Camera2: Add prepare for output streams
The prepare call asynchronously pre-allocates buffers for a given
output stream, and then fires the onPrepared callback.
Not implemented for Camera2Device or used in Camera2Client.
Change-Id: I1cccdfff846dd6985133c591dbdceed823929ade
diff --git a/services/camera/libcameraservice/device3/Camera3StreamInterface.h b/services/camera/libcameraservice/device3/Camera3StreamInterface.h
index ea90dd9..d177b57 100644
--- a/services/camera/libcameraservice/device3/Camera3StreamInterface.h
+++ b/services/camera/libcameraservice/device3/Camera3StreamInterface.h
@@ -89,6 +89,68 @@
virtual status_t cancelConfiguration() = 0;
/**
+ * Determine whether the stream has already become in-use (has received
+ * a valid filled buffer), which determines if a stream can still have
+ * prepareNextBuffer called on it.
+ */
+ virtual bool isUnpreparable() = 0;
+
+ /**
+ * Start stream preparation. May only be called in the CONFIGURED state,
+ * when no valid buffers have yet been returned to this stream.
+ *
+ * If no prepartion is necessary, returns OK and does not transition to
+ * PREPARING state. Otherwise, returns NOT_ENOUGH_DATA and transitions
+ * to PREPARING.
+ *
+ * Returns:
+ * OK if no more buffers need to be preallocated
+ * NOT_ENOUGH_DATA if calls to prepareNextBuffer are needed to finish
+ * buffer pre-allocation, and transitions to the PREPARING state.
+ * NO_INIT in case of a serious error from the HAL device
+ * INVALID_OPERATION if called when not in CONFIGURED state, or a
+ * valid buffer has already been returned to this stream.
+ */
+ virtual status_t startPrepare() = 0;
+
+ /**
+ * Check if the stream is mid-preparing.
+ */
+ virtual bool isPreparing() const = 0;
+
+ /**
+ * Continue stream buffer preparation by allocating the next
+ * buffer for this stream. May only be called in the PREPARED state.
+ *
+ * Returns OK and transitions to the CONFIGURED state if all buffers
+ * are allocated after the call concludes. Otherwise returns NOT_ENOUGH_DATA.
+ *
+ * Returns:
+ * OK if no more buffers need to be preallocated, and transitions
+ * to the CONFIGURED state.
+ * NOT_ENOUGH_DATA if more calls to prepareNextBuffer are needed to finish
+ * buffer pre-allocation.
+ * NO_INIT in case of a serious error from the HAL device
+ * INVALID_OPERATION if called when not in CONFIGURED state, or a
+ * valid buffer has already been returned to this stream.
+ */
+ virtual status_t prepareNextBuffer() = 0;
+
+ /**
+ * Cancel stream preparation early. In case allocation needs to be
+ * stopped, this method transitions the stream back to the CONFIGURED state.
+ * Buffers that have been allocated with prepareNextBuffer remain that way,
+ * but a later use of prepareNextBuffer will require just as many
+ * calls as if the earlier prepare attempt had not existed.
+ *
+ * Returns:
+ * OK if cancellation succeeded, and transitions to the CONFIGURED state
+ * INVALID_OPERATION if not in the PREPARING state
+ * NO_INIT in case of a serious error from the HAL device
+ */
+ virtual status_t cancelPrepare() = 0;
+
+ /**
* Fill in the camera3_stream_buffer with the next valid buffer for this
* stream, to hand over to the HAL.
*