HardwareBufferFrameQueue

@RequiresApi(value = 26)
@ExperimentalApi
interface HardwareBufferFrameQueue

Known direct subclasses
EncoderWriterHardwareBufferQueue

An implementation of HardwareBufferFrameQueue that uses an ImageWriter to forward frames to a SurfaceInfo.
PacketConsumerHardwareBufferFrameQueue

An implementation of HardwareBufferFrameQueue that manages a fixed-capacity pool of HardwareBuffers, that are forwarded to a downstream PacketConsumer.
SurfaceHolderHardwareBufferFrameQueue

A HardwareBufferFrameQueue that outputs frames to a SurfaceHolder.

A provider for HardwareBufferFrame instances that manages allocating the underlying HardwareBuffer instances, and forwards frames downstream for processing.

Summary

Nested types

Defines the configuration parameters required for a HardwareBuffer.

A builder for FrameFormat instances.

Public functions
HardwareBufferFrame?
dequeue(
    format: HardwareBufferFrameQueue.FrameFormat!,
    wakeupListener: Runnable!
)

Attempts to dequeue a HardwareBufferFrame matching the specified format.
Unit

Queues a HardwareBufferFrame for consumption by the downstream component.
Unit

Releases all resources associated with this instance.
Unit

Signals that no more frames will be queued.

Public functions

dequeue

fun dequeue(
    format: HardwareBufferFrameQueue.FrameFormat!,
    wakeupListener: Runnable!
): HardwareBufferFrame?

Attempts to dequeue a HardwareBufferFrame matching the specified format.

If the queue has reached its capacity and no buffers are available for reuse, this method returns null. In this case, the wakeupListener will be invoked when a buffer is eventually returned to the pool.

If this method is called multiple times without returning a frame, only the most recent wakeupListener is guaranteed to be invoked.

Parameters
format: HardwareBufferFrameQueue.FrameFormat!

The required format for the dequeued buffer.
wakeupListener: Runnable!

A callback to notify the caller when a buffer becomes available.
Returns
HardwareBufferFrame?

A HardwareBufferFrame, or null if the queue is currently full.

queue

fun queue(frame: HardwareBufferFrame!): Unit

Queues a HardwareBufferFrame for consumption by the downstream component.

Implementations may override release of the queued frame.

The implementation is responsible for ensuring the buffer is correctly reused or released once the downstream component has finished processing it.

Parameters
frame: HardwareBufferFrame!

The frame to be processed.

release

fun release(): Unit

Releases all resources associated with this instance.

signalEndOfStream

fun signalEndOfStream(): Unit

Signals that no more frames will be queued.

This propagates an end-of-stream signal to the downstream consumer.