mme_metadata_info_t

The metadata structure

Synopsis:

#include <mme/types.h>

typedef struct s_mme_metadata_info {
    int  len;
    char xmlbuf[1];
} mme_metadata_info_t;

Description:

The structure mme_metadata_info_t carries the metadata retrieved by mme_metadata_getinfo_current(), mme_metadata_getinfo_file() and mme_metadata_getinfo_library().

Member Type Description
len int The length, in bytes, of the xmlbuf string, including its NULL terminator. See XML content below.
xmlbuf char A NULL-terminated XML formated string containing metadata.

XML content

The MME's metadata API organizes metadata into groups and subgroups. You can use these groups and subgroups to request only the metadata you need, thereby optimizing performance and reducing resource consumption.

To request only specified metadata, use the following guidelines to set the character string referenced by a mme_metadata_getinfo_*() function's metadata_groups argument:

Supported <format> attributes

The table below list the attributes for the <format> element currently supported by the MME's metadata API.

Attribute Optional Description
height Yes The image height, in pixels.
width Yes The image width, in pixels.
mime_type Yes The content MIME type.
start_timepos Yes The image start time, in milliseconds, from the start of the track.
end_timepos Yes The image end time, in milliseconds, from the start of the track.
desc Yes An image description.
size Yes The image size, in bytes.
url Yes An external URL to the image.

Example: default XML content

Below a example of the default XML content returned in xmlbuf by a call to an mme_metadata_getinfo_*() function. No metadata group is enabled:

<?xml version="1.0" standalone="yes"?>
<container type="file">
    <track index="0">
        <audio>
            <stream index="0"/>
        </audio>
        <images>
            <image index="0"/>
            <image index="1"/>
        </images>
    </track>
</container>

Example: XML content with one metadata group enable

Below is an example of the XML content returned in xmlbuf by a call to an mme_metadata_getinfo_*() function. Only the <image>/<format> metadata group is enabled:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<container type="file">
    <track index="0">
        <audio>
            <stream index="0"/>
        </audio>
        <images>
            <image index="0">
                <format width="0" height="0" size="29316"/>
            </image>
            <image index="1"/>
        </images>
    </track>
</container>

Classification:

QNX Multimedia

See also:

mme_metadata_create_session(), mme_metadata_free_session(), mme_metadata_getinfo_current(), mme_metadata_getinfo_file(), mme_metadata_getinfo_library(), mme_metadata_image_cache_clear(), mme_metadata_image_load(), mme_metadata_image_unload(), mme_metadata_image_url_t, mme_metadata_session_t