Ensuring Video DRM Compatibility across Browsers & Platforms

Video DRM protection is now considered an essential part of the video infrastructure for premium content platforms. While DRM technologies help creators maximize their video revenues, they also bring the challenge of ensuring compatibility and a smooth playback experience across maximum devices and browsers.

This article presents key aspects affecting DRM compatibility, security levels, and steps that one can take to resolve compatibility issues. 

Three Key Video DRM Technologies to Secure Videos

There are three important DRM technologies that are used to secure videos across most platforms and services and they are –

• Google Widevine DRM
• Apple Fairplay DRM
• Microsoft Playready DRM

These three technologies have different levels of compatibility for different devices and browsers which we shall see next.

Compatible Devices and Browsers For Each DRM

Google Widevine DRM

• Desktop/Laptop Chrome, Firefox, Edge Browsers (Windows Version
• Android Chrome, Edge, Firefox browsers. (Android Version 5 & higher)
• Android App (Android Version>5). Native Apps are supported, web view apps are not well supported.
• Android TV
• Chromecast

Apple Fairplay DRM

• Mac Safari
• iOS Safari (iOS >11.2)
• iOS App. Native Apps are supported, web view apps are not supported.
• Apple TV

Microsoft Playready DRM

• Windows Desktop Edge Browser

Note

• Edge supports both Widevine and Playready DRM.
• Browsers should be updated. Generally, the last 2 or 3 versions are well supported.

If you look at the above list, then you can see certain browsers are not supported. E.g., Opera browser, default device browsers like the MI browser in Android, Chromium browser on Desktop; these are not supported. 

Thus, unlike simple nonsecure HTML5 video playback, which is well supported across all browsers, DRM-based playback support is limited to some key popular browsers.

Security Levels for DRM

There are HDCP security levels for each DRM, and it is in the hands of the DRM provider/platform to ensure optimum security without compromising on the playback experience and compatibility.

Widevine L1 vs. L3

Widevine has different security levels and it is common to see a mix of these across devices, and use-cases. Let’s take a quick look. 

1. Android and Desktop Devices can either have Widevine L1 or Widevine L3 security. And, from our experience, we’ve seen that almost all desktop devices are Widevine L3. 
2. Android devices are commonly seen with both L1 and L3 Security. Many modern phones are L1 while many old phones, especially the lower budget ones, are L3, but there can be exceptions to this rule.
3. Widevine L1 is more secure than Widevine L3 at the hardware level and ensures protection against screen capture in mobile apps.  Hollywood Studios generally require playing Ultra HD or Full HD (4k or 1080p) only on L1 devices while providing HD up to 720p for L3 devices. 

What we’ve just seen is a set of guidelines and ultimately, the decision is solely in hand of content provider and is an optional enforcement through DRM.

Playready DRM Security Levels

Just like Widevine, Playready allows setting up varying levels of security requirements. The different security levels signify how much protection is available by a combination of hardware, OS, and browser. The most important parameters in these security levels are the availability of protection systems such as

1. A secure place on the processor to decrypt,
2. A secure internal pipeline to connect to display (related to Verified Media Path)
3. HDCP levels
4. Another similar copy-protection tech such as DTCP or CGMS.  The ideal security level is a trade-off between compatibility and the level of protection required.
5. A large percentage of Apple devices default are compatible with the highest level of Fairplay DRM security. Thus, most platforms/DRM providers can keep the highest level of security with Fairplay DRM without compromising the playback experience. 

How & Why has DRM Compatibility Changed? What Does The Future Look Like?

While the compatibility of DRMs across Chrome, Safari and Native Apps has been consistent for many years; other browser support has varied over time.

Some changes which I have seen in past few years in DRM compatibility are –

• Edge Widevine DRM compatibility was not there earlier until Edge started development based on Chromium. It is now compatible with Widevine DRM.
• Desktop Firefox Widevine DRM compatibility was not there before 2015. 
• Android Firefox Widevine DRM compatibility – This was not compatible earlier but is now compatible. (from Firefox version 85 onwards)
• Android Opera Widevine DRM compatibility – Was compatible in most devices earlier but now mostly not compatible.
• Screen Capture protection in Chrome on Android – Many devices protected screen capture in Android chrome earlier, about 2 years back (though Google never claimed they would protect all Android Chrome playback from screen capture, it was present in most devices). Still, now in many devices, screen capture protection is not present in Android Chrome. 
• Fairplay DRM compatibility in iOS Chrome – Fairplay DRM support for IOS chrome is present for iOS 14 and higher. This is not so for iOS 13 and earlier versions.  

Reason for DRM Compatibility Changes with Time?

As you see, in all the above cases, the changes have been in the browsers which were not owned by the DRM provider company. 

E.g for Widevine DRM, non-Chrome browsers saw a change in compatibility; while for Fairplay DRM, non-Safari browser saw change in compatibility.

Google Widevine DRM requires browsers to include Widevine CDM (Content Decryption Module) as a part of the browser, so until the browser company partners with Google Widevine, it can not provide Widevine DRM support.

A few examples of this below –

• There was a huge hue and cry by DRM opposers when Firefox added Widevine DRM support in 2015. One can read the news and the discussion comments in this old news article.
• A new browser Metstream was denied Widevine DRM by Google (source)

Some Devices That Cause Frequent DRM Compatibility Issues

Ideally speaking, Widevine DRM should be compatible with all Android devices with OS 5 or higher. But in our experience at VdoCipher, we have seen about 0.2% to 0.4% of all Android devices not providing Widevine DRM support for Android Chrome and Android App.

Certain devices such as Redmi 4A, Redmi Note 8 Pro (not all devices of these models), some models of Oppo, Realme, Huawei give DRM compatibility errors. DRM errors are also faced in few other manufacturer devices.

We have also seen DRM compatibility go down in case of a wrong OS update by the manufacturer. Since these third-party manufacturers add their own modifications over the default Android OS and have hardware-based incompatibilities, these devices do not support Widevine DRM. 

Google has been working with various manufacturers to reduce issues over the years. The device manufacturers also try to correct the issue in their future OS updates. 

An example of an issue where Google is the manufacturer for its phone devices Pixel changed DRM settings for the device, which leads to users not playing HD content from Netflix; this can be read in this article.

What Can Be Done To Ensure Maximum DRM Compatibility?

There are few steps one can take to ensure the highest levels of DRM compatibility –

1. Ensure the right actionable error messages are displayed on non-compatible browsers and devices so that the viewer can understand and make the necessary modifications to play DRM content. E.g., if a browser/OS is not updated, the error message should indicate this issue clearly. Or, if the browser is not DRM compatible, then suggest a change in the browser. 
2. Some compatibility issues can be due to non-optimized DRM parameter management or wrong integration. E.g., an update by Widevine to enforce higher security left HBO Linux users facing playback issues; the issue was later corrected by HBO (source)
3. Only if the content provider is ready can one provide non DRM but encrypted playback. Various standard encryption protocols are available in the market (e.g., AES 128), or one can also modify them to enhance security. But if the highest security is required, then only DRM playback should be supported.
4. Improving Android Chrome DRM compatibility by VdoCipher – In the case of VdoCipher, we saw that Android chrome compatibility was particularly an issue in few devices. Thus along with our video hosting, we provided an alternate option for some viewers through our android player app called Zenplayer. It supports Widevine DRM playback and can be prompted directly from the Chrome browser.

I hope the above article gives you a larger perspective on why DRM is considered a difficult part of video infrastructure implementation for any video platform and steps one can take to improve the playback experience for their viewers.

If you are looking for a comprehensive video DRM solution that enables you to provide a smooth playback experience for your global viewers across the widest range of devices and browsers, check out VdoCipher.com.

This is a sponsored post by VdoCipher.com.