hi_vi_chn_attr

Description

Defines the attributes of a VI channel.

Prototype

typedef struct {
    hi_size              size;
    hi_pixel_format      pixel_format;
    hi_dynamic_range     dynamic_range;
    hi_video_format      video_format;
    hi_compress_mode     compress_mode;
    hi_u32               depth;
    hi_frame_rate_ctrl   frame_rate_ctrl;
    hi_u32               reserved[10];
} hi_vi_chn_attr;

Members

Member	Description
size	Target image size. It is a static attribute. That is, it cannot be changed after being set when a channel is created. This member must be configured, and the size must be within the range supported by the VI module. For details about the range, see Restrictions. The channel does not support image scaling. The channel size must be the same as the value of size configured in the pipe attributes.
pixel_format	Pixel format of the target image It is a static attribute. That is, it cannot be changed after being set when a channel is created. When the DIS or LDC function is disabled, the supported pixel formats are HI_PIXEL_FORMAT_YVU_SEMIPLANAR_422, HI_PIXEL_FORMAT_YVU_SEMIPLANAR_420 and HI_PIXEL_FORMAT_YUV_400. When the DIS or LDC is enabled, the supported pixel formats are HI_PIXEL_FORMAT_YVU_SEMIPLANAR_420 and HI_PIXEL_FORMAT_YUV_400.
dynamic_range	Dynamic range of the target image. It is a static attribute. That is, it cannot be changed after being set when a channel is created.
video_format	Target image or video format of the target image. The current version supports only the HI_VIDEO_FORMAT_LINEAR format.
compress_mode	Compression mode of the target image. It is a static attribute. That is, it cannot be changed after being set when a channel is created. It is not supported by the current version.
depth	Depth of the user picture queue. It is a static attribute. That is, it cannot be changed after being set when a channel is created. Value range: [0, 8]
frame_rate_ctrl	Frame rate control
reserved	Reserved. To ensure compatibility in later versions, use the memset struct for resetting and initialization. Do not explicitly access the reserved field in the code.

In the current version, the VI channel does not support scaling. Therefore, ensure that the size in the channel attribute is the same as that in the pipe attribute.
Set a proper depth value based on the actual load and jitter. The actual number of memory blocks allocated internally is calculated as follows: depth in the depth - hi_vi_frame_dump_attr attribute of the hi_vi_pipe_attr attribute when the hi_mpi_vi_enable_chn API is called to enable the channel + depth value in the chn attribute. Therefore, you are advised to ensure that the pipe dump attributes have been configured before enabling a channel.

Parent topic: VI