AVFrame * frame = (AVFrame *)args;SS_Vdec_BufInfo *stVdecBuf = (SS_Vdec_BufInfo *)frame->opaque;

This code is casting a void pointer called "args" to an AVFrame pointer called "frame". It then casts the "opaque" field of the AVFrame to an SS_Vdec_BufInfo pointer called "stVdecBuf". The "opaque" field is a generic pointer that can be used to store custom data for the AVFrame. In this case, it is being used to store a structure of type SS_Vdec_BufInfo.

相关问题

解释SS_Vdec_BufInfo *stVdecBuf = (SS_Vdec_BufInfo *)frame->opaque;

这段代码是将一个指向AVFrame结构体的指针frame中的opaque成员强制转换为SS_Vdec_BufInfo类型的指针，并赋值给stVdecBuf变量。

具体来说，AVFrame结构体是FFmpeg中表示一帧音视频数据的数据结构，其中opaque成员是一个void指针，用于存储用户自定义的数据。而SS_Vdec_BufInfo是用户自定义的一个结构体类型，用于存储音视频解码时需要的一些信息，例如解码缓冲区的大小和地址等。

因此，这段代码的作用是将用户自定义的数据（即SS_Vdec_BufInfo类型的数据）与FFmpeg中表示音视频数据的数据结构（即AVFrame结构体）关联起来，以便在音视频解码时能够方便地获取解码缓冲区的相关信息。

AVFrame * frame = (AVFrame *)args;

This line of code declares a pointer variable named "frame" that points to an AVFrame structure. The value assigned to the pointer is the memory address stored in the variable "args", which is assumed to be a pointer to an AVFrame structure.

This code is typically used in a multi-threaded environment where the AVFrame structure needs to be passed as an argument to a function or method executed in a separate thread. By passing a pointer to the AVFrame structure, the function or method can access and modify the structure's data without needing to make a copy of it.