[libcamera-devel] [PATCH v2 3/5] libcamera: pipeline: simple: Factor out format test to separate function

[Kieran Bingham]

Quoting Laurent Pinchart via libcamera-devel (2022-06-12 16:23:09)
> To prepare for the implementation of a more complex format discovery
> method, factor out code that tries a pipeline configuration to a
> separate function. No functional change intended.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
> 
> - Drop unused function declaration
> - Document the tryPipeline() function

Looks good to me.


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> ---
>  src/libcamera/pipeline/simple/simple.cpp | 118 +++++++++++++----------
>  1 file changed, 67 insertions(+), 51 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
> index b09368aee20b..3c90bdec60e0 100644
> --- a/src/libcamera/pipeline/simple/simple.cpp
> +++ b/src/libcamera/pipeline/simple/simple.cpp
> @@ -250,6 +250,8 @@ public:
>         std::queue<std::map<unsigned int, FrameBuffer *>> converterQueue_;
>  
>  private:
> +       void tryPipeline(unsigned int code, const Size &size);
> +
>         void converterInputDone(FrameBuffer *buffer);
>         void converterOutputDone(FrameBuffer *buffer);
>  };
> @@ -466,58 +468,11 @@ int SimpleCameraData::init()
>                 return ret;
>  
>         /*
> -        * Enumerate the possible pipeline configurations. For each media bus
> -        * format supported by the sensor, propagate the formats through the
> -        * pipeline, and enumerate the corresponding possible V4L2 pixel
> -        * formats on the video node.
> +        * Generate the list of possible pipeline configurations by trying each
> +        * media bus format supported by the sensor.
>          */
> -       for (unsigned int code : sensor_->mbusCodes()) {
> -               V4L2SubdeviceFormat format{};
> -               format.mbus_code = code;
> -               format.size = sensor_->resolution();
> -
> -               ret = setupFormats(&format, V4L2Subdevice::TryFormat);
> -               if (ret < 0) {
> -                       LOG(SimplePipeline, Debug)
> -                               << "Media bus code " << utils::hex(code, 4)
> -                               << " not supported for this pipeline";
> -                       /* Try next mbus_code supported by the sensor */
> -                       continue;
> -               }
> -
> -               V4L2VideoDevice::Formats videoFormats =
> -                       video_->formats(format.mbus_code);
> -
> -               LOG(SimplePipeline, Debug)
> -                       << "Adding configuration for " << format.size
> -                       << " in pixel formats [ "
> -                       << utils::join(videoFormats, ", ",
> -                                      [](const auto &f) {
> -                                              return f.first.toString();
> -                                      })
> -                       << " ]";
> -
> -               for (const auto &videoFormat : videoFormats) {
> -                       PixelFormat pixelFormat = videoFormat.first.toPixelFormat();
> -                       if (!pixelFormat)
> -                               continue;
> -
> -                       Configuration config;
> -                       config.code = code;
> -                       config.captureFormat = pixelFormat;
> -                       config.captureSize = format.size;
> -
> -                       if (!converter_) {
> -                               config.outputFormats = { pixelFormat };
> -                               config.outputSizes = config.captureSize;
> -                       } else {
> -                               config.outputFormats = converter_->formats(pixelFormat);
> -                               config.outputSizes = converter_->sizes(format.size);
> -                       }
> -
> -                       configs_.push_back(config);
> -               }
> -       }
> +       for (unsigned int code : sensor_->mbusCodes())
> +               tryPipeline(code, sensor_->resolution());
>  
>         if (configs_.empty()) {
>                 LOG(SimplePipeline, Error) << "No valid configuration found";
> @@ -541,6 +496,67 @@ int SimpleCameraData::init()
>         return 0;
>  }
>  
> +/*
> + * Generate a list of supported pipeline configurations for a sensor media bus
> + * code and size.
> + *
> + * First propagate the media bus code and size through the pipeline from the
> + * camera sensor to the video node. Then, query the video node for all supported
> + * pixel formats compatible with the media bus code. For each pixel format, store
> + * a full pipeline configuration in the configs_ vector.
> + */
> +void SimpleCameraData::tryPipeline(unsigned int code, const Size &size)
> +{
> +       /*
> +        * Propagate the format through the pipeline, and enumerate the
> +        * corresponding possible V4L2 pixel formats on the video node.
> +        */
> +       V4L2SubdeviceFormat format{};
> +       format.mbus_code = code;
> +       format.size = size;
> +
> +       int ret = setupFormats(&format, V4L2Subdevice::TryFormat);
> +       if (ret < 0) {
> +               /* Pipeline configuration failed, skip this configuration. */
> +               LOG(SimplePipeline, Debug)
> +                       << "Media bus code " << utils::hex(code, 4)
> +                       << " not supported for this pipeline";
> +               return;
> +       }
> +
> +       V4L2VideoDevice::Formats videoFormats = video_->formats(format.mbus_code);
> +
> +       LOG(SimplePipeline, Debug)
> +               << "Adding configuration for " << format.size
> +               << " in pixel formats [ "
> +               << utils::join(videoFormats, ", ",
> +                              [](const auto &f) {
> +                                      return f.first.toString();
> +                              })
> +               << " ]";
> +
> +       for (const auto &videoFormat : videoFormats) {
> +               PixelFormat pixelFormat = videoFormat.first.toPixelFormat();
> +               if (!pixelFormat)
> +                       continue;
> +
> +               Configuration config;
> +               config.code = code;
> +               config.captureFormat = pixelFormat;
> +               config.captureSize = format.size;
> +
> +               if (!converter_) {
> +                       config.outputFormats = { pixelFormat };
> +                       config.outputSizes = config.captureSize;
> +               } else {
> +                       config.outputFormats = converter_->formats(pixelFormat);
> +                       config.outputSizes = converter_->sizes(format.size);
> +               }
> +
> +               configs_.push_back(config);
> +       }
> +}
> +
>  int SimpleCameraData::setupLinks()
>  {
>         int ret;
> -- 
> Regards,
> 
> Laurent Pinchart
>