[libcamera-devel] [PATCH v3 2/7] libcamera: Add ColorSpace fields to StreamConfiguration

[Naushir Patuck]

Hi David,

Thank you for your patch.

On Wed, 20 Oct 2021 at 12:08, David Plowman <david.plowman at raspberrypi.com>
wrote:

> This is so that applications can choose appropriate color spaces which
> will then be passed down to the V4L2 devices.
>
> There are two fields: the "requestedColorSpace" which is the one an
> application wants, and the "actualColorSpace" which is what the
> underlying hardware can deliver, and which is filled in by the
> validate() method.
>
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  include/libcamera/stream.h |  4 ++++
>  src/libcamera/stream.cpp   | 25 +++++++++++++++++++++++++
>  2 files changed, 29 insertions(+)
>
> diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
> index 0c55e716..fe491ff5 100644
> --- a/include/libcamera/stream.h
> +++ b/include/libcamera/stream.h
> @@ -12,6 +12,7 @@
>  #include <string>
>  #include <vector>
>
> +#include <libcamera/color_space.h>
>  #include <libcamera/framebuffer.h>
>  #include <libcamera/geometry.h>
>  #include <libcamera/pixel_format.h>
> @@ -47,6 +48,9 @@ struct StreamConfiguration {
>
>         unsigned int bufferCount;
>
> +       ColorSpace requestedColorSpace;
> +       ColorSpace actualColorSpace;
> +
>

I had a brief look-ahead in this series, but it was not immediately
obvious to me why we would need requested and actual? Could
we make do with just one and update the user requested value
with what the HW will actually give us?


>         Stream *stream() const { return stream_; }
>         void setStream(Stream *stream) { stream_ = stream; }
>         const StreamFormats &formats() const { return formats_; }
> diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
> index b421e17e..1ddbbb8c 100644
> --- a/src/libcamera/stream.cpp
> +++ b/src/libcamera/stream.cpp
> @@ -329,6 +329,31 @@ StreamConfiguration::StreamConfiguration(const
> StreamFormats &formats)
>   * \brief Requested number of buffers to allocate for the stream
>   */
>
> +/**
> + * \var StreamConfiguration::requestedColorSpace
> + * \brief The ColorSpace this stream should have
> + *
> + * The generateConfiguration method will generate reasonable default
> + * values (ColorSpace::Jpeg for stills, ColorSpace::Rec709 for video and
> + * ColorSpace::Raw for raw streams) but applications are free to overwrite
> + * this value.
> + */
> +
> +/**
> + * \var StreamConfiguration::actualColorSpace
> + * \brief The ColorSpace the will be used for this stream
> + *
> + * This field is filled in by CameraConfiguration::validate().
> + * Normally this should match the requestedColorSpace, but it may differ
> + * if the hardware does not support it.
> + *
> + * In general cameras may have different constraints here, for example,
> + * they may require all output streams to share the same color space.
> + * Sometimes the fields within this color space may report "Undefined"
> + * values if the hardware drivers are going to use a color space that
> + * is not recognised by the ColorSpace class.
> + */
> +
>  /**
>   * \fn StreamConfiguration::stream()
>   * \brief Retrieve the stream associated with the configuration
> --
> 2.20.1
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.libcamera.org/pipermail/libcamera-devel/attachments/20211025/3984266a/attachment.htm>