[libcamera-devel] [PATCH v4 16/19] libcamera: ipu3: imgu: Calculate ImgU pipe configuration
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Jul 30 22:34:28 CEST 2020
Hi Jacopo,
Thank you for the patch.
On Mon, Jul 20, 2020 at 12:47:33PM +0200, Jacopo Mondi wrote:
> Instrument the ImgU component to dynamically calculate the image
> manipulation pipeline intermediate sizes.
>
> To correctly configure the ImgU it is necessary to program the IF, BDS
> and GDC sizes, which are currently fixed to the input frame size.
>
> The procedure used to calculate the intermediate sizes has been ported
> from the pipe_config.py python script, available at:
> https://github.com/intel/intel-ipu3-pipecfg
> at revision:
> 61e83f2f7606 ("Add more information into README")
>
> Define two structures (ImgUDevice::Pipe and ImgUDevice::PipeConfig)
> to allow the pipeline handler to supply and retrieve configuration
> parameters from the ImgU.
>
> Finally, add a new operation to the ImgUDevice that calculates
> the pipe configuration parameters based on the requested input and
> output sizes.
>
> Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
As commented on the previous version, I think there's quite a bit of
room for improvement in this code, including fairly low hanging fruits.
I however don't see a reason to block the feature, but please don't
hesitate to add improvements on top (if I don't beat you to it). In
particular, anything that we don't understand properly needs to be
logged, and we need to request more information.
Acked-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> src/libcamera/pipeline/ipu3/imgu.cpp | 349 +++++++++++++++++++++++++++
> src/libcamera/pipeline/ipu3/imgu.h | 20 ++
> 2 files changed, 369 insertions(+)
>
> diff --git a/src/libcamera/pipeline/ipu3/imgu.cpp b/src/libcamera/pipeline/ipu3/imgu.cpp
> index 4bec4b2f1a76..17b749435ee2 100644
> --- a/src/libcamera/pipeline/ipu3/imgu.cpp
> +++ b/src/libcamera/pipeline/ipu3/imgu.cpp
> @@ -7,6 +7,9 @@
>
> #include "imgu.h"
>
> +#include <limits>
> +#include <math.h>
> +
> #include <linux/media-bus-format.h>
>
> #include <libcamera/formats.h>
> @@ -14,11 +17,300 @@
>
> #include "libcamera/internal/log.h"
> #include "libcamera/internal/media_device.h"
> +#include "libcamera/internal/utils.h"
>
> namespace libcamera {
>
> LOG_DECLARE_CATEGORY(IPU3)
>
> +namespace {
> +
> +static constexpr unsigned int FILTER_H = 4;
> +
> +static constexpr unsigned int IF_ALIGN_W = 2;
> +static constexpr unsigned int IF_ALIGN_H = 4;
> +
> +static constexpr unsigned int BDS_ALIGN_W = 2;
> +static constexpr unsigned int BDS_ALIGN_H = 4;
> +
> +static constexpr unsigned int IF_CROP_MAX_W = 40;
> +static constexpr unsigned int IF_CROP_MAX_H = 540;
> +
> +static constexpr float BDS_SF_MAX = 2.5;
> +static constexpr float BDS_SF_MIN = 1.0;
> +static constexpr float BDS_SF_STEP = 0.03125;
> +
> +/* BSD scaling factors: min=1, max=2.5, step=1/32 */
> +const std::vector<float> bdsScalingFactors = {
> + 1, 1.03125, 1.0625, 1.09375, 1.125, 1.15625, 1.1875, 1.21875, 1.25,
> + 1.28125, 1.3125, 1.34375, 1.375, 1.40625, 1.4375, 1.46875, 1.5, 1.53125,
> + 1.5625, 1.59375, 1.625, 1.65625, 1.6875, 1.71875, 1.75, 1.78125, 1.8125,
> + 1.84375, 1.875, 1.90625, 1.9375, 1.96875, 2, 2.03125, 2.0625, 2.09375,
> + 2.125, 2.15625, 2.1875, 2.21875, 2.25, 2.28125, 2.3125, 2.34375, 2.375,
> + 2.40625, 2.4375, 2.46875, 2.5
> +};
> +
> +/* GDC scaling factors: min=1, max=16, step=1/4 */
> +const std::vector<float> gdcScalingFactors = {
> + 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25,
> + 4.5, 4.75, 5, 5.25, 5.5, 5.75, 6, 6.25, 6.5, 6.75, 7, 7.25, 7.5, 7.75,
> + 8, 8.25, 8.5, 8.75, 9, 9.25, 9.5, 9.75, 10, 10.25, 10.5, 10.75, 11,
> + 11.25, 11.5, 11.75, 12, 12.25, 12.5, 12.75, 13, 13.25, 13.5, 13.75, 14,
> + 14.25, 14.5, 14.75, 15, 15.25, 15.5, 15.75, 16,
> +};
> +
> +std::vector<ImgUDevice::PipeConfig> pipeConfigs;
> +
> +struct FOV {
> + float w;
> + float h;
> +
> + bool isLarger(const FOV &other)
> + {
> + if (w > other.w)
> + return true;
> + if (w == other.w && h > other.h)
> + return true;
> + return false;
> + }
> +};
> +
> +/* Approximate a scaling factor sf to the closest one available in a range. */
> +float findScaleFactor(float sf, const std::vector<float> &range,
> + bool roundDown = false)
> +{
> + if (sf <= range[0])
> + return range[0];
> + if (sf >= range[range.size() - 1])
> + return range[range.size() - 1];
> +
> +
> + float bestDiff = std::numeric_limits<float>::max();
> + unsigned int index = 0;
> + for (unsigned int i = 0; i < range.size(); ++i) {
> + float diff = std::abs(sf - range[i]);
> + if (diff < bestDiff) {
> + bestDiff = diff;
> + index = i;
> + }
> + }
> +
> + if (roundDown && index > 0 && sf < range[index])
> + index--;
> +
> + return range[index];
> +}
> +
> +bool isSameRatio(const Size &in, const Size &out)
> +{
> + float inRatio = static_cast<float>(in.width) /
> + static_cast<float>(in.height);
> + float outRatio = static_cast<float>(out.width) /
> + static_cast<float>(out.height);
> +
> + if (std::abs(inRatio - outRatio) > 0.1)
> + return false;
> +
> + return true;
> +}
> +
> +void calculateBDSHeight(ImgUDevice::Pipe *pipe, const Size &iif, const Size &gdc,
> + unsigned int bdsWidth, float bdsSF)
> +{
> + unsigned int minIFHeight = iif.height - IF_CROP_MAX_H;
> + unsigned int minBDSHeight = gdc.height + FILTER_H * 2;
> + unsigned int ifHeight;
> + float bdsHeight;
> +
> + if (!isSameRatio(pipe->input, gdc)) {
> + bool found = false;
> + float estIFHeight = static_cast<float>(iif.width * gdc.height) /
> + static_cast<float>(gdc.width);
> + estIFHeight = utils::clamp<float>(estIFHeight, minIFHeight, iif.height);
> + ifHeight = utils::alignUp(estIFHeight, IF_ALIGN_H);
> + while (ifHeight >= minIFHeight &&
> + static_cast<float>(ifHeight) / bdsSF >= minBDSHeight) {
> + bdsHeight = static_cast<float>(ifHeight) / bdsSF;
> + if (std::fmod(bdsHeight, 1.0) == 0) {
> + unsigned int bdsIntHeight = static_cast<unsigned int>(bdsHeight);
> + if (!(bdsIntHeight % BDS_ALIGN_H)) {
> + found = true;
> + break;
> + }
> + }
> +
> + ifHeight -= IF_ALIGN_H;
> + }
> +
> + ifHeight = utils::alignUp(estIFHeight, IF_ALIGN_H);
> + while (ifHeight <= iif.height &&
> + static_cast<float>(ifHeight) / bdsSF >= minBDSHeight) {
> + bdsHeight = static_cast<float>(ifHeight) / bdsSF;
> + if (std::fmod(bdsHeight, 1.0) == 0) {
> + unsigned int bdsIntHeight = static_cast<unsigned int>(bdsHeight);
> + if (!(bdsIntHeight % BDS_ALIGN_H)) {
> + found = true;
> + break;
> + }
> + }
> +
> + ifHeight += IF_ALIGN_H;
> + }
> +
> + if (found) {
> + unsigned int bdsIntHeight = static_cast<unsigned int>(bdsHeight);
> + pipeConfigs.push_back({ bdsSF, { iif.width, ifHeight },
> + { bdsWidth, bdsIntHeight }, gdc });
> + return;
> + }
> + } else {
> + ifHeight = utils::alignUp(iif.height, IF_ALIGN_H);
> + while (ifHeight > minIFHeight &&
> + static_cast<float>(ifHeight) / bdsSF >= minBDSHeight) {
> + bdsHeight = ifHeight / bdsSF;
> + if (std::fmod(ifHeight, 1.0) == 0 && std::fmod(bdsHeight, 1.0) == 0) {
> + unsigned int bdsIntHeight = static_cast<unsigned int>(bdsHeight);
> +
> + if (!(ifHeight % IF_ALIGN_H) &&
> + !(bdsIntHeight % BDS_ALIGN_H)) {
> + pipeConfigs.push_back({ bdsSF, { iif.width, ifHeight },
> + { bdsWidth, bdsIntHeight }, gdc });
> + }
> + }
> +
> + ifHeight -= IF_ALIGN_H;
> + }
> + }
> +}
> +
> +void calculateBDS(ImgUDevice::Pipe *pipe, const Size &iif, const Size &gdc,
> + float bdsSF)
> +{
> + unsigned int minBDSWidth = gdc.width + FILTER_H * 2;
> +
> + float sf = bdsSF;
> + while (sf <= BDS_SF_MAX && sf >= BDS_SF_MIN) {
> + float bdsWidth = static_cast<float>(iif.width) / sf;
> +
> + if (std::fmod(bdsWidth, 1.0) == 0) {
> + unsigned int bdsIntWidth = static_cast<unsigned int>(bdsWidth);
> + if (!(bdsIntWidth % BDS_ALIGN_W) && bdsWidth >= minBDSWidth)
> + calculateBDSHeight(pipe, iif, gdc, bdsIntWidth, sf);
> + }
> +
> + sf += BDS_SF_STEP;
> + }
> +
> + sf = bdsSF;
> + while (sf <= BDS_SF_MAX && sf >= BDS_SF_MIN) {
> + float bdsWidth = static_cast<float>(iif.width) / sf;
> +
> + if (std::fmod(bdsWidth, 1.0) == 0) {
> + unsigned int bdsIntWidth = static_cast<unsigned int>(bdsWidth);
> + if (!(bdsIntWidth % BDS_ALIGN_W) && bdsWidth >= minBDSWidth)
> + calculateBDSHeight(pipe, iif, gdc, bdsIntWidth, sf);
> + }
> +
> + sf -= BDS_SF_STEP;
> + }
> +}
> +
> +Size calculateGDC(ImgUDevice::Pipe *pipe)
> +{
> + const Size &in = pipe->input;
> + const Size &main = pipe->output;
> + const Size &vf = pipe->viewfinder;
> + Size gdc;
> +
> + if (!vf.isNull()) {
> + gdc.width = main.width;
> +
> + float ratio = static_cast<float>(main.width * vf.height) /
> + static_cast<float>(vf.width);
> + gdc.height = std::max(static_cast<float>(main.height), ratio);
> +
> + return gdc;
> + }
> +
> + if (!isSameRatio(in, main)) {
> + gdc = main;
> + return gdc;
> + }
> +
> + float totalSF = static_cast<float>(in.width) /
> + static_cast<float>(main.width);
> + float bdsSF = totalSF > 2 ? 2 : 1;
> + float yuvSF = totalSF / bdsSF;
> + float sf = findScaleFactor(yuvSF, gdcScalingFactors);
> +
> + gdc.width = static_cast<float>(main.width) * sf;
> + gdc.height = static_cast<float>(main.height) * sf;
> +
> + return gdc;
> +}
> +
> +FOV calcFOV(const Size &in, const ImgUDevice::PipeConfig &pipe)
> +{
> + FOV fov{};
> +
> + float inW = static_cast<float>(in.width);
> + float inH = static_cast<float>(in.height);
> + float ifCropW = static_cast<float>(in.width - pipe.iif.width);
> + float ifCropH = static_cast<float>(in.height - pipe.iif.height);
> + float gdcCropW = static_cast<float>(pipe.bds.width - pipe.gdc.width) * pipe.bds_sf;
> + float gdcCropH = static_cast<float>(pipe.bds.height - pipe.gdc.height) * pipe.bds_sf;
> + fov.w = (inW - (ifCropW + gdcCropW)) / inW;
> + fov.h = (inH - (ifCropH + gdcCropH)) / inH;
> +
> + return fov;
> +}
> +
> +} /* namespace */
> +
> +/**
> + * \struct PipeConfig
> + * \brief The ImgU pipe configuration parameters
> + *
> + * The ImgU image pipeline is composed of several hardware blocks that crop
> + * and scale the input image to obtain the desired output sizes. The
> + * scaling/cropping operations of those components is configured though the
> + * V4L2 selection API and the V4L2 subdev API applied to the ImgU media entity.
> + *
> + * The configurable components in the pipeline are:
> + * - IF: image feeder
> + * - BDS: bayer downscaler
> + * - GDC: geometric distorsion correction
> + *
> + * The IF crop rectangle is controlled by the V4L2_SEL_TGT_CROP selection target
> + * applied to the ImgU media entity sink pad number 0. The BDS scaler is
> + * controlled by the V4L2_SEL_TGT_COMPOSE target on the same pad, while the GDC
> + * output size is configured with the VIDIOC_SUBDEV_S_FMT IOCTL, again on pad
> + * number 0.
> + *
> + * The PipeConfig structure collects the sizes of each of those components
> + * plus the BDS scaling factor used to calculate the field of view
> + * of the final images.
> + */
> +
> +/**
> + * \struct Pipe
> + * \brief Describe the ImgU requested configuration
> + *
> + * The ImgU unit processes images through several components, which have
> + * to be properly configured inspecting the input image size and the desired
> + * output sizes. This structure collects the ImgU input configuration and the
> + * requested main output and viewfinder configurations.
> + *
> + * \var Pipe::input
> + * \brief The input image size
> + *
> + * \var Pipe::output
> + * \brief The requested main output size
> + *
> + * \var Pipe::viewfinder
> + * \brief The requested viewfinder size
> + */
> +
> /**
> * \brief Initialize components of the ImgU instance
> * \param[in] mediaDevice The ImgU instance media device
> @@ -74,6 +366,63 @@ int ImgUDevice::init(MediaDevice *media, unsigned int index)
> return 0;
> }
>
> +/**
> + * \brief Calculate the ImgU pipe configuration parameters
> + * \param[in] pipe The requested ImgU configuration
> + * \return An ImgUDevice::PipeConfig instance on success, an empty configuration
> + * otherwise
> + */
> +ImgUDevice::PipeConfig ImgUDevice::calculatePipeConfig(Pipe *pipe)
> +{
> + pipeConfigs.clear();
> +
> + LOG(IPU3, Debug) << "Calculating pipe configuration for: ";
> + LOG(IPU3, Debug) << "input: " << pipe->input.toString();
> + LOG(IPU3, Debug) << "main: " << pipe->output.toString();
> + LOG(IPU3, Debug) << "vf: " << pipe->viewfinder.toString();
> +
> + const Size &in = pipe->input;
> + Size gdc = calculateGDC(pipe);
> +
> + unsigned int ifWidth = utils::alignUp(in.width, IF_ALIGN_W);
> + unsigned int ifHeight = in.height;
> + unsigned int minIfWidth = in.width - IF_CROP_MAX_W;
> + float bdsSF = static_cast<float>(in.width) /
> + static_cast<float>(gdc.width);
> + float sf = findScaleFactor(bdsSF, bdsScalingFactors, true);
> + while (ifWidth >= minIfWidth) {
> + Size iif{ ifWidth, ifHeight };
> + calculateBDS(pipe, iif, gdc, sf);
> +
> + ifWidth -= IF_ALIGN_W;
> + }
> +
> + if (pipeConfigs.size() == 0) {
> + LOG(IPU3, Error) << "Failed to calculate pipe configuration";
> + return {};
> + }
> +
> + FOV bestFov = calcFOV(pipe->input, pipeConfigs[0]);
> + unsigned int bestIndex = 0;
> + unsigned int p = 0;
> + for (auto pipeConfig : pipeConfigs) {
> + FOV fov = calcFOV(pipe->input, pipeConfig);
> + if (fov.isLarger(bestFov)) {
> + bestFov = fov;
> + bestIndex = p;
> + }
> +
> + ++p;
> + }
> +
> + LOG(IPU3, Debug) << "Computed pipe configuration: ";
> + LOG(IPU3, Debug) << "IF: " << pipeConfigs[bestIndex].iif.toString();
> + LOG(IPU3, Debug) << "BDS: " << pipeConfigs[bestIndex].bds.toString();
> + LOG(IPU3, Debug) << "GDC: " << pipeConfigs[bestIndex].gdc.toString();
> +
> + return pipeConfigs[bestIndex];
> +}
> +
> /**
> * \brief Configure the ImgU unit input
> * \param[in] size The ImgU input frame size
> diff --git a/src/libcamera/pipeline/ipu3/imgu.h b/src/libcamera/pipeline/ipu3/imgu.h
> index 23ec1ca1c6ae..0b2dd1f965c1 100644
> --- a/src/libcamera/pipeline/ipu3/imgu.h
> +++ b/src/libcamera/pipeline/ipu3/imgu.h
> @@ -23,8 +23,28 @@ struct StreamConfiguration;
> class ImgUDevice
> {
> public:
> + struct PipeConfig {
> + float bds_sf;
> + Size iif;
> + Size bds;
> + Size gdc;
> +
> + bool isNull() const
> + {
> + return iif.isNull() || bds.isNull() || gdc.isNull();
> + }
> + };
> +
> + struct Pipe {
> + Size input;
> + Size output;
> + Size viewfinder;
> + };
> +
> int init(MediaDevice *media, unsigned int index);
>
> + PipeConfig calculatePipeConfig(Pipe *pipe);
> +
> int configureInput(const Size &size, V4L2DeviceFormat *inputFormat);
>
> int configureOutput(const StreamConfiguration &cfg,
--
Regards,
Laurent Pinchart
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