[libcamera-devel] [PATCH 3/6] pipeline: raspberrypi: Return a PixelFormat from findBestMode()

David Plowman david.plowman at raspberrypi.com
Fri Oct 22 15:13:36 CEST 2021


Hi Naush

Thanks for this patch!

On Fri, 22 Oct 2021 at 12:55, Naushir Patuck <naush at raspberrypi.com> wrote:
>
> It is more convenient to return a PixelFormat from findBestMode(), as the
> conversions from PixelFormat to V4L2SubdeviceFormat and V4L2DeviceFormat are
> simpler.

Yes indeed, though the PixelFormat still includes packing in an
"unhelpful" way, so there might be even better alternatives?

Best regards

David

>
> Add some internal helpers to perform these conversions.
>
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> ---
>  .../pipeline/raspberrypi/raspberrypi.cpp      | 73 +++++++++++++------
>  1 file changed, 52 insertions(+), 21 deletions(-)
>
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index 730f1575095c..0f13127a7748 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -50,6 +50,7 @@ namespace {
>
>  /* Map of mbus codes to supported sizes reported by the sensor. */
>  using SensorFormats = std::map<unsigned int, std::vector<Size>>;
> +using SensorMode = std::pair<PixelFormat, Size>;
>
>  SensorFormats populateSensorFormats(std::unique_ptr<CameraSensor> &sensor)
>  {
> @@ -61,6 +62,34 @@ SensorFormats populateSensorFormats(std::unique_ptr<CameraSensor> &sensor)
>         return formats;
>  }
>
> +inline V4L2DeviceFormat toV4L2DeviceFormat(SensorMode &mode)
> +{
> +       V4L2DeviceFormat deviceFormat;
> +
> +       deviceFormat.fourcc = V4L2PixelFormat::fromPixelFormat(mode.first);
> +       deviceFormat.size = mode.second;
> +       return deviceFormat;
> +}
> +
> +inline V4L2DeviceFormat toV4L2DeviceFormat(V4L2SubdeviceFormat &format)
> +{
> +       V4L2DeviceFormat deviceFormat;
> +
> +       deviceFormat.fourcc = BayerFormat::fromMbusCode(format.mbus_code).toV4L2PixelFormat();
> +       deviceFormat.size = format.size;
> +       return deviceFormat;
> +}
> +
> +inline V4L2SubdeviceFormat toV4L2SubdeviceFormat(SensorMode &mode)
> +{
> +       V4L2SubdeviceFormat subdeviceFormat;
> +       V4L2PixelFormat fourcc = V4L2PixelFormat::fromPixelFormat(mode.first);
> +
> +       subdeviceFormat.mbus_code = BayerFormat::fromV4L2PixelFormat(fourcc).toMbusCode();
> +       subdeviceFormat.size = mode.second;
> +       return subdeviceFormat;
> +}
> +
>  bool isRaw(PixelFormat &pixFmt)
>  {
>         /*
> @@ -87,10 +116,10 @@ double scoreFormat(double desired, double actual)
>         return score;
>  }
>
> -V4L2DeviceFormat findBestMode(const SensorFormats &formatsMap, const Size &req)
> +SensorMode findBestMode(const SensorFormats &formatsMap, const Size &req)
>  {
>         double bestScore = std::numeric_limits<double>::max(), score;
> -       V4L2DeviceFormat bestMode;
> +       SensorMode bestMode;
>
>  #define PENALTY_AR             1500.0
>  #define PENALTY_8BIT           2000.0
> @@ -101,8 +130,8 @@ V4L2DeviceFormat findBestMode(const SensorFormats &formatsMap, const Size &req)
>         /* Calculate the closest/best mode from the user requested size. */
>         for (const auto &iter : formatsMap) {
>                 const unsigned int mbus_code = iter.first;
> -               const V4L2PixelFormat v4l2Format = BayerFormat::fromMbusCode(mbus_code).toV4L2PixelFormat();
> -               const PixelFormatInfo &info = PixelFormatInfo::info(v4l2Format);
> +               const PixelFormat format = BayerFormat::fromMbusCode(mbus_code).toPixelFormat();
> +               const PixelFormatInfo &info = PixelFormatInfo::info(format);
>
>                 for (const Size &sz : iter.second) {
>                         double reqAr = static_cast<double>(req.width) / req.height;
> @@ -126,12 +155,12 @@ V4L2DeviceFormat findBestMode(const SensorFormats &formatsMap, const Size &req)
>
>                         if (score <= bestScore) {
>                                 bestScore = score;
> -                               bestMode.fourcc = v4l2Format;
> -                               bestMode.size = sz;
> +                               bestMode.first = format;
> +                               bestMode.second = sz;
>                         }
>
>                         LOG(RPI, Info) << "Mode: " << sz.width << "x" << sz.height
> -                                      << " fmt " << v4l2Format.toString()
> +                                      << " fmt " << format.toString()
>                                        << " Score: " << score
>                                        << " (best " << bestScore << ")";
>                 }
> @@ -364,8 +393,9 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>                          * Calculate the best sensor mode we can use based on
>                          * the user request.
>                          */
> -                       V4L2DeviceFormat sensorFormat = findBestMode(data_->sensorFormats_, cfg.size);
> -                       int ret = data_->unicam_[Unicam::Image].dev()->tryFormat(&sensorFormat);
> +                       SensorMode sensorMode = findBestMode(data_->sensorFormats_, cfg.size);
> +                       V4L2DeviceFormat unicamFormat = toV4L2DeviceFormat(sensorMode);
> +                       int ret = data_->unicam_[Unicam::Image].dev()->tryFormat(&unicamFormat);
>                         if (ret)
>                                 return Invalid;
>
> @@ -377,7 +407,7 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>                          * fetch the "native" (i.e. untransformed) Bayer order,
>                          * because the sensor may currently be flipped!
>                          */
> -                       V4L2PixelFormat fourcc = sensorFormat.fourcc;
> +                       V4L2PixelFormat fourcc = unicamFormat.fourcc;
>                         if (data_->flipsAlterBayerOrder_) {
>                                 BayerFormat bayer = BayerFormat::fromV4L2PixelFormat(fourcc);
>                                 bayer.order = data_->nativeBayerOrder_;
> @@ -386,15 +416,15 @@ CameraConfiguration::Status RPiCameraConfiguration::validate()
>                         }
>
>                         PixelFormat sensorPixFormat = fourcc.toPixelFormat();
> -                       if (cfg.size != sensorFormat.size ||
> +                       if (cfg.size != unicamFormat.size ||
>                             cfg.pixelFormat != sensorPixFormat) {
> -                               cfg.size = sensorFormat.size;
> +                               cfg.size = unicamFormat.size;
>                                 cfg.pixelFormat = sensorPixFormat;
>                                 status = Adjusted;
>                         }
>
> -                       cfg.stride = sensorFormat.planes[0].bpl;
> -                       cfg.frameSize = sensorFormat.planes[0].size;
> +                       cfg.stride = unicamFormat.planes[0].bpl;
> +                       cfg.frameSize = unicamFormat.planes[0].size;
>
>                         rawCount++;
>                 } else {
> @@ -483,7 +513,8 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>  {
>         RPiCameraData *data = cameraData(camera);
>         CameraConfiguration *config = new RPiCameraConfiguration(data);
> -       V4L2DeviceFormat sensorFormat;
> +       V4L2DeviceFormat unicamFormat;
> +       SensorMode sensorMode;
>         unsigned int bufferCount;
>         PixelFormat pixelFormat;
>         V4L2VideoDevice::Formats fmts;
> @@ -498,8 +529,9 @@ CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera *camera,
>                 switch (role) {
>                 case StreamRole::Raw:
>                         size = data->sensor_->resolution();
> -                       sensorFormat = findBestMode(data->sensorFormats_, size);
> -                       pixelFormat = sensorFormat.fourcc.toPixelFormat();
> +                       sensorMode = findBestMode(data->sensorFormats_, size);
> +                       unicamFormat = toV4L2DeviceFormat(sensorMode);
> +                       pixelFormat = sensorMode.first;
>                         ASSERT(pixelFormat.isValid());
>                         bufferCount = 2;
>                         rawCount++;
> @@ -609,10 +641,9 @@ int PipelineHandlerRPi::configure(Camera *camera, CameraConfiguration *config)
>         }
>
>         /* First calculate the best sensor mode we can use based on the user request. */
> -       V4L2DeviceFormat unicamFormat = findBestMode(data->sensorFormats_, rawStream ? sensorSize : maxSize);
> -
> -       unsigned int mbus_code = BayerFormat::fromV4L2PixelFormat(unicamFormat.fourcc).toMbusCode();
> -       V4L2SubdeviceFormat sensorFormat { .mbus_code = mbus_code, .size = unicamFormat.size };
> +       SensorMode sensorMode = findBestMode(data->sensorFormats_, rawStream ? sensorSize : maxSize);
> +       V4L2SubdeviceFormat sensorFormat = toV4L2SubdeviceFormat(sensorMode);
> +       V4L2DeviceFormat unicamFormat = toV4L2DeviceFormat(sensorMode);
>
>         ret = data->sensor_->setFormat(&sensorFormat);
>         if (ret)
> --
> 2.25.1
>


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