Interoperability Material Exchange
The Interoperability Material Exchange ( IMX ) format is a professional video format for video content in standard definition developed by Sony in 1999 as the successor to Digital Betacam . It is mainly used in the broadcast area on magnetic tape (IMX tape) and as an MXF file. In 2002, IMX was incorporated into the SMPTE standard 365M as the basis for the D-10 format .
IMX format
The IMX technology offers video compression with a data rate of 30 Mbit / s (6: 1 compression), 40 Mbit / s (4: 1 compression) or 50 Mbit / s (3.3: 1 compression), with color subsampling being 4 : 2: 2 and the color depth is 8 bits. The H.262 / MPEG-2 Part-2 standard is used for compression , with each individual image being compressed separately ( I-frame only, no use of Long-GOP). This means that the IMX format remains fully editable.
A special feature of the IMX format is the unique recording identifier UMID ( Unique Material Identifier ) in accordance with SMPTE Standard 330M. All IMX devices ensure that with any processing, even 1: 1 copies, the UMID is set to zero for the new material (cutting result / copy). This allows an original material to be clearly identified.
In contrast to the classic VTR formats, the IMX video films can also be addressed as files (in the sense of computer technology ) via special adapters . The files conform to the MXF standard. They can also be stored (as normal files) on other data carriers (e.g. on RAID systems or on optical data carriers ( MOD ) as XDCAM ).
specification
| Format name | Container | Video coding | Color depth | Color subsampling | Image size | Refresh rate and sampling | Video data rate, Mbit / s | Sound format |
|---|---|---|---|---|---|---|---|---|
| MPEG IMX | MXF | MPEG-2 422P @ ML | 8th | 4: 2: 2 | 720 × 576 | 25i, 25p | 30 (CBR), 40 (CBR), 50 (CBR) | PCM 8 ch / 16 bit / 48 kHz, or 4 ch / 24 bit / 48 kHz |
| 720 × 480 | 29.97i, 29.97p, 23.98p |
Use in DACH
In Germany, the IMX format was generally used by ARD, and even mainly used by NDR , RBB and WDR . The other broadcasters prefer other formats (e.g. DVCPro from Panasonic) or continue to Sony's Digital Betacam. The Austrian Broadcasting Corporation and the Swiss television also use the IMX format.
IMX tape
The IMX tape (Sony brand name: MPEG-IMX) is a 1/2-inch metal particle tape with a maximum playing time of 184 minutes in type L. Tapes with a playing time of 6 to 184 minutes are available. IMX camcorders use smaller B-type cassettes, also called S-tapes (short), with 6 to 124 minutes of recording time.