class ara::rds::IEEE1722DatagramRVF

Within the AUTOSAR module Raw Data Stream, the class ara::rds::IEEE1722DatagramRVF represents specific IEEE 1722 datagrams for the Raw Video Format for the structured transmission of uncompressed video streams SWS RawDataStream §1 “Raw Data Stream”. It bundles all image- and transmission-relevant metadata such as line counts, color spaces, frame rates, and protocol control bits in protected optional fields. Declared as a final data structure, it precludes further inheritance, but ensures deterministic and exception-free deallocation via base class pointers through a virtual destructor [SWS_RDS_90292].

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Context

Within the functional module Raw Data Stream (rds) of the AUTOSAR Adaptive Platform, the class ara::rds::IEEE1722DatagramRVF represents a concrete IEEE 1722 datagram for the Raw Video Format (RVF) SWS RawDataStream §1 “Raw Data Stream”. The Raw Video Format serves to transport uncompressed video streams over packet-based networks within the framework of Audio Video Bridging (AVB) and Time-Sensitive Networking (TSN). The data structure is defined in the header file ara/rds/raw_data_stream_IEEE1722.h [SWS_RDS_90276]. The class definition is provided with the keyword final and incorporates via protected inheritance (protected) both the generic base class IEEE1722Datagram and AVTPDUCommonStreamHeaderFields [SWS_RDS_90276]. Through this composition, the structure combines fundamental AVTP stream header fields with the specific metadata fields required for processing individual video lines and rasters.

Context diagram: Embedding of IEEE1722DatagramRVF into the class hierarchy with IEEE1722Datagram and AVTPDUCommonStreamHeaderFields. Sources: [SWS_RDS_90276], SWS RawDataStream §1 “Raw Data Stream”

Lifecycle

The lifecycle of an instance of IEEE1722DatagramRVF is largely determined by the processing pipeline of the Raw Data Stream. For proper cleanup of instances, the class declares a virtual destructor virtual ~IEEE1722DatagramRVF() noexcept [SWS_RDS_90292]. Although the class itself is marked as final [SWS_RDS_90276] and therefore cannot act as a base class for derived subclasses, the virtual design of the destructor ensures correct deallocation if instances are referenced and destroyed polymorphically via base class pointers.

The specifier noexcept on the destructor guarantees that under no circumstances can exceptions escape during the destruction process [SWS_RDS_90292]. In safety-critical automotive systems, this is an essential precondition for ensuring deterministic cleanup processes without abrupt program terminations. The AUTOSAR specification does not define explicit synchronization primitives for concurrent access for this data class; therefore, thread-safe handling must be ensured at the level of the surrounding streaming services if required.

Usage Path

In the practical processing sequence, the class acts as an information carrier for received video frames or video frames to be sent. Here, the structure bundles numerous fields that describe image dimensions, time reference, and color encoding in detail. For the geometric structure of the video, the active pixels active_pixels [SWS_RDS_90276], the total number of lines in a frame total_lines [SWS_RDS_90278], the line number line_number [SWS_RDS_90291], and the number of lines per packet num_lines [SWS_RDS_90289] are available.

For the correct interpretation of the pixel data stream, the class also encapsulates system-specific video format properties: the bit depth per pixel pixel_depth [SWS_RDS_90285], the pixel format pixel_format [SWS_RDS_90286], the color space colorspace [SWS_RDS_90288], and the frame rate frame_rate [SWS_RDS_90287]. In addition, there are AVTP-specific control and status bits of the transmission protocol: the field ap [SWS_RDS_90279], the flag f [SWS_RDS_90280], the field ef [SWS_RDS_90281], event fields such as evt [SWS_RDS_90282] and pd [SWS_RDS_90283], the flag i [SWS_RDS_90284], and the sequence number i_seq_num [SWS_RDS_90290].

A striking aspect is the consistent encapsulation of all variables in ara::core::Optional. This declaration suggests that datagrams may have incomplete headers or that certain metadata is only transmitted on demand depending on the AVTP packetization profile. All attributes are assigned the protection level protected [SWS_RDS_90276], [SWS_RDS_90278]. Since derivation by user code is impossible due to final, read and write access to these fields is likely implemented via internal helper classes or friended driver instances of the RDS module. Question Q-b1e31774561c4cd7 (open)