cDVD ("Compact DVD") discs, also known asmini-DVD[1] discs (not to be confused with8 cm DVDs), are regulardata CDs that containMPEG-2 orMPEG-1 video structured in accordance with theDVD-Video specifications (such as a VIDEO_TS directory containing properly authored IFO/BUP and VOB files, typically on aMode 1 data track formatted with theUDF 1.02 filesystem).[2]
In the early 2000s, CD recorders and their discs were significantly more available and inexpensive than DVD-R equipment, promoting demand for miniDVD; however, DVD-Video content on other media does not conform to specifications.
When using full resolution video and a singleAC-3 soundtrack at typical medium quality encoding settings, a 74 minute (650 MB) CD-R can hold approximately 10[3] to 15 minutes of material, increasing to about 45 minutes at rather lower quality.[4]
By using non-standard resolutions, longGOPs, moreB-frames, and high-compressionquantization matrices, it is possible to store up to 2 hours of video with audio and subtitles on a regular 80-minute CD.[citation needed]
Until 2003, few standalone DVD players supported the format, due to firmware limitations and/or not having drives capable of reading a CD atthe 9x rate needed to keep up with the maximum bitrate allowed in DVD-Video content,[2][5] but today, many models contain drives similar to those used on desktop computers, and more versatilefirmware as well, so that the proper playback of compact DVDs is often supported, but rarely documented (especially in North America and Europe).