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Groups > linux.kernel > #1610522 > unrolled thread
| Started by | Hans Verkuil <hverkuil@xs4all.nl> |
|---|---|
| First post | 2017-03-28 12:10 +0200 |
| Last post | 2017-03-29 15:30 +0200 |
| Articles | 2 — 2 participants |
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Re: [PATCH 0/3] Handling of reduced FPS in V4L2 Hans Verkuil <hverkuil@xs4all.nl> - 2017-03-28 12:10 +0200
Re: [PATCH 0/3] Handling of reduced FPS in V4L2 Jose Abreu <Jose.Abreu@synopsys.com> - 2017-03-29 15:30 +0200
| From | Hans Verkuil <hverkuil@xs4all.nl> |
|---|---|
| Date | 2017-03-28 12:10 +0200 |
| Subject | Re: [PATCH 0/3] Handling of reduced FPS in V4L2 |
| Message-ID | <tpWeD-62o-47@gated-at.bofh.it> |
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
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| From | Jose Abreu <Jose.Abreu@synopsys.com> |
|---|---|
| Date | 2017-03-29 15:30 +0200 |
| Message-ID | <tqlPI-7sg-13@gated-at.bofh.it> |
| In reply to | #1610522 |
Hi Hans, On 28-03-2017 11:07, Hans Verkuil wrote: > 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. The results include all the sources I have to test (Player x indicates a real player available in the market while Analyzer x indicates HDMI protocol analyzer). From the data I've collected the players are the ones with the less precise clock, thats what I was referring as a bad clock. But even with that deviations the algorithm computes the value ok. I think I don't have any player else to test here. Maybe, if you could, test the patch series with cobalt + adv with a player and check the precision? ( I think cobalt uses an adv as subdev, right? ) > >> ------------------------------------------------------------------------------ >> >> 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. No problem :) Please review the patch series (when you can) so that I can submit a next version. Best regards, Jose Miguel Abreu > > Regards, > > Hans
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