Treasured's Movie Repair Guide -- XDCAM

XDCAM is a professional recording format developed by Sony, but also used by other manufacturers like JVC. (This codec doesn't come pre-installed in Mac computers.)


XDCAM.png


Originally its two variants XDCAM and XDCAM HD could be recorded on expensive Blue-ray discs called Professional disc, and circa 2006 a third generation appeared, with XDCAM HD422 (4:2:2 subsampling, doubling the bitrate) and XDCAM EX, recorded on solid-state medium (SxS and SDHC cards).


XDCAM is derived from MPEG-2. XDCAM media comes inside a QuickTime mov container, a .MP4 file inside a BPAV structure, or in a .MXF file. In all cases, the file contains one video track and one or several audio tracks

XDCAM is almost identical to HDV, and sometimes Treasured cannot determine which of them is actually detected.


Repairability

XDCAM media is repaired without major problem. All families (XDCAM HD, XDCAM EX, XDCAM HD422, and special applications like nanoFlash), are supported.


A good file is recommended.
Even if the good file contains only a few frames, the fact that it was encoded with the exact settings of the damaged file will provide useful information:


This information can be guessed from a damaged file, but through a very lengthy trial-and-error iterative process.

Example: How to figure out the pixel size

Using an Hex Editor, you look for the 00 00 01 B3 hex pattern.

After 00 00 01 B3 we find 24 bits that encode picture size:

5A 04 38 is 5A0 x 438 pixels (1440 x 1080) 


How to repair a corrupt XDCAM movie

The easiest way is certainly to ask our Movie Repair Service to do it for you.

But for those who can program, here you have a few tips:


Techniques used are:


Video track can have a variety of codec fourcc (xdvd and 20 more) and is organized in keyframes and inter-frames. XDCAM frames are not stored in playback order, so there is a ctts table that specifies the offset between decode time and display time.

Note that we also find two tables called cslg and sdtp (sample dependencies) but these are optional: the movie works perfectly without them. In repairs we usually don't bother with recreating those tables.


Audio tracks often come in raw PCM 'sowt' of 'twos' formats, for example 48kHz stereo 16 bits.


Repair process consists of reindexing video frames. Frame reordering is possible if the pattern is predictable. Otherwise, the result will be shaky.


Audio scraping can also cause some problems. Sometimes the audio has some overlapping between frames, thus requiring a special scraping process.