Function: dvpp_create_channel

Applicability

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

Function Usage

Creates an image processing channel, which is reusable. After being destroyed, the channel is no longer available.

Prototype

C Prototype

        
             aclError acldvppCreateChannel(acldvppChannelDesc *channelDesc)

Python Function

        
             ret = acl.media.dvpp_create_channel(dvpp_channel_desc)

Parameter Description

Parameter	Description
dvpp_channel_desc	Int, pointer address of the channel description. The input data is created by calling acl.media.dvpp_create_channel_desc. In addition, for the Atlas inference products , you need to call dvpp_set_channel_desc_mode to specify the channel mode in the channel description and specify the function to be implemented by the image data processing channel. Currently, the VPC, JPEGD, PNGD, and JPEGE functions are supported. Unless the channel mode is specified, the system creates all these modes of channels by default, which may occupy more channel resources. (For details about the limit on the number of channels, see General Description.)

Parameter

Description

dvpp_channel_desc

Int, pointer address of the channel description. The input data is created by calling acl.media.dvpp_create_channel_desc.

In addition, for the Atlas inference products , you need to call dvpp_set_channel_desc_mode to specify the channel mode in the channel description and specify the function to be implemented by the image data processing channel. Currently, the VPC, JPEGD, PNGD, and JPEGE functions are supported. Unless the channel mode is specified, the system creates all these modes of channels by default, which may occupy more channel resources. (For details about the limit on the number of channels, see General Description.)

Return Value Description

Return Value	Description
ret	Int, error code: 0 on success; else, failure.

Restrictions

Channels are thread-unsafe, that is, a separate channel should be created for each thread.
Do not use a channel concurrently across streams.
acl.media.dvpp_create_channel creates a stream internally by calling acl.rt.create_stream once. The stream is used for a channel creation task, and is automatically destroyed when the task is complete.
When creating a channel, observe the restrictions of acl.rt.create_stream, such as the number of streams.

Reference

For details about the API call sequence and example, see Media Data Processing V1.

Parent topic: VPC/JPEGD/JPEGE/PNGD Channel