1 Scope Conformance

7.3.6 Stream Objects
7.3.6.1 General

A stream object, like a string object, is a sequence of bytes. Furthermore, a stream may be of unlimited length, whereas a string shall be subject to an implementation limit. For this reason, objects with potentially large amounts of data, such as images and page descriptions, shah be represented as streams.

NOTE 1 This sub-clause describes only the syntax for writing a stream as a sequence of bytes. The context in which a stream is referenced determines what the sequence of bytes represent.
A stream shall consist of a dictionary followed by zero or more bytes bracketed between the keywords stream (followed by newline) and endstream:
EXAMPLE dictonary
stream
…Zero or more bytes…
endstream
All streams shall be indirect objects (see 7.3.10, "Indirect Objects”) and the stream dictionary shall be a direct object. The keyword stream that follows the stream dictionary shall be followed by an end-of-line marker consisting of either a CARRIAGE RETURN and a LINE FEED or just a LINE FEED, and not by a CARRIAGE RETURN alone. The sequence of bytes that make up a stream lie between the end-of-line marker following the stream keyword and the endstream keyword; the stream dictionary specifies the exact number of bytes. There should be an end-of-line marker after the data and before endstream: this marker shall not be included in the stream length. There shall not be any extra bytes, other than white space, between endstraam and endobj.

Alternatively, beginning with PDF 1.2, the bytes may be contained in an external file, in which case the stream dictionary specifies the file, and any bytes between stream and endstream shall be ignored by a conforming reader.

NOTE 2 Without the restriction against following the keyword stream by a CARRIAGE RETURN alone, ii would be impossible to differentiate a stream that uses CARRIAGE RETURN as its ended-line marker and has a LINE FEED as its first byte of data from one that uses a CARRIAGE RETURN—I.INE FEED sequence to denote and- of-line.
Table 5 lists the entries common to all stream dictionaries: certain types of streams may have additional dictionary entries, as Indicated where those streams are described. The optional entries regarding fillers for the stream .indicate whether and how the data in the stream shall be transformed (decoded) before it is used. Filters are described further in 7.4, “Filters."