The Windows 10 Anniversary Update, which was the operating system's biggest update since it launched last year, seems to have caused many users' webcams to freeze. The issue comes from a change Microsoft made in how apps can access the webcam video streams, which Microsoft is now saying it didn't communicate well enough.
With Windows 10 Anniversary Update, Microsoft allows multiple apps to access webcam streams concurrently. Before, that wasn't possible without hurting streaming performance. Microsoft’s Mike M. from the Windows Camera Team (opens in new tab) said that the change was necessary so things like the Windows Hello webcam authentication or HoloLens would still work even when, say, Skype is running.
To make this possible, the company made it so that the stream goes uncompressed into the app (rather than having each app decode the same stream). Then, the apps can manipulate the data in a way that won’t impact the streaming performance of other apps.
Apps that use the webcam would have to support this change, otherwise they would stop working. Apps that only support encoded H.264 and MJPEG formats would freeze users’ webcams. This issue seem to have affected millions of users, as one commenter said on Microsoft’s MSDN website.
“We have a working product running for years and millions of unhappy users that are unable to use it at all after this update,” said “Dacuda,” a commenter on MSDN."We use the jpeg frames from the camera in order to scan. Our application is not able to use the camera, and our customers are in huge numbers daily complaining since the update was released," he added. "We are eagerly expecting windows update with a fix for this issue. Please make it with highest priority,” he pleaded.
Another commenter wrote:
“After spending days finding a solution we also stuck with the Anniversary update. Thousands of our customers can’t use our product now to process their payments by e-banking! We and especially our customers - which are your customers too - are really reliant on MJPEG!! Please fix this issue as soon as possible so our support is not overwhelmed with inquiries all day and we cannot offer another solution than downgrade Windows. Thanks a lot,” said Stephen B. on Microsoft’s MSDN website.
Microsoft’s Mike M. said that the company has been working with app developers since January to implement these changes into their apps. However, even if all app developers implemented the change, it would still be up to users to get the latest versions of the apps. That’s why Microsoft apologized for “failing to communicate” the change to users when the Anniversary Update arrived.
“So yes, MJPEG and H.264 being decoded / filtered out is the result of a set of features we needed to implement, and this behavior was planned, designed, tested, and flighted out to our partners and Windows Insiders around the end of January of this year,” said Mike M. from the Windows Camera Team.“We worked with partners to make sure their applications continued to function throughout this change, but we have done a poor job communicating this change out to you guys. We dropped the ball on that front, so I’d like to offer my apologies to you all. We’re working on getting better documentation out, to help answer any questions you may have,” he added.
Dacuda’s comment above makes it seem as if not all app makers were aware of the change. Also, because the stream is now uncompressed, that means more data gets sent from the camera for high resolutions. Because many webcams use USB 2.0 connections, they can’t handle that much uncompressed data, so the video data would now be sent at a lower resolution to the application. Before, developers could get high-resolution compressed videos straight from the camera, so 1080p at 30fps recording was possible even over USB 2.0 connections.
Microsoft said that it will offer a fix for MJPEG and H.264 apps soon, but it’s not clear yet what exactly these patches will fix. We will have to see if Microsoft will allow the apps to work as they did before in Windows 10, while encouraging developers to transition to the new solution as soon as possible, or whether it comes out with an alternative workaround that can satisfy everyone.