XDCam Format Updates

Sony has been moving forward with a number of significant developments in their XDCam line of products.  Two of the three new variations of the XDCam line that were announced back in April at NAB2007 have begun to ship to customers.  The dual layer upgrade to XDCam-HD increases the capacity from 23GB to 50GB, effectively doubling the recording time, but is only available in the newest revision of the XDCam-HD products, with the F335 and F355 camcorder replacing the previous F330 and F350, and the F75 deck replacing the F70.  Doubling the capacity is the only major feature enhancement in these new products.

The solid state flash memory based XDCam-EX is obviously targeted to compete with Panasonic’s P2 flash based recording.   XDCam-EX is different from standard XDCam-HD in a number of ways.  Instead or relying on BluRay based optical ProDiscs discs, it records to ExpressCard34 based Flash memory cards called SxS Pro cards.  While still 35Mb/s at maximum quality, the new EX format is able to encode the full 1920 pixel width for 1080i/p frame sizes instead of downsampling to 1440×1080 like XDCam-HD and HDV.  Clips are still saved as files on the recording medium, but XDCam-EX uses the MPEG4 wrapper with the .MP4 extension instead of the previous XDCam .MXF wrappers of the Media eXchange Format.  This is a bit confusing, as the data is actually processed using MPEG2 compression, but stored in an MPEG4 wrapper.  I am not clear as to what the specific advantages of that switch are to Sony or anyone else.  Supposedly the MP4 files straight from the camera can be imported into Premiere Pro CS3, but the performance is not currently realtime.  Sony has released a Utility to convert the XDCam-EX MP4 files to XDCam-HD MXF files for backwards compatibilty with tools that support the older format.  Supposedly these MXFs allows full 1920×1080 resolution files from the EX1 to be edited in realtime on a Matrox AXIO system, but this has not been confirmed by Matrox.  The PMW-EX1 is currently the only XDCam-EX based camcorder available, but I will elaborate on the details of that specific item in a future post.

Lastly there is the new higher end XDCam-MPEGHD422 standard, that seems to be in a postion to eventually replace HDCam tape.  At 50Mb/s, XDCam-422 will record full width 1920×1080 imagery at 4:2:2 with 8bit color.  This should surpass HDCam’s 1440×1080 3:1:1 8bit capability, at much lower data rates, and in a compression scheme that can be edited natively.  The only major limitation that remains is that Sony has not specifically announced 24fps support, and the first generation of XDCam-422 products may be targeted purely at the broadcast market.  The new PDW-700 has 2/3 in CCDs, similar to the F700 and F900 lines, but may be limited to the broadcast standards of 1080i and 720p 50 and 60.  With no 24fps support this product would still not replace the F900R, but one would imagine that the next follow-on product would surely add that capability.  I have not found any specific info on whether the actual files recorded to disc will be MXF, similar to the current XDCam-HD, or MP4 like the new XDCam-EX.  Due to the similar changes in frame size, my guess would be that there will be a switch to the new MPEG4 wrapper.  While more specific information has recently been released about them, the XDCam-422 line of products are still not expected to ship until after NAB2008.

Tags: Compression, Sony, XDCam