diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
index a404eccf34d9c93b..395148e45d342d92 100644
--- a/include/libcamera/stream.h
+++ b/include/libcamera/stream.h
@@ -7,6 +7,7 @@
 #ifndef __LIBCAMERA_STREAM_H__
 #define __LIBCAMERA_STREAM_H__
 
+#include <errno.h>
 #include <map>
 #include <memory>
 #include <string>
@@ -74,6 +75,7 @@ class Stream
 {
 public:
 	Stream();
+	virtual ~Stream(){};
 
 	std::unique_ptr<Buffer> createBuffer(unsigned int index);
 	std::unique_ptr<Buffer> createBuffer(const std::array<int, 3> &fds);
@@ -86,6 +88,15 @@ public:
 protected:
 	friend class Camera;
 
+	virtual int allocateBuffers(const StreamConfiguration &config,
+				    std::vector<FrameBuffer *> *buffers)
+	{
+		return -EINVAL;
+	}
+	virtual void releaseBuffers() { return; }
+	virtual int start() { return -EINVAL; }
+	virtual void stop() { return; }
+
 	int mapBuffer(const Buffer *buffer);
 	void unmapBuffer(const Buffer *buffer);
 
diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
index e70a1e307ecaa5ba..ba3f571b08cb0c41 100644
--- a/src/libcamera/stream.cpp
+++ b/src/libcamera/stream.cpp
@@ -520,6 +520,61 @@ std::unique_ptr<Buffer> Stream::createBuffer(const std::array<int, 3> &fds)
  * \return The memory type used by the stream
  */
 
+/**
+ * \fn Stream::allocateBuffers()
+ * \brief Allocate buffers from the stream
+ * \param[in] config A configuration describing the buffer(s) to be allocated
+ * \param[out] buffers Array of buffers successfully allocated
+ *
+ * Allocate buffers matching exactly what is described in \a config and return
+ * then in \a buffers. If buffers matching \a config can't be allocated an error
+ * shall be returned and no buffers returned in \a buffers.
+ *
+ * This is a helper which may be used by libcamera helper classes to allocate
+ * buffers from the stream itself. The allocated buffers may then be treated
+ * in the same way as if they where externally allocated.
+ *
+ * The only intended caller is buffer allocator helpers and the function must
+ * be implemeted by all subclasses of Stream.
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+
+/**
+ * \fn Stream::releaseBuffers()
+ * \brief Relase buffers allocated from the stram
+ *
+ * This is a helper which release buffers allocated using allocateBuffers(). The
+ * only intended caller is buffer allocator helpers.
+ *
+ * The only intended caller is buffer allocator helpers and the function must
+ * be implemeted by all subclasses of Stream.
+ */
+
+/**
+ * \fn Stream::start()
+ * \brief Prepare a stream for capture
+ *
+ * The subclss shall prepare the stream for capture and if needed allocate
+ * resources to allow for that. No buffers may be allocated from the stream
+ * using allocateBuffers() after a stream have been started.
+ *
+ * The only intended caller is the camera base class and the function must be
+ * implemeted by all subclasses of Stream.
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+
+/**
+ * \fn Stream::stop()
+ * \brief Stop a stream after capture
+ *
+ * The subclass shall free all resources allocated in start().
+ *
+ * The only intended caller is the camera base class and the function must be
+ * implemeted by all subclasses of Stream.
+ */
+
 /**
  * \brief Map a Buffer to a buffer memory index
  * \param[in] buffer The buffer to map to a buffer memory index