avformat_alloc_context returns null

Question

I'm currently trying to play a video from a stream through FFMPEG. I'm currently stuck however on a particular section: regardless of what I do, avformat_alloc_context(); seems to return null.

Would anyone perhaps know what might be going on?

I've been referencing the link below: Reading a file located in memory with libavformat

Answer 1

1 Call av_register_all() fisrt.(Initialize libavformat and register all the muxers, demuxers and protocols)

2 Check code like avformat_open_input(&pFormatCtx, file_name, NULL, NULL) ,did that return not-0.If that,pFormatCtx return nil;