ADL feature request: modifying pixel clock on the fly

Discussion created by madshi on Sep 30, 2010
Latest reply on Nov 16, 2010 by madshi
for smooth video playback without dropped/repeated frames

When doing high quality video rendering with a PC, one sooner or later runs into problems with mismatching video and audio hardware clocks, resulting in the necessity to drop or repeat video frames at specific intervals. This might not be a problem for YouTube watching, but for high quality (e.g. Blu-Ray) playback, if we want to rival hardware Blu-Ray player quality, it's very important to have a perfectly smooth experience without any video frame drops or repeats.

I'd like to see a new ADL API for changing the pixel clock dynamically, without invoking a full output mode reset. This would be used to adjust the video clock dynamically during video playback to match the audio hardware clock.

If you AMD guys are willing to add such an API, it would be great if you could allow very small step changes. The steps should be smaller than what e.g. ADLDetailedTiming.sPixelClock allows. The smaller the steps, the better...



Edit: Found the following undocumented ADL APIs:
- ADL_Display_CurrentPixelClock_Get
- ADL_Display_PixelClockCaps_Get
- ADL_Display_PixelClockAllowableRange_Set

Maybe they already do what I need? Does anybody have the documentation for these APIs?