Function: dvpp_png_decode_async

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

Decodes PNG images. This API is asynchronous. For details about the supported formats, see Table 1.

**Table 1** Supported formats
Function	Input Image Format	Output Image Format
Set the output format to PIXEL_FORMAT_UNKNOWN. That is, the output image has the same format as the input image.	RGB/GRAY	RGB
Set the output format to PIXEL_FORMAT_UNKNOWN. That is, the output image has the same format as the input image.	RGBA/AGRAY	RGBA
Set the output format to PIXEL_FORMAT_RGB_888. That is, the input image is converted to a specified format for output.	RGB/RGBA/GRAY/AGRAY	RGB

Prototype

C Prototype

        
             aclError acldvppPngDecodeAsync(acldvppChannelDesc *channelDesc,const void *data,uint32_t size,acldvppPicDesc *outputDesc,aclrtStream stream)

Python Function

        
             ret = acl.media.dvpp_png_decode_async(dvpp_channel_desc, data, size, output_desc, stream)

Parameter Description

Parameter	Description
dvpp_channel_desc	Int, pointer address of the channel description. It must be the same as dvpp_channel_desc passed to the acl.media.dvpp_create_channel call.
data	Int, pointer address of the memory address of the input image.
size	Int, actual size of the input image, in bytes.
output_desc	Int, pointer address of the output image information. When it is used as an input, the user needs to: Call acl.media.dvpp_create_pic_desc to create an image description. Call acl.media.dvpp_set_pic_desc series to set the output buffer address, buffer size, and image format. Call acl.media.dvpp_png_predict_dec_size to predict the output buffer size. Call acl.media.dvpp_png_get_image_info to obtain the original PNG image information (such as the width and height). For details about the requirements on the output image format and output buffer, see Functions and Restrictions. When it is used as an output, the user can obtain the decoded output from the buffer address.
stream	Int, stream.

Return Value Description

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

Restrictions

This API is asynchronous. The API call delivers a task rather than executes a task. After this API is called, call the synchronization API (for example, acl.rt.synchronize_stream) to ensure that the task is complete.

Reference

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

Parent topic: PNGD