cdrtools (formerly cdrecord) creates home-burned CDs/DVDs with a CDR/CDRW/DVD/BluRay recorder. It works as a burn engine for several applications. It supports CD/DVD/BD recorders from many different vendors; all SCSI-3/mmc- and ATAPI/mmc-compliant drives should also work. Supported features include IDE/ATAPI, parallel port, and SCSI drives; audio CDs, data CDs, and mixed CDs; full multi-session support; CD-RWs, DVD-R/-RW, DVD+R/+RW, BD-R/BD-RE; and TAO, DAO, RAW, and human-readable error messages. cdrtools includes remote SCSI support and can access local or remote CD/DVD/BD writers.
pngcrush is an excellent batch-mode compression utility for PNG images. Depending on the application that created the original PNGs, it can improve the file size anywhere from a few percent to 40% or more (completely losslessly). The utility also allows specified PNG chunks (e.g. text comments) to be inserted or deleted, and it can fix incorrect gamma info written by Photoshop 5.0 as well as the erroneous iCCP chunk written by Photoshop 5.5.
Vobcopy copies DVD .vob files to hard disk (thanks to libdvdread), decrypting them on the way (if libdvdcss is installed) and merges them into 2 GB files (or larger) with the name extracted from the DVD. It checks for enough free space on the destination drive and compares the copied size to the size on DVD (in case something went wrong during the copying). It can also mirror a whole DVD video part and copy single files.
Cdrdao records audio/data CD-Rs in disk-at-once (DAO) mode based on a textual description of the CD contents (toc-file). Features include full control over length and contents of pre-gaps (pause areas between tracks). Pre-gaps may be completely omitted, e.g. for dividing live recordings into tracks. Control over sub-channel data like catalog numbers, copy, pre-emphasis, 2-/4-channel flags, ISRC code, and index marks are provided as well. GCDMaster is a Gnome GUI front-end that lets you import MP3 and WAV files, select track markers and cut/copy/paste audio snippets before burning.
The FAAC project includes the AAC encoder FAAC and decoder FAAD2. It supports several MPEG-4 object types (LC, Main, LTP, HE AAC, PS) and file formats (ADTS AAC, raw AAC, MP4), multichannel and gapless en/decoding as well as MP4 metadata tags. The codecs are compatible with standard-compliant audio applications using one or more of these profiles.
Speex is a patent-free compression format designed especially for speech. It is specialized for voice communications at low bit-rates in the 2-45 kbps range. Possible applications include Voice over IP (VoIP), Internet audio streaming, audio books, and archiving of speech data (e.g. voice mail).