylvain Corvaisier

Independent streaming and iOS engineer

Last modified: January 15th, 2025