VIDEO PIPELINE API

[中文]

Overview

This section mainly describes the API introductions, and related data structures of the video pipeline. The video pipeline is a component that manages the flow of video data, including encoding, decoding, and display.

API Reference

Header File

Functions

avdk_err_t bk_video_pipeline_new(bk_video_pipeline_handle_t *handle, bk_video_pipeline_config_t *config)

Video Pipeline API.

This file provides the external interface for the video pipeline module, which handles various video operations including H264 encoding and image rotation. The video pipeline provides a unified management interface for functions such as video encoding/decoding and image rotation, simplifying the complexity of multi-module collaborative work.

Create a new video pipeline instance

This function creates and initializes a new video pipeline instance with the specified configuration.

Parameters

  • handle – [out] Pointer to store the video pipeline handle

  • config – [in] Video pipeline configuration parameters

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_open_h264e(bk_video_pipeline_handle_t handle, bk_video_pipeline_h264e_config_t *config)

Open H.264 encoder.

This function opens and configures the H.264 encoder module in the video pipeline.

Parameters

  • handle – [in] Video pipeline handle

  • config – [in] Video pipeline configuration parameters for H.264 encoding

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_close_h264e(bk_video_pipeline_handle_t handle)

Close H.264 encoder.

This function closes the H.264 encoder module in the video pipeline.

Parameters

handle – [in] Video pipeline handle

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_open_rotate(bk_video_pipeline_handle_t handle, bk_video_pipeline_decode_config_t *config)

Open image rotation module.

This function opens and configures the image rotation module in the video pipeline.

Parameters

  • handle – [in] Video pipeline handle

  • config – [in] Video pipeline configuration parameters for image rotation

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_close_rotate(bk_video_pipeline_handle_t handle)

Close image rotation module.

This function closes the image rotation module in the video pipeline.

Parameters

handle – [in] Video pipeline handle

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_get_module_status(bk_video_pipeline_handle_t handler, video_pipeline_module_t module, video_pipeline_module_status_t *status)

Get the status of a video pipeline module.

This function retrieves the enable status of a specified module in the video pipeline.

Parameters

  • handler – [in] Video pipeline handle

  • module – [in] Module to query (H264E or ROTATE)

  • status – [out] Pointer to store the module status

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_reset_decode(bk_video_pipeline_handle_t handler)

Reset the decode module to re-detect image format.

This function is used when switching cameras to internally re-acquire the image format. It resets the decode module in the video pipeline.

Parameters

handler – [in] Video pipeline handle

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_delete(bk_video_pipeline_handle_t handle)

Delete the video pipeline instance.

This function deletes and frees resources associated with a video pipeline instance.

Parameters

handle – [in] Video pipeline handle

Returns

  • BK_OK: Success

  • Others: Fail

avdk_err_t bk_video_pipeline_ioctl(bk_video_pipeline_handle_t handle, video_pipeline_ioctl_cmd_t cmd, void *param)

Extended interface for video pipeline Used for additional functionalities like getting encoder status.

This function provides an extended interface for additional functionalities in the video pipeline.

Parameters

  • handle – [in] Video pipeline handle

  • cmd – [in] Command code (defined in pipeline_ext_cmd_t)

  • param – [inout] Command parameters

Returns

  • BK_OK: Success

  • Others: Fail

API Typedefs

Callback Function Usage Notes:

When implementing callback functions for video pipeline operations, please keep in mind:

  • bk_h264e_callback_t: Blocking operations (such as long waits, sleep, etc.) are NOT recommended in callback functions to avoid impacting encoding performance and system responsiveness. Callback functions should only perform lightweight operations such as setting flags, sending messages/semaphores, etc. Move time-consuming operations to other tasks.

  • jpeg_callback_t: Blocking operations are generally NOT recommended in callback functions to avoid impacting decoding performance and system responsiveness. However, the read() callback is an exception - it may perform short blocking waits to acquire a ready JPEG buffer. Other callback functions should only perform lightweight operations such as setting flags, sending messages/semaphores, etc.

  • decode_callback_t: Blocking operations (such as long waits, sleep, etc.) are NOT recommended in callback functions to avoid impacting decoding performance and system responsiveness. Callback functions should only perform lightweight operations such as setting flags, sending messages/semaphores, etc. Move time-consuming operations to other tasks.

Header File

Structures

struct bk_h264e_callback_t

H.264 encoder callback structure.

This structure defines the callback functions for H.264 encoding operations, including memory allocation and completion notification.

Warning

Callback Function Usage Notes:

  • Blocking operations (such as long waits, sleep, etc.) are NOT recommended in callback functions to avoid impacting encoding performance and system responsiveness.

  • Callback functions should only perform lightweight operations such as setting flags, sending messages/semaphores, etc. Move time-consuming operations to other tasks.

Public Members

frame_buffer_t *(*malloc)(uint32_t size)

Allocate memory for frame buffer.

Param size

Size of memory to allocate

Return

Pointer to allocated frame buffer

void (*complete)(frame_buffer_t *frame, bk_err_t result)

Frame encoding completion callback.

Param frame

Pointer to the frame buffer

Param result

Result of the encoding operation

struct jpeg_callback_t

JPEG decode callback structure.

This structure defines the callback functions for JPEG decoding operations

Warning

Callback Function Usage Notes:

  • Blocking operations (such as long waits, sleep, etc.) are NOT recommended in callback functions to avoid impacting decoding performance and system responsiveness.

  • Callback functions should only perform lightweight operations such as setting flags, sending messages/semaphores, etc. Move time-consuming operations to other tasks.

  • Exception: The read() callback may perform short blocking waits to acquire a ready JPEG buffer.

Public Members

frame_buffer_t *(*read)(uint32_t timeout_ms)

Callback to read/acquire a prepared JPEG buffer, short blocking wait is allowed

bk_err_t (*complete)(bk_err_t result, frame_buffer_t *out_frame)

Callback when decoding is complete

struct decode_callback_t

Image codec callback structure.

This structure defines the callback functions for image codec operations

Warning

Callback Function Usage Notes:

  • Blocking operations (such as long waits, sleep, etc.) are NOT recommended in callback functions to avoid impacting decoding performance and system responsiveness.

  • Callback functions should only perform lightweight operations such as setting flags, sending messages/semaphores, etc. Move time-consuming operations to other tasks.

Public Members

frame_buffer_t *(*malloc)(uint32_t size)

Callback to allocate frame buffer

bk_err_t (*free)(frame_buffer_t *frame)

Callback to free frame buffer

bk_err_t (*complete)(dec_end_type_t format_type, bk_err_t result, frame_buffer_t *out_frame)

Callback when processing is complete Rotation angle

struct bk_video_pipeline_h264e_config

Video pipeline H.264 encoder configuration structure.

This structure defines the configuration parameters for the H.264 encoder in the video pipeline

Public Members

uint16_t width

Width of the video frame

uint16_t height

Height of the video frame

uint32_t fps

Frames per second

media_rotate_t sw_rotate_angle

Software rotation angle

const bk_h264e_callback_t *h264e_cb

H.264 encoder callback functions

struct bk_video_pipeline_decode_config

Video pipeline decode configuration structure.

This structure defines the configuration parameters for the decode module in the video pipeline

Public Members

media_rotate_mode_t rotate_mode

Rotation mode (1: software rotation, 0: hardware rotation)

media_rotate_t rotate_angle

Rotation angle

struct bk_video_pipeline_config

Video pipeline configuration structure.

This structure defines the main configuration parameters for the video pipeline

Public Members

const jpeg_callback_t *jpeg_cbs

JPEG decode callback functions

const decode_callback_t *decode_cbs

Image codec callback functions

struct bk_video_pipeline

Video pipeline operations structure.

This structure defines the operations available for the video pipeline instance

Public Members

avdk_err_t (*open_h264e)(bk_video_pipeline_handle_t handle, bk_video_pipeline_h264e_config_t *config)

Open H.264 encoder

avdk_err_t (*close_h264e)(bk_video_pipeline_handle_t handle)

Close H.264 encoder

avdk_err_t (*open_rotate)(bk_video_pipeline_handle_t handle, bk_video_pipeline_decode_config_t *config)

Open image rotation module

avdk_err_t (*close_rotate)(bk_video_pipeline_handle_t handle)

Close image rotation module

avdk_err_t (*reset_decode)(bk_video_pipeline_handle_t handle)

Reset decode module, This function is used when switching cameras to internally re-acquire the image format.

avdk_err_t (*get_module_status)(bk_video_pipeline_handle_t handle, video_pipeline_module_t module, video_pipeline_module_status_t *status)

Get module enable state

avdk_err_t (*delete_video_pipeline)(bk_video_pipeline_handle_t handle)

Delete the video pipeline instance

avdk_err_t (*ioctl)(bk_video_pipeline_handle_t handle, video_pipeline_ioctl_cmd_t cmd, void *param)

Extended interface for additional functionalities

Macros

delete_video_pipeline

Video Pipeline Types.

This file defines the data types, enumerations, and structures used by the video pipeline module. The video pipeline provides a unified management interface for functions such as video encoding/decoding and image rotation, simplifying the complexity of multi-module collaborative work.

BK_H264_ENCODE_864X480_30FPS_CONFIG()

Default H.264 encoding configuration for 864x480 resolution at 30 FPS.

This macro provides a default configuration for H.264 encoding with:

  • Resolution: 864x480

  • Frame rate: 30 FPS

  • Software decode rotate angle: default:0 range:(0, 90, 180, 270)

Type Definitions

typedef struct bk_video_pipeline_h264e_config bk_video_pipeline_h264e_config_t

Video pipeline H.264 encoder configuration structure.

This structure defines the configuration parameters for the H.264 encoder in the video pipeline

typedef struct bk_video_pipeline_decode_config bk_video_pipeline_decode_config_t

Video pipeline decode configuration structure.

This structure defines the configuration parameters for the decode module in the video pipeline

typedef struct bk_video_pipeline_config bk_video_pipeline_config_t

Video pipeline configuration structure.

This structure defines the main configuration parameters for the video pipeline

typedef struct bk_video_pipeline *bk_video_pipeline_handle_t

Video pipeline handle type.

This is the handle type for the video pipeline instance

typedef struct bk_video_pipeline bk_video_pipeline_t

Video pipeline operations structure.

This structure defines the operations available for the video pipeline instance

Enumerations

enum dec_end_type_t

Decoder end type enumeration.

This enumeration defines the different types of decoder end operations

Values:

enumerator HW_DEC_END

Hardware decoding end

enumerator SW_DEC_END

Software decoding end

enum h264e_state_t

H.264 encoder working state enumeration.

This enumeration defines the working states of the H.264 encoder

Values:

enumerator H264E_STATE_IDLE

Encoder idle state

enumerator H264E_STATE_ENCODING

Encoder encoding state

enum video_pipeline_module_t

Video pipeline module type enumeration.

This enumeration defines the different module types in the video pipeline

Values:

enumerator VIDEO_PIPELINE_MODULE_H264E

H.264 encoder module

enumerator VIDEO_PIPELINE_MODULE_ROTATE

Image rotation module

enum video_pipeline_module_status_t

Video pipeline module status enumeration.

This enumeration defines the enable status of modules in the video pipeline

Values:

enumerator VIDEO_PIPELINE_MODULE_DISABLED

Module disabled state

enumerator VIDEO_PIPELINE_MODULE_ENABLED

Module enabled state

enum video_pipeline_ioctl_cmd_t

Video pipeline extended command enumeration.

This enumeration defines the extended commands for the video pipeline

Values:

enumerator VIDEO_PIPELINE_IOCTL_CMD_BASE

Base command start value