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

[Jean-Michel Hautbois]

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 ?
> 
> 
>>>
>>> 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);