hi_mpi_vi_get_chn_frame

The Atlas 200/300/500 Inference Product does not support this API.

The Atlas Training Series Product does not support this API.

Description

Obtains video image information from a specified VI channel. The image information includes the width, height, pixel format, timestamp, and addresses of YUV components.

Restrictions

This API can be called only after a VI pipe is created by calling hi_mpi_vi_create_pipe.

Images can be obtained through this API only when the channel is enabled and the queue depth is not 0.
The images can be released after being obtained for multiple times. However, you are advised to call the release API each time after you call this API.
The obtained address information comes from the temporary buffer used in the module. Call hi_mpi_vi_release_chn_frame to release the buffer after using it.
You can wait for readable image information in select or epoll mode by calling hi_mpi_vi_get_chn_fd. After video input data is available, obtain images by calling hi_mpi_vi_get_chn_frame in non-blocking mode.

Prototype

hi_s32 hi_mpi_vi_get_chn_frame(hi_vi_pipe vi_pipe, hi_vi_chn vi_chn, hi_video_frame_info *frame_info, hi_s32 milli_sec)

Parameters

Parameter	Input/Output	Description
vi_pipe	Input	Pipe ID. Value range: [0, 12)
vi_chn	Input	VI channel ID. Value range: [0, 1)
frame_info	Input	Structure of the VI frame information.
milli_sec	Input	Timeout parameter. The options are as follows: -1: blocking mode. In this mode, the program waits until images are obtained. 0: non-blocking mode > 0: timeout interval (ms). If no image is obtained within the configured timeout interval, timeout occurs.

Returns

0: success
Other values: failure. For details, see VI Return Codes.

Parent topic: VI