Class (GI Struct)

GstBase-1.0GstBaseByteReader

GstBase.ByteReader provides a byte reader that can read different integer and floating point types from a memory buffer. It provides functions for reading signed/unsigned, little/big endian integers of 8, 16, 24, 32 and 64 bits and functions for reading little/big endian floating points numbers of 32 and 64 bits. It also provides functions to read NUL-terminated strings in various character encodings.

Index

Constructors

Properties

byte: number
data: Uint8Array
size: number
$gtype: GType<ByteReader>

Methods

  • Free-function: g_free

    Returns a newly-allocated copy of the current data position if at least size bytes are left and updates the current position. Free with g_free() when no longer needed.

    Returns [boolean, Uint8Array<ArrayBufferLike>]

    true if successful, false otherwise.

  • Free-function: g_free

    Returns a newly-allocated copy of the current data position if there is a NUL-terminated UTF-16 string in the data (this could be an empty string as well), and advances the current position.

    No input checking for valid UTF-16 is done. This function is endianness agnostic - you should not assume the UTF-16 characters are in host endianness.

    This function will fail if no NUL-terminator was found in in the data.

    Note: there is no peek or get variant of this function to ensure correct byte alignment of the UTF-16 string.

    Returns [boolean, number[]]

    true if a string could be read, false otherwise. The string put into str must be freed with g_free() when no longer needed.

  • Free-function: g_free

    Returns a newly-allocated copy of the current data position if there is a NUL-terminated UTF-32 string in the data (this could be an empty string as well), and advances the current position.

    No input checking for valid UTF-32 is done. This function is endianness agnostic - you should not assume the UTF-32 characters are in host endianness.

    This function will fail if no NUL-terminator was found in in the data.

    Note: there is no peek or get variant of this function to ensure correct byte alignment of the UTF-32 string.

    Returns [boolean, number[]]

    true if a string could be read, false otherwise. The string put into str must be freed with g_free() when no longer needed.

  • Free-function: g_free

    FIXME:Reads (copies) a NUL-terminated string in the GstBase.ByteReader instance, advancing the current position to the byte after the string. This will work for any NUL-terminated string with a character width of 8 bits, so ASCII, UTF-8, ISO-8859-N etc. No input checking for valid UTF-8 is done.

    This function will fail if no NUL-terminator was found in in the data.

    Returns [boolean, string[]]

    true if a string could be read into str, false otherwise. The string put into str must be freed with g_free() when no longer needed.

  • Returns a constant pointer to the current data position if at least size bytes are left and updates the current position.

    Returns [boolean, Uint8Array<ArrayBufferLike>]

    true if successful, false otherwise.

  • Read a 32 bit big endian floating point value into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a 32 bit little endian floating point value into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a 64 bit big endian floating point value into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a 64 bit little endian floating point value into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 16 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 16 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 24 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 24 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 32 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 32 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 64 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 64 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 8 bit integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Returns a constant pointer to the current data position if there is a NUL-terminated string in the data (this could be just a NUL terminator), advancing the current position to the byte after the string. This will work for any NUL-terminated string with a character width of 8 bits, so ASCII, UTF-8, ISO-8859-N etc.

    No input checking for valid UTF-8 is done.

    This function will fail if no NUL-terminator was found in in the data.

    Returns [boolean, string[]]

    true if a string could be found, false otherwise.

  • Read an unsigned 16 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 16 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 24 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 24 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 32 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 32 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 64 bit big endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 64 bit little endian integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 8 bit integer into val and update the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • 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.

    Parameters

    • mask: number

      mask to apply to data before matching against pattern

    • pattern: number

      pattern to match (after mask is applied)

    • offset: number

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

    • size: number

      number of bytes to scan from offset

    Returns number

    offset of the first match, or -1 if no match was found. Example: |[ // 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 ]|

  • 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.

    Parameters

    • mask: number

      mask to apply to data before matching against pattern

    • pattern: number

      pattern to match (after mask is applied)

    • offset: number

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

    • size: number

      number of bytes to scan from offset

    Returns [number, number]

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

  • Returns a constant pointer to the current data position if at least size bytes are left and keeps the current position.

    Returns [boolean, Uint8Array<ArrayBufferLike>]

    true if successful, false otherwise.

  • Read a 32 bit big endian floating point value into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a 32 bit little endian floating point value into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a 64 bit big endian floating point value into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a 64 bit little endian floating point value into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 16 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 16 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 24 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 24 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 32 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 32 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 64 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 64 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read a signed 8 bit integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Returns a constant pointer to the current data position if there is a NUL-terminated string in the data (this could be just a NUL terminator). The current position will be maintained. This will work for any NUL-terminated string with a character width of 8 bits, so ASCII, UTF-8, ISO-8859-N etc.

    No input checking for valid UTF-8 is done.

    This function will fail if no NUL-terminator was found in in the data.

    Returns [boolean, string[]]

    true if a string could be skipped, false otherwise.

  • Read an unsigned 16 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 16 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 24 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 24 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 32 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 32 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 64 bit big endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 64 bit little endian integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Read an unsigned 8 bit integer into val but keep the current position.

    Returns [boolean, number]

    true if successful, false otherwise.

  • Sets the new position of a GstBase.ByteReader instance to pos in bytes.

    Parameters

    • pos: number

      The new position in bytes

    Returns boolean

    true if the position could be set successfully, false otherwise.

  • Skips a NUL-terminated UTF-16 string in the GstBase.ByteReader instance, advancing the current position to the byte after the string.

    No input checking for valid UTF-16 is done.

    This function will fail if no NUL-terminator was found in in the data.

    Returns boolean

    true if a string could be skipped, false otherwise.

  • Skips a NUL-terminated UTF-32 string in the GstBase.ByteReader instance, advancing the current position to the byte after the string.

    No input checking for valid UTF-32 is done.

    This function will fail if no NUL-terminator was found in in the data.

    Returns boolean

    true if a string could be skipped, false otherwise.

  • Skips a NUL-terminated string in the GstBase.ByteReader instance, advancing the current position to the byte after the string. This will work for any NUL-terminated string with a character width of 8 bits, so ASCII, UTF-8, ISO-8859-N etc. No input checking for valid UTF-8 is done.

    This function will fail if no NUL-terminator was found in in the data.

    Returns boolean

    true if a string could be skipped, false otherwise.