XML Binary Formatting

Collaboration diagram for XML Binary Formatting:

Functions
GF_Err	gf_xml_parse_bit_sequence (GF_XMLNode *bsroot, const char *parent_url, u8 **out_data, u32 *out_data_size)
	bit-sequence XML parser More...
GF_Err	gf_xml_parse_bit_sequence_bs (GF_XMLNode *bsroot, const char *parent_url, const char *base_media, GF_BitStream *bs)
	bit-sequence XML parser More...

Detailed Description

Binarization using XML in GPAC

GPAC uses a special node name BS (for BitSequence) in XML documents to transform text data into sequences of bits. This function inspects all child elements of the node and converts children node names BS into bits. BS take the following attributes:

• bits: value gives the number of bits used to code a value or a length
• value: value is a 32 bit signed value
• dataOffset: value gives an offset into a file
• dataLength: value gives the number of bits bytes to copy in a file
• dataFile: value gives the name of the source file
• textmode: indicates whether the file shall be opened in text or binary mode before reading
• text: or string: value gives a string (length is first coded on number of bits in bits attribute)
• fcc: value gives a four character code, coded on 32 bits
• ID128: value gives a 128 bit vlue in hexadecimal
• data64: value gives data coded as base64
• data: value gives data coded in hexa

Function Documentation

gf_xml_parse_bit_sequence()

GF_Err gf_xml_parse_bit_sequence	(	GF_XMLNode *	bsroot,
		const char *	parent_url,
		u8 **	out_data,
		u32 *	out_data_size
	)

Parameters

bsroot	the root node of XML document describing the bitstream to create
parent_url	URL of the parent document
out_data	pointer to output buffer allocated by the function to store the result
out_data_size	pointer to output buffer size allocated by the function to store the result

Returns

error code if any or GF_OK

gf_xml_parse_bit_sequence_bs()

GF_Err gf_xml_parse_bit_sequence_bs	(	GF_XMLNode *	bsroot,
		const char *	parent_url,
		const char *	base_media,
		GF_BitStream *	bs
	)

Parses XML bit sequence in an existing bitstream object. The syntax for the XML is the same as in gf_xml_parse_bit_sequence

Parameters

bsroot	the root node of XML document describing the bitstream to create
parent_url	URL of the parent document
base_media	URL of base media file if any, relative to parent url. May be NULL
bs	target bitstream to write the result into. The bitstream must be a dynamic write bitstream object

Returns

error code or GF_OK