#Powerdvd 18 id3 software#
If software with ID3v2.2.0 and below support should encounter version three or higher it should simply ignore the whole tag. All revisions are backwards compatible while major versions are not. The first byte of ID3v2 version is it's major version, while the second byte is its revision number. The first three bytes of the tag are always "ID3" to indicate that this is an ID3v2 tag, directly followed by the two version bytes. The ID3v2 tag header, which should be the first information in the file, is 10 bytes as follows: ID3v2/file identifier "ID3" The value of the padding bytes must be $00. A possible purpose of this padding is to allow for adding a few additional frames or enlarge existing frames within the tag without having to rewrite the entire file. It is permitted to include padding after all the final frame (at the end of the ID3 tag), making the size of all the frames together smaller than the size given in the head of the tag. The byteorder in multibyte numbers is most significant byte first (e.g. The bitorder in ID3v2 is most significant bit first (MSB). The ID3 tag described in this document is mainly targeted at files encoded with MPEG-1/2 layer I, MPEG-1/2 layer II, MPEG-1/2 layer III and MPEG-2.5, but may work with other types of encoded audio. If a total revision of the ID3v2 tag should be needed, there is a version number and a size descriptor in the ID3v2 header. At the start of every frame there is an identifier that explains the frames' format and content, and a size descriptor that allows software to skip unknown frames. It is constructed as a container for several information blocks, called frames, whose format need not be known to the software that encounters them. The second criterion has made a more noticeable impact on the design of the ID3v2 tag. If, for any reason, coincidence make a syncsignal appear within the tag it will be taken care of by the 'unsynchronisation scheme' described in section 5. Since the ID3v2 tag doesn't contain a valid syncsignal, no software will attempt to play the tag. The first criterion is met by the simple fact that the MPEG decoding software uses a syncsignal, embedded in the audiostream, to 'lock on to' the audio. The two biggest design goals were to be able to implement ID3v2 without disturbing old software too much and that ID3v2 should be as flexible and expandable as possible. A numeric string is a string that consists of the characters 0-9 only. A field is a piece of information one value, a string etc. The tag consists of a header, frames and optional padding. A frame is a block of information in the tag. The most significant bit (MSB) of a byte is called 'bit 7' and the least significant bit (LSB) is called 'bit 0'.Ī tag is the whole tag described in this document. %x is used to indicate a bit with unknown content. $xx is used to indicate a byte with unknown content. Numbers preceded with $ are hexadecimal and numbers preceded with % are binary. In the examples, text within "" is a text string exactly as it appears in a file.
0 kommentar(er)
