3.4 Media Module API Manual#
Attention
This module has undergone significant changes since firmware version V0.7. If you are using firmware before V0.7, please refer to the old version documentation.
1. Overview#
The media module of the CanMV K230 platform is a software abstraction layer mainly used to encapsulate the media data link and media buffer operations of the CanMV K230 platform.
2. API Introduction#
The media module of the CanMV K230 platform provides a static class MediaManager, which contains the methods described in the following sections.
2.1 init#
Description
After the user completes the configuration of the buffer, call the init method to initialize. This method must be executed last.
Syntax
MediaManager.init()
Parameters
Parameter Name |
Description |
Input / Output |
|---|---|---|
None |
Return Values
Return Value |
Description |
|---|---|
None |
2.2 deinit#
Description
This method is used to destroy all requested buffers.
Syntax
MediaManager.deinit()
Parameters
Parameter Name |
Description |
Input / Output |
|---|---|---|
None |
Return Values
Return Value |
Description |
|---|---|
None |
2.3 _config#
Description Used to configure the media buffer.
Syntax
MediaManager._config(config)
Parameters
Parameter Name |
Description |
Input / Output |
|---|---|---|
config |
Media buffer config parameters |
Input |
Return Values
Return Value |
Description |
|---|---|
0 |
Success |
Non-zero |
Failure, the value is [error code] |
Notes
This method is only for internal use when encapsulating this module interface by various media submodules (e.g., camera, video encoding, etc.) of the CanMV K230 platform. Upper-layer application developers do not need to pay attention to it.
2.4 link#
Description
This method is used to establish connections between channels of different modules to achieve automatic data flow, without manual operation by the user. The Display module can automatically create a link through bind_layer.
Syntax
MediaManager.link(src=(mod,dev,chn), dst=(mod,dev,chn))
Parameters
Parameter Name |
Description |
Input / Output |
|---|---|---|
None |
Return Values
Return Value |
Description |
|---|---|
|
Notes
This method is only for internal use when encapsulating this module interface by various media submodules (e.g., camera, video encoding, etc.) of the CanMV K230 platform. Upper-layer application developers do not need to pay attention to it.
2.5 Buffer Management#
2.5.1 get#
Description
After _config is completed, the user can obtain the buffer through the MediaManager.Buffer.get method. This method must be called after init is executed.
Syntax
MediaManager.Buffer.get(size)
Parameters
Parameter Name |
Description |
Input / Output |
|---|---|---|
size |
Requested |
Input |
Return Values
Return Value |
Description |
|---|---|
|
Success |
2.5.2 Release Memory#
Description
The user can manually release the obtained buffer.
Syntax
buffer.__del__()
Parameters
Parameter Name |
Description |
Input / Output |
|---|---|---|
None |
Return Values
Return Value |
Description |
|---|---|
None |
3. Data Structure Description#
The media module of the CanMV K230 platform includes the following data definitions.
3.1 Media Module ID#
Description
The currently defined media module IDs of the CanMV K230 platform. Users need to set the corresponding module ID when creating media links.
Definition
# CanMV K230 Media Module Definitions
AUDIO_IN_MOD_ID = K_ID_AI # Audio input device module
AUDIO_OUT_MOD_ID = K_ID_AO # Audio output device module
AUDIO_ENCODE_MOD_ID = K_ID_AENC # Audio encoding device module
AUDIO_DECODE_MOD_ID = K_ID_ADEC # Audio decoding device module
CAMERA_MOD_ID = K_ID_VI # Camera device module
DISPLAY_MOD_ID = K_ID_VO # Display device module
DMA_MOD_ID = K_ID_DMA # DMA device module
DPU_MOD_ID = K_ID_DPU # DPU device module
VIDEO_ENCODE_MOD_ID = K_ID_VENC # Video encoding device module
VIDEO_DECODE_MOD_ID = K_ID_VDEC # Video decoding device module
3.2 Media Device ID#
Description
The currently defined media device IDs of the CanMV K230 platform. Users need to set the corresponding device ID when creating media links.
Definition
# Audio Device ID Definitions
# TODO
# Camera Device ID Definitions
CAM_DEV_ID_0 = VICAP_DEV_ID_0
CAM_DEV_ID_1 = VICAP_DEV_ID_1
CAM_DEV_ID_2 = VICAP_DEV_ID_2
CAM_DEV_ID_MAX = VICAP_DEV_ID_MAX
# Display Device ID Definitions
DISPLAY_DEV_ID = K_VO_DISPLAY_DEV_ID
# DMA Device ID Definitions
# TODO
# DPU Device ID Definitions
# TODO
# Video Encoding Device ID Definitions
# TODO
# Video Decoding Device ID Definitions
# TODO
3.3 Media Device Channel ID#
Description
The currently defined media device channel IDs of the CanMV K230 platform. Users need to set the corresponding device channel ID when creating media links.
Definition
# Audio Channel ID Definitions
# TODO
# Camera Channel ID Definitions
CAM_CHN_ID_0 = VICAP_CHN_ID_0
CAM_CHN_ID_1 = VICAP_CHN_ID_1
CAM_CHN_ID_2 = VICAP_CHN_ID_2
CAM_CHN_ID_MAX = VICAP_CHN_ID_MAX
# Display Channel ID Definitions
DISPLAY_CHN_ID_0 = K_VO_DISPLAY_CHN_ID0
DISPLAY_CHN_ID_1 = K_VO_DISPLAY_CHN_ID1
DISPLAY_CHN_ID_2 = K_VO_DISPLAY_CHN_ID2
DISPLAY_CHN_ID_3 = K_VO_DISPLAY_CHN_ID3
DISPLAY_CHN_ID_4 = K_VO_DISPLAY_CHN_ID4
DISPLAY_CHN_ID_5 = K_VO_DISPLAY_CHN_ID5
DISPLAY_CHN_ID_6 = K_VO_DISPLAY_CHN_ID6
# DMA Channel ID Definitions
# TODO
# DPU Channel ID Definitions
# TODO
# Video Encoding Channel ID Definitions
# TODO
# Video Decoding Channel ID Definitions
# TODO
Related Data Types and Interfaces#
None
4. Example Program#
Example
from media.media import *
config = k_vb_config()
config.max_pool_cnt = 1
config.comm_pool[0].blk_size = 1024
config.comm_pool[0].blk_cnt = 1
config.comm_pool[0].mode = VB_REMAP_MODE_NOCACHE
ret = MediaManager._config(config)
if not ret:
raise RuntimeError("Buffer configuration failed.")
MediaManager.init()
buffer = MediaManager.Buffer.get(1024)
print(buffer)
buffer.__del__()
MediaManager.deinit()