Formats are interpreted, starting from the format definition. It specifies the format name (root DDS type) followed by any associated attributes. Attributes are ignored, if they are not relevant to the specified format. Attribute defaults are based upon the format name, media (tape, disk, pipe, ...), and mode (read, write, update).

format= name attributes

Various data formats can be described by zero or more Line Headers (associated with the entire dataset) and one or more Trace Headers (associated to each trace in a dataset). The data Samples are actually defined as another Trace Header. These Header structures are specified by "fmt:" definitions (See Fmt Control).

Standard Predefined Formats:

Standard, predefined formats have a reserved name (i.e. usp, segy, ...). They require a specific fmt: sequence in the data stream (Line Header followed by traces) and specific fields, within each format (TrcNum, LASTTR, etc.). These restrictions are enforced by DDS. Standard formats are described in the following subsections and are a subset of the generic DDS format.

The generic DDS format is assumed, when the format name is not a recognized standard. Generic formats may be very simple. For example, data may be accessed as a byte stream, or as a cube of ieee floats. Generic formats may also be very complex. This allows DDS to encompass many standard formats, and allows new ones to be created as needed.

Currently Supported Dataset Formats:

Name     Description
-----     -----------
usp      BP Amoco USP format
segy     SEGY standard
segy1    SEGY standard Rev. 1
su       Colorado School of Mines CWP/Seismic Un*x
sep      Stanford Exploration Project
asp      Generic DDS (Flexible Header & Samples)
cube     Samples only (any type)
fcube    Samples only (float4† type)
fcubex   Samples only (float4x† type)
dcube    Samples only (float8† type)
dcubex   Samples only (float8x† type)
ccube    Samples only (complex8† type)
ccubex   Samples only (complex8x† type)
icube    Samples only (integer4† type)
icubex   Samples only (integer4x† type)
i2cube   Samples only (integer† type)
i2cubex  Samples only (integer2x† type)
i1cube   Samples only (integer† type)
    

If a "format=" definition is not provided, DDS will attempt to auto-detect the binary format. As long as data is in a standard predefined format with a few basic constraints, DDS should be able to detect the format.

^† See Data Types for more details.