DirectFB is a thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, an integrated windowing system with support for translucent windows and multiple display layers on top of the Linux framebuffer device. It is a complete hardware abstraction layer with software fallbacks for every graphics operation that is not supported by the underlying hardware.
v4l-utils is a collection of various video4linux (V4L) and DVB utilities. libv4l is an accompanying collection of libraries that adds a thin abstraction layer on top of video4linux2 (V4L2) devices. The purpose of this layer is to make it easy for application writers to support a wide variety of devices without having to write separate code for different devices in the same class. It consists of 3 different libraries. libv4lconvert offers functions to convert from any (known) pixel format to V4l2_PIX_FMT_BGR24 or V4l2_PIX_FMT_YUV420. libv4l1 offers the (deprecated) v4l1 API on top of v4l2 devices, independent of the drivers for those devices supporting v4l1 compatibility (which many v4l2 drivers do not). libv4l2 offers the v4l2 API on top of v4l2 devices, while adding support for the application transparent libv4lconvert conversion where necessary.
Quicktime for Linux lets you read and write Quicktime movies using several codecs. There are many Quicktime libraries for Linux; this one emphasizes reliability and accuracy while not stressing economy. Also included are frontends to several of the codecs which don't require Quicktime encapsulation, header dump, chunk extraction, and recovery tools.
pHash is an implementation of various perceptual hashing algorithms. A perceptual hash is a fingerprint of a multimedia file derived from various features from its content. Unlike cryptographic hash functions that rely on the avalanche effect of small changes in input leading to drastic changes in the output, perceptual hashes are "close" to one another if the features are similar. Potential applications include copyright protection, similarity searches for media files, or even digital forensics.
The GNU Compact Disc Input and Control library encapsulates CD-ROM reading and control for applications wishing to be oblivious to the OS- and device-dependent properties of a CD-ROM. It provides an API for access to SCSI-MMC (multimedia commands) and support for CD image types like BIN/CUE, cdrdao's TOC, and Nero's NRG, which gives applications using the library the ability to read disc images as though they were CDs. ISO-9660 filesystem support is included, as are utility programs for displaying CD and CD-ROM drive information, reading the blocks of a CD, and extracting files from an ISO-9660 filesytem image. cdparanoia is also included.