ipa: rkisp1: awb: Store per-frame information in frame context

Rework the algorithm's usage of the active state and frame context to
store data in the right place.

The active state stores two distinct categories of information:

- The consolidated value of all algorithm controls. Requests passed to
  the queueRequest() function store values for controls that the
  application wants to modify for that particular frame, and the
  queueRequest() function updates the active state with those values.
  The active state thus contains a consolidated view of the value of all
  controls handled by the algorithm.

- The value of parameters computed by the algorithm when running in auto
  mode. Algorithms running in auto mode compute new parameters every
  time statistics buffers are received (either synchronously, or
  possibly in a background thread). The latest computed value of those
  parameters is stored in the active state in the process() function.

The frame context also stores two categories of information:

- The value of the controls to be applied to the frame. These values are
  typically set in the queueRequest() function, from the consolidated
  control values stored in the active state. The frame context thus
  stores values for all controls related to the algorithm, not limited
  to the controls specified in the corresponding request, but
  consolidated from all requests that have been queued so far.

  For controls that can be specified manually or computed by the
  algorithm depending on the operation mode (such as the colour gains),
  the control value will be stored in the frame context in
  queueRequest() only when operating in manual mode. When operating in
  auto mode, the values are computed by the algorithm and stored in the
  frame context in prepare(), just before being stored in the ISP
  parameters buffer.

  The queueRequest() function can also store ancillary data in the frame
  context, such as flags to indicate if (and what) control values have
  changed compared to the previous request.

- Status information computed by the algorithm for a frame. For
  instance, the colour temperature estimated by the algorithm from ISP
  statistics calculated on a frame is stored in the frame context for
  that frame in the process() function.

The active state and frame context thus both contain identical members
for most control values, but store values that have a different meaning.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 43 insertions, 8 deletions

diff --git a/src/ipa/rkisp1/ipa_context.cpp b/src/ipa/rkisp1/ipa_context.cpp
index c7d5b1b6..ba80a070 100644
--- a/src/ipa/rkisp1/ipa_context.cpp
+++ b/src/ipa/rkisp1/ipa_context.cpp
@@ -120,17 +120,29 @@ namespace libcamera::ipa::rkisp1 {
  * \struct IPAActiveState::awb.gains
  * \brief White balance gains
  *
- * \var IPAActiveState::awb.gains.red
- * \brief White balance gain for R channel
+ * \struct IPAActiveState::awb.gains.manual
+ * \brief Manual white balance gains (set through requests)
  *
- * \var IPAActiveState::awb.gains.green
- * \brief White balance gain for G channel
+ * \var IPAActiveState::awb.gains.manual.red
+ * \brief Manual white balance gain for R channel
  *
- * \var IPAActiveState::awb.gains.blue
- * \brief White balance gain for B channel
+ * \var IPAActiveState::awb.gains.manual.green
+ * \brief Manual white balance gain for G channel
  *
- * \var IPAActiveState::awb.temperatureK
- * \brief Estimated color temperature
+ * \var IPAActiveState::awb.gains.manual.blue
+ * \brief Manual white balance gain for B channel
+ *
+ * \struct IPAActiveState::awb.gains.automatic
+ * \brief Automatic white balance gains (computed by the algorithm)
+ *
+ * \var IPAActiveState::awb.gains.automatic.red
+ * \brief Automatic white balance gain for R channel
+ *
+ * \var IPAActiveState::awb.gains.automatic.green
+ * \brief Automatic white balance gain for G channel
+ *
+ * \var IPAActiveState::awb.gains.automatic.blue
+ * \brief Automatic white balance gain for B channel
  *
  * \var IPAActiveState::awb.autoEnabled
  * \brief Whether the Auto White Balance algorithm is enabled
@@ -202,6 +214,29 @@ namespace libcamera::ipa::rkisp1 {
  */
 
 /**
+ * \var IPAFrameContext::awb
+ * \brief Automatic White Balance parameters for this frame
+ *
+ * \struct IPAFrameContext::awb.gains
+ * \brief White balance gains
+ *
+ * \var IPAFrameContext::awb.gains.red
+ * \brief White balance gain for R channel
+ *
+ * \var IPAFrameContext::awb.gains.green
+ * \brief White balance gain for G channel
+ *
+ * \var IPAFrameContext::awb.gains.blue
+ * \brief White balance gain for B channel
+ *
+ * \var IPAFrameContext::awb.temperatureK
+ * \brief Estimated color temperature
+ *
+ * \var IPAFrameContext::awb.autoEnabled
+ * \brief Whether the Auto White Balance algorithm is enabled
+ */
+
+/**
  * \var IPAFrameContext::sensor
  * \brief Sensor configuration that used been used for this frame
  *