[libcamera-devel] [PATCH 3/3] ipa: ipu3: Add a IPAFrameContext queue
Kieran Bingham
kieran.bingham at ideasonboard.com
Thu Apr 21 12:41:01 CEST 2022
Hi Umang,
Quoting Umang Jain via libcamera-devel (2022-03-10 20:51:30)
> Having a single IPAFrameContext queue is limiting especially when
> we need to preserve per-frame controls coming in through
> libcamera::Request. Right now, we are not processing any controls
> on the IPA side (processControls()) but sooner or later we need to
> preserve the controls setting for the frames in the context in a
> retrievable fashion. Hence a std::deque is introduced to preserve
> the frame context of the incoming request's settings as soon as it is
> queued.
>
> Since IPAIPU3::processControls() is executed on
> IPU3CameraData::queuePendingRequests() code path, we need to store the
> incoming control setting in a separate IPAFrameContext and push that
> into the queue. The IPAFrameContext is then dropped when processing for
> that frame has been finished.
Great, having an identifiable (by frame number) context is going to make
things a lot easier I think.
>
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> ---
> src/ipa/ipu3/algorithms/agc.cpp | 16 ++++-----
> src/ipa/ipu3/algorithms/agc.h | 4 +--
> src/ipa/ipu3/algorithms/awb.cpp | 17 +++++-----
> src/ipa/ipu3/algorithms/tone_mapping.cpp | 14 ++++----
> src/ipa/ipu3/ipa_context.cpp | 42 ++++++++++++++++++++++++
> src/ipa/ipu3/ipa_context.h | 12 +++++++
> src/ipa/ipu3/ipu3.cpp | 41 +++++++++++++++++++----
> 7 files changed, 115 insertions(+), 31 deletions(-)
>
> diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp
> index cdc1327a..b24744f2 100644
> --- a/src/ipa/ipu3/algorithms/agc.cpp
> +++ b/src/ipa/ipu3/algorithms/agc.cpp
> @@ -87,7 +87,7 @@ int Agc::configure(IPAContext &context,
> [[maybe_unused]] const IPAConfigInfo &configInfo)
> {
> IPASessionConfiguration &configuration = context.configuration;
> - IPAFrameContext &frameContext = context.frameContext;
> + IPAFrameContext &frameContext = context.getFrameContext(0);
I 'almost' want to call this context.frameContext(0); as an implicit
getter. But the 'get' does make it explicit.
>
> stride_ = configuration.grid.stride;
>
> @@ -182,14 +182,14 @@ utils::Duration Agc::filterExposure(utils::Duration exposureValue)
> * \param[in] yGain The gain calculated based on the relative luminance target
> * \param[in] iqMeanGain The gain calculated based on the relative luminance target
> */
> -void Agc::computeExposure(IPAContext &context, double yGain,
> - double iqMeanGain)
> +void Agc::computeExposure(const uint32_t frame, IPAContext &context,
> + double yGain, double iqMeanGain)
> {
> const IPASessionConfiguration &configuration = context.configuration;
> - IPAFrameContext &frameContext = context.frameContext;
> /* Get the effective exposure and gain applied on the sensor. */
> - uint32_t exposure = frameContext.sensor.exposure;
> - double analogueGain = frameContext.sensor.gain;
> + uint32_t exposure = context.prevFrameContext.sensor.exposure;
> + double analogueGain = context.prevFrameContext.sensor.gain;
> + IPAFrameContext &frameContext = context.getFrameContext(frame);
I would have almost expected to see
IPAFrameContext &previous = context.getFrameContext(frame - 1);
But we might have occasions where that wasn't processed or not
available, so I guess having the most recent parameters referenced
directly probably makes sense, and also reduces having to look them up
each algorithm...
That makes me think a name such as 'mostRecent' might be more
informative? I'm not sure... (There are many previous frames, but only
one mostRecent...?)
I was also going to argue/wonder why it wasn't a pointer to the existing
queue entry - but I suspect we might be freeing it when the frame is
completed, so a copy or move is likely easiest ... maybe that's an
optimisation later, and depends on how big it is if we are copying the
data.
>
> /* Use the highest of the two gain estimates. */
> double evGain = std::max(yGain, iqMeanGain);
> @@ -344,7 +344,7 @@ void Agc::process(const uint32_t frame, IPAContext &context, const ipu3_uapi_sta
> double yTarget = kRelativeLuminanceTarget;
>
> for (unsigned int i = 0; i < 8; i++) {
> - double yValue = estimateLuminance(context.frameContext,
> + double yValue = estimateLuminance(context.prevFrameContext,
> context.configuration.grid.bdsGrid,
> stats, yGain);
> double extraGain = std::min(10.0, yTarget / (yValue + .001));
> @@ -357,7 +357,7 @@ void Agc::process(const uint32_t frame, IPAContext &context, const ipu3_uapi_sta
> break;
> }
>
> - computeExposure(context, yGain, iqMeanGain);
> + computeExposure(frame, context, yGain, iqMeanGain);
> frameCount_++;
> }
>
> diff --git a/src/ipa/ipu3/algorithms/agc.h b/src/ipa/ipu3/algorithms/agc.h
> index e48506e5..f35de05f 100644
> --- a/src/ipa/ipu3/algorithms/agc.h
> +++ b/src/ipa/ipu3/algorithms/agc.h
> @@ -34,8 +34,8 @@ private:
> double measureBrightness(const ipu3_uapi_stats_3a *stats,
> const ipu3_uapi_grid_config &grid) const;
> utils::Duration filterExposure(utils::Duration currentExposure);
> - void computeExposure(IPAContext &context, double yGain,
> - double iqMeanGain);
> + void computeExposure(const uint32_t frame, IPAContext &context,
> + double yGain, double iqMeanGain);
> double estimateLuminance(IPAFrameContext &frameContext,
> const ipu3_uapi_grid_config &grid,
> const ipu3_uapi_stats_3a *stats,
> diff --git a/src/ipa/ipu3/algorithms/awb.cpp b/src/ipa/ipu3/algorithms/awb.cpp
> index f1e753e6..00ac2984 100644
> --- a/src/ipa/ipu3/algorithms/awb.cpp
> +++ b/src/ipa/ipu3/algorithms/awb.cpp
> @@ -390,16 +390,17 @@ void Awb::calculateWBGains(const ipu3_uapi_stats_3a *stats)
> void Awb::process(const uint32_t frame, IPAContext &context, const ipu3_uapi_stats_3a *stats)
> {
> calculateWBGains(stats);
> + IPAFrameContext &frameContext = context.getFrameContext(frame);
This code's reason enough here to keep the explicit 'get' in
getFrameContext for me I think.
> /*
> * Gains are only recalculated if enough zones were detected.
> * The results are cached, so if no results were calculated, we set the
> * cached values from asyncResults_ here.
> */
> - context.frameContext.awb.gains.blue = asyncResults_.blueGain;
> - context.frameContext.awb.gains.green = asyncResults_.greenGain;
> - context.frameContext.awb.gains.red = asyncResults_.redGain;
> - context.frameContext.awb.temperatureK = asyncResults_.temperatureK;
> + frameContext.awb.gains.blue = asyncResults_.blueGain;
> + frameContext.awb.gains.green = asyncResults_.greenGain;
> + frameContext.awb.gains.red = asyncResults_.redGain;
> + frameContext.awb.temperatureK = asyncResults_.temperatureK;
> }
>
> constexpr uint16_t Awb::threshold(float value)
> @@ -450,10 +451,10 @@ void Awb::prepare([[maybe_unused]] const uint32_t frame, IPAContext &context, ip
> params->acc_param.bnr.opt_center_sqr.y_sqr_reset = params->acc_param.bnr.opt_center.y_reset
> * params->acc_param.bnr.opt_center.y_reset;
> /* Convert to u3.13 fixed point values */
> - params->acc_param.bnr.wb_gains.gr = 8192 * context.frameContext.awb.gains.green;
> - params->acc_param.bnr.wb_gains.r = 8192 * context.frameContext.awb.gains.red;
> - params->acc_param.bnr.wb_gains.b = 8192 * context.frameContext.awb.gains.blue;
> - params->acc_param.bnr.wb_gains.gb = 8192 * context.frameContext.awb.gains.green;
> + params->acc_param.bnr.wb_gains.gr = 8192 * context.prevFrameContext.awb.gains.green;
> + params->acc_param.bnr.wb_gains.r = 8192 * context.prevFrameContext.awb.gains.red;
> + params->acc_param.bnr.wb_gains.b = 8192 * context.prevFrameContext.awb.gains.blue;
> + params->acc_param.bnr.wb_gains.gb = 8192 * context.prevFrameContext.awb.gains.green;
>
> LOG(IPU3Awb, Debug) << "Color temperature estimated: " << asyncResults_.temperatureK;
>
> diff --git a/src/ipa/ipu3/algorithms/tone_mapping.cpp b/src/ipa/ipu3/algorithms/tone_mapping.cpp
> index bba5bc9a..f0fbaaf7 100644
> --- a/src/ipa/ipu3/algorithms/tone_mapping.cpp
> +++ b/src/ipa/ipu3/algorithms/tone_mapping.cpp
> @@ -42,7 +42,7 @@ int ToneMapping::configure(IPAContext &context,
> [[maybe_unused]] const IPAConfigInfo &configInfo)
> {
> /* Initialise tone mapping gamma value. */
> - context.frameContext.toneMapping.gamma = 0.0;
> + context.frameContextQueue.front().toneMapping.gamma = 0.0;
In another call you used getFrameContext(0). Which one is more
appropriate? Will it always be the same requirement? (to get the first,
or 0th?)
Does the front of the queue represent frame 0, or frame 10 if there are
ten frames on the queue?
Perhaps a helper wrapper around the queue would let us declare methods
that are more descriptive? (Though I don't know which names are helpful
yet, so maybe it's overkill)
frameContextQueue.first() // Oldest?
frameContextQueue.last() // Newest?
frameContextQueue.mostRecent()
frameContextQueue.mostRecentWithFilledStatistics() ?
frameContextQueue.get(n)
frameContextQueue.start(n)
frameContextQueue.finish(n)
(Or such, if they are useful)
> return 0;
> }
> @@ -62,7 +62,7 @@ void ToneMapping::prepare([[maybe_unused]] const uint32_t frame,
> {
> /* Copy the calculated LUT into the parameters buffer. */
> memcpy(params->acc_param.gamma.gc_lut.lut,
> - context.frameContext.toneMapping.gammaCorrection.lut,
> + context.prevFrameContext.toneMapping.gammaCorrection.lut,
> IPU3_UAPI_GAMMA_CORR_LUT_ENTRIES *
> sizeof(params->acc_param.gamma.gc_lut.lut[0]));
>
> @@ -73,7 +73,7 @@ void ToneMapping::prepare([[maybe_unused]] const uint32_t frame,
>
> /**
> * \brief Calculate the tone mapping look up table
> - * \param frame The frame number
> + te* \param frame The frame number
Oops?
> * \param context The shared IPA context
> * \param stats The IPU3 statistics and ISP results
> *
> @@ -83,6 +83,8 @@ void ToneMapping::prepare([[maybe_unused]] const uint32_t frame,
> void ToneMapping::process(const uint32_t frame, IPAContext &context,
> [[maybe_unused]] const ipu3_uapi_stats_3a *stats)
> {
> + IPAFrameContext &frameContext = context.getFrameContext(frame);
> +
It does seem like we should do this lookup once before calling process()
on all algorithms perhaps.
> /*
> * Hardcode gamma to 1.1 as a default for now.
> *
> @@ -90,11 +92,11 @@ void ToneMapping::process(const uint32_t frame, IPAContext &context,
> */
> gamma_ = 1.1;
>
> - if (context.frameContext.toneMapping.gamma == gamma_)
> + if (frameContext.toneMapping.gamma == gamma_)
> return;
>
> struct ipu3_uapi_gamma_corr_lut &lut =
> - context.frameContext.toneMapping.gammaCorrection;
> + frameContext.toneMapping.gammaCorrection;
>
> for (uint32_t i = 0; i < std::size(lut.lut); i++) {
> double j = static_cast<double>(i) / (std::size(lut.lut) - 1);
> @@ -104,7 +106,7 @@ void ToneMapping::process(const uint32_t frame, IPAContext &context,
> lut.lut[i] = gamma * 8191;
> }
>
> - context.frameContext.toneMapping.gamma = gamma_;
> + frameContext.toneMapping.gamma = gamma_;
> }
>
> } /* namespace ipa::ipu3::algorithms */
> diff --git a/src/ipa/ipu3/ipa_context.cpp b/src/ipa/ipu3/ipa_context.cpp
> index 9c4ec936..41cbf717 100644
> --- a/src/ipa/ipu3/ipa_context.cpp
> +++ b/src/ipa/ipu3/ipa_context.cpp
> @@ -24,6 +24,48 @@ namespace libcamera::ipa::ipu3 {
> * may also be updated in the start() operation.
> */
>
> +/**
> + * \brief Retrieve the context of a particular frame
> + * \param[in] frame Frame number
> + *
> + * Retrieve the frame context of the \a frame.
> + *
> + * \return The frame context of the given frame number or nullptr, if not found
This doesn't match the implementation below.
> + */
> +IPAFrameContext &IPAContext::getFrameContext(const uint32_t frame)
> +{
> + auto iter = frameContextQueue.begin();
> + while (iter != frameContextQueue.end()) {
> + if (iter->frame == frame)
> + return *iter;
> +
> + iter++;
> + }
> +
> + /*
> + * \todo Handle the case where frame-context is not found here.
> + * Should we be FATAL ?
We're in IPA here - so fatal could kill the IPA process without killing
or signalling the libcamera process. That's something we need to figure
out separately...
We might end up hitting this if we try to do something like
getFrameContext( frame - 1 );
just after a frame was missed or not processed for some reason (like a
buffer underflow) which would mean we wouldn't have had stats on that
frame. So we need to work out how to handle that gracefully, and as
correctly as possible.
> + */
> + return *iter; /* returns frameContextQueue.end() */
> +}
> +
> +/**
> + * \brief Construct a IPAFrameContext instance
> + */
> +IPAFrameContext::IPAFrameContext() = default;
> +
> +/**
> + * \brief Move constructor for IPAFrameContext
> + * \param[in] other The other IPAFrameContext
> + */
> +IPAFrameContext::IPAFrameContext(IPAFrameContext &&other) = default;
> +
> +/**
> + * \brief Move assignment operator for IPAFrameContext
> + * \param[in] other The other IPAFrameContext
> + */
> +IPAFrameContext &IPAFrameContext::operator=(IPAFrameContext &&other) = default;
> +
> /**
> * \struct IPAFrameContext
> * \brief Per-frame context for algorithms
> diff --git a/src/ipa/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h
> index d993359a..eca346d6 100644
> --- a/src/ipa/ipu3/ipa_context.h
> +++ b/src/ipa/ipu3/ipa_context.h
> @@ -8,6 +8,8 @@
>
> #pragma once
>
> +#include <deque>
> +
> #include <linux/intel-ipu3.h>
>
> #include <libcamera/base/utils.h>
> @@ -39,6 +41,12 @@ struct IPASessionConfiguration {
> };
>
> struct IPAFrameContext {
> + uint32_t frame;
> +
> + IPAFrameContext();
> + IPAFrameContext(IPAFrameContext &&other);
> + IPAFrameContext &operator=(IPAFrameContext &&other);
> +
> struct {
> uint32_t exposure;
> double gain;
> @@ -66,8 +74,12 @@ struct IPAFrameContext {
> };
>
> struct IPAContext {
> + IPAFrameContext &getFrameContext(const uint32_t frame);
> IPASessionConfiguration configuration;
> IPAFrameContext frameContext;
> +
> + std::deque<IPAFrameContext> frameContextQueue;
> + IPAFrameContext prevFrameContext;
> };
>
> } /* namespace ipa::ipu3 */
> diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
> index 3d5c5706..f3128b0a 100644
> --- a/src/ipa/ipu3/ipu3.cpp
> +++ b/src/ipa/ipu3/ipu3.cpp
> @@ -349,6 +349,8 @@ int IPAIPU3::start()
> */
> void IPAIPU3::stop()
> {
> + while (!context_.frameContextQueue.empty())
> + context_.frameContextQueue.pop_front();
would deque::clear() be more distinct here?
> }
>
> /**
> @@ -451,6 +453,14 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
> */
> ctrls_ = configInfo.sensorControls;
>
> + /*
> + * Insert a initial context into the queue to faciliate
> + * algo->configure() below.
> + */
> + IPAFrameContext initContext;
> + initContext.frame = 0;
I ... am not 100% sure about how to handle this.
Shouldn't this be frameStarted(0). ... and what happens if you've added
this frameContext(0) here, and then the PH delivers a frameStarted(0)
event?
> + context_.frameContextQueue.push_back(std::move(initContext));
> +
> calculateBdsGrid(configInfo.bdsOutputSize);
>
> /* Clean frameContext at each reconfiguration. */
> @@ -501,10 +511,25 @@ void IPAIPU3::unmapBuffers(const std::vector<unsigned int> &ids)
>
> void IPAIPU3::frameStarted([[maybe_unused]] const uint32_t frame)
> {
> + IPAFrameContext newContext;
> + newContext.frame = frame;
> +
> + context_.frameContextQueue.push_back(std::move(newContext));
> }
>
> void IPAIPU3::frameCompleted([[maybe_unused]] const uint32_t frame)
> {
> + while (!context_.frameContextQueue.empty()) {
> + auto &fc = context_.frameContextQueue.front();
> + if (fc.frame < frame)
> + context_.frameContextQueue.pop_front();
> +
> + /* Keep newer frames */
> + if (fc.frame >= frame) {
> + context_.prevFrameContext = std::move(fc);
> + break;
> + }
> + }
I could see us making a dedicated templated queue class specialised to
the needs of keeping contexts around and remembering the most recent
completed data, which could then be used by other IPAs... But lets get
this working and right first and then we can refactor to something
generically re-usable I think.
> }
>
> /**
> @@ -547,8 +572,9 @@ void IPAIPU3::processStatsBuffer(const uint32_t frame, const int64_t frameTimest
> const ipu3_uapi_stats_3a *stats =
> reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());
>
> - context_.frameContext.sensor.exposure = sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
> - context_.frameContext.sensor.gain = camHelper_->gain(sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>());
> + IPAFrameContext &curFrameContext = context_.getFrameContext(frame);
> + curFrameContext.sensor.exposure = sensorControls.get(V4L2_CID_EXPOSURE).get<int32_t>();
> + curFrameContext.sensor.gain = camHelper_->gain(sensorControls.get(V4L2_CID_ANALOGUE_GAIN).get<int32_t>());
>
> parseStatistics(frame, frameTimestamp, stats);
> }
> @@ -623,11 +649,11 @@ void IPAIPU3::parseStatistics(unsigned int frame,
> int64_t frameDuration = (vBlank + sensorInfo_.outputSize.height) * lineDuration;
> ctrls.set(controls::FrameDuration, frameDuration);
>
> - ctrls.set(controls::AnalogueGain, context_.frameContext.sensor.gain);
> + ctrls.set(controls::AnalogueGain, context_.prevFrameContext.sensor.gain);
This doesn't sound right - when we set this metadata, it should be
reflecting the gain that was set for that frame.
We really need a full sequence diagram of the operations from the app
(queueing a request) to the PH - to the IPA and when frames are
received over CSI2 and handled by the ISP...
https://sequencediagram.org/ looks helpful for us to make that.
>
> - ctrls.set(controls::ColourTemperature, context_.frameContext.awb.temperatureK);
> + ctrls.set(controls::ColourTemperature, context_.prevFrameContext.awb.temperatureK);
>
> - ctrls.set(controls::ExposureTime, context_.frameContext.sensor.exposure * lineDuration);
> + ctrls.set(controls::ExposureTime, context_.prevFrameContext.sensor.exposure * lineDuration);
>
> /*
> * \todo The Metadata provides a path to getting extended data
> @@ -651,8 +677,9 @@ void IPAIPU3::parseStatistics(unsigned int frame,
> */
> void IPAIPU3::setControls(unsigned int frame)
> {
> - int32_t exposure = context_.frameContext.agc.exposure;
> - int32_t gain = camHelper_->gainCode(context_.frameContext.agc.gain);
> + IPAFrameContext &context = context_.getFrameContext(frame);
> + int32_t exposure = context.agc.exposure;
> + int32_t gain = camHelper_->gainCode(context.agc.gain);
We need to check and think about when these controls get set too. But -
I also think that's going to be part of the reworkign delayed
controls/perframe control support ... so maybe it's something to
consider on top anyway.
>
> ControlList ctrls(ctrls_);
> ctrls.set(V4L2_CID_EXPOSURE, exposure);
> --
> 2.31.0
>
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