pngd_create_chn

Applicability

Product	Supported/Unsupported
Atlas 350 Accelerator Card	√
Atlas A3 training product/Atlas A3 inference product	√
Atlas A2 training product/Atlas A2 inference product	√
Atlas training product	x
Atlas inference product	√
Atlas 200I/500 A2 inference product	√

Description

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)

Parameters

Parameter	Description
chn	Int, decoding channel ID. The value range of this parameter is [0, 128). The maximum number of channels is 128. NOTE: For the Atlas inference product, in the Ascend virtual instance scenario, different Ascend virtual instance templates impose different restrictions on the number of channels. 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. For the Atlas A2 training product/Atlas A2 inference product, in the Ascend virtual instance scenario, different Ascend virtual instance profiles impose different restrictions on the number of channels: 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 at 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. To view the computing power specifications of Ascend virtual instances in different scenarios, run the npu-smi info -t template-info command on the server where AI processor is installed.
attr	Dict, dictionary of 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:

For the Atlas inference product, in the Ascend virtual instance scenario, different Ascend virtual instance templates impose different restrictions on the number of channels.

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.

For the Atlas A2 training product/Atlas A2 inference product, in the Ascend virtual instance scenario, different Ascend virtual instance profiles impose different restrictions on the number of channels:

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 at 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.

To view the computing power specifications of Ascend virtual instances in different scenarios, run the npu-smi info -t template-info command on the server where AI processor is installed.

attr

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

Return Value

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

Restrictions

The channel ID of a single device must not be greater than 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