[libcamera-devel] [PATCH v13] libcamera: controls: Generate and use fixed-sized Span types

Christian Rauch Rauch.Christian at gmx.de
Wed Aug 3 22:13:23 CEST 2022


Hi Kieran,

Am 03.08.22 um 14:17 schrieb Kieran Bingham:
> Quoting Jacopo Mondi via libcamera-devel (2022-08-03 10:44:01)
>> Hi Christian,
>>
>> On Tue, Aug 02, 2022 at 11:03:24PM +0200, Christian Rauch wrote:
>>> Define Span types explicitly as either variable- or fixed-sized. This
>>> introduces a new convention for defining Span dimensions in the property
>>> and control value definitions and generates Span types as variable-sized
>>> Span<T> or as fixed-sized Span<T,N>.
>>>
>>> Signed-off-by: Christian Rauch <Rauch.Christian at gmx.de>
>>> Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
>>
>> The issue with gcc8 seems now solved.
>>
>> One more tag and I hope we can collect the patch ?
>
> What are the user facing API changes here? (i.e. how much does this
> break applications?)

Everything that touches fixed-sized Spans with explicit types (i.e. no
auto) need a change that defines the size. variable-sized spans should
behave as before. E.g. in the diff you can see that something like
"Span<const int32_t> levels = *blackLevels;"
needs to be set the Span size as template paremter:
"Span<const int32_t, 4> levels = *blackLevels;"

But overall, I only had to change this in 5 places in the entire
codebase to make this compile. So I don't think the impact will be that big.

>
> I'm surprised there are no updates to the python bindings in this patch
> ?
>
> Is that all handled gracefully? (Is it tested?)

I compiled ("meson build_py -Dpycamera=enabled") and ran the tests
("ninja -C build_py/ test") without failures. Is there another way to
test that the python bindings work?

A quick glimpse into "py_controls_generated.cpp" tells me that Spans are
not used there.

>
> --
> Kieran
>
>
>>
>> Thanks
>>   j
>>
>>> ---
>>>  include/libcamera/controls.h        |  2 +-
>>>  src/ipa/raspberrypi/raspberrypi.cpp | 19 +++++++++--------
>>>  src/libcamera/control_ids.yaml      |  4 ++--
>>>  src/libcamera/property_ids.yaml     |  4 ++--
>>>  src/qcam/dng_writer.cpp             |  2 +-
>>>  utils/gen-controls.py               | 32 ++++++++++++++++++++---------
>>>  6 files changed, 38 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
>>> index b1b52acb..ebc168fc 100644
>>> --- a/include/libcamera/controls.h
>>> +++ b/include/libcamera/controls.h
>>> @@ -168,7 +168,7 @@ public:
>>>
>>>               using V = typename T::value_type;
>>>               const V *value = reinterpret_cast<const V *>(data().data());
>>> -             return { value, numElements_ };
>>> +             return T{ value, numElements_ };
>>>       }
>>>
>>>  #ifndef __DOXYGEN__
>>> diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
>>> index 6befdd71..69c73f8c 100644
>>> --- a/src/ipa/raspberrypi/raspberrypi.cpp
>>> +++ b/src/ipa/raspberrypi/raspberrypi.cpp
>>> @@ -567,18 +567,19 @@ void IPARPi::reportMetadata()
>>>
>>>       AwbStatus *awbStatus = rpiMetadata_.getLocked<AwbStatus>("awb.status");
>>>       if (awbStatus) {
>>> -             libcameraMetadata_.set(controls::ColourGains, { static_cast<float>(awbStatus->gainR),
>>> -                                                             static_cast<float>(awbStatus->gainB) });
>>> +             libcameraMetadata_.set(controls::ColourGains,
>>> +                                    Span<const float, 2>({ static_cast<float>(awbStatus->gainR),
>>> +                                                           static_cast<float>(awbStatus->gainB) }));
>>>               libcameraMetadata_.set(controls::ColourTemperature, awbStatus->temperatureK);
>>>       }
>>>
>>>       BlackLevelStatus *blackLevelStatus = rpiMetadata_.getLocked<BlackLevelStatus>("black_level.status");
>>>       if (blackLevelStatus)
>>>               libcameraMetadata_.set(controls::SensorBlackLevels,
>>> -                                    { static_cast<int32_t>(blackLevelStatus->blackLevelR),
>>> -                                      static_cast<int32_t>(blackLevelStatus->blackLevelG),
>>> -                                      static_cast<int32_t>(blackLevelStatus->blackLevelG),
>>> -                                      static_cast<int32_t>(blackLevelStatus->blackLevelB) });
>>> +                                    Span<const int32_t, 4>({ static_cast<int32_t>(blackLevelStatus->blackLevelR),
>>> +                                                             static_cast<int32_t>(blackLevelStatus->blackLevelG),
>>> +                                                             static_cast<int32_t>(blackLevelStatus->blackLevelG),
>>> +                                                             static_cast<int32_t>(blackLevelStatus->blackLevelB) }));
>>>
>>>       FocusStatus *focusStatus = rpiMetadata_.getLocked<FocusStatus>("focus.status");
>>>       if (focusStatus && focusStatus->num == 12) {
>>> @@ -883,7 +884,7 @@ void IPARPi::queueRequest(const ControlList &controls)
>>>                       if (gains[0] != 0.0f && gains[1] != 0.0f)
>>>                               /* A gain of 0.0f will switch back to auto mode. */
>>>                               libcameraMetadata_.set(controls::ColourGains,
>>> -                                                    { gains[0], gains[1] });
>>> +                                                    Span<const float, 2>({ gains[0], gains[1] }));
>>>                       break;
>>>               }
>>>
>>> @@ -1167,8 +1168,8 @@ void IPARPi::applyFrameDurations(Duration minFrameDuration, Duration maxFrameDur
>>>
>>>       /* Return the validated limits via metadata. */
>>>       libcameraMetadata_.set(controls::FrameDurationLimits,
>>> -                            { static_cast<int64_t>(minFrameDuration_.get<std::micro>()),
>>> -                              static_cast<int64_t>(maxFrameDuration_.get<std::micro>()) });
>>> +                            Span<const int64_t, 2>({ static_cast<int64_t>(minFrameDuration_.get<std::micro>()),
>>> +                                                     static_cast<int64_t>(maxFrameDuration_.get<std::micro>()) }));
>>>
>>>       /*
>>>        * Calculate the maximum exposure time possible for the AGC to use.
>>> diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml
>>> index ecab3ae9..5fa168c6 100644
>>> --- a/src/libcamera/control_ids.yaml
>>> +++ b/src/libcamera/control_ids.yaml
>>> @@ -291,7 +291,7 @@ controls:
>>>          transformation. The 3x3 matrix is stored in conventional reading
>>>          order in an array of 9 floating point values.
>>>
>>> -      size: [3x3]
>>> +      size: [3,3]
>>>
>>>    - ScalerCrop:
>>>        type: Rectangle
>>> @@ -525,7 +525,7 @@ controls:
>>>          the window where the focal distance for the objects shown in that part
>>>          of the image are closest to the camera.
>>>
>>> -      size: [n]
>>> +      size: []
>>>
>>>    - AfTrigger:
>>>        type: int32_t
>>> diff --git a/src/libcamera/property_ids.yaml b/src/libcamera/property_ids.yaml
>>> index 11b7ebdc..a87485d7 100644
>>> --- a/src/libcamera/property_ids.yaml
>>> +++ b/src/libcamera/property_ids.yaml
>>> @@ -497,7 +497,7 @@ controls:
>>>
>>>    - PixelArrayOpticalBlackRectangles:
>>>        type: Rectangle
>>> -      size: [n]
>>> +      size: []
>>>        description: |
>>>          The pixel array region(s) which contain optical black pixels
>>>          considered valid for calibration purposes.
>>> @@ -592,7 +592,7 @@ controls:
>>>
>>>    - PixelArrayActiveAreas:
>>>        type: Rectangle
>>> -      size: [n]
>>> +      size: []
>>>        description: |
>>>          The PixelArrayActiveAreas property defines the (possibly multiple and
>>>          overlapping) portions of the camera sensor readable pixel matrix
>>> diff --git a/src/qcam/dng_writer.cpp b/src/qcam/dng_writer.cpp
>>> index 5b94b3f2..b4362537 100644
>>> --- a/src/qcam/dng_writer.cpp
>>> +++ b/src/qcam/dng_writer.cpp
>>> @@ -517,7 +517,7 @@ int DNGWriter::write(const char *filename, const Camera *camera,
>>>
>>>       const auto &blackLevels = metadata.get(controls::SensorBlackLevels);
>>>       if (blackLevels) {
>>> -             Span<const int32_t> levels = *blackLevels;
>>> +             Span<const int32_t, 4> levels = *blackLevels;
>>>
>>>               /*
>>>                * The black levels control is specified in R, Gr, Gb, B order.
>>> diff --git a/utils/gen-controls.py b/utils/gen-controls.py
>>> index 3f99b5e2..46ba4394 100755
>>> --- a/utils/gen-controls.py
>>> +++ b/utils/gen-controls.py
>>> @@ -7,6 +7,8 @@
>>>  # gen-controls.py - Generate control definitions from YAML
>>>
>>>  import argparse
>>> +from functools import reduce
>>> +import operator
>>>  import string
>>>  import sys
>>>  import yaml
>>> @@ -22,6 +24,24 @@ def format_description(description):
>>>      return '\n'.join([(line and ' * ' or ' *') + line for line in description])
>>>
>>>
>>> +def get_ctrl_type(ctrl):
>>> +    ctrl_type = ctrl['type']
>>> +    ctrl_size_arr = ctrl.get('size')
>>> +
>>> +    if ctrl_type == 'string':
>>> +        return 'std::string'
>>> +    elif ctrl_size_arr is not None:
>>> +        if len(ctrl_size_arr) > 0:
>>> +            # fixed-sized Span
>>> +            ctrl_span_size = reduce(operator.mul, ctrl_size_arr)
>>> +            return f"Span<const {ctrl_type}, {ctrl_span_size}>"
>>> +        else:
>>> +            # variable-sized Span
>>> +            return f"Span<const {ctrl_type}>"
>>> +    else:
>>> +        return ctrl_type
>>> +
>>> +
>>>  def generate_cpp(controls):
>>>      enum_doc_start_template = string.Template('''/**
>>>   * \\enum ${name}Enum
>>> @@ -50,11 +70,7 @@ ${description}
>>>          name, ctrl = ctrl.popitem()
>>>          id_name = snake_case(name).upper()
>>>
>>> -        ctrl_type = ctrl['type']
>>> -        if ctrl_type == 'string':
>>> -            ctrl_type = 'std::string'
>>> -        elif ctrl.get('size'):
>>> -            ctrl_type = 'Span<const %s>' % ctrl_type
>>> +        ctrl_type = get_ctrl_type(ctrl)
>>>
>>>          info = {
>>>              'name': name,
>>> @@ -135,11 +151,7 @@ def generate_h(controls):
>>>
>>>          ids.append('\t' + id_name + ' = ' + str(id_value) + ',')
>>>
>>> -        ctrl_type = ctrl['type']
>>> -        if ctrl_type == 'string':
>>> -            ctrl_type = 'std::string'
>>> -        elif ctrl.get('size'):
>>> -            ctrl_type = 'Span<const %s>' % ctrl_type
>>> +        ctrl_type = get_ctrl_type(ctrl)
>>>
>>>          info = {
>>>              'name': name,
>>> --
>>> 2.34.1
>>>


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