[libcamera-devel] [RFC 1/2] libcamera: v4l2_subdevice: Replace ImageFormats with a map
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Jul 2 16:33:20 CEST 2020
Hi Kieran,
On Thu, Jul 02, 2020 at 03:13:12PM +0100, Kieran Bingham wrote:
> On 02/07/2020 15:04, Laurent Pinchart wrote:
> > On Wed, Jul 01, 2020 at 11:16:49PM +0200, Niklas Söderlund wrote:
> >> Replace the V4L2Subdevice usage of the ImageForamts class with a
> >
> > s/ImageForamts/ImageFormats/
> >
> >> std::map and the utils::map_keys() helper.
> >>
> >> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> >> ---
> >> include/libcamera/internal/camera_sensor.h | 6 ++----
> >> include/libcamera/internal/v4l2_subdevice.h | 4 +++-
> >> src/libcamera/camera_sensor.cpp | 12 ++++++------
> >> src/libcamera/v4l2_subdevice.cpp | 16 ++++++++--------
> >> test/v4l2_subdevice/list_formats.cpp | 16 ++++++++--------
> >> 5 files changed, 27 insertions(+), 27 deletions(-)
> >>
> >> diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
> >> index 7f07413f95602881..06c8292ca30129de 100644
> >> --- a/include/libcamera/internal/camera_sensor.h
> >> +++ b/include/libcamera/internal/camera_sensor.h
> >> @@ -16,13 +16,11 @@
> >>
> >> #include "libcamera/internal/formats.h"
> >> #include "libcamera/internal/log.h"
> >> +#include "libcamera/internal/v4l2_subdevice.h"
> >>
> >> namespace libcamera {
> >>
> >> class MediaEntity;
> >> -class V4L2Subdevice;
> >> -
> >> -struct V4L2SubdeviceFormat;
> >>
> >> struct CameraSensorInfo {
> >> std::string model;
> >> @@ -75,7 +73,7 @@ private:
> >>
> >> std::string model_;
> >>
> >> - ImageFormats formats_;
> >> + V4L2Subdevice::Formats formats_;
> >> Size resolution_;
> >> std::vector<unsigned int> mbusCodes_;
> >> std::vector<Size> sizes_;
> >> diff --git a/include/libcamera/internal/v4l2_subdevice.h b/include/libcamera/internal/v4l2_subdevice.h
> >> index a3ecf123f640dd54..02ee3e914a8b1d92 100644
> >> --- a/include/libcamera/internal/v4l2_subdevice.h
> >> +++ b/include/libcamera/internal/v4l2_subdevice.h
> >> @@ -32,6 +32,8 @@ struct V4L2SubdeviceFormat {
> >> class V4L2Subdevice : public V4L2Device
> >> {
> >> public:
> >> + using Formats = std::map<unsigned int, std::vector<SizeRange>>;
> >> +
> >> enum Whence {
> >> ActiveFormat,
> >> TryFormat,
> >> @@ -51,7 +53,7 @@ public:
> >> int setSelection(unsigned int pad, unsigned int target,
> >> Rectangle *rect);
> >>
> >> - ImageFormats formats(unsigned int pad);
> >> + Formats formats(unsigned int pad);
> >>
> >> int getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> >> Whence whence = ActiveFormat);
> >> diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
> >> index b14b4051dca606b9..3c9b05feef4e0861 100644
> >> --- a/src/libcamera/camera_sensor.cpp
> >> +++ b/src/libcamera/camera_sensor.cpp
> >> @@ -18,7 +18,6 @@
> >>
> >> #include "libcamera/internal/formats.h"
> >> #include "libcamera/internal/utils.h"
> >> -#include "libcamera/internal/v4l2_subdevice.h"
> >>
> >> /**
> >> * \file camera_sensor.h
> >> @@ -245,15 +244,15 @@ int CameraSensor::init()
> >>
> >> /* Enumerate, sort and cache media bus codes and sizes. */
> >> formats_ = subdev_->formats(pad_);
> >> - if (formats_.isEmpty()) {
> >> + if (formats_.empty()) {
> >> LOG(CameraSensor, Error) << "No image format found";
> >> return -EINVAL;
> >> }
> >>
> >> - mbusCodes_ = formats_.formats();
> >> + mbusCodes_ = utils::map_keys(formats_);
> >> std::sort(mbusCodes_.begin(), mbusCodes_.end());
> >>
> >> - for (const auto &format : formats_.data()) {
> >> + for (const auto &format : formats_) {
> >> const std::vector<SizeRange> &ranges = format.second;
> >> std::transform(ranges.begin(), ranges.end(), std::back_inserter(sizes_),
> >> [](const SizeRange &range) { return range.max; });
> >> @@ -359,9 +358,10 @@ V4L2SubdeviceFormat CameraSensor::getFormat(const std::vector<unsigned int> &mbu
> >> uint32_t bestCode = 0;
> >>
> >> for (unsigned int code : mbusCodes) {
> >> - const std::vector<SizeRange> &ranges = formats_.sizes(code);
> >> + if (formats_.find(code) == formats_.end())
> >> + continue;
> >>
> >> - for (const SizeRange &range : ranges) {
> >> + for (const SizeRange &range : formats_.at(code)) {
> >
> > const auto formats = formats_.find(code);
> > if (formats == formats_.end())
> > continue;
> >
> > for (const SizeRange &range : formats->second) {
> >
> > to avoid a double lookup. Feel free to rename formats to ranges or to
> > iter (or to something else) if you think it would be more readable.
> >
> >> const Size &sz = range.max;
> >>
> >> if (sz.width < size.width || sz.height < size.height)
> >> diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
> >> index 32c6c7acc11a6a3f..6dbe6d7590e4ae16 100644
> >> --- a/src/libcamera/v4l2_subdevice.cpp
> >> +++ b/src/libcamera/v4l2_subdevice.cpp
> >> @@ -217,6 +217,11 @@ uint8_t V4L2SubdeviceFormat::bitsPerPixel() const
> >> * any device left open will be closed, and any resources released.
> >> */
> >>
> >> +/**
> >> + * \typedef V4L2Subdevice::Formats
> >> + * \brief A map of supported media bus formats to frame sizes
> >> + */
> >> +
> >> /**
> >> * \enum V4L2Subdevice::Whence
> >> * \brief Specify the type of format for getFormat() and setFormat() operations
> >> @@ -340,9 +345,9 @@ int V4L2Subdevice::setSelection(unsigned int pad, unsigned int target,
> >> *
> >> * \return A list of the supported device formats
> >> */
> >> -ImageFormats V4L2Subdevice::formats(unsigned int pad)
> >> +V4L2Subdevice::Formats V4L2Subdevice::formats(unsigned int pad)
> >> {
> >> - ImageFormats formats;
> >> + Formats formats;
> >>
> >> if (pad >= entity_->pads().size()) {
> >> LOG(V4L2, Error) << "Invalid pad: " << pad;
> >> @@ -354,12 +359,7 @@ ImageFormats V4L2Subdevice::formats(unsigned int pad)
> >> if (sizes.empty())
> >> return {};
> >>
> >> - if (formats.addFormat(code, sizes)) {
> >> - LOG(V4L2, Error)
> >> - << "Could not add sizes for media bus code "
> >> - << code << " on pad " << pad;
> >> - return {};
> >> - }
> >> + formats[code] = sizes;
> >
> > Do we want to keep the error check ? If so, it could be done with
> > insert(), which returns a std::pair<iterator, bool> where the bool tells
> > whether the insertion takes place or an element was already present.
> > With C++17 that could be written
> >
> > const auto [iter, success] = formats.insert(sizes);
> > if (!success) {
> > ...
> > }
> >
> > but with C++14 we would need
> >
> > const auto inserted = formats.insert(sizes);
> > if (!inserted.second) {
> > ...
> > }
> >
> > which is less nice. Maybe it's not worth it.
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> >
>
> With [0], GCC 11 will move to C++17 by default, and that .first .second
> usage from std::pair makes me cringe horribly every time I see it.
>
> What points hold us back from moving to C++17 ?
Mostly gcc-5 and gcc-6 support (not sure about clang). I haven't
investigated what dropping gcc-5 and gcc-6 support would mean, whether
nobody will notice or if there are distributions (including more exotic
ones for the embedded space) still using them actively.
> and do you foresee a
> particular point that we could upgrade? or are we going to remain at
> C++14 for the foreseeable future ?
I think it's a matter of balance between the need to support older
compilers, and the benefit we would get from C++17. I don't think we
need to remain at C++14 for the foreseeable future, but I think we first
need to check what dropping gcc-5 and gcc-6 would mean.
> [0]
> https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=0801f419440c14f6772b28f763ad7d40f7f7a580
> (c++: Change the default dialect to C++17.)
>
> >> }
> >>
> >> return formats;
> >> diff --git a/test/v4l2_subdevice/list_formats.cpp b/test/v4l2_subdevice/list_formats.cpp
> >> index a55af1100d9ab498..a6044c044036acd4 100644
> >> --- a/test/v4l2_subdevice/list_formats.cpp
> >> +++ b/test/v4l2_subdevice/list_formats.cpp
> >> @@ -47,29 +47,29 @@ void ListFormatsTest::printFormats(unsigned int pad,
> >> int ListFormatsTest::run()
> >> {
> >> /* List all formats available on existing "Scaler" pads. */
> >> - ImageFormats formats;
> >> + V4L2Subdevice::Formats formats;
> >>
> >> formats = scaler_->formats(0);
> >> - if (formats.isEmpty()) {
> >> + if (formats.empty()) {
> >> cerr << "Failed to list formats on pad 0 of subdevice "
> >> << scaler_->entity()->name() << endl;
> >> return TestFail;
> >> }
> >> - for (unsigned int code : formats.formats())
> >> - printFormats(0, code, formats.sizes(code));
> >> + for (unsigned int code : utils::map_keys(formats))
> >> + printFormats(0, code, formats[code]);
> >>
> >> formats = scaler_->formats(1);
> >> - if (formats.isEmpty()) {
> >> + if (formats.empty()) {
> >> cerr << "Failed to list formats on pad 1 of subdevice "
> >> << scaler_->entity()->name() << endl;
> >> return TestFail;
> >> }
> >> - for (unsigned int code : formats.formats())
> >> - printFormats(1, code, formats.sizes(code));
> >> + for (unsigned int code : utils::map_keys(formats))
> >> + printFormats(1, code, formats[code]);
> >>
> >> /* List format on a non-existing pad, format vector shall be empty. */
> >> formats = scaler_->formats(2);
> >> - if (!formats.isEmpty()) {
> >> + if (!formats.empty()) {
> >> cerr << "Listing formats on non-existing pad 2 of subdevice "
> >> << scaler_->entity()->name()
> >> << " should return an empty format list" << endl;
--
Regards,
Laurent Pinchart
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