[libcamera-devel] [RFC PATCH 2/2] android: camera_request: Lifetime of a Camera3RequestDescriptor
Umang Jain
umang.jain at ideasonboard.com
Wed Nov 10 08:30:49 CET 2021
This commit provides a sketch regarding Camera3RequestDescriptor
which is aids tracking each capture reuquest placed by the android
framework to libcamera HAL.
Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
src/android/camera_request.cpp | 97 ++++++++++++++++++++++++++++++++++
1 file changed, 97 insertions(+)
diff --git a/src/android/camera_request.cpp b/src/android/camera_request.cpp
index 4e017792..824b667d 100644
--- a/src/android/camera_request.cpp
+++ b/src/android/camera_request.cpp
@@ -18,6 +18,9 @@ using namespace libcamera;
*
* A utility class that groups information about a capture request to be later
* reused at request complete time to notify the framework.
+ *
+ * Also, refer to the Camera3RequestDescriptor's lifetime diagram at the end of
+ * this file.
*/
Camera3RequestDescriptor::Camera3RequestDescriptor(
@@ -105,3 +108,97 @@ Camera3RequestDescriptor::StreamBuffer::StreamBuffer(StreamBuffer &&) = default;
Camera3RequestDescriptor::StreamBuffer &
Camera3RequestDescriptor::StreamBuffer::operator=(Camera3RequestDescriptor::StreamBuffer &&) = default;
+
+/*******************************************************************************
+ * Lifetime of a Camera3RequestDescriptor tracking a capture request placed by
+ * Android Framework
+ *******************************************************************************
+ *
+ *
+ * Android Framework
+ * │
+ * │ ┌──────────────────────────────────â”
+ * │ │camera3_capture_request_t │
+ * │ │ │
+ * │ │Requested output streams │
+ * │ │ stream1 stream2 stream3 ... │
+ * │ └──────────────────────────────────┘
+ * â–¼
+ * ┌─────────────────────────────────────────────────────────────â”
+ * │ libcamera HAL │
+ * ├─────────────────────────────────────────────────────────────┤
+ * │ CameraDevice │
+ * │ │
+ * │ processCaptureRequest(camera3_capture_request_t request) │
+ * │ │
+ * │ - Create Camera3RequestDescriptor tracking this request │
+ * │ - Streams requiring post-processing is stored as a │
+ * │ map Camera3Requestdescriptor::pendingStreamsToProcess │
+ * │ - Add this Camera3RequestDescriptor to descriptors' queue │
+ * │ CameraDevice::descriptors_ │
+ * │ │ ┌─────────────────────────â”
+ * │ - Queue the capture request to libcamera core ────────────┤►│libcamera core │
+ * │ │ ├─────────────────────────┤
+ * │ │ │- Capture from Camera │
+ * │ │ │ │
+ * │ │ │- Emit │
+ * │ │ │ Camera::requestComplete│
+ * │ requestCompleted(Request *request) ◄───────────────────────┼─┼──── │
+ * │ │ │ │
+ * │ - Check request completion status │ └─────────────────────────┘
+ * │ │
+ * │ - If(pendingStreamsToProcess > 0) │
+ * │ Queue all entries from pendingStreamsToProcess │
+ * │ else │ │
+ * │ completeDescriptor() │ └──────────────────────â”
+ * │ │ │
+ * │ ┌──────────────────────────┴───┬──────────────────┠│
+ * │ │ │ │ │
+ * │ ┌──────────▼────────────┠┌───────────▼─────────┠▼ │
+ * │ │CameraStream1 │ │CameraStream2 │ .... │
+ * │ ├┬───┬───┬──────────────┤ ├┬───┬───┬────────────┤ │
+ * │ ││ │ │ │ ││ │ │ │ │
+ * │ │▼───▼───▼──────────────┤ │▼───▼───▼────────────┤ │
+ * │ │PostProcessorWorker ├─ │PostProcessorWorker │ │
+ * │ │ │ │ │ │
+ * │ │ xxxxxxxxxxxxxxxxxxx │ │ xxxxxxxxxxxxxxxxxxx │ │
+ * │ │ x PostProcessor x │ │ x PostProcessor x │ │
+ * │ │ x process() x │ │ x process() x │ │
+ * │ │ x x │ │ x x │ │
+ * │ │ x Emit x │ │ x Emit x │ │
+ * │ │ x processComplete x │ │ x processComplete x │ │
+ * │ │ x x │ │ x x │ │
+ * │ │ xxxxxxxxxxxxxxx│xxx │ │ xxxxxxxxxxxxxxx│xxx │ │
+ * │ │ │ │ │ │ │ │
+ * │ │ │ │ │ │ │ │
+ * │ └────────────────┼──────┘ └────────────────┼────┘ │
+ * │ │ │ │
+ * │ │ │ │
+ * │ │ │ │
+ * │ ▼ ▼ │
+ * │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx │
+ * │ x CameraDevice x x CameraDevice x │
+ * │ x x x x │
+ * │ x streamProcessingComplete() x x streamProcessingComplete() x │
+ * │ x x x x │
+ * │ x - Check and set buffer status x x - Check and set buffer status x │
+ * │ x - Remove post-processing entry x x - Remove post-processing entry x │
+ * │ x from pendingStreamsToProcess x x from pendingStreamsToProcess x │
+ * │ x x x x │
+ * │ x - If(pendingStreamsToProcess.empty()x x - If(pendingStreamsToProcess.empty()x │
+ * │ x completeDescriptor x x completeDescriptor x │
+ * │ x x x x │
+ * │ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx │
+ * │ │
+ * └────────────────────────────────────────────────────────────────────────────────────┘
+ *
+ *
+ *
+ *
+ *
+ *
+ * xxxxxxxxxxxxxx
+ * x x - PostProcessorWorker's thread
+ * x x
+ * xxxxxxxxxxxxxx
+ */
--
2.31.0
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