# CMBufferQueueDequeueIfDataReady(_:) Dequeues a buffer from a queue, if it’s ready. ``` func CMBufferQueueDequeueIfDataReady(_ queue: CMBufferQueue) -> CMBuffer? ``` ## Parameters `queue` The `CMBufferQueue` from which to dequeue a buffer (if the buffer is ready). ## Return Value The dequeued buffer. Will be `NULL` if the queue is empty, or if the buffer to be dequeued is not yet ready. ## Discussion The buffer is released by the queue, but it is also retained for the client. Buffer ownership is thereby transferred from queue to client. The client need not retain the buffer, but is responsible to release it when done with it. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)