ByteReader.maskedScanUint32

Scan for pattern pattern with applied mask mask in the byte reader data, starting from offset offset relative to the current position.

The bytes in pattern and mask are interpreted left-to-right, regardless of endianness. All four bytes of the pattern must be present in the byte reader data for it to match, even if the first or last bytes are masked out.

It is an error to call this function without making sure that there is enough data (offset+size bytes) in the byte reader.

class ByteReader
uint
maskedScanUint32
(
uint mask
,
uint pattern
,
uint offset
,
uint size
)

Parameters

mask uint

mask to apply to data before matching against pattern

pattern uint

pattern to match (after mask is applied)

offset uint

offset from which to start scanning, relative to the current position

size uint

number of bytes to scan from offset

Return Value

Type: uint

offset of the first match, or -1 if no match was found.

Examples

|[ // Assume the reader contains 0x00 0x01 0x02 ... 0xfe 0xff

gst_byte_reader_masked_scan_uint32 (reader, 0xffffffff, 0x00010203, 0, 256); // -> returns 0 gst_byte_reader_masked_scan_uint32 (reader, 0xffffffff, 0x00010203, 1, 255); // -> returns -1 gst_byte_reader_masked_scan_uint32 (reader, 0xffffffff, 0x01020304, 1, 255); // -> returns 1 gst_byte_reader_masked_scan_uint32 (reader, 0xffff, 0x0001, 0, 256); // -> returns -1 gst_byte_reader_masked_scan_uint32 (reader, 0xffff, 0x0203, 0, 256); // -> returns 0 gst_byte_reader_masked_scan_uint32 (reader, 0xffff0000, 0x02030000, 0, 256); // -> returns 2 gst_byte_reader_masked_scan_uint32 (reader, 0xffff0000, 0x02030000, 0, 4); // -> returns -1