[PATCH v6 09/18] libcamera: ipa: add Soft IPA

Andrei Konovalov andrey.konovalov.ynk at gmail.com
Tue Apr 2 22:34:13 CEST 2024


Hi Laurent and Milan,

On 28.03.2024 01:36, Andrei Konovalov wrote:
> Hi Laurent,
> 
> Thank you for the review!
> 
> On 27.03.2024 19:38, Laurent Pinchart wrote:
>> Hi Milan and Andrey,
>>
>> Thank you for the patch.
>>
>> On Tue, Mar 19, 2024 at 01:35:56PM +0100, Milan Zamazal wrote:
>>> From: Andrey Konovalov <andrey.konovalov at linaro.org>
>>>
>>> Define the Soft IPA main and event interfaces, add the Soft IPA
>>> implementation.
>>>
>>> The current src/ipa/meson.build assumes the IPA name to match the
>>> pipeline name. For this reason "-Dipas=simple" is used for the
>>> Soft IPA module.
>>
>> This should be addressed, please record this as a \todo item somewhere.
> 
> Ack
> 
>>> Auto exposure/gain and AWB implementation by Dennis, Toon and Martti.
>>>
>>> Auto exposure/gain targets a Mean Sample Value of 2.5 following
>>> the MSV calculation algorithm from:
>>> https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
>>>
>>> Tested-by: Bryan O'Donoghue <bryan.odonoghue at linaro.org> # sc8280xp Lenovo x13s
>>> Tested-by: Pavel Machek <pavel at ucw.cz>
>>> Reviewed-by: Pavel Machek <pavel at ucw.cz>
>>> Signed-off-by: Andrey Konovalov <andrey.konovalov at linaro.org>
>>> Co-developed-by: Dennis Bonke <admin at dennisbonke.com>
>>> Signed-off-by: Dennis Bonke <admin at dennisbonke.com>
>>> Co-developed-by: Marttico <g.martti at gmail.com>
>>> Signed-off-by: Marttico <g.martti at gmail.com>
>>> Co-developed-by: Toon Langendam <t.langendam at gmail.com>
>>> Signed-off-by: Toon Langendam <t.langendam at gmail.com>
>>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>>> ---
>>>   Documentation/Doxyfile.in         |   1 +
>>>   include/libcamera/ipa/meson.build |   1 +
>>>   include/libcamera/ipa/soft.mojom  |  28 +++
>>>   meson_options.txt                 |   2 +-
>>>   src/ipa/simple/data/meson.build   |   9 +
>>>   src/ipa/simple/data/soft.conf     |   3 +
>>>   src/ipa/simple/meson.build        |  25 +++
>>>   src/ipa/simple/soft_simple.cpp    | 326 ++++++++++++++++++++++++++++++
>>>   8 files changed, 394 insertions(+), 1 deletion(-)
>>>   create mode 100644 include/libcamera/ipa/soft.mojom
>>>   create mode 100644 src/ipa/simple/data/meson.build
>>>   create mode 100644 src/ipa/simple/data/soft.conf
>>>   create mode 100644 src/ipa/simple/meson.build
>>>   create mode 100644 src/ipa/simple/soft_simple.cpp
>>>
>>> diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in
>>> index a86ea6c1..2be8d47b 100644
>>> --- a/Documentation/Doxyfile.in
>>> +++ b/Documentation/Doxyfile.in
>>> @@ -44,6 +44,7 @@ EXCLUDE                = @TOP_SRCDIR@/include/libcamera/base/span.h \
>>>                            @TOP_SRCDIR@/src/libcamera/pipeline/ \
>>>                            @TOP_SRCDIR@/src/libcamera/tracepoints.cpp \
>>>                            @TOP_BUILDDIR@/include/libcamera/internal/tracepoints.h \
>>> +                         @TOP_BUILDDIR@/include/libcamera/ipa/soft_ipa_interface.h \
>>
>> Why is this needed ?
>>
>>>                            @TOP_BUILDDIR@/src/libcamera/proxy/
>>>   EXCLUDE_PATTERNS       = @TOP_BUILDDIR@/include/libcamera/ipa/*_serializer.h \
>>> diff --git a/include/libcamera/ipa/meson.build b/include/libcamera/ipa/meson.build
>>> index f3b4881c..3352d08f 100644
>>> --- a/include/libcamera/ipa/meson.build
>>> +++ b/include/libcamera/ipa/meson.build
>>> @@ -65,6 +65,7 @@ pipeline_ipa_mojom_mapping = {
>>>       'ipu3': 'ipu3.mojom',
>>>       'rkisp1': 'rkisp1.mojom',
>>>       'rpi/vc4': 'raspberrypi.mojom',
>>> +    'simple': 'soft.mojom',
>>>       'vimc': 'vimc.mojom',
>>>   }
>>> diff --git a/include/libcamera/ipa/soft.mojom b/include/libcamera/ipa/soft.mojom
>>> new file mode 100644
>>> index 00000000..c249bd75
>>> --- /dev/null
>>> +++ b/include/libcamera/ipa/soft.mojom
>>> @@ -0,0 +1,28 @@
>>> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
>>> +
>>> +/*
>>> + * \todo Document the interface and remove the related EXCLUDE_PATTERNS entry.
>>
>> Ah that's why.
> 
> Yes, because, well... all the other IPAs were doing that...
> 
>> It doesn't have to be done before merging, but could you
>> address this sooner than later ?
> 
> I can't promise a lot, but I'll look into that.
> 
>>> + */
>>> +
>>> +module ipa.soft;
>>> +
>>> +import "include/libcamera/ipa/core.mojom";
>>> +
>>> +interface IPASoftInterface {
>>> +    init(libcamera.IPASettings settings,
>>> +         libcamera.SharedFD fdStats,
>>> +         libcamera.SharedFD fdParams,
>>
>> The IPA and soft ISP run in separate threads. How do you guarantee that
>> the stats and params are not accessed concurrently by both ?
> 
> I tried avoiding using a pool of buffers for stats and params, and used just a
> single chunk of shared memory to pass the stats from soft ISP (its worker thread)
> to IPA, and the other chunk for params.
> 
> The soft ISP accumulates the stats in its member variable, and after all the stats
> for the frame are calculated, the member variable is copyed to the shared memory and
> statReady signal is emitted (so using the member var implements some kind of double
> buffering). This way the write to the stats shared memory happens once per frame and
> is short in time right before emitting the statReady signal.
> The callback executed on receiving statReady signal invokes the IPA's processStats
> function. So the IPA's processStats() is called soon after the statReady is emitted.
> If the IPA finish processing the stats before the next frame is processed by the soft IPS
> and the stats for the next frame are written into the shared memory, there is no concurrent
> acess.
> 
> This doesn't strictly guarantee that the stats are not accessed concurrently by the IPA and
> soft ISP. But unless the video stream from the camera sensor overloads the system this
> scheme works OK. And if the load is high the concurrent access isn't impossible, and can harm
> the image quality, but doesn't lead to critical problems like invalid pointers as the stats
> structure only contains numbers and an array of fixed size.
> 
>> Shouldn't
>> you have a pool of buffers for each, mimicking what is done with
>> hardware ISPs ?
> 
> This would definitely work, but is a more heavy wait implementation.
> 
> On the other side, the current implementation is less universal (isn't very scalable), more fragile,
> and can't reliably associate the stats and the params with the given frame from the camera sensor.
> 
> So let me try to implement what you suggested ("a pool of buffers for each, mimicking what is done with
> hardware ISPs").

I won't be able to do this particular part by tomorrow...
So a branch I plan to publish tomorrow - with this patch updated to address the review comments
and the [PATCH v6 18/18] "libcamera: Soft IPA: use CameraSensorHelper for analogue gain" merged
into the earlier ones - would not use the pool of buffers for the stats and the params (yet).

Thanks,
Andrei

>>> +         libcamera.ControlInfoMap sensorCtrlInfoMap)
>>> +        => (int32 ret);
>>> +    start() => (int32 ret);
>>> +    stop();
>>> +    configure(libcamera.ControlInfoMap sensorCtrlInfoMap)
>>> +        => (int32 ret);
>>> +
>>> +    [async] processStats(libcamera.ControlList sensorControls);
>>> +};
>>> +
>>> +interface IPASoftEventInterface {
>>> +    setSensorControls(libcamera.ControlList sensorControls);
>>> +    setIspParams(int32 dummy);
>>
>> Drop the dummy value.
> 
> libcamera docs do allow signals with zero parameters.
> But when I tried having zero parameters for an EventInterface function,
> it didn't work for me iirc.
> Let me double check.
> 
>>> +};
>>> diff --git a/meson_options.txt b/meson_options.txt
>>> index 99dab96d..2644bef0 100644
>>> --- a/meson_options.txt
>>> +++ b/meson_options.txt
>>> @@ -27,7 +27,7 @@ option('gstreamer',
>>>   option('ipas',
>>>           type : 'array',
>>> -        choices : ['ipu3', 'rkisp1', 'rpi/vc4', 'vimc'],
>>> +        choices : ['ipu3', 'rkisp1', 'rpi/vc4', 'simple', 'vimc'],
>>>           description : 'Select which IPA modules to build')
>>>   option('lc-compliance',
>>> diff --git a/src/ipa/simple/data/meson.build b/src/ipa/simple/data/meson.build
>>> new file mode 100644
>>> index 00000000..33548cc6
>>> --- /dev/null
>>> +++ b/src/ipa/simple/data/meson.build
>>> @@ -0,0 +1,9 @@
>>> +# SPDX-License-Identifier: CC0-1.0
>>> +
>>> +conf_files = files([
>>> +    'soft.conf',
>>> +])
>>> +
>>> +install_data(conf_files,
>>> +             install_dir : ipa_data_dir / 'soft',
>>> +             install_tag : 'runtime')
>>> diff --git a/src/ipa/simple/data/soft.conf b/src/ipa/simple/data/soft.conf
>>> new file mode 100644
>>> index 00000000..0c70e7c0
>>> --- /dev/null
>>> +++ b/src/ipa/simple/data/soft.conf
>>
>> We use YAML files for all IPAs, could you do the same here ? It
>> shouldn't be much extra work as the file is empty :-)
> 
> OK
> 
>>> @@ -0,0 +1,3 @@
>>> +# SPDX-License-Identifier: LGPL-2.1-or-later
>>> +#
>>> +# Dummy configuration file for the soft IPA.
>>> diff --git a/src/ipa/simple/meson.build b/src/ipa/simple/meson.build
>>> new file mode 100644
>>> index 00000000..3e863db7
>>> --- /dev/null
>>> +++ b/src/ipa/simple/meson.build
>>> @@ -0,0 +1,25 @@
>>> +# SPDX-License-Identifier: CC0-1.0
>>> +
>>> +ipa_name = 'ipa_soft_simple'
>>> +
>>> +mod = shared_module(ipa_name,
>>> +                    ['soft_simple.cpp', libcamera_generated_ipa_headers],
>>> +                    name_prefix : '',
>>> +                    include_directories : [ipa_includes, libipa_includes],
>>> +                    dependencies : libcamera_private,
>>> +                    link_with : libipa,
>>> +                    install : true,
>>> +                    install_dir : ipa_install_dir)
>>> +
>>> +if ipa_sign_module
>>> +    custom_target(ipa_name + '.so.sign',
>>> +                  input : mod,
>>> +                  output : ipa_name + '.so.sign',
>>> +                  command : [ipa_sign, ipa_priv_key, '@INPUT@', '@OUTPUT@'],
>>> +                  install : false,
>>> +                  build_by_default : true)
>>> +endif
>>> +
>>> +subdir('data')
>>> +
>>> +ipa_names += ipa_name
>>> diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp
>>> new file mode 100644
>>> index 00000000..312df4ba
>>> --- /dev/null
>>> +++ b/src/ipa/simple/soft_simple.cpp
>>> @@ -0,0 +1,326 @@
>>> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
>>> +/*
>>> + * Copyright (C) 2023, Linaro Ltd
>>> + *
>>> + * soft_simple.cpp - Simple Software Image Processing Algorithm module
>>> + */
>>> +
>>> +#include <sys/mman.h>
>>> +
>>> +#include <libcamera/base/file.h>
>>> +#include <libcamera/base/log.h>
>>> +#include <libcamera/base/shared_fd.h>
>>> +
>>> +#include <libcamera/control_ids.h>
>>> +#include <libcamera/controls.h>
>>> +
>>> +#include <libcamera/ipa/ipa_interface.h>
>>> +#include <libcamera/ipa/ipa_module_info.h>
>>> +#include <libcamera/ipa/soft_ipa_interface.h>
>>> +
>>> +#include "libcamera/internal/camera_sensor.h"
>>
>> Not needed.
> 
> OK
> 
>>> +#include "libcamera/internal/software_isp/debayer_params.h"
>>> +#include "libcamera/internal/software_isp/swisp_stats.h"
>>> +
>>> +namespace libcamera {
>>> +
>>> +LOG_DEFINE_CATEGORY(IPASoft)
>>> +
>>> +namespace ipa::soft {
>>> +
>>> +class IPASoftSimple : public ipa::soft::IPASoftInterface
>>> +{
>>> +public:
>>> +    IPASoftSimple()
>>> +        : params_(static_cast<DebayerParams *>(MAP_FAILED)),
>>
>> Initialize this to nullptr, that's more standard, and will make the
>> tests in the destructor nicer. init() will have to set the pointers to
>> null if mmap() calls fail.
> 
> OK
> 
>>> +          stats_(static_cast<SwIspStats *>(MAP_FAILED)), ignore_updates_(0)
>>
>> s/ignore_updates_/ignoreUpdates_/
> 
> OK
> 
>>> +    {
>>> +    }
>>> +
>>> +    ~IPASoftSimple()
>>> +    {
>>> +        if (stats_ != MAP_FAILED)
>>> +            munmap(stats_, sizeof(SwIspStats));
>>> +        if (params_ != MAP_FAILED)
>>> +            munmap(params_, sizeof(DebayerParams));
>>> +    }
>>
>> No need to inline this.
> 
> OK
> 
>>> +
>>> +    int init(const IPASettings &settings,
>>> +         const SharedFD &fdStats,
>>> +         const SharedFD &fdParams,
>>> +         const ControlInfoMap &sensorInfoMap) override;
>>> +    int configure(const ControlInfoMap &sensorInfoMap) override;
>>> +
>>> +    int start() override;
>>> +    void stop() override;
>>> +
>>> +    void processStats(const ControlList &sensorControls) override;
>>> +
>>> +private:
>>> +    void updateExposure(double exposureMSV);
>>> +
>>> +    SharedFD fdStats_;
>>> +    SharedFD fdParams_;
>>> +    DebayerParams *params_;
>>> +    SwIspStats *stats_;
>>> +
>>> +    int32_t exposure_min_, exposure_max_;
>>> +    int32_t again_min_, again_max_;
>>> +    int32_t again_, exposure_;
>>> +    unsigned int ignore_updates_;
>>> +};
>>> +
>>> +int IPASoftSimple::init([[maybe_unused]] const IPASettings &settings,
>>> +            const SharedFD &fdStats,
>>> +            const SharedFD &fdParams,
>>> +            const ControlInfoMap &sensorInfoMap)
>>> +{
>>> +    fdStats_ = fdStats;
>>
>> As you never use fdStats_ and fdParams_ after this function returns,
>> there's no need to store a copy.
> 
> Good catch. OK
> 
>>> +    if (!fdStats_.isValid()) {
>>> +        LOG(IPASoft, Error) << "Invalid Statistics handle";
>>> +        return -ENODEV;
>>> +    }
>>> +
>>> +    fdParams_ = fdParams;
>>> +    if (!fdParams_.isValid()) {
>>> +        LOG(IPASoft, Error) << "Invalid Parameters handle";
>>> +        return -ENODEV;
>>> +    }
>>> +
>>> +    params_ = static_cast<DebayerParams *>(mmap(nullptr, sizeof(DebayerParams),
>>> +                            PROT_WRITE, MAP_SHARED,
>>> +                            fdParams_.get(), 0));
>>> +    if (params_ == MAP_FAILED) {
>>> +        LOG(IPASoft, Error) << "Unable to map Parameters";
>>> +        return -errno;
>>> +    }
>>
>>     void *mem = mmap(nullptr, sizeof(DebayerParams), PROT_WRITE, MAP_SHARED,
>>              fdParams_.get(), 0));
>>     if (mem == MAP_FAILED) {
>>         LOG(IPASoft, Error) << "Unable to map Parameters";
>>         return -errno;
>>     }
>>
>>     params_ = static_cast<DebayerParams *>(mem);
> 
> OK
> 
>>> +
>>> +    stats_ = static_cast<SwIspStats *>(mmap(nullptr, sizeof(SwIspStats),
>>> +                        PROT_READ, MAP_SHARED,
>>> +                        fdStats_.get(), 0));
>>> +    if (stats_ == MAP_FAILED) {
>>> +        LOG(IPASoft, Error) << "Unable to map Statistics";
>>> +        return -errno;
>>> +    }
>>> +
>>> +    if (sensorInfoMap.find(V4L2_CID_EXPOSURE) == sensorInfoMap.end()) {
>>> +        LOG(IPASoft, Error) << "Don't have exposure control";
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    if (sensorInfoMap.find(V4L2_CID_ANALOGUE_GAIN) == sensorInfoMap.end()) {
>>> +        LOG(IPASoft, Error) << "Don't have gain control";
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +int IPASoftSimple::configure(const ControlInfoMap &sensorInfoMap)
>>> +{
>>> +    const ControlInfo &exposure_info = sensorInfoMap.find(V4L2_CID_EXPOSURE)->second;
>>
>> s/exposure_info/exposureInfo/
>>
>> I'll let you address the other snake_case to camelCase conversions in
>> the series :-)
> 
> OK
> 
>>> +    const ControlInfo &gain_info = sensorInfoMap.find(V4L2_CID_ANALOGUE_GAIN)->second;
>>> +
>>> +    exposure_min_ = exposure_info.min().get<int32_t>();
>>> +    exposure_max_ = exposure_info.max().get<int32_t>();
>>> +    if (!exposure_min_) {
>>> +        LOG(IPASoft, Warning) << "Minimum exposure is zero, that can't be linear";
>>> +        exposure_min_ = 1;
>>> +    }
>>> +
>>> +    again_min_ = gain_info.min().get<int32_t>();
>>> +    again_max_ = gain_info.max().get<int32_t>();
>>
>> Add a blank line.
> 
> OK
> 
>>> +    /*
>>> +     * The camera sensor gain (g) is usually not equal to the value written
>>> +     * into the gain register (x). But the way how the AGC algorithm changes
>>> +     * the gain value to make the total exposure closer to the optimum assumes
>>> +     * that g(x) is not too far from linear function. If the minimal gain is 0,
>>> +     * the g(x) is likely to be far from the linear, like g(x) = a / (b * x + c).
>>> +     * To avoid unexpected changes to the gain by the AGC algorithm (abrupt near
>>> +     * one edge, and very small near the other) we limit the range of the gain
>>> +     * values used.
>>> +     */
>>> +    if (!again_min_) {
>>> +        LOG(IPASoft, Warning) << "Minimum gain is zero, that can't be linear";
>>> +        again_min_ = std::min(100, again_min_ / 2 + again_max_ / 2);
>>> +    }
>>
>> A patch further in the series addresses this by using
>> CameraSensorHelper. It should be squashed with this patch.
> 
> OK
> 
>>> +
>>> +    LOG(IPASoft, Info) << "Exposure " << exposure_min_ << "-" << exposure_max_
>>> +               << ", gain " << again_min_ << "-" << again_max_;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +int IPASoftSimple::start()
>>> +{
>>> +    return 0;
>>> +}
>>> +
>>> +void IPASoftSimple::stop()
>>> +{
>>> +}
>>> +
>>> +/*
>>> + * The number of bins to use for the optimal exposure calculations.
>>> + */
>>> +static constexpr unsigned int kExposureBinsCount = 5;
>>
>> Missing blank line. Same below.
> 
> OK
> 
>>> +/*
>>> + * The exposure is optimal when the mean sample value of the histogram is
>>> + * in the middle of the range.
>>> + */
>>> +static constexpr float kExposureOptimal = kExposureBinsCount / 2.0;
>>> +/*
>>> + * The below value implements the hysteresis for the exposure adjustment.
>>> + * It is small enough to have the exposure close to the optimal, and is big
>>> + * enough to prevent the exposure from wobbling around the optimal value.
>>> + */
>>> +static constexpr float kExposureSatisfactory = 0.2;
>>
>> Move these to the beginning of the file, just before the IPASoftSimple
>> definition.
> 
> OK
> 
>>> +
>>> +void IPASoftSimple::processStats(const ControlList &sensorControls)
>>> +{
>>> +    /*
>>> +     * Calculate red and blue gains for AWB.
>>> +     * Clamp max gain at 4.0, this also avoids 0 division.
>>> +     */
>>> +    if (stats_->sumR_ <= stats_->sumG_ / 4)
>>> +        params_->gainR = 1024;
>>> +    else
>>> +        params_->gainR = 256 * stats_->sumG_ / stats_->sumR_;
>>> +
>>> +    if (stats_->sumB_ <= stats_->sumG_ / 4)
>>> +        params_->gainB = 1024;
>>> +    else
>>> +        params_->gainB = 256 * stats_->sumG_ / stats_->sumB_;
>>> +
>>> +    /* Green gain and gamma values are fixed */
>>> +    params_->gainG = 256;
>>> +    params_->gamma = 0.5;
>>> +
>>> +    setIspParams.emit(0);
>>
>> Do you envision switching to the libipa/algorithm.h API at some point ?
>> If so, it would be nice to record it somewhere.
> 
> At some point, yes.
> Will mention that.
> 
>>> +
>>> +    /*
>>> +     * AE / AGC, use 2 frames delay to make sure that the exposure and
>>> +     * the gain set have applied to the camera sensor.
>>> +     */
>>> +    if (ignore_updates_ > 0) {
>>> +        --ignore_updates_;
>>> +        return;
>>> +    }
>>
>> Also something that could be improved and that should be recorded
>> somewhere.
> 
> OK
> 
>>> +
>>> +    /*
>>> +     * Calculate Mean Sample Value (MSV) according to formula from:
>>> +     * https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf
>>> +     */
>>> +    constexpr unsigned int yHistValsPerBin =
>>> +        SwIspStats::kYHistogramSize / kExposureBinsCount;
>>> +    constexpr unsigned int yHistValsPerBinMod =
>>> +        SwIspStats::kYHistogramSize /
>>> +        (SwIspStats::kYHistogramSize % kExposureBinsCount + 1);
>>> +    int ExposureBins[kExposureBinsCount] = {};
>>
>> s/ExposureBins/exposureBins/
> 
> OK
> 
>>> +    unsigned int denom = 0;
>>> +    unsigned int num = 0;
>>> +
>>> +    for (unsigned int i = 0; i < SwIspStats::kYHistogramSize; i++) {
>>> +        unsigned int idx = (i - (i / yHistValsPerBinMod)) / yHistValsPerBin;
>>> +        ExposureBins[idx] += stats_->yHistogram[i];
>>> +    }
>>> +
>>> +    for (unsigned int i = 0; i < kExposureBinsCount; i++) {
>>> +        LOG(IPASoft, Debug) << i << ": " << ExposureBins[i];
>>> +        denom += ExposureBins[i];
>>> +        num += ExposureBins[i] * (i + 1);
>>> +    }
>>> +
>>> +    float exposureMSV = (float)num / denom;
>>
>> C++ casts.
> 
> OK
> 
>>> +
>>> +    /* sanity check */
>>
>> s/sanity/Sanity/
> 
> OK
> 
>>> +    if (!sensorControls.contains(V4L2_CID_EXPOSURE) ||
>>> +        !sensorControls.contains(V4L2_CID_ANALOGUE_GAIN)) {
>>> +        LOG(IPASoft, Error) << "Control(s) missing";
>>> +        return;
>>> +    }
>>> +
>>> +    ControlList ctrls(sensorControls);
>>
>> You shouldn't copy the control list, but instead create one from the
>> ControlInfoMap that you get in init() (and that you then need to stored
>> in the IPA class).
> 
> OK, thanks
> 
>>> +
>>> +    exposure_ = ctrls.get(V4L2_CID_EXPOSURE).get<int32_t>();
>>> +    again_ = ctrls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
>>
>>     exposure_ = sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
>>     again_ = sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>();
> 
> OK
> 
>>> +
>>> +    updateExposure(exposureMSV);
>>> +
>>> +    ctrls.set(V4L2_CID_EXPOSURE, exposure_);
>>> +    ctrls.set(V4L2_CID_ANALOGUE_GAIN, again_);
>>> +
>>> +    ignore_updates_ = 2;
>>> +
>>> +    setSensorControls.emit(ctrls);
>>> +
>>> +    LOG(IPASoft, Debug) << "exposureMSV " << exposureMSV
>>> +                << " exp " << exposure_ << " again " << again_
>>> +                << " gain R/B " << params_->gainR << "/" << params_->gainB;
>>> +}
>>> +
>>> +void IPASoftSimple::updateExposure(double exposureMSV)
>>> +{
>>> +    /* DENOMINATOR of 10 gives ~10% increment/decrement; DENOMINATOR of 5 - about ~20% */
>>
>> Line wrap, and the DENOMINATOR needs to be renamed to kExpDenominator.
> 
> OK
> 
> Thanks for the review,
> Andrei
> 
>>> +    static constexpr uint8_t kExpDenominator = 10;
>>> +    static constexpr uint8_t kExpNumeratorUp = kExpDenominator + 1;
>>> +    static constexpr uint8_t kExpNumeratorDown = kExpDenominator - 1;
>>> +
>>> +    int next;
>>> +
>>> +    if (exposureMSV < kExposureOptimal - kExposureSatisfactory) {
>>> +        next = exposure_ * kExpNumeratorUp / kExpDenominator;
>>> +        if (next - exposure_ < 1)
>>> +            exposure_ += 1;
>>> +        else
>>> +            exposure_ = next;
>>> +        if (exposure_ >= exposure_max_) {
>>> +            next = again_ * kExpNumeratorUp / kExpDenominator;
>>> +            if (next - again_ < 1)
>>> +                again_ += 1;
>>> +            else
>>> +                again_ = next;
>>> +        }
>>> +    }
>>> +
>>> +    if (exposureMSV > kExposureOptimal + kExposureSatisfactory) {
>>> +        if (exposure_ == exposure_max_ && again_ != again_min_) {
>>> +            next = again_ * kExpNumeratorDown / kExpDenominator;
>>> +            if (again_ - next < 1)
>>> +                again_ -= 1;
>>> +            else
>>> +                again_ = next;
>>> +        } else {
>>> +            next = exposure_ * kExpNumeratorDown / kExpDenominator;
>>> +            if (exposure_ - next < 1)
>>> +                exposure_ -= 1;
>>> +            else
>>> +                exposure_ = next;
>>> +        }
>>> +    }
>>> +
>>> +    exposure_ = std::clamp(exposure_, exposure_min_, exposure_max_);
>>> +    again_ = std::clamp(again_, again_min_, again_max_);
>>> +}
>>> +
>>> +} /* namespace ipa::soft */
>>> +
>>> +/*
>>> + * External IPA module interface
>>> + */
>>> +extern "C" {
>>> +const struct IPAModuleInfo ipaModuleInfo = {
>>> +    IPA_MODULE_API_VERSION,
>>> +    0,
>>> +    "SimplePipelineHandler",
>>> +    "simple",
>>> +};
>>> +
>>> +IPAInterface *ipaCreate()
>>> +{
>>> +    return new ipa::soft::IPASoftSimple();
>>> +}
>>> +
>>> +} /* extern "C" */
>>> +
>>> +} /* namespace libcamera */
>>


More information about the libcamera-devel mailing list