On 27/03/17 13:58, Jose Abreu wrote: > Hi Hans, > > > On 24-03-2017 12:28, Hans Verkuil wrote: >> On 03/24/17 13:21, Jose Abreu wrote: >>> Hi Hans, >>> >>> >>> On 24-03-2017 12:12, Hans Verkuil wrote: >>>> On 03/24/17 12:52, Jose Abreu wrote: >>>>> Hi Hans, >>>>> >>>>> >>>>>>> Can you please review this series, when possible? And if you >>>>>>> could test it on cobalt it would be great :) >>>>>> Hopefully next week. >>>>> Thanks :) >>>>> >>>>>> Did you have some real-world numbers w.r.t. measured >>>>>> pixelclock frequencies and 60 vs 59.94 Hz and 24 vs 23.976 Hz? >>>>> I did make some measurements but I'm afraid I didn't yet test >>>>> with many sources (I mostly tested with signal generators which >>>>> should have a higher precision clock than real sources). I have a >>>>> bunch of players here, I will test them as soon as I can. >>>>> Regarding precision: for our controller is theoretically and >>>>> effectively enough: The worst case is for 640x480, and even in >>>>> that case the difference between 60Hz and 59.94Hz is > 1 unit of >>>>> the measuring register. This still doesn't solve the problem of >>>>> having a bad source with a bad clock, but I don't know if we can >>>>> do much more about that. >>>> I would really like to see a table with different sources sending >>>> these different framerates and the value that your HW detects. >>>> >>>> If there is an obvious and clear difference, then this feature makes >>>> sense. If it is all over the place, then I need to think about this >>>> some more. >>>> >>>> To be honest, I expect that you will see 'an obvious and clear' >>>> difference, but that is no more than a gut feeling at the moment and >>>> I would like to see some proper test results. >>> Ok, I will make a table. The test procedure will be like this: >>> - Measure pixel clock value using certified HDMI analyzer >>> - Measure pixel clock using our controller >>> - Compare the values obtained from analyzer, controller and >>> the values that the source is telling to send (the value >>> displayed in source menu for example [though, some of them may >>> not discriminate the exact frame rate, thats why analyzer should >>> be used also]). >>> >>> Seems ok? I will need some time, something like a week because my >>> setup was "borrowed". >> That sounds good. Sorry for adding to your workload, but there is no >> point to have a flag that in practice is meaningless. >> >> I'm actually very curious about the results! > > I managed to do the tests but unfortunately I can't publish the > full results (at least until I get approval). > > I can say that the results look good. As you expected we have > some sources with a bad clock but this is correctly detected by > the controller (and also by the HDMI analyzer). > > Using the v4l2_calc_framerate function I managed to get this: > > | Source | Resolution | v4l2_calc_framerate() > ------------------------------------------------------------------------------ > | Analyzer 1 | 640x480@59.94 | 59.92 > | Analyzer 1 | 640x480@60 | 60 > | Analyzer 1 | 1920x1080@60 | 60 > | Player 1 | 1920x1080@59.94 | 59.94 > | Player 2 | 1920x1080@59.94 | 59.93 > | Player 3 | 3840x2160@59.94 | 59.94 > | Player 4 | 1920x1080@59.94 | 59.94 > | Player 5 | 1920x1080@59.94 | 59.93 > | Player 6 | 1280x720@50 | 50 > | Player 7 | 1920x1080@59.94 | 59.93 > | Player 8 | 1920x1080@60 | 60 > | Analyzer 2 | 720x480@59.94 | 59.94 > | Analyzer 2 | 720x480@60 | 60 > | Analyzer 2 | 1920x1080@59.94 | 59.93 > | Analyzer 2 | 1920x180@60 | 60 > | Analyzer 2 | 3840x2160@23.98 | 23.97 > | Analyzer 2 | 3840x2160@24 | 24 > | Analyzer 2 | 3840x2160@29.97 | 29.96 > | Analyzer 2 | 3840x2160@30 | 30 > | Analyzer 2 | 3840x2160@59.94 | 59.93 > | Analyzer 2 | 3840x2160@60 | 60 Nice! Are the sources with a bad clock included in these results? I only see deviations of 0.02 at most, so I don't think so. > ------------------------------------------------------------------------------ > > What do you think? Shall we continue integrating this new patch > or drop it? Yes, we can continue. This is what I wanted to know :-) Thank you for testing this, much appreciated. Regards, Hans
