When XVCD ( eXtended Video CD) is a non-standard Video CD ( VCD) for storing video data on a normal CD -ROM or CD -R ( W), which provides a longer playing time.
A normal VCD is encoded in MPEG -1 process with constant bit rate (CBR ), ie, all scenes are with default 1150 kbit / s encoding the video stream; regardless of whether it is a fast, motion- rich scene or largely static still image.
The extended- VCD is MPEG-1 encoding, variable bit rate ( VBR), i.e., the bit rate is increased in quick scenes to about 2000 Kbit / s, but it may in quiet scenes up to 300 kbit / s fall. It will also work with a modified quantization matrix, and - in order to obtain more space - the bit rate of the audio track is reduced, and, if necessary, in addition, the GOP ( Group of Pictures) extended.
With these changes, a feature film by about 2 hours length to be stored on a single CD.
In addition to VCD, there are other options for resolutions from 352 × 288 up to 720 × 576 pixels, and in the PAL and NTSC television standards, which can be found under the heading " eXtended ". Colloquially be XVCD for MPEG1, VCD resolution and 1- CD file size for a video file has prevailed.
Through close alignment (here " variable bit rate " ) to the SVCD standard can play most DVD players XVCDs in the VCD resolution (352 × 288 PAL or 352 × 240 NTSC). Experience has shown that especially "cheap player " in the lower ( consumer ) price range here less (!) Have problems. History comes this extension of the format from the Asian region to license-free to store complete movies to CD and play on the easiest video players can.
XVCD variants ( XVCD MVCD, KVCD, AVCD ... ) essentially differ by resolution, bit rate, GOP and the quantization matrix used. It should possibly be paid to possible compatibility issues, for example in the area of "permitted resolutions " or to extreme GOP values . MVCD / KVCD for example, are primarily CD formats (VCD). The DVD-Video specification is clearly more severe and possibly lead to playback errors. This is very different depending on the DVD player model.
Development of the format
Designed and invented was the XVCD format from Thomas Steg in Karlsruhe in February 2000.
Background of the development was the first availability of Far Eastern cheap DVD players that were not limited to the reproduction pressed DVD and Video CD, but the first time could also play home-burned video CDs, MP3 files and pictures. One of the first nationwide commercially published multi-format player was the (predominantly composed of PC components ) Yamakawa AVPhile 713/715. The unit took it not as accurate with the playing of non-compliant CDs while other standard DVD player refused even fired blanks immediately. Due to the growing fan base of the player arose the desire to burn higher-resolution video material and own and play.
However, the biggest hurdle was the refusal at the time of popular burning programs not being able to burn CD- compliant video streams. In lengthy search of all burning programs on the market succeeded Thomas Steg remove this barrier by replacing a certain older DLL of the CD burning program NTI CDMaker so that each non -compliant Video CD format could be burned. Even a mix of MPEG2 stream, burned as MPEG1 Video CD was possible ( = XSVCD - eXtended Super Video CD).
The approach to making a XVCD was made after long test series for the first time in spring 2000 in DVDBoard.de to the public and the newly crowned Video CD standard awarded the designation XVCD ( eXtended Video CD). From there, the creation of a XVCD with better image quality and higher data rate distributed soon to the whole world. Manufacturer subsequently published devices advertised generous with the support of the standard XVCD journals written instructions for creating such disks and even updates of popular burning programs were finally non- compliant video files.
Since using the MPEG1 format with high data rates, but overextended many standard players and the format SVCD slowly became widespread on MPEG2 base, as well as playback of DivX AVI files to create / burn them reamed video files completed with the time and is no longer used nowadays. Likewise repressed the availability of DVD burners for home users use / use self-created video CDs.