1 files changed, 72 insertions, 0 deletions
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 698dd525..11d68456 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -290,6 +290,78 @@ const ControlInfoMap &PipelineHandler::controls(Camera *camera)
  */
 
 /**
+ * \fn PipelineHandler::exportFrameBuffers()
+ * \brief Allocate buffers for \a stream
+ * \param[in] camera The camera
+ * \param[in] stream The stream to allocate buffers for
+ * \param[out] buffers Array of buffers successfully allocated
+ *
+ * This method allocates buffers for the \a stream from the devices associated
+ * with the stream in the corresponding pipeline handler. Those buffers shall be
+ * suitable to be added to a Request for the stream, and shall be mappable to
+ * the CPU through their associated dmabufs with mmap().
+ *
+ * The method may only be called after the Camera has been configured and before
+ * it gets started, or after it gets stopped. It shall be called only for
+ * streams that are part of the active camera configuration, and at most once
+ * per stream until buffers for the stream are freed with freeFrameBuffers().
+ *
+ * exportFrameBuffers() shall also allocate all other resources required by
+ * the pipeline handler for the stream to prepare for starting the Camera. This
+ * responsibility is shared with importFrameBuffers(), and one and only one of
+ * those two methods shall be called for each stream until the buffers are
+ * freed. The pipeline handler shall support all combinations of
+ * exportFrameBuffers() and importFrameBuffers() for the streams contained in
+ * any camera configuration.
+ *
+ * The only intended caller is the FrameBufferAllocator helper.
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+
+/**
+ * \fn PipelineHandler::importFrameBuffers()
+ * \brief Prepare \a stream to use external buffers
+ * \param[in] camera The camera
+ * \param[in] stream The stream to prepare for import
+ *
+ * This method prepares the pipeline handler to use buffers provided by the
+ * application for the \a stream.
+ *
+ * The method may only be called after the Camera has been configured and before
+ * it gets started, or after it gets stopped. It shall be called only for
+ * streams that are part of the active camera configuration, and at most once
+ * per stream until buffers for the stream are freed with freeFrameBuffers().
+ *
+ * importFrameBuffers() shall also allocate all other resources required by the
+ * pipeline handler for the stream to prepare for starting the Camera. This
+ * responsibility is shared with exportFrameBuffers(), and one and only one of
+ * those two methods shall be called for each stream until the buffers are
+ * freed. The pipeline handler shall support all combinations of
+ * exportFrameBuffers() and importFrameBuffers() for the streams contained in
+ * any camera configuration.
+ *
+ * The only intended caller is Camera::start().
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+
+/**
+ * \fn PipelineHandler::freeFrameBuffers()
+ * \brief Free buffers allocated from the stream
+ * \param[in] camera The camera
+ * \param[in] stream The stream to free buffers for
+ *
+ * This method shall free all buffers and all other resources allocated for the
+ * \a stream by exportFrameBuffers() or importFrameBuffers(). It shall be
+ * called only after a successful call to either of these two methods, and only
+ * once per stream.
+ *
+ * The only intended callers are Camera::stop() and the FrameBufferAllocator
+ * helper.
+ */
+
+/**
  * \fn PipelineHandler::allocateBuffers()
  * \brief Allocate buffers for a stream
  * \param[in] camera The camera the \a stream belongs to