Jun
Sony has surprised its users with an update for the PMW-300 and PMW-400, two ENG-mount shoulder cameras.
The new firmware version allows to increase the recording quality, being able to capture images in HD (1920 x 1080) using Sony’s XAVC codec. XAVC is based on the H.264 codec, so it is more efficient than MPEG-2, and is intraframe, fully encoding each frame without the need to reference previous or subsequent frames. This type of compression greatly facilitates editing and results in fewer artifacts, especially in shots with a lot of movement.
The codec has a 10-bit depth and 4:2:2 sampling. Its 100Mb/s rate is about half that of Apple ProRes (HQ), which is considered a visually lossless codec. However, it has been decided to go with XAVC at 100Mb/s because it will require half the storage and less computer power than ProRes.
Typically, cameras involving mass production (even professional ones) handle codecs through specialized chips (usually ASICs). In other cases of lower production, the encoding is handled by FPGAs (Field Programmable Gate Arrays), which allows reprogramming all cameras by running software.
This fact implies that either Sony has started putting FPGAs in its cameras (which doesn’t seem like the best option), or it has designed chips that handle a wide range of codecs and what this update has done is unlock an existing capability.
In any case, you will now be able to work with XAVC at 100Mbit/s. To get the new functionality, PMW-300 users will need to upgrade to firmware version 1.2, and v1.3 for the PMW-400.
