Bas, just a heads up: We're having trouble getting "overhead-free" frame capturing to work in a DirectComposition world. This is somewhat understandable: With DC, Firefox is no longer responsible for computing the assembled window "scene"; this work is now done by the window manager. A buffer with the window pixel contents no longer exists. So frame capturing is now asking us to compute something that we don't have, so it will fundamentally come with some overhead. Either Firefox will need to do some extra work to do the compositing itself (which is what we've been doing in the past anyway), or we need to get the window pixels from the window manager somehow. The latter has multiple problems: It's either synchronous and slow, or asynchronous with uncertain contents (could return old frames and even skip frames), and it also has to do extra work because our window might be occluded. Do you have ideas or preferences of how to address this?
Bug 1602643 Comment 5 Edit History
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Bas, just a heads up: We're having trouble getting "overhead-free" frame recording to work in a DirectComposition world. This is somewhat understandable: With DC, Firefox is no longer responsible for computing the assembled window "scene"; this work is now done by the window manager. A buffer with the window pixel contents no longer exists. So frame recording is now asking us to compute something that we don't have, so it will fundamentally come with some overhead. Either Firefox will need to do some extra work to do the compositing itself (which is what we've been doing in the past anyway), or we need to get the window pixels from the window manager somehow. The latter has multiple problems: It's either synchronous and slow, or asynchronous with uncertain contents (could return old frames and even skip frames), and it also has to do extra work because our window might be occluded. Do you have ideas or preferences of how to address this?
Bas, just a heads up: We're having trouble getting "overhead-free" frame recording to work in a DirectComposition world. This is somewhat understandable: With DC, Firefox is no longer responsible for computing the assembled window "scene"; this work is now done by the window manager. A buffer with the window pixel contents no longer exists. So frame recording is now asking us to compute something that we don't have, so it will fundamentally come with some overhead. Either Firefox will need to do some extra work to do the compositing itself (which is what we've been doing in the past anyway), or we need to get the window pixels from the window manager somehow. The latter has multiple problems: It's either synchronous and slow, or asynchronous with uncertain contents (could return old frames and even skip frames), and it also has to do extra work because our window might be occluded. Do you have ideas or preferences for how to address this?