hi_mpi_venc_start_chn

Applicable Products

Product	Supported
Ascend 950PR / Ascend 950DT	√
Atlas A3 training products / Atlas A3 inference products	√
Atlas A2 training products / Atlas A2 inference products	√
Atlas 200I/500 A2 inference products	√
Atlas inference products	√
Atlas training products	☓

Function

Enables an encoding channel to start receiving source images. The encoding channel automatically stops receiving images when the specified receive limit is reached.

Prototype

hi_s32 hi_mpi_venc_start_chn(hi_venc_chn chn, const hi_venc_start_param *recv_param)

Parameters

Parameter	Input/Output	Description
chn	Input	Encoding channel ID. Ascend 950PR / Ascend 950DT : The value range of the encoding channel ID is [0, 256). The maximum number of JPEGE channels is 256. Atlas A3 training products / Atlas A3 inference products : The value range of the encoding channel ID is [0, 256). The maximum number of JPEGE channels is 256. Atlas A2 training products / Atlas A2 inference products : The value range of the encoding channel ID is [0, 256). The maximum number of JPEGE channels is 256. Atlas 200I/500 A2 inference products : The value range of this parameter is [0, 128). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 128. Atlas inference products : The value range of this parameter is [0, 256). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 256.
recv_param	Input	Pointer to the received picture parameter. This pointer indicates the number of frames to be received.

Parameter

Input/Output

Description

chn

Input

Encoding channel ID.

Ascend 950PR / Ascend 950DT : The value range of the encoding channel ID is [0, 256). The maximum number of JPEGE channels is 256.

Atlas A3 training products / Atlas A3 inference products : The value range of the encoding channel ID is [0, 256). The maximum number of JPEGE channels is 256.

Atlas A2 training products / Atlas A2 inference products : The value range of the encoding channel ID is [0, 256). The maximum number of JPEGE channels is 256.

Atlas 200I/500 A2 inference products : The value range of this parameter is [0, 128). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 128.

Atlas inference products : The value range of this parameter is [0, 256). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 256.

recv_param

Input

Pointer to the received picture parameter. This pointer indicates the number of frames to be received.

Returns

0: success
Other values: failure. For details, see VENC/JPEGE Return Codes.

Restrictions

Ensure that a channel has been created. Otherwise, the error code HI_ERR_VENC_UNEXIST is returned.
If the number of frames to be received is set to -1, the number of frames is not specified.
If a channel has started receiving images, calling this API again to specify its frame receive limit before the channel has stopped receiving images will return an unallowed operation.
If a channel has started to receive images, you can call this API again without specifying the number of frames to be received before the channel stops receiving images.
The encoder starts images receiving and encoding only after this API call.

Reference

For details about the API call sequence and example, see JPEGE and VENC.

Parent topic: Video Encoder (VENC) and JPEG Encoder (JPEGE)