AVCREC

AVCREC is a format for recording and playback of high definition video in BDAV (Blu-ray Audio/Visual) format using conventional DVD recordable discs as recording media. Presently AVCREC is tightly integrated with ISDB broadcast standard and is not marketed outside Japan.
Overview.
AVCREC was defined in 2007 as the means of recording of high definition ISDB broadcasts on existing DVD recordable discs. Using widespread DVDs offers consumers an immediate economical option for HD content storage on DVDs.
AVCREC is a more economical and simple version of Blu-ray video adapted for set-top device video recording, just like AVCHD is an economical version of Blu-ray video adapted to video cameras.
An AVCREC recorder can use either MPEG4/AVC or MPEG-2 video encoding to record the video. In the so-called "DR mode" a recorder does not re-compress the incoming signal, fully preserving the original quality of a broadcast program. Some devices offer "long play" modes with compression up to 5x higher than original signal, with corresponding loss of quality. MPEG4/AVC is usually used for "long play" modes as a more effective compression scheme compared to MPEG-2.
Playing back AVCREC video.
Recorded AVCREC video can be played back on a recording device, on a compatible Blu-ray player or on a computer.