Schedule 1 was created by the International Organization for Standardization (ISO) as part of the ISO/IEC 23008 standard for video coding

Schedule 1 is a technical specification that defines how video data gets organized and transmitted in modern game engines and streaming applications. The ISO — a Geneva-based organization made up of standards bodies from 168 countries — developed it alongside the IEC (International Electrotechnical Commission) to create a universal language for how computers handle video compression and playback.

The standard emerged from decades of work on video compression formats. Before Schedule 1, different companies used different methods to encode video, which meant game developers and streaming platforms had to support multiple formats or risk losing compatibility. The ISO/IEC standard created a single framework that hardware manufacturers, software companies, and game studios could all build around.

Understanding who made Schedule 1 matters because it explains why your graphics card, your game engine, and your streaming software all speak the same language for video. It is not a proprietary tool owned by one company — it is a shared specification that belongs to the technical community.

Key Takeaways

  • The ISO and IEC jointly created Schedule 1 as part of a formal video coding standard, not a single company or person.
  • The standard emerged from working groups that included engineers from hardware makers, software companies, and research institutions across multiple countries.
  • Schedule 1 defines how video data is structured so that different devices and programs can decode it the same way.
  • Game developers use Schedule 1 specifications when choosing graphics APIs and compression methods for their projects.

How the ISO and IEC developed the standard

The ISO and IEC do not create standards in a single office or by decree. Instead, they convene working groups — committees made up of engineers, researchers, and representatives from companies that have a stake in the technology. For video coding standards, these groups included people from NVIDIA, AMD, Intel, Microsoft, Apple, Google, and dozens of universities and research labs.

These working groups meet regularly to propose new features, test existing ones, and debate trade-offs. A proposal might come from a researcher at a university, a hardware engineer at a GPU manufacturer, or a software developer at a game studio. The group tests it, measures how well it works, and votes on whether to include it in the standard.

The process takes years. The group publishes drafts, gathers feedback from the broader technical community, revises based on that feedback, and repeats until they reach consensus. Only then does the standard get published as an official ISO/IEC specification that anyone can reference and build on.

Why game developers need to understand Schedule 1

When you choose a game engine like Unreal Engine or Unity, you are choosing software that already understands Schedule 1. The engine's graphics pipeline — the code that takes your 3D models and turns them into pixels on screen — is built around standards like this one. You do not have to implement Schedule 1 yourself; the engine does it for you.

However, understanding that Schedule 1 exists helps you make better decisions about compression, streaming, and compatibility. If you are building a game that streams video to players, or that needs to run on multiple devices, knowing that Schedule 1 is the common language means you can trust that your video will play the same way on a Windows PC, a Mac, an Android phone, and a PlayStation.

It also explains why certain features are available in your engine and others are not. If your graphics API does not support a particular compression method, it is often because that method is not part of the standard yet, or because hardware manufacturers have not all implemented it.

The difference between Schedule 1 and other video standards

Schedule 1 is one part of a larger family of video coding standards. The ISO/IEC also maintains H.264, H.265 (HEVC), and VP9 — all different ways of compressing video. Each has different trade-offs: some compress more aggressively but require more processing power to decode, others are simpler but produce larger files.

Game developers typically care about which standard their target hardware supports. A mobile game might use H.264 because older phones still have hardware decoders for it. A PC game might use H.265 because modern graphics cards can decode it quickly. A streaming service might use VP9 because it offers good compression without requiring licensing fees.

Schedule 1 sits within this ecosystem as a formal specification that ensures all these formats can coexist and that new formats can be added without breaking existing ones. It is the rulebook that keeps the different formats compatible.

How Schedule 1 affects your hardware choices

When you buy a graphics card, the manufacturer has already built in support for the video standards that matter most — usually including H.264 and H.265. This hardware support means your GPU can decode video without using your CPU, which saves power and processing cycles for your game logic.

The reason your graphics card supports these specific standards is that they are part of the ISO/IEC specification. Manufacturers know that if they implement the standard, their hardware will work with any software that also implements it. This mutual agreement is what makes the ecosystem work.

If you are building a game that needs to play video — a cinematic, a tutorial, a replay — you are relying on the fact that Schedule 1 and related standards exist. Without them, you would have to write custom code for every device and every operating system.

The ongoing evolution of video standards

Schedule 1 is not static. The ISO/IEC working groups continue to meet and propose improvements. New compression techniques get tested, new use cases get addressed, and the standard gets updated. These updates happen roughly every few years, and they are backward-compatible — older hardware can still decode video made with older versions of the standard.

Game developers do not have to track these updates closely unless they are working on cutting-edge features like real-time ray-traced video or 8K streaming. For most projects, the standards that were current when your engine was released will still be relevant years later.

However, staying aware of the standard's direction helps you future-proof your game. If you know that a new compression method is coming in the next version of the standard, you can design your video pipeline to support it when hardware manufacturers add it.

Where to find the actual Schedule 1 specification

The full ISO/IEC 23008 standard is available from the ISO directly, but it is not free — standards documents typically cost between $100 and $300. However, you do not need to buy it unless you are implementing a video codec from scratch, which most game developers never do.

Instead, you can find summaries and technical overviews on the websites of companies that implement the standard: NVIDIA's developer documentation, AMD's graphics resources, and Intel's media guides all explain how their hardware supports these standards. Your game engine's documentation will also explain which video formats it supports and how to use them.

If you are curious about the technical details, research papers from the working group members are often published in academic journals and conference proceedings. These papers explain the reasoning behind specific design choices and are usually free to read.

Frequently Asked Questions

Do I need to understand Schedule 1 to make games?

No. Your game engine handles the technical details. You only need to understand it if you are working on video streaming, compression optimization, or cross-platform compatibility issues. Most game developers never interact with Schedule 1 directly.

Is Schedule 1 the same as H.265?

No. H.265 (HEVC) is one video codec. Schedule 1 is part of the larger ISO/IEC standard that defines how multiple codecs fit together and how new ones can be added. H.265 is one implementation of the standard.

Why do different devices support different video formats?

Hardware manufacturers choose which formats to support based on market demand and licensing costs. Schedule 1 ensures that whatever formats they choose will work together. Older devices might not support newer formats because they were built before those formats existed.

Can I use any video format in my game?

You can use any format your engine supports and that your target hardware can decode. Most modern engines support H.264 and H.265. If you use a format that older devices do not support, those devices will not be able to play your game.

Who decides what goes into the next version of Schedule 1?

The ISO/IEC working groups decide, through a voting process. Members from hardware companies, software companies, universities, and government bodies all have a say. Proposals come from any member, and consensus is required to add new features.