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Sony seems to consistently introduce new technological wonders that set the consumer electronics industry to talking. But the company's latest achievement in camcorder technology tops all the rest. It's called the MD Discam TM (Model DCM-M1 at $2,299 MSRP), and it is the world's first MD (MiniDisc) disc-based camcorder with nonlinear editing built-in!
MPEG-2 Recording Quality
What makes the Sony DCM-M1 Discam different from the other non-tape-based camcorder (Hitachi's MPEG camera) is its use of MPEG-2 recording technology. Hitachi uses MPEG-1, a lower-quality standard. MPEG-2 is the highest-quality/most-efficient digital video format available today. It is the standard of DVD movies and digital satellite transmission, so its picture quality is excellent.
MPEG-2 recording is the hottest new trend in capturing high-quality video with computers today. Normally, a MPEG-2 video capture board takes up an entire PCI slot in your computer, but Sony has reduced that down to a radically smaller size to fit inside of its DCM-M1 camcorder.
And, along with this miniaturization, the MPEG-2 recording is done in real time on the MiniDisc. I emphasize that this is a real-time process because it wasn't too long ago that all MPEG-2 processing was generally done in a non-real-time manner. And, it was a very expensive and lengthy process.
The DCM-M1 Discam actually offers modes of MPEG-2 recording quality: High Bit Rate at 8MB per second (MBps); Variable Bit Rate; and Low Bit Rate (4MBps). What's the difference between them? You probably guessed it--quality versus recording time. In the High Bit Rate mode setting, the video quality is the best, with very few MPEG-compression artifacts visible. But the trade-off is recording time. On a provided MD View disc, only about 10 minutes can be recorded in this High Bit Rate/High Quality mode. The 4MBps Low Bit Rate mode offers double the recording time--20 minutes--but at some loss in image quality.
The third recording quality mode is known as Variable Bit Rate, a very sophisticated process in which the internal computers within the Discam examine every scene frame by frame in real time and decide on the amount of MPEG-2 compression to apply. It's a variable process, based on scene content, so the recording time is variable. The Sony DCM-M 1 spec sheet says as little as 13 minutes or as much as 20 minutes of recording time are possible.