IRIG106wiki

Image Data, Format 0 packets are used to record digitized video images.

The layout of the CSDW is shown in Figure 6-42. The uLength value is the number bytes in each segment. The bIntraPckHdr flag indicated the presence of the intra-packet data header. The uSum value indicates if and how an image is segmented in the data packet. The uPart value indicates which part of a possibly segmented image is contained in the data packet.

struct SuImageF0_ChanSpec 
    { 
    uint32_t    uLength         : 27;   // Segment byte length 
    uint32_t    bIntraPckHdr    :  1;   // Intra-packet header flag 
    uint32_t    uSum            :  2;   // 
    uint32_t    uPart           :  2;   // 
    }; 

Individual image data messages follow the CSDW. Each message may have an optional intra-packet data header followed by the image data. The intra-packet data header, if present (indicated by bIntraPckHdr = 1), is an eight byte representation of time in either 48-bit relative time format derived from the RTC (format shown in Figure 6-5) , or as absolute time. If this time is absolute time, it is in either Chapter 4 weighted 48-bit time (format shown in Figure 6-6) or IEEE 1588 time format (format shown in Figure 6-7).

The format of the image data portion of the packet is not specified in Chapter 10. The image format is specified in the TMATS setup record attribute “R-x\SIT-n”. Note that an even number of bytes is allocated for message data. If the data contains an odd number of bytes, then one unused filler byte is inserted at the end of the data.

Chapter 10 of IRIG 106-07 (and prior editions of the standard) incorrectly state that Bit 7 of the Packet Flags (in the packet header) is used to determine if the intra-packet time is relative time or absolute time. The correct bit to use is Bit 6. This handbook is based on (and correlates to) the IRIG 106-07 edition; however the “bit 7” error will be corrected in future releases of this handbook.

Image Data, Format 1 packets are used to record digitized still images. Several formats for image compression are supported by Format 1.

The layout of the CSDW is shown in Figure 6-43. The uFormat value indicates the format of the image data. The bIntraPckHdr flag indicated the presence of the intra-packet data header. The uSum value indicates if and how an image is segmented in the data packet. The uPart value indicates which part of a possibly segmented image is contained in the data packet.

struct SuImageF1_ChanSpec 
    { 
    uint32_t    uReserved       : 23;   // 
    uint32_t    uFormat         :  4;   // Image format 
    uint32_t    bIntraPckHdr    :  1;   // Intra-packet header flag 
    uint32_t    uSum            :  2;   // 
    uint32_t    uPart           :  2;   // 
    }; 

Individual image data messages follow the CSDW. Each message may have an optional intra-packet data header (indicated by bIntraPckHdr = 1) followed by the image data. The format of the intra-packet data header is shown in Figure 6-44. The suIntrPckTime value is an eight byte representation of time in either 48-bit relative time format derived from the RTC (format shown in Figure 6-5) , or as absolute time. If this time is absolute time, it is in either Chapter 4 weighted 48-bit time (format shown in Figure 6-6) or IEEE 1588 time format (format shown in Figure 6-7). The uMsgLength value indicates the length of the following still image or segment.

struct SuImageF1_Header 
    { 
    uint64_t    suIntraPckTime;         // Reference time 
    uint32_t    uMsgLength;             // Message length 
    }; 

Chapter 10 of IRIG 106-07 (and prior editions of the standard) incorrectly state that Bit 7 of the Packet Flags (in the packet header) is used to determine if the intra-packet time is relative time or absolute time. The correct bit to use is Bit 6. This handbook is based on (and correlates to) the IRIG 106-07 edition; however the “bit 7” error will be corrected in future releases of this handbook.

Reserved for future use.