| Message ID | 20230328085521.7409-1-david.plowman@raspberrypi.com |
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Hi David, On Tue, Mar 28, 2023 at 09:55:19AM +0100, David Plowman via libcamera-devel wrote: > Hi everyone > > Here's an updated version of flicker avoidance controls. It's similar > to what I had previously, except that I've split the control which > gave an explicit flicker period into two, one for reporting a > currently detected value, and another for setting a custom flicker > period. So we now have 3 controls in total. > > In terms of Android, the AeFlickerDetected control corresponds fairly > directly to Android's scene_flicker control, which is (from my reading > of it) merely reporting any currently detected flicker period. That's my understanding too. > AeFlickerDetected, however, allows arbitrary flicker periods > to be identified, not just 50 or 60Hz. Out of curiosity, what are the use cases you envision for other frequencies ? > The other controls (AeFlickerMode and AeFlickerCustom) correspond to > Android's anti-banding control. Again, we extend it to allow arbitrary > flicker periods. > > Hope that all makes sense! > > Thanks > David > > David Plowman (2): > libcamera: controls: Add controls for AEC/AGC flicker avoidance > ipa: raspberrypi: Handle AEC/AGC flicker controls > > src/ipa/raspberrypi/raspberrypi.cpp | 80 +++++++++++++++++++++++++++ > src/libcamera/control_ids.yaml | 84 +++++++++++++++++++++++------ > 2 files changed, 147 insertions(+), 17 deletions(-)
Hi Laurent Thanks for the questions! On Tue, 4 Apr 2023 at 06:46, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi David, > > On Tue, Mar 28, 2023 at 09:55:19AM +0100, David Plowman via libcamera-devel wrote: > > Hi everyone > > > > Here's an updated version of flicker avoidance controls. It's similar > > to what I had previously, except that I've split the control which > > gave an explicit flicker period into two, one for reporting a > > currently detected value, and another for setting a custom flicker > > period. So we now have 3 controls in total. > > > > In terms of Android, the AeFlickerDetected control corresponds fairly > > directly to Android's scene_flicker control, which is (from my reading > > of it) merely reporting any currently detected flicker period. > > That's my understanding too. > > > AeFlickerDetected, however, allows arbitrary flicker periods > > to be identified, not just 50 or 60Hz. > > Out of curiosity, what are the use cases you envision for other > frequencies ? I think the most obvious use cases are when people have LEDs that run at other frequencies. Probably not such an issue for regular users, but I could imagine it being useful in lab or technical environments, and we do have a few of those. But I agree it's not 100% clear, so alternatives are still definitely worth considering! Thanks David > > > The other controls (AeFlickerMode and AeFlickerCustom) correspond to > > Android's anti-banding control. Again, we extend it to allow arbitrary > > flicker periods. > > > > Hope that all makes sense! > > > > Thanks > > David > > > > David Plowman (2): > > libcamera: controls: Add controls for AEC/AGC flicker avoidance > > ipa: raspberrypi: Handle AEC/AGC flicker controls > > > > src/ipa/raspberrypi/raspberrypi.cpp | 80 +++++++++++++++++++++++++++ > > src/libcamera/control_ids.yaml | 84 +++++++++++++++++++++++------ > > 2 files changed, 147 insertions(+), 17 deletions(-) > > -- > Regards, > > Laurent Pinchart
Hi David, On Tue, Apr 04, 2023 at 10:10:45AM +0100, David Plowman wrote: > On Tue, 4 Apr 2023 at 06:46, Laurent Pinchartwrote: > > On Tue, Mar 28, 2023 at 09:55:19AM +0100, David Plowman via libcamera-devel wrote: > > > Hi everyone > > > > > > Here's an updated version of flicker avoidance controls. It's similar > > > to what I had previously, except that I've split the control which > > > gave an explicit flicker period into two, one for reporting a > > > currently detected value, and another for setting a custom flicker > > > period. So we now have 3 controls in total. > > > > > > In terms of Android, the AeFlickerDetected control corresponds fairly > > > directly to Android's scene_flicker control, which is (from my reading > > > of it) merely reporting any currently detected flicker period. > > > > That's my understanding too. > > > > > AeFlickerDetected, however, allows arbitrary flicker periods > > > to be identified, not just 50 or 60Hz. > > > > Out of curiosity, what are the use cases you envision for other > > frequencies ? > > I think the most obvious use cases are when people have LEDs that run > at other frequencies. Probably not such an issue for regular users, > but I could imagine it being useful in lab or technical environments, > and we do have a few of those. But I agree it's not 100% clear, so > alternatives are still definitely worth considering! I thought about LED lightning an hour after sending the question :-) This sounds like a good use case. I don't have an alternative proposal, I think yours makes sense. > > > The other controls (AeFlickerMode and AeFlickerCustom) correspond to > > > Android's anti-banding control. Again, we extend it to allow arbitrary > > > flicker periods. > > > > > > Hope that all makes sense! > > > > > > Thanks > > > David > > > > > > David Plowman (2): > > > libcamera: controls: Add controls for AEC/AGC flicker avoidance > > > ipa: raspberrypi: Handle AEC/AGC flicker controls > > > > > > src/ipa/raspberrypi/raspberrypi.cpp | 80 +++++++++++++++++++++++++++ > > > src/libcamera/control_ids.yaml | 84 +++++++++++++++++++++++------ > > > 2 files changed, 147 insertions(+), 17 deletions(-)