[PATCH 2/2] libcamera: Add Unsigned 16-bits Control Type

[Kieran Bingham]

Quoting Harvey Yang (2024-10-11 18:55:12)
> From: Yudhistira Erlandinata <yerlandinata at google.com>
> 
> Some camera metadata is of length 16-bits,
> for example JPEG metadata headers.
> 
> Signed-off-by: Yudhistira Erlandinata <yerlandinata at chromium.org>
> Co-developed-by: Harvey Yang <chenghaoyang at chromium.org>
> Signed-off-by: Harvey Yang <chenghaoyang at chromium.org>
> ---
>  include/libcamera/controls.h  | 6 ++++++
>  src/libcamera/controls.cpp    | 8 ++++++++
>  src/libcamera/v4l2_device.cpp | 9 +++++++++
>  3 files changed, 23 insertions(+)
> 
> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
> index 25f68040d..1987ca5f5 100644
> --- a/include/libcamera/controls.h
> +++ b/include/libcamera/controls.h
> @@ -29,6 +29,7 @@ enum ControlType {
>         ControlTypeNone,
>         ControlTypeBool,
>         ControlTypeByte,
> +       ControlTypeUnsigned16,
>         ControlTypeUnsigned32,
>         ControlTypeInteger32,
>         ControlTypeInteger64,
> @@ -63,6 +64,11 @@ struct control_type<uint8_t> {
>         static constexpr std::size_t size = 0;
>  };
>  
> +template<>
> +struct control_type<uint16_t> {
> +       static constexpr ControlType value = ControlTypeUnsigned16;

Does this also need to set the size? What is size - why is it always
zero? 

> +};
> +
>  template<>
>  struct control_type<uint32_t> {
>         static constexpr ControlType value = ControlTypeUnsigned32;
> diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
> index 8ae295191..3a840bb22 100644
> --- a/src/libcamera/controls.cpp
> +++ b/src/libcamera/controls.cpp
> @@ -54,6 +54,7 @@ static constexpr size_t ControlValueSize[] = {
>         [ControlTypeNone]               = 0,
>         [ControlTypeBool]               = sizeof(bool),
>         [ControlTypeByte]               = sizeof(uint8_t),
> +       [ControlTypeUnsigned16]         = sizeof(uint16_t),
>         [ControlTypeUnsigned32]         = sizeof(uint32_t),
>         [ControlTypeInteger32]          = sizeof(int32_t),
>         [ControlTypeInteger64]          = sizeof(int64_t),
> @@ -75,6 +76,8 @@ static constexpr size_t ControlValueSize[] = {
>   * The control stores a boolean value
>   * \var ControlTypeByte
>   * The control stores a byte value as an unsigned 8-bit integer
> + * \var ControlTypeUnsigned16
> + * The control stores an unsigned 16-bit integer value
>   * \var ControlTypeUnsigned32
>   * The control stores an unsigned 32-bit integer value
>   * \var ControlTypeInteger32
> @@ -233,6 +236,11 @@ std::string ControlValue::toString() const
>                         str += std::to_string(*value);
>                         break;
>                 }
> +               case ControlTypeUnsigned16: {
> +                       const uint16_t *value = reinterpret_cast<const uint16_t *>(data);
> +                       str += std::to_string(*value);
> +                       break;
> +               }
>                 case ControlTypeUnsigned32: {
>                         const uint32_t *value = reinterpret_cast<const uint32_t *>(data);
>                         str += std::to_string(*value);
> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> index f3454ba24..cb7327171 100644
> --- a/src/libcamera/v4l2_device.cpp
> +++ b/src/libcamera/v4l2_device.cpp
> @@ -492,6 +492,9 @@ ControlType V4L2Device::v4l2CtrlType(uint32_t ctrlType)
>         case V4L2_CTRL_TYPE_BOOLEAN:
>                 return ControlTypeBool;
>  
> +       case V4L2_CTRL_TYPE_U16:
> +               return ControlTypeUnsigned16;
> +
>         case V4L2_CTRL_TYPE_U32:
>                 return ControlTypeUnsigned32;
>  
> @@ -543,6 +546,11 @@ std::optional<ControlInfo> V4L2Device::v4l2ControlInfo(const v4l2_query_ext_ctrl
>                                    static_cast<uint8_t>(ctrl.maximum),
>                                    static_cast<uint8_t>(ctrl.default_value));
>  
> +       case V4L2_CTRL_TYPE_U16:
> +               return ControlInfo(static_cast<uint16_t>(ctrl.minimum),
> +                                  static_cast<uint16_t>(ctrl.maximum),
> +                                  static_cast<uint16_t>(ctrl.default_value));
> +
>         case V4L2_CTRL_TYPE_U32:
>                 return ControlInfo(static_cast<uint32_t>(ctrl.minimum),
>                                    static_cast<uint32_t>(ctrl.maximum),
> @@ -634,6 +642,7 @@ void V4L2Device::listControls()
>                 case V4L2_CTRL_TYPE_BITMASK:
>                 case V4L2_CTRL_TYPE_INTEGER_MENU:
>                 case V4L2_CTRL_TYPE_U8:
> +               case V4L2_CTRL_TYPE_U16:
>                 case V4L2_CTRL_TYPE_U32:
>                         break;
>                 /* \todo Support other control types. */
> -- 
> 2.47.0.rc1.288.g06298d1525-goog
>