126 Chapter 8 Working with Sony XDCAM Formats
XDCAM, XDCAM HD, and XDCAM EX Format Specifications
XDCAM (SD) records MXF file–based media to an optical disc format. XDCAM HD
extends XDCAM to include HD video. XDCAM EX adds full-resolution 1920 x 1080 or
1280 x 720 modes and ExpressCard-based recording.
Storage Medium
XDCAM and XDCAM HD use a 120 mm disc—like CD and DVD discs—that can record
23.3 GB of media by using a 405 nm blue-violet laser. Although the Sony Professional
Disc uses a blue-violet laser, it is not compatible with Blu-ray Disc technology. The Sony
Professional Disc supports a transfer speed of 72 Mbps (or 144 Mbps with dual heads),
whereas a consumer Blu-ray Disc has a maximum rate of 36 Mbps.
XDCAM EX records to Sony SxS solid-state ExpressCard/34 media.
All video and audio content is stored on disc within MXF container files. Much like
QuickTime movie files, MXF files can store video and audio data in almost any frame
rate and codec, as well as metadata about the content, such as the date of recording,
GPS positioning data, and so on.
Video Standard
XDCAM supports NTSC and PAL using either the DVCAM or IMX format:
ÂDVCAM: 25 Mbps DV
ÂMPEG IMX: 30, 40, or 50 Mbps MPEG-2 (I-frame only)
XDCAM camcorders can also record low-resolution MPEG-4 proxy files (1.5 Mbps) for
quick previewing before ingesting into your editing system. Proxy file dimensions are
352 x 240 (NTSC) or 352 x 288 (PAL), adhering to the Common Intermediate Format
(CIF) standard. 500 MB of disc space is reserved for storing general-purpose files such
as text files, EDLs, project files, graphics, and so on.