[libcamera-devel] [PATCH v4 12/14] ipa: ipu3: Cache line duration at configure call

[Jean-Michel Hautbois]

On 12/11/2021 17:19, Kieran Bingham wrote:
> Quoting Jean-Michel Hautbois (2021-11-12 16:03:53)
>> Hi Kieran,
>>
>> On 12/11/2021 14:21, Kieran Bingham wrote:
>>> Quoting Umang Jain (2021-11-12 12:36:21)
>>>> Hi JM,
>>>>
>>>> On 11/11/21 7:39 PM, Jean-Michel Hautbois wrote:
>>>>> We use the line duration several times in the IPAIPU3. Instead of
>>>>> recalculating it each time, cache the value as a utils::Duration. When
>>>>> the value is needed, cast it to a std::micro value.
>>>
>>> Aren't values always 'needed' when they're obtained? This isn't quite
>>> helping improve the clarity.
>>>
>>> Why is it needed in micros, vs other usages?
>>
>> OK, I may have to specify it is documented in
>> src/libcamera/control_ids.yaml ?
>>
>> '''
>> - ExposureTime:
>>       type: int32_t
>>       description: |
>> Exposure time (shutter speed) for the frame applied in the sensor
>> device. This value is specified in micro-seconds.
>> '''
>>
>> How can I reference this file in the commit message ?
> 
> I don't think you need to reference the file, just the fact that
> ExposureTime and FrameDuration units are in micro-seconds, and so the
> Duration is cast accordingly.

Thanks,

'''
We use the line duration several times in the IPAIPU3. Instead of
recalculating it each time, cache the value as a utils::Duration.
ExposureTime and FrameDuration units are in micro-seconds, cast the
Duration accordingly.

As sensorInfo is no longer used in updateSessionConfiguration remove the
reference to it.
'''

> 
> 
> 
>>>>> As sensorInfo is no longer used in updateSessionConfiguration remove the
>>>>> reference to it.
>>>>>
>>>>> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
>>>>> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>>>>
>>>>
>>>> Reviewed-by: Umang Jain <umang.jain at ideasonboard.com>
>>>>
>>>>> ---
>>>>>     src/ipa/ipu3/ipu3.cpp | 29 +++++++++++++----------------
>>>>>     1 file changed, 13 insertions(+), 16 deletions(-)
>>>>>
>>>>> diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
>>>>> index d3195de6..f1597f78 100644
>>>>> --- a/src/ipa/ipu3/ipu3.cpp
>>>>> +++ b/src/ipa/ipu3/ipu3.cpp
>>>>> @@ -148,8 +148,7 @@ private:
>>>>>         void updateControls(const IPACameraSensorInfo &sensorInfo,
>>>>>                             const ControlInfoMap &sensorControls,
>>>>>                             ControlInfoMap *ipaControls);
>>>>> -     void updateSessionConfiguration(const IPACameraSensorInfo &sensorInfo,
>>>>> -                                     const ControlInfoMap &sensorControls);
>>>>> +     void updateSessionConfiguration(const ControlInfoMap &sensorControls);
>>>>>         void processControls(unsigned int frame, const ControlList &controls);
>>>>>         void fillParams(unsigned int frame, ipu3_uapi_params *params);
>>>>>         void parseStatistics(unsigned int frame,
>>>>> @@ -174,6 +173,8 @@ private:
>>>>>         uint32_t minGain_;
>>>>>         uint32_t maxGain_;
>>>>>     
>>>>> +     utils::Duration lineDuration_;
>>>>> +
>>>>>         /* Interface to the Camera Helper */
>>>>>         std::unique_ptr<CameraSensorHelper> camHelper_;
>>>>>     
>>>>> @@ -188,16 +189,12 @@ private:
>>>>>      * \brief Compute IPASessionConfiguration using the sensor information and the
>>>>>      * sensor V4L2 controls
>>>>>      */
>>>>> -void IPAIPU3::updateSessionConfiguration(const IPACameraSensorInfo &sensorInfo,
>>>>> -                                      const ControlInfoMap &sensorControls)
>>>>> +void IPAIPU3::updateSessionConfiguration(const ControlInfoMap &sensorControls)
>>>>>     {
>>>>>         const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
>>>>>         int32_t minExposure = v4l2Exposure.min().get<int32_t>();
>>>>>         int32_t maxExposure = v4l2Exposure.max().get<int32_t>();
>>>>>     
>>>>> -     utils::Duration lineDuration = sensorInfo.lineLength * 1.0s
>>>>> -                                  / sensorInfo.pixelRate;
>>>>> -
>>>>>         const ControlInfo &v4l2Gain = sensorControls.find(V4L2_CID_ANALOGUE_GAIN)->second;
>>>>>         int32_t minGain = v4l2Gain.min().get<int32_t>();
>>>>>         int32_t maxGain = v4l2Gain.max().get<int32_t>();
>>>>> @@ -209,8 +206,8 @@ void IPAIPU3::updateSessionConfiguration(const IPACameraSensorInfo &sensorInfo,
>>>>>          *
>>>>>          * \todo take VBLANK into account for maximum shutter speed
>>>>>          */
>>>>> -     context_.configuration.agc.minShutterSpeed = minExposure * lineDuration;
>>>>> -     context_.configuration.agc.maxShutterSpeed = maxExposure * lineDuration;
>>>>> +     context_.configuration.agc.minShutterSpeed = minExposure * lineDuration_;
>>>>> +     context_.configuration.agc.maxShutterSpeed = maxExposure * lineDuration_;
>>>>>         context_.configuration.agc.minAnalogueGain = camHelper_->gain(minGain);
>>>>>         context_.configuration.agc.maxAnalogueGain = camHelper_->gain(maxGain);
>>>>>     }
>>>>> @@ -239,11 +236,10 @@ void IPAIPU3::updateControls(const IPACameraSensorInfo &sensorInfo,
>>>>>          * exposure min, max and default and convert it from lines to
>>>>>          * microseconds.
>>>>>          */
>>>>> -     double lineDuration = sensorInfo.lineLength / (sensorInfo.pixelRate / 1e6);
>>>>>         const ControlInfo &v4l2Exposure = sensorControls.find(V4L2_CID_EXPOSURE)->second;
>>>>> -     int32_t minExposure = v4l2Exposure.min().get<int32_t>() * lineDuration;
>>>>> -     int32_t maxExposure = v4l2Exposure.max().get<int32_t>() * lineDuration;
>>>>> -     int32_t defExposure = v4l2Exposure.def().get<int32_t>() * lineDuration;
>>>>> +     int32_t minExposure = v4l2Exposure.min().get<int32_t>() * lineDuration_.get<std::micro>();
>>>>> +     int32_t maxExposure = v4l2Exposure.max().get<int32_t>() * lineDuration_.get<std::micro>();
>>>>> +     int32_t defExposure = v4l2Exposure.def().get<int32_t>() * lineDuration_.get<std::micro>();
>>>>>         controls[&controls::ExposureTime] = ControlInfo(minExposure, maxExposure,
>>>>>                                                         defExposure);
>>>>>     
>>>>> @@ -463,11 +459,13 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
>>>>>     
>>>>>         calculateBdsGrid(configInfo.bdsOutputSize);
>>>>>     
>>>>> +     lineDuration_ = sensorInfo_.lineLength * 1.0s / sensorInfo_.pixelRate;
>>>>> +
>>>>>         /* Update the camera controls using the new sensor settings. */
>>>>>         updateControls(sensorInfo_, ctrls_, ipaControls);
>>>>>     
>>>>>         /* Update the IPASessionConfiguration using the sensor settings. */
>>>>> -     updateSessionConfiguration(sensorInfo_, ctrls_);
>>>>> +     updateSessionConfiguration(ctrls_);
>>>>>     
>>>>>         for (auto const &algo : algorithms_) {
>>>>>                 int ret = algo->configure(context_, configInfo);
>>>>> @@ -627,8 +625,7 @@ void IPAIPU3::parseStatistics(unsigned int frame,
>>>>>         setControls(frame);
>>>>>     
>>>>>         /* \todo Use VBlank value calculated from each frame exposure. */
>>>>> -     int64_t frameDuration = sensorInfo_.lineLength * (defVBlank_ + sensorInfo_.outputSize.height) /
>>>>> -                             (sensorInfo_.pixelRate / 1e6);
>>>>> +     int64_t frameDuration = (defVBlank_ + sensorInfo_.outputSize.height) * lineDuration_.get<std::micro>();
>>>>>         ctrls.set(controls::FrameDuration, frameDuration);
>>>>>     
>>>>>         ctrls.set(controls::ColourTemperature, context_.frameContext.awb.temperatureK);