Function: dvpp_png_decode_async

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)
Function Usage	Asynchronous API for decoding PNG images. For details about the supported formats, see Table 1.
Input Description	dvpp_channel_desc: int, pointer address of the channel description. It must be the same as the dvpp_channel_desc argument 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 this argument 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 this argument is used as an output, the user can obtain the decoding output from the buffer address. stream: int, stream.
Return Value	ret: int, error code. 0 indicates success. Other values indicate 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.

**Table 1** Supported formats
Function	Input Format	Output 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

Parent topic: PNGD