Just-In-Time encoding, also known as Just-In-Time packaging, is a method where video content is encoded and packaged in real-time, just before delivery to the viewer. It is different than traditional encoding, where videos are pre-encoded into various formats and stored on servers.
JIT encoding processes the video content only when a request is made by the viewers. This real-time encoding ensures that the content is processed according to the viewer’s requirements such as bandwidth and device capacity with other specific requirements.
The term packaged is mentioned here, to understand Just in time encoding. Let us start by understanding what video packaging is.
Video packaging is also known as video encoding it is a process of converting digital video content from one format to another, a step in ensuring compatibility and performance across various platforms and devices providing a better watching experience.
Key Aspects of Video Packaging:
Now that we understand what video packaging is, lets us dive deeper into understanding more about different modes of packaging.
In the linear packaging process, live video is first converted into an MPEG-2 Transport Stream (TS) and then processed by a packager. This packager divides the stream into smaller segments, creating individual files.
These files are either used as the source for a content distribution network (CDN) or transferred to the CDN's origin server. The CDN then takes over the task of delivering these segments to the end users.
To improve efficiency, the CDN replicates the segments at its edge locations. This approach reduces the need for every client request to travel back to the central network and the packager, thus optimizing the delivery process and decreasing network congestion.
Drawbacks of linear packaging
While linear packaging has been a traditional method for video delivery, it presents several challenges in today's streaming landscape:
File-based packaging, involves converting a file from its original format into an HTTP-compatible format. File based packaging is mostly used for VOD (Video on Demand) where pre-recorded encoded content is converted from one format into an HTTP deliverable format.
For instance, a TS file format designed for legacy TS streamers can be transformed into an HLS segmented format. In offline packaging, all the segments and playlists are pre-created and stored, ready for future delivery.
Drawbacks of file packaging in streaming
While file packaging has been a traditional method for distributing video content, it presents several challenges in the modern streaming landscape:
Edge packaging is particularly favoured for live streaming delivery, as it helps reduce core network bandwidth by minimizing the load on central servers by moving the packager to an edge site, co-located with the CDN, the same packaging functions are performed closer to the end-user. This approach maintains the efficiency of packaging processes while optimizing network performance and reducing latency.
Drawbacks of edge packaging
Traditional encoding is tough to work with due to the need to support a wide range of devices, each requiring different resolutions and bitrates. High-quality streams demand more bandwidth, and adaptive bitrate (ABR) streaming must handle varying network conditions. Managing multiple versions of videos increases storage and delivery costs, and the time-consuming process led to delays.
Traditional video processing involves pre-rendering a video into multiple formats for different devices and network conditions. This process, while ensuring compatibility, demands substantial storage and computational resources. Furthermore, it lacks the flexibility to adapt to dynamically changing network conditions.
In contrast, Just-in-Time (JIT) encoding offers a more efficient approach. By processing a single master video file only when requested, JIT significantly reduces storage requirements and computational overhead. Moreover, it empowers real-time adaptation to varying network conditions, delivering optimal video quality for each viewer.
This dynamic approach not only enhances viewer experience but also optimizes resource utilization.
JITP addresses storage and bandwidth challenges by dynamically encoding video content now it is requested by the viewer, rather than storing multiple pre-encoded versions. This approach optimizes both storage and bandwidth usage:
Storage Efficiency: Instead of storing numerous video files like what happens in traditional encoding method in JITP things are bit different it stores a single high-quality master copy. When a user requests a video to play, JITP encodes it on-the-fly into the appropriate format and resolution required reducing the overall storage consumption.
Bandwidth Optimization: JIT encoding videos in real-time based on user device and network conditions this steps ensures better streaming quality while minimizing bandwidth consumption. This adaptive streaming capability adjusts video quality dynamically to match available bandwidth, delivering a seamless experience for the viewers even with different network speed and device compatibility.
The Process begins with the storage of high-quality source video files in a central repository. These files, often in a mezzanine format (like ProRes or DNxHD), serve as the pristine source material for subsequent encoding.
When a user initiates a request to stream a video, the JIT encoding system assesses several factors to determine the optimal encoding parameters:
Client device characteristics: The system identifies the type of device (e.g., smartphone, tablet, smart TV) and its capabilities such as screen resolution, supported codecs, and processing power.
Network conditions: It evaluates the current network bandwidth and latency to gauge the appropriate bitrate and streaming protocol (e.g., HLS, MPEG-DASH) for seamless playback.
User preferences: Optionally, user settings or preferences may influence encoding decisions, such as language preference or accessibility features.
Once the system has gathered relevant information, it proceeds with the real-time encoding process:
Transcoding: The JIT encoding system transcodes the original source video into a format and bitrate optimized for the specific device and network conditions identified earlier.
Adaptive bitrate streaming: For adaptive bitrate streaming, multiple versions of the video may be generated simultaneously at varying bitrates (e.g., 720p, 1080p) to accommodate fluctuations in network speed without interrupting playback quality.
Codec conversion: If necessary, the system converts the video into a codec compatible with the client device, ensuring efficient decoding and playback.
Following encoding, the JIT system packages the transcoded video into the appropriate streaming format:
Segmentation: The video stream is segmented into chunks or segments, typically a few seconds long, to facilitate adaptive bitrate streaming. Each segment is encoded at different quality levels to provide smooth transitions between bitrates during playback.
Manifest file generation: A manifest file (e.g., .m3u8 for HLS) is generated that contains metadata and URLs pointing to each segment. This file guides the client device on how to retrieve and playback the video segments seamlessly.
To ensure efficient delivery, the JIT encoded video segments and manifest file are distributed across a Content Delivery Network (CDN):
Edge Caching: CDNs (Content Delivery Networks) cache video segments at edge servers geographically closer to the end-users, reducing latency and improving streaming performance.
Load Balancing: CDNs balance traffic load across multiple servers to handle concurrent requests efficiently, especially during peak viewing times.
Just-In-Time (JIT) encoding makes video streaming better by encoding videos right when needed, saving storage space, and ensuring smooth playback on any device. This approach cuts costs, can handles high demand and delivers high-quality video by adapting to different devices and network conditions. At FastPix we are committed to make video simpler and a create better experience for the viewers.