Radius Studio Video

• FourCC: PGVV
• Company: Radius
• Samples: http://samples.mplayerhq.hu/V-codecs/PGVV-RadiusStudio/

PGVV is apparently a video codec generated by either the Video Vision hardware grabber card, or with the Radius Studio software. All the brochures and reviews say that it is using an "adaptive JPEG". Probably it means adaptive rate control as described in their patent 5,621,820. It is a slight variation of JPEG.

Original product page on archive.org.

There are two versions of the codec known which can be distinguished by 16-bit (big-endian) field at offset 8 of the frame data.

Version 0 frame header (all values are big-endian):

 4 bytes - first field size
 4 bytes - second field size (0 for progressive images)
 2 bytes - version (0)
 1 byte  - unknown
 1 byte  - quality
 4 bytes - unknown (frame flags?)

Version 1 frame header:

 4 bytes - zero
 4 bytes - second field size (0 for progressive images)
 2 bytes - version (0)
 1 byte  - unknown
 1 byte  - quality
 4 bytes - unknown (frame flags?)
 4 bytes - unknown
 4 bytes - first field size
 4 bytes - unknown
 4 bytes - unknown

After the header the first field data follows, then padding to multiple of 2048 and the second field data.

Field data is almost standard JPEG data without escaping with two luma and two chroma blocks per macroblock. The coefficients are coded almost the same, only chroma DC values are coded as the difference to each other (i.e. U DC is coded as the difference to the previous V DC and vice versa instead of per-component DC prediction in JPEG).