Video Buffers

Functions handle allocation and exchange of video buffers. More...

Functions
int	video_enqueue (const struct device *dev, struct video_buffer *buf)
	Pass a video buffer to a video device.
int	video_dequeue (const struct device *dev, struct video_buffer **vbuf, k_timeout_t timeout)
	Get a video buffer from a video device.
struct video_buffer *	video_buffer_aligned_alloc (size_t size, size_t align, k_timeout_t timeout)
	Allocate aligned video buffer.
struct video_buffer *	video_buffer_alloc (size_t size, k_timeout_t timeout)
	Allocate video buffer.
struct video_buffer *	video_import_buffer (uint8_t *mem, size_t sz)
	Import an external memory to the video buffer pool.
int	video_buffer_release (struct video_buffer *buf)
	Release a video buffer.
int	video_transfer_buffer (const struct device *src, const struct device *sink, enum video_buf_type src_type, enum video_buf_type sink_type, k_timeout_t timeout)
	Transfer a buffer between 2 video device.
int	video_set_signal (const struct device *dev, struct k_poll_signal *sig)
	Register/Unregister k_poll signal for a video endpoint.

Detailed Description

Functions handle allocation and exchange of video buffers.

Function Documentation

video_buffer_aligned_alloc()

struct video_buffer * video_buffer_aligned_alloc	(	size_t	size,
		size_t	align,
		k_timeout_t	timeout )

#include <video.h>

Allocate aligned video buffer.

Parameters

size	Size of the video buffer (in bytes).
align	Alignment of the requested memory, must be a power of two.
timeout	Timeout duration or K_NO_WAIT

Returns

pointer to allocated video buffer

video_buffer_alloc()

struct video_buffer * video_buffer_alloc	(	size_t	size,
		k_timeout_t	timeout )

#include <video.h>

Allocate video buffer.

Parameters

size	Size of the video buffer (in bytes).
timeout	Timeout duration or K_NO_WAIT

Returns

pointer to allocated video buffer

video_buffer_release()

int video_buffer_release

(

struct video_buffer *

buf

)

#include <video.h>

Release a video buffer.

Parameters

buf	Pointer to the video buffer to release.

Return values

0	on success or a negative errno on failure

video_dequeue()

int video_dequeue	(	const struct device *	dev,
		struct video_buffer **	vbuf,
		k_timeout_t	timeout )

#include <video.h>

Get a video buffer from a video device.

Dequeue an empty (output) or filled (capturing) video buffer in the driver’s endpoint outgoing queue.

Parameters

dev	Pointer to the device structure for the driver instance.
vbuf	Buffer returned from the video device.
timeout	Timeout duration or K_NO_WAIT

Return values

0	Is successful.
-EINVAL	If parameters are invalid.
-EIO	General input / output error.

video_enqueue()

int video_enqueue	(	const struct device *	dev,
		struct video_buffer *	buf )

#include <video.h>

Pass a video buffer to a video device.

Enqueue an empty (capturing) or filled (output) video buffer in the driver’s endpoint incoming queue.

Parameters

dev	Pointer to the device structure for the driver instance.
buf	Pointer to the video buffer.

Return values

0	Is successful.
-EINVAL	If parameters are invalid.
-EIO	General input / output error.

video_import_buffer()

struct video_buffer * video_import_buffer	(	uint8_t *	mem,
		size_t	sz )

#include <video.h>

Import an external memory to the video buffer pool.

Import an externally allocated memory as a video_buffer in the video buffer pool

Parameters

mem	Pointer to the external memory
sz	Size of the external memory

Returns

Pointer to the imported video_buffer holding the external memory on success, NULL on failure

video_set_signal()

int video_set_signal	(	const struct device *	dev,
		struct k_poll_signal *	sig )

#include <video.h>

Register/Unregister k_poll signal for a video endpoint.

Register a poll signal to the endpoint, which will be signaled on frame completion (done, aborted, error). Registering a NULL poll signal unregisters any previously registered signal.

Parameters

dev	Pointer to the device structure for the driver instance.
sig	Pointer to k_poll_signal

Return values

0	If successful, -ERRNO code otherwise.

video_transfer_buffer()

int video_transfer_buffer	(	const struct device *	src,
		const struct device *	sink,
		enum video_buf_type	src_type,
		enum video_buf_type	sink_type,
		k_timeout_t	timeout )

#include <video.h>

Transfer a buffer between 2 video device.

Helper function which dequeues a buffer from a source device and enqueues it into a sink device, changing its buffer type between the two.

Parameters

src	Video device from where buffer is dequeued (source)
sink	Video device into which the buffer is queued (sink)
src_type	Video buffer type on the source device
sink_type	Video buffer type on the sink device
timeout	Timeout to be applied on dequeue

Returns

0 on success, otherwise a negative errno code