v4l2_context.h File Reference

#include <stdatomic.h>
#include <linux/videodev2.h>
#include "libavcodec/avcodec.h"
#include "libavutil/pixfmt.h"
#include "libavutil/frame.h"
#include "libavutil/buffer.h"
#include "v4l2_buffers.h"

Go to the source code of this file.

Data Structures
struct	V4L2Context

Functions
int	ff_v4l2_context_init (V4L2Context *ctx)
	Initializes a V4L2Context. More...
int	ff_v4l2_context_set_format (V4L2Context *ctx)
	Sets the V4L2Context format in the v4l2 driver. More...
int	ff_v4l2_context_get_format (V4L2Context *ctx, int probe)
	Queries the driver for a valid v4l2 format and copies it to the context. More...
void	ff_v4l2_context_release (V4L2Context *ctx)
	Releases a V4L2Context. More...
int	ff_v4l2_context_set_status (V4L2Context *ctx, uint32_t cmd)
	Sets the status of a V4L2Context. More...
int	ff_v4l2_context_dequeue_packet (V4L2Context *ctx, AVPacket *pkt)
	Dequeues a buffer from a V4L2Context to an AVPacket. More...
int	ff_v4l2_context_dequeue_frame (V4L2Context *ctx, AVFrame *f, int timeout)
	Dequeues a buffer from a V4L2Context to an AVFrame. More...
int	ff_v4l2_context_enqueue_packet (V4L2Context *ctx, const AVPacket *pkt)
	Enqueues a buffer to a V4L2Context from an AVPacket. More...
int	ff_v4l2_context_enqueue_frame (V4L2Context *ctx, const AVFrame *f)
	Enqueues a buffer to a V4L2Context from an AVFrame. More...

Function Documentation

ff_v4l2_context_init()

int ff_v4l2_context_init

(

V4L2Context *

ctx

)

Initializes a V4L2Context.

Parameters

[in]

ctx

A pointer to a V4L2Context. See V4L2Context description for required variables.

Returns

0 in case of success, a negative value representing the error otherwise.

Definition at line 722 of file v4l2_context.c.

Referenced by ff_v4l2_m2m_codec_full_reinit(), v4l2_configure_contexts(), and v4l2_try_start().

ff_v4l2_context_set_format()

int ff_v4l2_context_set_format

(

V4L2Context *

ctx

)

Sets the V4L2Context format in the v4l2 driver.

Parameters

[in]

ctx

A pointer to a V4L2Context. See V4L2Context description for required variables.

Returns

0 in case of success, a negative value representing the error otherwise.

Definition at line 703 of file v4l2_context.c.

Referenced by ff_v4l2_m2m_codec_full_reinit(), ff_v4l2_m2m_codec_reinit(), and v4l2_configure_contexts().

ff_v4l2_context_get_format()

int ff_v4l2_context_get_format	(	V4L2Context *	ctx,
		int	probe
	)

Queries the driver for a valid v4l2 format and copies it to the context.

Parameters

[in]	ctx	A pointer to a V4L2Context. See V4L2Context description for required variables.
[in]	probe	Probe only and ignore changes to the format.

Returns

0 in case of success, a negative value representing the error otherwise.

Definition at line 676 of file v4l2_context.c.

Referenced by ff_v4l2_m2m_codec_full_reinit(), ff_v4l2_m2m_codec_reinit(), and v4l2_probe_driver().

ff_v4l2_context_release()

void ff_v4l2_context_release

(

V4L2Context *

ctx

)

Releases a V4L2Context.

Parameters

[in]

ctx

A pointer to a V4L2Context. The caller is reponsible for freeing it. It must not be used after calling this function.

Definition at line 708 of file v4l2_context.c.

Referenced by ff_v4l2_m2m_codec_end(), ff_v4l2_m2m_codec_full_reinit(), ff_v4l2_m2m_codec_reinit(), and v4l2_m2m_destroy_context().

ff_v4l2_context_set_status()

int ff_v4l2_context_set_status	(	V4L2Context *	ctx,
		uint32_t	cmd
	)

Sets the status of a V4L2Context.

Parameters

[in]	ctx	A pointer to a V4L2Context.
[in]	cmd	The status to set (VIDIOC_STREAMON or VIDIOC_STREAMOFF). Warning: If VIDIOC_STREAMOFF is sent to a buffer context that still has some frames buffered, those frames will be dropped.

Returns

0 in case of success, a negative value representing the error otherwise.

Definition at line 572 of file v4l2_context.c.

Referenced by ff_v4l2_m2m_codec_end(), ff_v4l2_m2m_codec_full_reinit(), ff_v4l2_m2m_codec_reinit(), v4l2_receive_packet(), v4l2_stop_decode(), v4l2_stop_encode(), and v4l2_try_start().

ff_v4l2_context_dequeue_packet()

int ff_v4l2_context_dequeue_packet	(	V4L2Context *	ctx,
		AVPacket *	pkt
	)

Dequeues a buffer from a V4L2Context to an AVPacket.

The pkt must be non NULL.

Parameters

[in]	ctx	The V4L2Context to dequeue from.
[in,out]	pkt	The AVPacket to dequeue to.

Returns

0 in case of success, AVERROR(EAGAIN) if no buffer was ready, another negative error in case of error.

Definition at line 656 of file v4l2_context.c.

Referenced by v4l2_receive_packet().

ff_v4l2_context_dequeue_frame()

int ff_v4l2_context_dequeue_frame	(	V4L2Context *	ctx,
		AVFrame *	f,
		int	timeout
	)

Dequeues a buffer from a V4L2Context to an AVFrame.

The frame must be non NULL.

Parameters

[in]	ctx	The V4L2Context to dequeue from.
[in,out]	f	The AVFrame to dequeue to.
[in]	timeout	The timeout for dequeue (-1 to block, 0 to return immediately, or milliseconds)

Returns

0 in case of success, AVERROR(EAGAIN) if no buffer was ready, another negative error in case of error.

Definition at line 636 of file v4l2_context.c.

Referenced by v4l2_receive_frame().

ff_v4l2_context_enqueue_packet()

int ff_v4l2_context_enqueue_packet	(	V4L2Context *	ctx,
		const AVPacket *	pkt
	)

Enqueues a buffer to a V4L2Context from an AVPacket.

The packet must be non NULL. When the size of the pkt is null, the buffer is not queued but a V4L2_DEC_CMD_STOP command is sent instead to the driver.

Parameters

[in]	ctx	The V4L2Context to enqueue to.
[in]	pkt	A pointer to an AVPacket.

Returns

0 in case of success, a negative error otherwise.

Definition at line 611 of file v4l2_context.c.

Referenced by v4l2_receive_frame().

ff_v4l2_context_enqueue_frame()

int ff_v4l2_context_enqueue_frame	(	V4L2Context *	ctx,
		const AVFrame *	f
	)

Enqueues a buffer to a V4L2Context from an AVFrame.

The frame must be non NULL.

Parameters

[in]	ctx	The V4L2Context to enqueue to.
[in]	f	A pointer to an AVFrame to enqueue.

Returns

0 in case of success, a negative error otherwise.

Definition at line 586 of file v4l2_context.c.

Referenced by v4l2_send_frame().