Monday, September 17, 2007

XDCAM EX Codec

I tracked down some more info about the codec used for the new Sony XDCAM PMW-EX1 camcorder. As you can see from the table above, there are two general recording codecs. The HQ model has a higher maximum bit rate that is variable and also includes different resolutions--either 1920x1080 or 1280x720. The SP mode is basically the same codec as HDV 1080 line variation that Sony uses in the Z1 and V1. It is a constant bit-rate at 25mb/s at a resolution of 1440x1080. The advantage of working in this mode is that the signal is compatible with gear that knows HDV, like FCP or an HDV deck. So that while shooting, you could record to a Sony HDV deck or you could record with capture now in FCP through firewire out on the camera.

Interestingly, the SP mode has the same limitations on variable frame rate as other Sony camcorders, like the V1. That is, you can record 24p (or really 23.98p) but it it recorded with pulldown into a regular 60i (29.97interlaced) signal. So to edit that in native 24 fps, you need to remove the pulldown, which is tricky to do (especially so if you want to keep your timecode.) It looks like the HQ mode handles real variable frame-rate, recording the signal in the frame-rate that you set and not trying to squeeze (or stretch) it into 30 interlaced fps. All XDCAM EX media files have a MP4 (MPEG-4) wrapper.

No DV or DVCam recording. The bad thing about that is that you could have squeezed a lot more video on the expensive SxS cards with support for standard definition recording. Prices are around $500 for 8GB and $900 for 16GB now. With 16GB of memory you get as little as 50 min. in HQ mode, and exactly 70 min. in SP mode.

We are still waiting for a direct interface for importing from the memory cards into FCP. I'm not sure if there is any support right now for the files on the memory card and FCP yet, but hopefully Apple is working on getting a good solution soon.

Here's a direct quote from the rather large PDF that I got this info from:

The SP mode supports 1440 x 1080 resolution at 25 Mb/s,
which provides compatibility with HDV 1080i products.
Footage recorded in the SP mode can be seamlessly
integrated into HDV-compatible editing systems by
connecting the camcorder via the i.LINKTM* (HDV)
interface. It can also be recorded on XDCAM HD's optical
disc through the use of the supplied Clip Browser software.

1 comment:

Unknown said...

XDCam EX SP mode offers an identical datarate to DV/DVCam (25 Mbit/s), so you wouldn't be able to fit any more DV or DVCam footage onto the same size media, were the mode available.

Of course, a long-GOP SD resolution version of the XDCam codec could have been used, but that would mean introducing a new non-standard format for SD, which frankly probably wouldn't fly these days...