pngd_create_chn

Applicability

Product	Supported (√/x)
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas training products	x
Atlas inference products	√
Atlas 200I/500 A2 inference products	√

Function Usage

Creates a decoding channel based on the configured channel attributes.

Prototype

C Prototype

hi_s32 hi_mpi_pngd_create_chn(hi_pngd_chn chn, const hi_pngd_chn_attr *attr)

Python Function

ret = acl.himpi.pngd_create_chn(chn, attr)

Parameter Description

Parameter	Description
chn	Int, decoding channel ID. The value range of this parameter is [0, 128). The maximum number of channels is 128. NOTE: The restrictions on the number of channels are different based on the following Ascend virtual instance templates on the Atlas inference products: When the vir04_4c_dvpp template is used, the total number of channels is fixed at 128. When the vir04_3c_ndvpp template is used, the DVPP function is not used. Therefore, the total number of channels is 0. When other templates are used, Total number of channels = Allocation specification x 128. If the total number of channels is not an integer, round down the value. The restrictions on the number of channels are different based on the following Ascend virtual instance templates on the Atlas A2 training products/Atlas A2 inference products: When the vir12_3c_32g_m, vir10_3c_16g_m or vir10_3c_32g_m profile is used, the total number of channels is fixed to 128. When the vir12_3c_32g_nm, vir10_3c_16g_nm or vir10_3c_32g_nm template is used, the DVPP function is not used. Therefore, the total number of channels is 0. When other templates are used, Total number of channels = Allocation specification x 128. If the total number of channels is not an integer, round down the value. You can run the npu-smi info -t template-info command on the server where Ascend AI Processor is installed to view the computing power specifications of the Ascend virtual instance in each scenario.
attr	Dict, dictionary of the decoding channel attributes. For details, see hi_pngd_chn_attr.

Parameter

Description

chn

Int, decoding channel ID.

The value range of this parameter is [0, 128). The maximum number of channels is 128.

NOTE:

The restrictions on the number of channels are different based on the following Ascend virtual instance templates on the Atlas inference products:

When the vir04_4c_dvpp template is used, the total number of channels is fixed at 128.
When the vir04_3c_ndvpp template is used, the DVPP function is not used. Therefore, the total number of channels is 0.
When other templates are used, Total number of channels = Allocation specification x 128. If the total number of channels is not an integer, round down the value.

The restrictions on the number of channels are different based on the following Ascend virtual instance templates on the Atlas A2 training products/Atlas A2 inference products:

When the vir12_3c_32g_m, vir10_3c_16g_m or vir10_3c_32g_m profile is used, the total number of channels is fixed to 128.
When the vir12_3c_32g_nm, vir10_3c_16g_nm or vir10_3c_32g_nm template is used, the DVPP function is not used. Therefore, the total number of channels is 0.
When other templates are used, Total number of channels = Allocation specification x 128. If the total number of channels is not an integer, round down the value.

You can run the npu-smi info -t template-info command on the server where Ascend AI Processor is installed to view the computing power specifications of the Ascend virtual instance in each scenario.

attr

Dict, dictionary of the decoding channel attributes. For details, see hi_pngd_chn_attr.

Return Value Description

Return Value	Description
ret	Int, error code. 0: success. Other values: failures. For details, see PNGD Return Codes.

Restrictions

The channel ID of a single device cannot exceed the maximum channel ID.
If attr is left empty, the error code HI_ERR_PNGD_NULL_PTR is returned.
Before this API call, ensure that a channel has not been created yet or has been destroyed. Otherwise, a failure is returned.
If the system memory is insufficient, the error code HI_ERR_PNGD_NO_MEM is returned. In this case, you can expand the OS memory as needed.
When a setting in the channel attributes pointed by attr exceeds the decoding capability set, the error code HI_ERR_PNGD_ILLEGAL_PARAM is returned.

Reference

For the API call sequence, see Functions and Restrictions.

Parent topic: PNGD APIs