FC-AV: The Fibre Channel - Audio Video standard. The official designation of the standard is ANSI INCITS 356-2002. The standard defines the FC-AV container system that provides a framework onto which various digital Audio/Video formats can be mapped. Video Frame: Refers to an entire “pixel space”, for example an XGA image at 1024 x 768 pixels. A video frame may be larger than an image contained therein. The image in a video frame is the Active Image Area.

FC-AV Frame: One video frame is broken down into multiple FC-AV frames for transmission. An FC frame is limited to a maximum of 2112 bytes. For example, an XGA image with 24 bits/pixel requires two FC-AV frames (1024 pixels x 3 bytes/pixel = 3072 bytes) to transmit the pixel information in one 1024 pixel row. Each FC Frame would contain half a row, or 1536 bytes.  An FC frame may contain several lines of video data, or less than a single line, depending on the number of pixels in a row and the number of bytes per pixel.

FC-AV Container: An FC-AV term for all the FC Frames taken together, which includes the container header, and various objects representing ancillary data, audio, and video. One container contains a complete Video Frame. The FC-AV Container Structure diagram in the FC-AV Overview section shows that within a FC sequence of FC frames, there is a “payload”. All of the information in the payload taken together forms the container. By grouping video, audio, and ancillary data into relatively large data sets to be transported as a unit, the container is an optimal transmission system.

Container Objects: Four types of Container Objects are defined within the Simple Header Mode of SPDV profile. Object 0 carries ancillary data; Object 1 carries audio data – but this isn’t used in the SPDV profile; Object 2 carries video data; and Object 3 also carries video data, but is only used for interlaced video.

Vertical Sync: Indicates start of Frame (start of image container)

Horizontal Sync: Indicates the start of the row timing within the video frame

Data Enable: Indicates the beginning of active image pixel information.

Horizontal Blanking: This is adopted from an analog CRT perspective. After scanning a horizontal row, from left to right, the electron beam needed time to move from right back to left to begin to scan the next line. The time needed to move the electron beam was the horizontal blanking. In the digital world, the horizontal blanking is the time needed after transmitting a FC Frame (which contains some video data) to transmit that video data to a display. The horizontal blanking is usually filled with IDLE characters.

Vertical Blanking: Like the Horizontal Blanking, this term comes from the analog TV world. The time required to reposition the electron beam from the lower right hand corner, to the upper left hand corner is the vertical blanking. In the digital world, the vertical blanking is the time between video frames. For example, if transmitting at a rate of 30Hz, a new video frame will be sent every 1/30 of a second. If the entire time needed to transmit the frame is 1/60 of a second, then there is 1/60 of a second left over before beginning the transmission of the next video frame, this left-over time is the vertical blanking inserted between each Video Frame. The vertical blanking is accomplished by inserting IDLE characters.

Active Image Area: The image that is visible on a display, all special characters are stripped off, and vertical and horizontal blanking areas removed.

Horizontal Scan Direction: Adopted from CRT technology, a line is draw from left to right.

Vertical Scan Direction: Adopted from CRT technology, lines are drawn from top to bottom.

Payload: The FC Frame payload carries all the components of the container (header, ancillary data, and object data). Technically, the Payload is the FC Frame minus the Frame Header, the CRC, and Start of Frame (SOF) and End of Frame (EOF) delimiters.

Field: For analog TV, a video frame is broken into two fields, a Odd field (all the odd lines of a video frame) and an Even Field (all the even lines)

Interlace: The method by which analog TVs display a video frame, first refreshing the Odd field, followed by the even field.

CRC: This stands for "Cyclic Redundancy Code". The term "CRC" seems to be reserved for algorithms that are based on the "polynomial" division. The essential mathematical operation in the calculation of a CRC is binary division, and the remainder from the division determines the CRC. CRC's cannot, however, be safely relied upon to verify data integrity. CRC types are often identified by the polynomial, which is the number used as the divisor. 

8B/10B Encoding: The IBM patented encoding method used for encoding 8-bit data bytes to 10-bit Transmission Characters. Data bytes are converted to Transmission Characters to improve the physical signal such that the following benefits are achieved: bit synchronization is more easily achieved, design of receivers and transmitters is simplified, error detection is improved, and control characters (i.e., the Special Character) can be distinguished from data characters. This encoding is used by Fibre Channel, Gigabit Ethernet, 10 Gigabit Ethernet, and ATM transmission interfaces.

Simple Parametric Digital Video: SPDV: A profile that defines a container header that has one fixed length header with 4 objects. SPDV defines a mapping based on the container system defined in Clause 5 of ANSI INCITS 356-2002. The target of this profile is real-time digital video for avionics systems. SPVD uses a Simple Header Mode of operation, which means the container header is exactly 22 Long Words (88 bytes) in length.

Frame Header Control Protocol: FHCP: is a low-overhead way to send FC-AV containers, which lends itself to low-latency, efficient data transmission. FHCP is defined in Clause 7 of ANSI INCITS 356-2002.

Special Characters: When using 8B/10B encoding, there are two types of characters, data characters, and special characters. When a character is converted from 8bits to 10 bits, the serializer must be told if a byte is Data or a Special Character (by asserting a given pin on the serializer). Common special characters are: K28.0, K28.1, K28.2, K28.3, K28.4, K28.5, K28.6, K28.7, K23.7, K27.7, K29.7, and K30.7. These characters can be used to indicate Start of Frame, End of Frame, Start of line, End of Line, IDLE or other needed control characters.

Fibre Channel Levels: Fibre channel has multiple layers of implementation, beginning with Level 0, the physical level progressing to level 4.  FC-AV relies on portions of Levels 0-2, and the Frame Header Control Protocol from layer 4.