<div dir="ltr"><div dir="ltr">Hi David, Thanks for the great patch!</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Mar 10, 2022 at 10:53 PM Jean-Michel Hautbois <<a href="mailto:jeanmichel.hautbois@ideasonboard.com">jeanmichel.hautbois@ideasonboard.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi David,<br>
<br>
Thanks for the patch !<br>
<br>
On 10/03/2022 13:05, David Plowman via libcamera-devel wrote:<br>
> This patch describes a series of controls that allow applications to<br>
> drive AF algorithms:<br>
> <br>
> AfMode - manual, auto or continuous<br>
> AfRange - full, macro or normal<br>
> AfSpeed - fast or slow<br>
> AfWindow - AF window locations<br>
> AfTrigger - start (trigger an AF scan) or cancel<br>
> AfPause - pause continuous AF<br>
> LensPosition - position of lens from lens driver<br>
> AfState - reset, scanning, focused or failed<br>
> ---<br>
> src/libcamera/control_ids.yaml | 271 +++++++++++++++++++++++++--------<br>
> 1 file changed, 211 insertions(+), 60 deletions(-)<br>
> <br>
> diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml<br>
> index 9d4638ae..89636d82 100644<br>
> --- a/src/libcamera/control_ids.yaml<br>
> +++ b/src/libcamera/control_ids.yaml<br>
> @@ -406,27 +406,6 @@ controls:<br>
> The camera will cancel any active or completed metering sequence.<br>
> The AE algorithm is reset to its initial state.<br>
> <br>
> - - AfTrigger:<br>
> - type: int32_t<br>
> - draft: true<br>
> - description: |<br>
> - Control for AF trigger. Currently identical to<br>
> - ANDROID_CONTROL_AF_TRIGGER.<br>
> -<br>
> - Whether the camera device will trigger autofocus for this request.<br>
> - enum:<br>
> - - name: AfTriggerIdle<br>
> - value: 0<br>
> - description: The trigger is idle.<br>
> - - name: AfTriggerStart<br>
> - value: 1<br>
> - description: The AF routine is started by the camera.<br>
> - - name: AfTriggerCancel<br>
> - value: 2<br>
> - description: |<br>
> - The camera will cancel any active trigger and the AF routine is<br>
> - reset to its initial state.<br>
> -<br>
> - NoiseReductionMode:<br>
> type: int32_t<br>
> draft: true<br>
> @@ -507,45 +486,6 @@ controls:<br>
> The AE algorithm has started a pre-capture metering session.<br>
> \sa AePrecaptureTrigger<br>
> <br>
> - - AfState:<br>
> - type: int32_t<br>
> - draft: true<br>
> - description: |<br>
> - Control to report the current AF algorithm state. Currently identical to<br>
> - ANDROID_CONTROL_AF_STATE.<br>
> -<br>
> - Current state of the AF algorithm.<br>
> - enum:<br>
> - - name: AfStateInactive<br>
> - value: 0<br>
> - description: The AF algorithm is inactive.<br>
> - - name: AfStatePassiveScan<br>
> - value: 1<br>
> - description: |<br>
> - AF is performing a passive scan of the scene in continuous<br>
> - auto-focus mode.<br>
> - - name: AfStatePassiveFocused<br>
> - value: 2<br>
> - description: |<br>
> - AF believes the scene is in focus, but might restart scanning.<br>
> - - name: AfStateActiveScan<br>
> - value: 3<br>
> - description: |<br>
> - AF is performing a scan triggered by an AF trigger request.<br>
> - \sa AfTrigger<br>
> - - name: AfStateFocusedLock<br>
> - value: 4<br>
> - description: |<br>
> - AF believes has focused correctly and has locked focus.<br>
> - - name: AfStateNotFocusedLock<br>
> - value: 5<br>
> - description: |<br>
> - AF has not been able to focus and has locked.<br>
> - - name: AfStatePassiveUnfocused<br>
> - value: 6<br>
> - description: |<br>
> - AF has completed a passive scan without finding focus.<br>
> -<br>
> - AwbState:<br>
> type: int32_t<br>
> draft: true<br>
> @@ -690,4 +630,215 @@ controls:<br>
> value. All of the custom test patterns will be static (that is the<br>
> raw image must not vary from frame to frame).<br>
> <br>
> + - AfMode:<br>
> + type: int32_t<br>
<br>
Same open question for almost all: why int32_t and not uint8_t ?<br>
We won't have negative values ? Maybe is it yaml ?<br>
<br>
> + draft: true<br>
> + description: |<br>
> + Control to set the mode of the AF (autofocus) algorithm. Applications<br>
> + are allowed to set a new mode, and to send additional controls for<br>
> + that new mode, in the same request.<br>
> + enum:<br>
> + - name: AfModeManual<br>
> + value: 0<br>
> + description: |<br>
> + The AF algorithm is in manual mode. In this mode it will never<br>
> + perform any action nor move the lens of its own accord. The only<br>
> + autofocus controls that have an immediate effect are AfMode (to<br>
> + switch out of manual mode) and LensPosition (so that the lens can<br>
> + be moved "manually").<br>
<br>
Alignment changed in the paragraph. I wonder if the part "The only <br>
autofocus [...] "manually")." should be moved in the top description ?<br>
<br>
> +<br>
> + In this mode the AfState will always report AfStateReset.<br>
> + - name: AfModeAuto<br>
> + value: 1<br>
> + description: |<br>
> + The AF algorithm is in auto mode. This means that the algorithm<br>
> + will never move the lens or change state unless the AfTrigger<br>
> + control is used. The AfTrigger control can be used to initiate a<br>
> + focus scan, the results of which will also be reported by AfState.<br>
> +<br>
> + If the autofocus algorithm is moved from AfModeAuto to another<br>
> + mode while a scan is in progress, the scan is cancelled<br>
> + immediately, without waiting for the scan to finish.<br>
> +<br>
> + When first entering this mode the AfState will report<br>
<br>
Alignment broken ?<br>
<br>
> + AfStateReset. When a trigger control is sent, AfState will<br>
> + report AfStateScanning for a period before spontaneously<br>
> + changing to AfStateFocused or AfStateFailed, depending on the<br>
> + outcome of the scan. It will remain in this state until another<br>
> + scan is initiated by the AfTrigger control. If a scan is<br>
> + cancelled (without changing to another mode), AfState will return<br>
> + to AfStateReset.<br>
> + - name: AfModeContinuous<br>
> + value: 2<br>
> + description: |<br>
> + The AF algorithm is in continuous mode. This means that the lens<br>
> + can re-start a scan spontaneously at any moment, without any user<br>
> + intervention. The AfState still reports whether the algorithm is<br>
> + currently scanning or not, though the application has no ability<br>
> + to initiate or cancel scans, nor move the lens for itself.<br>
> +<br>
<br>
Alignement broken ?<br>
<br>
> + When set to AfModeContinuous, the system will immediately initiate<br>
> + a scan so AfState will report AfStateScanning, and will settle on<br>
> + one of AfStateFocused or AfStateFailed, depending on the scan<br>
> + result.<br>
> +<br>
> + The continuous autofocus behaviour can be paused with the<br>
> + AfPause control. Pausing the algorithm does not change the value<br>
> + reported by AfState, so that applications can determine the<br>
> + state of the algorithm when the pause control took effect. Once<br>
> + un-paused ("resumed"), the algorithm starts again from exactly<br>
> + where it left off when it paused.<br></blockquote><div>An open question: </div><div>Should we make Macro and Continuous mandatory? Or they can be optional depending on the algorithm implementation?</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
I find this difficult to follow without having a state machine in some <br>
drawn way... Is it something we could include in the documentation ? <br>
Seeing which Control changes to which one, which states are then <br>
triggered, etc. ?<br>
<br>
> +<br>
> + - AfRange:<br>
> + type: int32_t<br>
> + draft: true<br>
> + description: |<br>
> + Control to set the range of focus distances that is scanned.<br>
> + enum:<br>
> + - name: AfRangeNormal<br>
> + value: 0<br>
> + description: |<br>
> + A wide range of focus distances is scanned, all the way from<br>
> + infinity down to close distances, though depending on the<br>
> + implementation, possibly not including the very closest macro<br>
> + positions.<br>
<br>
Alignment broken ?<br>
<br>
> + - name: AfRangeMacro<br>
> + value: 1<br>
> + description: Only close distances are scanned.<br>
> + - name: AfRangeFull<br>
> + value: 2<br>
> + description: |<br>
> + The full range of focus distances is scanned just as with<br>
> + AfRangeNormal but this time including the very closest macro<br>
> + positions.<br>
> +<br>
> + - AfSpeed:<br>
> + type: int32_t<br>
> + draft: true<br>
> + description: |<br>
> + Control that determines whether the AF algorithm is to move the lens<br>
> + as quickly as possible or more steadily. For example, during video<br>
> + recording it may be desirable not to move the lens too abruptly, but<br>
> + when in a preview mode (waiting for a still capture) it may be<br>
> + helpful to move the lens as quickly as is reasonably possible.<br>
> + enum:<br>
> + - name: AfSpeedNormal<br>
> + value: 0<br>
> + description: Move the lens at its usual speed.<br>
> + - name: AfSpeedFast<br>
> + value: 1<br>
> + description: Move the lens more quickly.<br>
> +<br>
<br>
Can we somehow configure this speed ?<br>
<br>
> + - AfWindow:<br>
> + type: Rectangle<br>
> + draft: true<br>
> + description: |<br>
> + Sets the focus windows used by the AF algorithm. The units used express<br>
s/windows/window ?<br>
> + a proportion of the ScalerCrop control (or if unavailable, of the entire<br>
> + image), as u0.16 format numbers.<br>
> +<br>
> + In order to be activated, a rectangle must be programmed with non-zero<br>
> + width and height. If no rectangles are programmed in this way, then the<br>
> + system will choose its own single default window in the centre of the<br>
> + image.<br>
> +<br>
> + The details of how the windows are used are platform dependent. We note<br>
> + that when there is more than one AF window, a typical implementation<br>
> + might find the optimal focus position for each one and finally select<br>
> + the window closest to the camera.<br>
<br>
Alignment broken ?<br>
<br>
> +<br>
> + size: [platform dependent]<br>
> +<br>
> + - AfTrigger:<br>
> + type: int32_t<br>
> + draft: true<br>
> + description: |<br>
> + This control starts an autofocus scan when AfMode is set to AfModeAuto,<br>
> + and can also be used to terminate a scan early.<br>
> +<br>
> + It is ignored if AfMode is set to AfModeContinuous.<br>
> +<br>
> + enum:<br>
> + - name: AfTriggerStart<br>
> + value: 0<br>
> + description: Start an AF scan. Ignored if a scan is in progress.<br>
> + - name: AfTriggerCancel<br>
> + value: 1<br>
> + description: Cancel an AF scan. Ingored if no scan is in progress.<br>
<br>
Does cancelling a scan make the lens stay at its current position ? Or <br>
should it be reset ?<br>
<br>
> +<br>
> + - AfPause:<br>
> + type: int32_t<br>
> + draft: true<br>
> + description: |<br>
> + This control has no effect except when in continuous autofocus mode<br>
> + (AfModeContinuous). It can be used to pause any lens movements while<br>
> + (for example) images are captured. The algorithm remains inactive<br>
> + until it is instructed to resume.<br>
> +<br>
> + enum:<br>
> + - name: AfPauseImmediate<br>
> + value: 0<br>
> + description: |<br>
> + Pause the continuous autofocus algorithm immediately, whether or<br>
> + not any kind of scan is underway. The AfState will continue to<br>
> + report whatever value it had when the control was enacted.<br>
> + - name AfPauseDeferred<br>
> + value: 1<br>
> + description: |<br>
> + Pause the continuous autofocus algorithm as soon as it is no longer<br>
> + scanning. The AfState will report AfStateFocused or AfStateFailed,<br>
> + depending on whether the final scan succeeds or not. If no scan is<br>
> + in currently progress, the algorithm will pause immediately.<br>
<br></blockquote><div>Just to confirm. Since we removed the AftriggerIdle, I guess the two controls AfTriggerStart and AfPauseDeferred should be continuously set until the state becomes focused or failed? If so, is it better to mention it in the description?</div><div>For AfPauseImmediate, should it only report the state as failed when it's scanning and reset?</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Alignment broken ?<br>
<br>
> + - name: AfPauseResume<br>
> + value: 2<br>
> + description: |<br>
<br>
Alignment broken ?<br>
<br>
> + Resume continous autofocus operation. The algorithm starts again<br>
> + from exactly where it left off, with AfState unchanged (one of<br>
> + AfStateFocused, AfStateFailed or following AfPauseImmediate it<br>
> + might also have been in the AfStateScanning state).<br>
> +<br>
> + - LensPosition:<br>
> + type: int32_t<br>
> + draft: true<br>
> + description: |<br>
> + Acts as a control to instruct the lens to move to a particular position<br>
> + and also reports back the position of the lens for each frame.<br>
> +<br>
> + The units are determined by the lens driver.<br>
> +<br>
> + The LensPosition control is ignored unless the AfMode is set to<br>
> + AfModeManual.<br>
> +<br>
> + - AfState:<br>
> + type: int32_t<br>
> + draft: true<br>
> + description: |<br>
> + Reports the current state of the AF algorithm.<br>
> + enum:<br>
> + - name: AfStateReset<br>
> + value: 0<br>
> + description: |<br>
> + The AF algorithm reports this state when:<br>
> + * It is in manual mode (AfModeManual).<br>
> + * The system has entered auto mode (AfModeAuto) but no scan<br>
> + has yet been initiated.<br>
> + * The system is in auto mode (AfModeAuto) and a scan has been<br>
> + cancelled.<br>
> + - name: AfStateScanning<br>
> + value: 1<br>
> + description: |<br>
> + AF is performing a scan. This state can be entered spontaneously<br>
> + if AfMode is set to AfModeContinuous, otherwise it requires the<br>
> + application to use the AfTrigger control to start the scan.<br>
> + - name: AfStateFocused<br>
> + value: 2<br>
> + description: |<br>
> + An AF scan has been performed and the algorithm believes the<br>
> + scene is in focus.<br>
> + - name: AfStateFailed<br>
> + value: 3<br>
> + description: |<br>
> + An AF scan has been performed but the algorithm has not been able<br>
> + to find the best focus position.<br>
<br>
I confirm my wish of having a graphical state machine :-).<br></blockquote><div>Vote +1 :-). </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
Great work, thanks for it !<br>
JM<br>
<br>
> +<br>
> ...<br>
</blockquote></div></div>