OpusTags Struct Reference

The metadata from an Ogg Opus stream. More...

#include <opusfile.h>

Data Fields
char **	user_comments
	The array of comment string vectors.
int *	comment_lengths
	An array of the corresponding length of each vector, in bytes.
int	comments
	The total number of comment streams.
char *	vendor
	The null-terminated vendor string.

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Detailed Description

The metadata from an Ogg Opus stream.

This structure holds the in-stream metadata corresponding to the 'comment' header packet of an Ogg Opus stream. The comment header is meant to be used much like someone jotting a quick note on the label of a CD. It should be a short, to the point text note that can be more than a couple words, but not more than a short paragraph.

The metadata is stored as a series of (tag, value) pairs, in length-encoded string vectors, using the same format as Vorbis (without the final "framing bit"), Theora, and Speex, except for the packet header. The first occurrence of the '=' character delimits the tag and value. A particular tag may occur more than once, and order is significant. The character set encoding for the strings is always UTF-8, but the tag names are limited to ASCII, and treated as case-insensitive. See the Vorbis comment header specification for details.

In filling in this structure, libopusfile will null-terminate the user_comments strings for safety. However, the bitstream format itself treats them as 8-bit clean vectors, possibly containing NUL characters, so the comment_lengths array should be treated as their authoritative length.

This structure is binary and source-compatible with a vorbis_comment, and pointers to it may be freely cast to vorbis_comment pointers, and vice versa. It is provided as a separate type to avoid introducing a compile-time dependency on the libvorbis headers.

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Field Documentation

char** OpusTags::user_comments

The array of comment string vectors.

int* OpusTags::comment_lengths

An array of the corresponding length of each vector, in bytes.

int OpusTags::comments

The total number of comment streams.

char* OpusTags::vendor

The null-terminated vendor string.

This identifies the software used to encode the stream.

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The documentation for this struct was generated from the following file:

• /home/giles/projects/opusfile/include/opusfile.h