Here is a list of all modules:
[detail level 1234]
 ASS styles
 ASS functions
 end of Dialogue Event
 libavcodecEncoding/Decoding Library
 Frame parsing
 Native Codecs
 External library wrappers
 Hardware Accelerators bridge
 send/receive encoding and decoding API overviewThe avcodec_send_packet()/avcodec_receive_frame()/avcodec_send_frame()/ avcodec_receive_packet() functions provide an encode/decode API, which decouples input and output
 Core functions/structures.
 Utility functions
 Pixel formatsFunctions for working with pixel formats
 FFT functions
 Bitstream filters
 AVPacketTypes and functions for working with AVPacket
 libavdeviceSpecial devices muxing/demuxing library
 libavfilterGraph-based frame editing library
 Buffer sink API
 Buffer sink accessorsGet the properties of the stream
 Buffer source API
 libavformatI/O and Muxing/Demuxing Library
 DemuxingDemuxers read a media file and split it into chunks of data (packets). A packet contains one or more encoded frames which belongs to a single elementary stream. In the lavf API this process is represented by the avformat_open_input() function for opening a file, av_read_frame() for reading a single packet and finally avformat_close_input(), which does the cleanup
 MuxingMuxers take encoded data in the form of AVPackets and write it into files or other output bytestreams in the specified container format
 I/O Read/Write
 Native Demuxers
 External library wrappers
 I/O Protocols
 Public Metadata API
 Core functions
 Utility functions
 RIFF FourCCsGet the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the following code:
 libavutilCommon code shared across all FFmpeg libraries
 Crypto and Hashing
 Hash Functions
 Colorspace Utility
 String Manipulation
 Memory Management
 Alignment MacrosHelper macros for declaring aligned variables
 Function AttributesFunction attributes applicable to memory handling functions
 Heap ManagementFunctions responsible for allocating, freeing, and copying memory
 Dynamic ArrayUtilities to make an array grow when needed
 Miscellaneous FunctionsOther functions related to memory allocation
 Data Structures
 AVDictionarySimple key:value store
 Video related
 Display transformation matrix functions
 Spherical video mapping
 Stereo3D types and functions
 Audio related
 Audio FIFO Buffer
 Audio channel masksA channel layout is a 64-bits integer with a bit set for every channel. The number of bits set must be equal to the number of channels. The value 0 means that the channel layout is not known
 Audio channel layouts
 Audio downmix metadata
 Audio sample formatsAudio sample format enumeration and related convenience functions
 Samples manipulationFunctions that manipulate audio samples
 Error Codes
 Logging Facility
 Logging Constants
 Preprocessor String Macros
 Library Version Macros
 Image relatedAVPicture types, pixel formats and basic image planes manipulation
 Version and Build diagnosticsMacros and function useful to check at compiletime and at runtime which version of libavutil is in use
 Media TypeMedia Type
 Device context creation flagsAVHWFramesContext.hwctx is currently not used
 libpostprocVideo postprocessing library
 libswresampleAudio resampling, sample format conversion and mixing library
 libswscaleColor conversion and scaling library