avformatcloseinput

avformat_close_input is a function from FFmpeg’s libavformat library used to close an input format context that was previously opened with avformat_open_input or related calls. Its canonical name is avformat_close_input and its signature is void avformat_close_input(AVFormatContext **ps). The function takes the address of a pointer to an AVFormatContext and is responsible for freeing all resources associated with that input and for setting the pointer to NULL.

When invoked, avformat_close_input closes the underlying input (including any network or file IO), frees internal data structures such as streams and metadata, and releases the AVFormatContext itself. It ensures that resources allocated for demuxing, buffering, and format-specific state are correctly released, preventing memory leaks in applications that process media files or streams.

Usage generally follows opening the input, performing demuxing or stream analysis, and then cleaning up. A typical pattern is to declare an AVFormatContext pointer, call avformat_open_input to initialize it, and later call avformat_close_input to free resources and reset the pointer to NULL. After the call, the original pointer should be considered invalid until reinitialized.

Notes: avformat_close_input handles null and already-closed pointers gracefully; if ps or *ps is NULL, the function simply returns. This function is the recommended cleanup routine for input contexts created with FFmpeg’s demuxing APIs, ensuring that all associated resources are released in a safe and centralized manner.