This tutorial is very outdated, eg. `AVPicture`, which is used throughout, is completely deprecated and removed from the library, so you will simply encounter linker errors trying to follow this tutorial and will have to replace every `avpicture` call made in the tutorial. Also, `avcodec_decode_video2` is deprecated and you have to use `avcodec_send_packet` and `avcodec_receive_frame`.

The FFmpeg libraries are possibly the worst thing I have ever worked with in my life. I have never been more afraid to use a library than this. FFmpeg libraries randomly break themselves, so if you find an answer from a few years ago, chances are it's useless. Want to free an AVPacket? `av_free_packet` is deprecated,. You can use `av_packet_unref` (but there's _also_ a function named `av_packet_free` that doesn't do quite the same thing).

Most questions on Stack Overflow or related platforms have no replies, the library is not well-documented (requiring you to always read the massive source code and the API reference). In addition, some things are outright undocumented and missing from the API reference or documentation and require reading often-unfinished conversations on the mailing lists with no solution. The FFmpeg libraries have very little error handling, which means if you're a bad C developer like me you are required to recompile FFmpeg with debugging information unstripped so you can trace segfaults in gdb.

https://github.com/leandromoreira/ffmpeg-libav-tutorial/ is a better and more up-to-date tutorial than this one.