aclvdecSendFrame

Description

Feeds a stream (the input buffer, as well as the output buffer) to the decoder for decoding. This API is asynchronous.

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, aclrtSynchronizeStream) to ensure that the task is complete.
Ensure that a channel has been created. Otherwise, an error code is returned.
A stream must be fed in frame mode, which means that a complete frame must be fed in every call to this API.
It is not allowed to send an empty stream packet with eos = 0 (stream length is 0 or stream address is empty).
After all streams are sent, a frame with eos = 1 can be sent, indicating the end of the current stream file. After the EOS frame is fed to the decoder, this API call returns the decoding result only after all received frames are decoded and the user-defined callback function handling is complete.
Due to stream exception or decoding timeout, the aclvdecSendFrame API may fail to send frames or the EOS frame. You are advised to obtain the return code of this API when writing code. If this API fails to be called, handle the exception.
aclrtLaunchCallback is encapsulated in aclvdecSendFrame to insert a callback function that needs to be executed to the stream. When you implement the VDEC function, aclrtLaunchCallback does not need to be called separately.

Prototype

aclError aclvdecSendFrame(aclvdecChannelDesc *channelDesc,

acldvppStreamDesc *input,

acldvppPicDesc *output,

aclvdecFrameConfig *config,

void *userData)

Parameters

Parameter	Input/Output	Description
channelDesc	Input	Pointer to the channel description. Must be the same as the channelDesc argument passed to the aclvdecCreateChannel call. Call aclvdecSetChannelDesc series to set the decoding channel description, including the channel ID, thread, callback function, and video coding protocol. NOTE: For the Atlas 200/300/500 Inference Product and Atlas Training Series Product , due to software restrictions, it is not allowed to set the channel description by using the aclvdecSetChannelDescRefFrameNum call. Doing so results in an error return.
input	Input	Pointer to the input stream description. The user needs to allocate input buffer in advance. Call acldvppCreateStreamDesc to create a stream description, and call acldvppSetStreamDesc series to set the stream description (such as the buffer address of stream data). The input stream format is subject to the format set in the channel description. The acldvppSetStreamDescFormat call to set the input stream format is invalid. For details about requirements on the resolution and format of the input video stream, see Functions and Restrictions.
output	Input/Output	Pointer to the output image description. The user needs to allocate output buffer in advance. When output is used as an input, the user needs to: Call acldvppCreatePicDesc to create an image description. Call acldvppSetPicDesc series to set the data buffer, buffer size, width, height, and format of the output image. The output width and height correspond to four parameters: width, height, widthStride, and heightStride. When the width is less than 16, widthStride must be a multiple of 32 instead of 16. If none of the four parameters are set, the input width and height are used. If only some of the four parameters are set, the API returns an error. If the output image format is set in this API call, the setting is applied. Otherwise, the setting in the channel description is applied. For details about the requirements on the output image format, see Functions and Restrictions. When output is used as an output, the user must obtain the decoding output by calling the acldvppGetPicDesc series in the callback function. For an interlaced stream, two fields are transmitted every frame. It is normal that one of two transmitted fields has no decoding output and the error code ERR_DECODE_NOPIC = 0x20000 is returned. The decoding output of the interlaced stream is stored in the output buffer corresponding to the odd field.
config	Input	Pointer to the decoding configuration. This parameter is reserved and can be set to NULL currently.
userData	Input	Pointer to the user-defined data. If you want to obtain the sequence number of the decoded frame, define the userData parameter. Then, the sequence number can be passed to the VDEC callback function to determine the frame to be processed.

Returns