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eIQ MPP Hardware Abstraction Layer API

Contents

eIQ MPP Hardware Abstraction Layer API#

MPP-HAL VERSION 3.7

Chapter 1#

This is the documentation for the Hardware Abstraction Layer(HAL) API.

1.1 HAL overview#

The hardware abstraction layer is used to abstract hardware and software components. With the usage of an HAL abstraction, the vision pipeline will be leveraging hardware accelerated components whenever possible.

1.1.1 MPP hal description#

The HAL is presented with respect of the following points:

  • A common header file “hal.h” includes all hardware top level functions.

  • All hardware top level functions are using the prefix: “hal_ “.

  • For each platform all hal_ functions defined in hal.h should be implemented at least with an empty function.

Here is an overview:

Figure 1.1 HAL overview

1.1.2 MPP HAL components#

  1. Source elements HAL

  • Camera

  • Static image

  1. processing elements HAL

  • Graphics driver

  • Vision algorithms

  • Labeled rectangle

  1. Sink elements HAL

  • Display

1.1.3 Supported devices#

At present, the MPP HAL supports the following devices:

  • Cameras:

    • OV5640

    • MT9M114

    • OV7670

    • Logitech C920 PRO HD WEBCAM

  • Displays:

    • LVGL

    • RK055AHD091

    • RK055MHD091

    • RK043FN02H-CT

    • Mikroe TFT Proto 5(SSD1963 controller)

    • NXP’s LCD-PAR-S035 (ST7796S controller)

    • FBdev

  • Graphics:

    • PXP

    • CPU

    • GPU

  • JPEG Decoder:

    • JPEG SW

    • JPEG HW

1.1.4 Supported boards#

Currently, the MPP HAL supports the following boards:

  • (deprecated) evkmimxrt1170 is supported with the following devices:

    • Cameras: OV5640.

    • Displays: RK055AHD091 and RK055MHD091.

  • (deprecated) evkbimxrt1050 is supported with the following devices:

    • Cameras: MT9M114.

    • Displays: RK043FN02H-CT.

  • evkbmimxrt1170 is supported by porting the following devices:

    • Cameras: OV5640.

    • Displays: LVGL, RK055AHD091 and RK055MHD091.

  • frdmmcxn947 is supported by porting the following devices:

    • Cameras: OV7670.

    • Displays: Mikroe TFT Proto 5” and NXP’s LCD-PAR-S035.

  • mimxrt700evk is supported by porting the following devices:

    • Cameras: OV7670, Logitech C920 PRO HD WEBCAM

    • Displays: RK055AHD091 and RK055MHD091.

How to port new boards/devices: The MPP Hal provides the flexibility to the user to port new boards and devices(cameras and displays).

Supporting new boards: To support a new board a new file hal_{board_name} should be added under the ‘hal’ directory.

Supporting new devices: The hal components that can support new devices are:

  • Cameras

  • Display

  • Graphics processing

A new device can simply be supported by:

  • Providing the approriate hal_{device_module} implementation.

  • Adding his name and setup entry point to the appropriate device list in the associated board hal_{board_name} file.

Enabling/Disabling Hal components and devices:

  • The HAL components can be enabled/disabled from “mpp_config.h” using the compilation flags(HAL_ENABLE_{component_name}).

  • The HAL devices can also be enabled/disabled from “mpp_config.h” using the compilation flags(HAL_ENABLE_{device_name}).

Chapter 2#

2.1 HAL Types#

Data Structures

Macros

Typedefs

Enumerations#

}

}

}

  • enum gfx_rotate_target_t {

    kGFXRotateTarget_None,

    kGFXRotate_SRCSurface,

    kGFXRotate_DSTSurface

}

}

}

}

}

}

Functions

2.1.1 Detailed Description#

This section provides the detailed documentation for the MPP HAL types.

2.1.1.1 Data Structure Documentation#

camera_dev_static_config_t#

struct camera_dev_static_config_t

Structure that characterizes the camera device.

Data Fields

type

name

description

int

height

buffer height

int

width

buffer width

int

pitch

buffer pitch

int

left

left position

int

top

top position

int

right

right position

int

bottom

bottom position

mpp_rotate_degree_t

rotate

rotate degree

mpp_flip_mode_t

flip

flip

int

swapByte

swap byte per two bytes

mpp_pixel_format_t

format

pixel format

int

framerate

frame rate

int

stripe_size

stripe size in bytes

bool

stripe

stripe mode

uint32_t

n_streams

number of total output video streams

uint32_t

min_stream_req_cnt

minimum number of enqueue calls to wait for

uint32_t

crt_stream_req_cnt

number of streams requested for enqueue

mpp_exec_flag_t

req_cnt_type

flag to control stream request counting

mpp_camera_stream_cfg

stream[NUM_STREAMS]

stream configuration

bool

stream_requested[NUM_STREAMS]

flag to track if a stream is required for enqueue

bool

in_advance_enqueue

flag to indicate advance enqueue mode

camera_dev_private_capability_t#

struct camera_dev_private_capability_t

Camera device private capability.

Data Fields

type

name

description

camera_dev_callback_t

callback

callback

void ∗

param

parameter for the callback

camera_dev#

struct _camera_dev

Camera devices can enqueue and dequeue frames as well as react to events from input devices via the “input← Notify” function. Camera devices can use any number of interfaces, including MIPI and CSI as long as the HAL driver implements the necessary functions found in camera_dev_operator_t. Examples of camera devices include the Orbbec U1S 3D SLM camera module and the OnSemi MT9M114 camera module.

Data Fields

int

id

unique id which is assigned by camera manager during registration

char

name[HAL_DEVICE_NAME_MAX_L

[ENGTHname of]] the device

const camera_dev_operator_t ∗

ops

operations

camera_dev_static_config_t

config

static configurations

camera_dev_private_capability_t

cap

private capability

void ∗

data

device private data

static_image_static_config_t#

struct static_image_static_config_t

Structure that characterizes the image element.

Data Fields

type

name

description

int

height

buffer height

int

width

buffer width

int

left

left position

int

top

top position

int

right

right position

int

bottom

bottom position

mpp_pixel_format_t

format

pixel format

bool

stripe

stripe mode

int

compressed_size

compressed size in bytes

static_image#

struct _static_image

Attributes of an image element.

Data Fields

type

name

description

int

id

unique id which is assigned by image manager

const static_image_operator_t ∗

ops

operations

static_image_static_config_t

config

static configs

int

stripe_idx

the current stripe index

uint8_t ∗

buffer

static image buffer

gfx_surface_t#

struct gfx_surface_t

Gfx surface parameters.

Data Fields

type

name

description

int

height

buffer height

int

width

buffer width

int

pitch

buffer pitch

int

left

left position

int

top

top position

int

right

right position

int

bottom

bottom position

int

swapByte

swap byte per two bytes

mpp_pixel_format_t

format

pixel format

void ∗

buf

buffer

void ∗

lock

the structure is determined by hal and set to null if not use in hal

gfx_rotate_config_t#

struct gfx_rotate_config_t

gfx rotate configuration.

Data Fields

type

name

description

gfx_rotate_target_t

target

mpp_rotate_degree_t

degree

gfx_dev#

struct _gfx_dev

Data Fields

type

name

description

int

id

const gfx_dev_operator_t

ops

gfx_surface_t

src

gfx_surface_t

dst

mpp_callback_t

callback

void ∗

user_data

hal_rect_t#

struct hal_rect_t

rectangle positions.

Data Fields

type

name

description

int

top

int

left

int

bottom

int

right

vdec_dev_t#

struct _vdec_dev

Data Fields

type

name

description

int

id

const vdec_dev_operator_t ∗

ops

mpp_callback_t

callback

void ∗

user_data

model_param_t#

struct model_param_t

Structure passed to HAL as description of the binary model provided by user.

Data Fields

Field Documentation

model_data#

const void∗ model_param_t::model_data pointer to model binary

model_size#

int model_param_t::model_size model binary size

model_input_mean#

float model_param_t::model_input_mean

model ‘mean’ of input values, used for normalization

model_input_std#

float model_param_t::model_input_std

model_input_std#

model ‘standard deviation’ of input values, used for normalization

inference_params

mpp_inference_params_t model_param_t::inference_params inference parameters

height#

int model_param_t::height frame height

width#

int model_param_t::width frame width

format#

mpp_pixel_format_t model_param_t::format pixel format

inputtype#

mpp_tensor_type_t model_param_t::inputType input type

tensor_order#

tensor_order#

mpp_tensor_order_t model_param_t::tensor_order tensor order

evt_callback_f

int(∗ model_param_t::evt_callback_f) (mpp_t mpp, mpp_evt_t evt, void ∗evt_data, void ∗user_data)

the callback to be called when model output is ready

evt_callback_f#

void∗ model_param_t::cb_userdata

pointer to user data, should be passed by callback

valgo_dev_private_capability_t#

struct valgo_dev_private_capability_t

Valgo devices private capability.

Data Fields

type

name

description

void ∗

param

param for the callback

vision_frame_t#

struct vision_frame_t

Characteristics that need to be defined by a vision algo.

Data Fields

type

name

description

int

height

frame height

int

width

frame width

int

pitch

frame pitch

mpp_pixel_format_t

format

pixel format

void ∗

input_buf

pixel input buffer

vision_algo_dev_t#

struct _vision_algo_dev

Attributes of a vision algo device.

Data Fields

type

name

description

int

id

unique id which is assigned by algorithm manager during the registration

char

name[HAL_DEVICE_NAME_MAX_L

[ENGTHname to]] identify

valgo_dev_private_capability_t

cap

private capability

const vision_algo_dev_operator_t

∗

ops

operations

vision_algo_private_data_t

priv_data

private data

display_dev_private_capability_t#

struct _display_dev_private_capability

Structure that characterizes the display device.

Data Fields

type

name

description

int

height

buffer height

int

width

buffer width

int

pitch

buffer pitch

int

left

left position

int

top

top position

int

right

right position

int

bottom

bottom position

int

stripe_height

stripe height (0 if stripe mode is off)

bool

stripe

stripe mode

mpp_rotate_degree_t

rotate

rotate degree

mpp_pixel_format_t

format

pixel format

int

nbFrameBuffer

number of input buffers

void ∗∗

frameBuffers

array of pointers to frame buffer

mpp_callback_t

callback

callback

void ∗

user_data

parameter for the callback

void ∗

handle

Handle to the LVGL widget ‘image’.

void ∗∗

p_in_buf_addr

Pointer to current input buffer address.

display_dev_t#

Attributes of a display device. hal display device declaration.

Display devices can be used to display images, GUI overlays, etc. Examples of display devices include display panels like the RK024hh298 display, and external displays like UVC (video over USB).

Data Fields

type

name

description

int

id

unique id which is assigned by the display manager during the registration

char

name[HAL_DEVICE_NAME_MAX_L

[ENGTHname of]] the device

const display_dev_operator_t ∗

ops

operations

display_dev_private_capability_t

cap

private capability

hw_buf_desc_t#

struct hw_buf_desc_t

the hardware specific buffer requirements

Data Fields

type

name

description

int

stride

the number of bytes between 2 lines of image

int

nb_lines

the number of lines required (set to 0 if the element doesn’t require a specific number of lines)

int

alignment

alignment requirement in bytes

int

max_image_size

the number of bytes allocated

bool

cacheable

if true, HW will require cache maintenance

unsigned char ∗

addr

the aligned buffer address

unsigned char ∗

heap_p

pointer to the heap that should be freed

hal_img_decoder_setup_t#

struct hal_img_decoder_setup_t!

Data Fields

type

name

description

const char ∗

vdec_dev_name

img_decoder_setup_func_t

decoder_setup_func

hal_graphics_setup_t#

struct hal_graphics_setup_t

Data Fields

type

name

description

const char ∗

gfx_dev_name

graphic_setup_func_t

gfx_setup_func

hal_display_setup_t#

struct hal_display_setup_t

Data Fields

type

name

description

const char ∗

display_name

display_setup_func_t

display_setup_func

hal_camera_setup_t#

struct hal_camera_setup_t

Data Fields

type

name

description

const char ∗

camera_name

camera_setup_func_t

camera_setup_func

checksum_data_t#

struct checksum_data_t

computed checksum

Data Fields

type

name

description

checksum_type_t

type

checksum calculation method

uint32_t

value

checksum value

2.1.1.2 Macro Definition Documentation#

HAL_GFX_DEV_CPU_NAME

#define HAL_GFX_DEV_CPU_NAME hal graphics (gfx) device declaration.

gui_printf_buf_size#

Graphics processing devices can be used to perform conversion from one image format to another, resize images and compose images on top of one another. Examples of graphics devices include the PXP (pixel pipeline) found on many i.MXRT series MCUs. Name of the graphic device using CPU operations

GUI_PRINTF_BUF_SIZE

#define GUI_PRINTF_BUF_SIZE Local text buffer size.

hal_vdec_dev_name#

#define HAL_VDEC_DEV_NAME

hal video decoder (vdec) device declaration.

max_input_ports#

Video decoder devices can be used to perform decompression of image. Examples of decoder devices include the PNG/JPEG HW or SW found on many i.MXRT series MCUs. Name of the jpeg decoder device using CPU operations

MAX_INPUT_PORTS

#define MAX_INPUT_PORTS

HAL public types header.

maximum number of element inputs/outputs

hal_device_name_max_l#

HAL_DEVICE_NAME_MAX_LENGTH

#define HAL_DEVICE_NAME_MAX_LENGTH maximum length of device name

2.1.1.3 Typedef Documentation#

camera_dev_callback_t#

typedef int(∗ camera_dev_callback_t) (const camera_dev_t ∗dev, camera_event_t event, void ∗param, uint8_t fromISR)

Callback function to notify camera manager that one frame is dequeued.

Parameters

name

description

dev

Device structure of the camera device calling this function

event

id of the event that took place

param

Parameters

fromISR

True if this operation takes place in an irq, 0 otherwise

Returns

0 if the operation was successfully

mpp_callback_t#

typedef int(∗ mpp_callback_t) (mpp_t mpp, mpp_evt_t evt, void ∗evt_data, void ∗user_data) The mpp callback function prototype.

img_decoder_setup_func_t#

typedef int(∗ img_decoder_setup_func_t) (vdec_dev_t ∗) video decoder setup

graphic_setup_func_t#

typedef int(∗ graphic_setup_func_t) (gfx_dev_t ∗) graphics setup

display_setup_func_t#

typedef int(∗ display_setup_func_t) (display_dev_t ∗) display setup

camera_setup_func_t#

typedef int(∗ camera_setup_func_t) (const char ∗, camera_dev_t ∗) camera setup

2.1.1.4 Enumeration Type Documentation#

hal_camera_status_t#

enum hal_camera_status_t Camera return status.

Enumerator

label

description

kStatus_HAL_CameraSuccess

HAL camera successful.

kStatus_HAL_CameraBusy

Camera is busy.

kStatus_HAL_CameraNoData

No data available from camera.

kStatus_HAL_CameraNonBlocking

Camera will return immediately.

kStatus_HAL_CameraError

Error occurs on HAL Camera.

camera_event_t#

enum camera_event_t

Type of events that are supported by calling the callback function.

Enumerator

label

description

kCameraEvent_SendFrame

Camera new frame is available.

kCameraEvent_CameraDeviceInit

Camera device finished the initialization process.

hal_image_status_t#

enum hal_image_status_t static image return status

Enumerator

label

description

MPP_kStatus_HAL_ImageSuccess

Successfully.

MPP_kStatus_HAL_ImageError

Error occurs on HAL Image.

gfx_rotate_target_t#

enum gfx_rotate_target_t gfx rotate target

hal_valgo_status_t#

enum hal_valgo_status_t

Valgo Error codes for hal operations.

Enumerator

label

description

kStatus_HAL_ValgoSuccess

Successfully.

kStatus_HAL_ValgoMallocError

memory allocation failed for HAL algorithm

kStatus_HAL_ValgoInitError

algorithm initialization error

kStatus_HAL_ValgoError

Error occurs in HAL algorithm.

kStatus_HAL_ValgoStop

HAL algorithm stop.

display_event_t#

enum display_event_t

Type of events that are supported by calling the callback function.

Enumerator

label

description

kDisplayEvent_RequestFrame

Display finished sending the frame asynchronously, provide another frame.

hal_display_status_t#

enum hal_display_status_t Error codes for display hal devices.

Enumerator

label

description

kStatus_HAL_DisplaySuccess

HAL display successful.

kStatus_HAL_DisplayTxBusy

Display tx is busy.

kStatus_HAL_DisplayNonBlocking

Display will return immediately.

kStatus_HAL_DisplayError

Error occurs on HAL Display.

mpp_memory_policy_t#

enum mpp_memory_policy_t

The memory allocation policy of an element’s hal.

During the pipeline construction, the HAL uses this enum to tell the pipeline if it already owns input/ouput buffers. Before the pipeline starts, the memory manager will map the existing buffers to elements and allocate missing buffers from the heap.

Enumerator

label

description

HAL_MEM_ALLOC_NONE

element requires buffers to be provided by other elements, or by the pipeline

HAL_MEM_ALLOC_INPUT

element allocates its input buffer, it may require output buffers to be provided by other elements, or by the pipeline

HAL_MEM_ALLOC_OUTPUT

element allocates its output buffer, it may require input buffers to be provided by other elements, or by the pipeline

HAL_MEM_ALLOC_BOTH

element allocates both its input and output buffers

checksum_type_t#

enum checksum_type_t checksum calculation method

Enumerator

label

description

CHECKSUM_TYPE_PISANO

checksum computed using Pisano

CHECKSUM_TYPE_CRC_ELCDIF

checksum computed CRC from ELCDIF

2.1.1.5 Function Documentation#

HAL_GfxDev_CPU_Register()

int HAL_GfxDev_CPU_Register ( gfx_dev_t ∗ dev )

Register the graphic device with the CPU operations.

Parameters

in/out

name

description

in

dev

graphic device to register

Returns

error code (0: success, otherwise: failure)

HAL_GfxDev_GPU_Register()

int HAL_GfxDev_GPU_Register ( gfx_dev_t ∗ dev )

Register the graphic device with the GPU operations.

Parameters

in/out

name

description

in

dev

graphic device to register

Returns

error code (0: success, otherwise: failure)

hal_jpeg_cpu_register#

int HAL_JPEG_CPU_Register (

vdec_dev_t ∗ dev ) Register the jpeg SW decoder device.

Parameters

in/out

name

description

in

dev

decoder device to register

-

-

-

Returns

error code (0: success, otherwise: failure)

hal_jpeg_hw_register#

int HAL_JPEG_HW_Register (

vdec_dev_t ∗ dev ) Register the jpeg HW decoder device.

Parameters

in/out

name

description

in

dev

decoder device to register

-

-

-

Returns

error code (0: success, otherwise: failure)

2.2 HAL OPERATIONS#

Data Structures

Typedefs

  • typedef int(∗mpp_callback_t) (mpp_t mpp, mpp_evt_t evt, void ∗evt_data, void ∗user_data)

  • typedef int(∗mpp_callback_t) (mpp_t mpp, mpp_evt_t evt, void ∗evt_data, void ∗user_data)

Functions

  • void GUI_DrawText (uint16_t ∗lcd_buf, uint16_t fcolor, uint16_t bcolor, uint32_t width, int x, int y, const char ∗label)

  • static void hal_draw_pixel565 (uint16_t ∗pDst, uint32_t x, uint32_t y, uint16_t color, uint32_t lcd_w)

  • static void hal_draw_text565 (uint16_t ∗lcd_buf, uint16_t fcolor, uint16_t bcolor, uint32_t width, int x, int y, const char ∗label, int stripe_top, int stripe_bottom)

  • static void hal_draw_rect565 (uint16_t ∗lcd_buf, hal_rect_t rect, mpp_color_t rgb, uint32_t width, int stripe← _top, int stripe_bottom)

  • static int get_bitpp (mpp_pixel_format_t type)

  • void swap_2_bytes (uint8_t ∗data, int size)

2.2.1 Detailed Description#

This section provides the detailed documentation for the MPP HAL operations that needs to be implemented for each component.

2.2.1.1 Data Structure Documentation#
camera_dev_operator_t#

struct camera_dev_operator_t

Operation that needs to be implemented by a camera device.

Data Fields

Field Documentation

init

hal_camera_status_t(∗ camera_dev_operator_t::init) (camera_dev_t ∗dev, mpp_camera_params_t ∗config, camera_dev_callback_t callback, void ∗param)

init#

initialize the dev

deinit

hal_camera_status_t(∗ camera_dev_operator_t::deinit) (camera_dev_t ∗dev)

deinit#

deinitialize the dev

start

hal_camera_status_t(∗ camera_dev_operator_t::start) (const camera_dev_t ∗dev)

start#

start the dev

stop

hal_camera_status_t(∗ camera_dev_operator_t::stop) (const camera_dev_t ∗dev)

stop#

stop the dev

enqueue

hal_camera_status_t(∗ camera_dev_operator_t::enqueue) (const camera_dev_t ∗dev, void ∗data) enqueue a buffer to the dev

dequeue

hal_camera_status_t(∗ camera_dev_operator_t::dequeue) (const camera_dev_t ∗dev, void ∗∗data, int ∗stripe)

dequeue#

dequeue a buffer from the dev (blocking)

get_buf_desc

hal_camera_status_t(∗ camera_dev_operator_t::get_buf_desc) (const camera_dev_t ∗dev, hw_buf_desc_t ∗out_buf, mpp_memory_policy_t ∗policy)

get buffer descriptors and policy

lock

hal_camera_status_t(∗ camera_dev_operator_t::lock) (const camera_dev_t ∗dev) lock the device for exclusive access and operations

unlock#

hal_camera_status_t(∗ camera_dev_operator_t::unlock) (const camera_dev_← t ∗dev)

unlock the device after exclusive operations

static_image_operator_t#

struct static_image_operator_t

Operation that needs to be implemented by an image element.

Data Fields

init#

init

hal_image_status_t(∗ static_image_operator_t::init) (static_image_t ∗elt, mpp← _img_params_t ∗config, void ∗param)

initialize the elt

dequeue#

hal_image_status_t(∗ static_image_operator_t::dequeue) (static_image_← t ∗elt, hw_buf_desc_t ∗out_buf, int ∗stripe_num)

dequeue a buffer from the elt

gfx_dev_operator_t#

struct gfx_dev_operator_t

Operation that needs to be implemented by gfx device.

Data Fields

vdec_dev_operator_t#

  • int(∗finish )(gfx_dev_t ∗dev)

struct vdec_dev_operator_t

Operation that needs to be implemented by vdec device.

Data Fields

  • int(∗init )(vdec_dev_t ∗dev, void ∗param)

  • int(∗deinit )(const vdec_dev_t ∗dev)

  • int(∗ get_buf_desc )(const vdec_dev_t ∗dev, hw_buf_desc_t ∗in_buf, hw_buf_desc_t ∗out_buf, mpp_memory_policy_t ∗policy)

  • int(∗decode )(const vdec_dev_t ∗dev, uint8_t ∗pSrc, uint8_t ∗pDst, int32_t jpg_size, uint32_t row_stride)

vision_algo_dev_operator_t#

struct vision_algo_dev_operator_t

Operation that needs to be implemented by a vision algorithm device.

Data Fields

init#

init

hal_valgo_status_t(∗ vision_algo_dev_operator_t::init) (vision_algo_dev_t ∗dev, model_param_t ∗param)

initialize the dev

deinit#

hal_valgo_status_t(∗ vision_algo_dev_operator_t::deinit) (vision_algo_dev_t ∗dev)

deinitialize the dev

run#

hal_valgo_status_t(∗ vision_algo_dev_operator_t::run) (const vision_algo_dev_t ∗dev, void ∗data)

get_buf_desc#

get_buf_desc

hal_valgo_status_t(∗ vision_algo_dev_operator_t::get_buf_desc) (const vision_algo_dev_t ∗dev, hw_buf_desc_t ∗in_buf, mpp_memory_policy_t ∗policy)

read input parameters

display_dev_operator_t#

struct display_dev_operator_t

Operation that needs to be implemented by a display device.

Data Fields

init#

**Field Documentation **

init

hal_display_status_t(∗ display_dev_operator_t::init) (display_dev_t ∗dev, mpp← _display_params_t ∗config, mpp_callback_t callback, void ∗user_data)

initialize the dev

deinit

hal_display_status_t(∗ display_dev_operator_t::deinit) (const display_dev_t ∗dev)

deinitialize the dev

start

hal_display_status_t(∗ display_dev_operator_t::start) (display_dev_t ∗dev) start the dev

stop

blit#

hal_display_status_t(∗ display_dev_operator_t::stop) (display_dev_t ∗dev) stop the dev

blit

hal_display_status_t(∗ display_dev_operator_t::blit) (const display_dev_t ∗dev, void ∗frame, int stripe)

blit a buffer to the dev

get_buf_desc

hal_display_status_t(∗ display_dev_operator_t::get_buf_desc) (const display_dev_t ∗dev, hw_buf_desc_t ∗in_buf, mpp_memory_policy_t ∗policy)

get buffer descriptors and policy

2.2.1.2 Typedef Documentation#

mpp_callback_t

typedef int(∗ mpp_callback_t) (mpp_t mpp, mpp_evt_t evt, void ∗evt_data, void ∗user_data) The mpp callback function prototype.

2.2.1.3 Function Documentation#
GUI_DrawText#

void GUI_DrawText ( uint16_t ∗ lcd_buf, uint16_t fcolor, uint16_t bcolor, uint32_t width, int x, int y, const char ∗ label )

Draws text stored in label pointer to LCD buffer. This function copy content of data from label text buffer to the LCD.

Parameters

name

description

lcd_buf

LCD buffer address destination for drawing text

fcolor

foreground color in rgb565 format

bcolor

background color in rgb565 format

width

LCD width

x

drawing position on X axe

y

drawing position on Y axe

label

C string pointed by label

Returns

hal_draw_pixel565#

static void hal_draw_pixel565 ( uint16_t ∗ pDst, uint32_t x, uint32_t y, uint16_t color, uint32_t lcd_w )

Draws pixel with RGB565 color to defined point.

Parameters

name

description

pDst

image data address of destination buffer

x

drawing position on X axe

y

drawing position on Y axe

color

RGB565 encoded value

lcd_w

lcd width
hal_draw_text565#

static void hal_draw_text565 ( uint16_t ∗ lcd_buf, uint16_t fcolor, uint16_t bcolor, uint32_t width, int x, int y, const char ∗ label, int stripe_top, int stripe_bottom ) [static]

Draws text stored in label pointer to LCD buffer. This function copy content of data from label text buffer to the LCD.

Parameters

name

description

lcd_buf

LCD buffer address destination for drawing text

fcolor

foreground color in rgb565 format

bcolor

background color in rgb565 format

width

LCD width

x

drawing position on X axe

y

drawing position on Y axe

format

C string pointed by format

Returns

The return number of written chars to the buffer

hal_draw_rect565#

static void hal_draw_rect565 ( uint16_t ∗ lcd_buf, hal_rect_t rect, mpp_color_t rgb, uint32_t width, int stripe_top, int stripe_bottom ) [static]

Draws rectangle.

Parameters

in/out

name

description

in

lcd_buf

LCD buffer address destination for drawing rectangle

in

color

background color in rgb565 format

in

x

drawing position on X axe

in

y

drawing position on Y axe

in

xsize

rectangle width

in

ysize

rectangle height

in

r

0-255 red color value

in

g

0-255 green color value

in

b

0-255 blue color value

in

width

LCD width

Returns

N/A

get_bitpp#

**get_bitpp()**static int get_bitpp (

mpp_pixel_format_t type ) [static]

returns the number of bits per pixel per format, unknown format return 0

swap_2_bytes#

**swap_2_bytes()**void swap_2_bytes (

uint8_t ∗ data,

int size )

Swaps a buffer’s MSB and LSB bytes..

Parameters

name

description

data

pointer to the buffer to be converted(from little endian to big endian and vice-versa).

size

buffer size.

HAL Types

Data Structures

Macros

Enumerations

  • enum virtual_usb_cam_msg_type_e {

    VIRT_USB_CAM_NOMSG ,

    VIRT_USB_CAM_CONFIG,

    VIRT_USB_CAM_CONFIG_ACK, VIRT_USB_CAM_CONFIG_ERR ,

    VIRT_USB_CAM_REQRGB ,

    VIRT_USB_CAM_REQIR,

    VIRT_USB_CAM_REQRGBIR ,

    VIRT_USB_CAM_RSPRGB ,

    VIRT_USB_CAM_RSPIR ,

    VIRT_USB_CAM_RSPRGBIR ,

    VIRT_USB_CAM_ERROR }

  • enum virtual_usb_cam_user_id_e {

    RTSP_USER_ID ,

    MPP_USER_ID }

  • enum virtual_usb_cam_col_format_e { VIRT_USB_CAM_JPEG }

Detailed Description

This section provides the detailed documentation for the MPP HAL VIRTUAL CAMERA types.

Data Structure Documentation

virtual_usb_cam_config_msg_t#

struct virtual_usb_cam_config_msg_t

Structure that characterizes the payload of the camera config message sent from core 0 to core 1. Data Fields

uint32_t

camera_width

Width of the camera output in pixels.

uint32_t

camera_height

Height of the camera output in pixels.

virtual_usb_cam_col_format_e

color_format

Color format for the camera output (e.g., JPEG)

uint32_t

fps

Frames per second for camera capture rate.
virtual_usb_cam_req_msg_t#

struct virtual_usb_cam_req_msg_t

Structure that characterizes the payload of the camera request message containing frame buffer addresses for RGB and IR data.

Data Fields

uint32_t

rgb_frame_addr

Physical address of the RGB frame buffer.

uint32_t

rgb_max_frame_size

Maximum size allocated for RGB frame buffer.

uint32_t

ir_frame_addr

Physical address of the IR frame buffer.

uint32_t

ir_max_frame_size

Maximum size allocated for IR frame buffer.

struct virtual_usb_cam_rsp_msg_t

Structure that characterizes the payload of the camera request message containing frame addresses and sizes for RGB and IR data.

Data Fields

uint32_t

rgb_frame_addr

Physical address of the RGB frame buffer (looped back by the core 1 camera app)

uint32_t

rgb_frame_size

Size in bytes of the RGB frame data.

uint32_t

ir_frame_addr

Physical address of the IR frame buffer (looped back by the core 1 camera app)

uint32_t

ir_frame_size

Size in bytes of the IR frame data.
virtual_usb_cam_msg_t#

struct virtual_usb_cam_msg_t

Structure that characterizes the messages sent between cores. Data Fields

virtual_usb_cam_msg_type_e

msg_type

Type of message being sent (config, request, response, etc.)

virtual_usb_cam_user_id_e

user_id

Identifier for the user/component sending the message (RTSP or MPP)

union msg_payload_u

msg_payload

Union containing the actual message data based on msg_type.

Macro Definition Documentation

target_camera0_width#

#define TARGET_CAMERA0_WIDTH

Buffer alignment requirement for camera device buffers in bytes.

core1_ept_address#

#define CORE1_EPT_ADDRESS

mpp_ept_addresss#

Endpoint address for Core 1 inter-core communication channel.

MPP_EPT_ADDRESSS

#define MPP_EPT_ADDRESSS

Endpoint address for MPP (Media Processing Pipeline) inter-core communication channel. MPP might use a range of endpoints starting with 40 and up to 49 included

rtsp_ept_address#

RTSP_EPT_ADDRESS

#define RTSP_EPT_ADDRESS

Endpoint address for RTSP (Real Time Streaming Protocol) inter-core communication channel.

app_ep_ready_event_data#

#define APP_EP_READY_EVENT_DATA

Event data value indicating that the application endpoint is ready for communication.

Enumeration Type Documentation

virtual_usb_cam_msg_type_e#

enum virtual_usb_cam_msg_type_e

Structure that characterizes the exchanged message types between core 0 and core 1.

virtual_usb_cam_col_format_e#

enum virtual_usb_cam_col_format_e

Structure that characterizes the color format for the camera output.

2.3 HAL Setup Functions#

Functions

2.3.1 Detailed Description#

This section provides the detailed documentation for the HAL setup functions that should be defined by each device.

2.3.1.1 Function Documentation#

hal_label_rectangle()

int hal_label_rectangle ( uint8_t ∗ frame, int width, int height, mpp_pixel_format_t format, mpp_labeled_rect_t ∗ lr, int stripe, int stripe_max )

Implementation of hal labeled rectangle component that draws a rectangle and a text on an input image.

Parameters

in/out

name

description

in

frame

The buffer address

in

width

Image width

in

height

Image height

in

format

Image format

in

lr

Labeled rectangle parameters

in

stripe

stripe number (0=no stripe)

in

stripe_max

max nb of stripes

Returns

0

hal_landmark#

**hal_landmark()**int hal_landmark (

uint8_t ∗ frame,

int width,

int height,

mpp_pixel_format_t format,

mpp_landmark_t ∗ lk,

int stripe,

int stripe_max )

Implementation of hal landmark component that draws a landmark on an input image. Parameters

in/out

name

description

in

frame

The buffer address

in

width

Image width

in

height

Image height

in

format

Image format

in

lk

landmark parameters

in

stripe

stripe number (0=no stripe)

in

stripe_max

max nb of stripes

Returns

0

hal_inference_tflite_setup#

int hal_inference_tflite_setup ( vision_algo_dev_t ∗ dev )

Hal setup function for inference engine Tensorflow-Lite Micro.

Parameters

in/out

name

description

in

dev

vision algo device to register

Returns

error code (0: success, otherwise: failure)

hal_display_setup()

int hal_display_setup ( const char ∗ name, display_dev_t ∗ dev )

Register with a display device specified by name. If name is NULL, return error.

Parameters

in/out

name

description

in

name

display name

in

dev

display device to register

Returns

error code (0: success, otherwise: failure)

hal_camera_setup#

hal_camera_setup()

int hal_camera_setup ( const char ∗ name, camera_dev_t ∗ dev )

Register with a camera device specified by name. If name is NULL, return error.

Parameters

in/out

name

description

in

name

camera name

in

dev

camera device to register

Returns

error code (0: success, otherwise: failure)

hal_gfx_setup#

hal_gfx_setup()

int hal_gfx_setup ( const char ∗ name, gfx_dev_t ∗ dev )

Register with a graphic processing device specified by name.

If name is NULL, the first available graphic processing supported by Hw will be selected. The graphic device using CPU operations will be selected if name is not specified and if no graphic processing is available for the Hw.

Parameters

in/out

name

description

in

name

graphic processing device performing the image conversion

in

dev

graphic device to register

Returns

error code (0: success, otherwise: failure)

hal_img_decoder_setup#

int hal_img_decoder_setup ( const char ∗ name, vdec_dev_t ∗ dev )

Register with an image decoder device specified by name.

If name is NULL, the first available decoder supported by Hw will be selected. The decoder device using CPU operations will be selected if name is not specified and if no decoder is available for the Hw.

Parameters

in/out

name

description

in

name

image decoding device name

in

dev

decoder device to register

Returns

error code (0: success, otherwise: failure)

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