Unibrain 830 - Manual (Page 12)

Unibrain Fire-i 530/630/830 Operation Manual Page 6
1.6. Pixel Data
The Unibrain Fire-i ultra compact form Series complies with the IIDC 1394-Based Digital Camera Specification
V1.31 where data packets are transmitted by a FireWire TM interface as isochronous packets. Every video format,
mode and frame rate has a different video data format. (Pixel data source: IIDC V1.31 Specification)
Isochronous Data Block Packet Format
0 - 7 8 - 15 16 - 23 24 - 31
Data Length tg channel tCode Sy
Header CRC
Video data payload
Data CRC
Where the following fields are defined in the IEEE 1394 standard as:
Data length: number of bytes in the data field tg: (tag field) shall be set to zero
channel: isochronous channel number, as programmed in the iso_channel field of the cam_sta_ctrl register
tCode: (transaction code) shall be set to the isochronous data block packet tCode
sy: (synchronization value) shall be set to 0001h on the first isochronous data block of a frame, and shall be set to
zero on all other isochronous data blocks
Video data payload: shall contain the digital video information, as defined in the following sections of the
Video data Payload Structure
Pn : Pixel number / packet
K : Pn x n (n = 0…..N-1)
(Pn x N = Total pixel number /frame)
<YUV (4: 2: 2) format >
U-(K+0) Y-(K+0) V-(K+0) Y-(K+1)
U-(K+2) Y-(K+2) V-(K+2) Y-(K+3)
U-(K+4) Y-(K+4) V-(K+4) Y-(K+5)
U-(K+Pn-6) Y-(K+Pn-6) V-(K+Pn-6) Y-(K+Pn-5)
U-(K+Pn-4) Y-(K+Pn-4) V-(K+Pn-4) Y-(K+Pn-3)
U-(K+Pn-2) Y-(K+Pn-2) V-(K+Pn-2) Y-(K+Pn-1)
<YUV (4: 1: 1) format >
U-(K+0) Y-(K+0) Y-(K+1) V-(K+0)
Y-(K+2) Y-(K+3) U-(K+4) Y-(K+4)
Y-(K+5) V-(K+4) V-(K+4) Y-(K+5)