The MinimumRequests property reports the minimum number of capture
requests that the camera pipeline requires to have queued in order to
sustain capture operations. At this quantity, there's no guarantee that
frames won't be dropped or that manual per-frame controls will apply
correctly. The quantity needed for those may be added as separate
properties in the future.
By default the property is set to 1 in the CameraSensor constructor, and
it can be overridden by each pipeline. The uvcvideo pipeline explicitly
sets the property to 1 since it doesn't have a CameraSensor.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
---
Changes in v7:
- Thanks to Kieran:
- Renamed property from MinNumRequests to MinimumRequests
- Thanks to Jacopo:
- Changed property's description
Changes in v6:
- Thanks to Naushir:
- Removed comment from Raspberrypi MinNumRequests setting
- Removed an extra blank line
src/libcamera/camera_sensor.cpp | 1 +
src/libcamera/pipeline/rkisp1/rkisp1.cpp | 2 ++
src/libcamera/pipeline/simple/simple.cpp | 2 ++
src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 2 ++
src/libcamera/pipeline/vimc/vimc.cpp | 2 ++
src/libcamera/property_ids.yaml | 10 ++++++++++
6 files changed, 19 insertions(+)
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index cde431cc4c80..d8ed010bfd08 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -57,6 +57,7 @@ CameraSensor::CameraSensor(const MediaEntity *entity)
: entity_(entity), pad_(UINT_MAX), bayerFormat_(nullptr),
properties_(properties::properties)
{
+ properties_.set(properties::MinimumRequests, 1);
}
/**
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 42911a8fdfdb..cb4ca9a85fa8 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -24,6 +24,7 @@
#include <libcamera/ipa/core_ipa_interface.h>
#include <libcamera/ipa/rkisp1_ipa_interface.h>
#include <libcamera/ipa/rkisp1_ipa_proxy.h>
+#include <libcamera/property_ids.h>
#include <libcamera/request.h>
#include <libcamera/stream.h>
@@ -944,6 +945,7 @@ int PipelineHandlerRkISP1::createCamera(MediaEntity *sensor)
/* Initialize the camera properties. */
data->properties_ = data->sensor_->properties();
+ data->properties_.set(properties::MinimumRequests, 3);
/*
* \todo Read dealy values from the sensor itself or from a
diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index b29fff9820e5..348c554c8be4 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -25,6 +25,7 @@
#include <libcamera/camera.h>
#include <libcamera/control_ids.h>
+#include <libcamera/property_ids.h>
#include <libcamera/request.h>
#include <libcamera/stream.h>
@@ -436,6 +437,7 @@ int SimpleCameraData::init()
}
properties_ = sensor_->properties();
+ properties_.set(properties::MinimumRequests, 3);
return 0;
}
diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
index 0f634b8da609..6ad7fb3c9f0c 100644
--- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
@@ -525,6 +525,8 @@ int UVCCameraData::init(MediaDevice *media)
properties_.set(properties::PixelArraySize, resolution);
properties_.set(properties::PixelArrayActiveAreas, { Rectangle(resolution) });
+ properties_.set(properties::MinimumRequests, 1);
+
/* Initialise the supported controls. */
ControlInfoMap::Map ctrls;
diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp
index 12f7517fd0ae..44c198ccf8b8 100644
--- a/src/libcamera/pipeline/vimc/vimc.cpp
+++ b/src/libcamera/pipeline/vimc/vimc.cpp
@@ -21,6 +21,7 @@
#include <libcamera/control_ids.h>
#include <libcamera/controls.h>
#include <libcamera/formats.h>
+#include <libcamera/property_ids.h>
#include <libcamera/request.h>
#include <libcamera/stream.h>
@@ -516,6 +517,7 @@ int VimcCameraData::init()
/* Initialize the camera properties. */
properties_ = sensor_->properties();
+ properties_.set(properties::MinimumRequests, 2);
return 0;
}
diff --git a/src/libcamera/property_ids.yaml b/src/libcamera/property_ids.yaml
index 12ecbce5eed4..23ef0e9d38c4 100644
--- a/src/libcamera/property_ids.yaml
+++ b/src/libcamera/property_ids.yaml
@@ -678,6 +678,16 @@ controls:
\todo Turn this property into a "maximum control value" for the
ScalerCrop control once "dynamic" controls have been implemented.
+ - MinimumRequests:
+ type: int32_t
+ description: |
+ The minimum number of capture requests that the camera pipeline requires
+ to have queued in order to sustain capture operations.
+
+ This property usually corresponds to the minimum number of memory
+ buffers needed to fill the capture pipeline composed of hardware
+ processing blocks.
+
# ----------------------------------------------------------------------------
# Draft properties section
--
2.32.0