Structure of the RFC 3986 URI

The element BaseURL syntax rules for MPEG Dash follow RFC 3986, which requires a simple understanding:

I.1 the name of each part of the URI

Foo://example.com:8042/over/there?name=ferret#nose

\_/   \______________/\_________/ \_________/ \__/

|                          |                     |             | |

Scheme Authority path Query fragment

| _________________________|__

/ \ /                                           \

Urn:example:animal:ferret:nose

Scheme: The name of the agreement, beginning with a letter, followed by an Italian letter / number /+/-/. the combination.

Scheme = ALPHA * (alpha/digit/"+"/"-"/".")

Authority: Starts with a double slash "//" but does not include "//" to immediately follow the first '/' or? or #(# here

Call number sign) ends without including the symbol, or until the URL ends.

authority = [userinfo "@"] host [":" Port]

the part within [] is an optional part.

Path: after authority , begin with / start with the first one immediately after? or # end or until the end of the URL .

Query: with? At the end of the first # , or until the end of the URL ,query often

"Key=value" form to carry some authentication information.

Fragment: Starts with # until the URL ends. Fragment is often used to mark a reference to a primary resource's secondary

Resources.

Reference rules for I.2 URIs

Uri-reference:uri-reference may be a URI or relative-reference , when uri-reference the prefix does not

When matching scheme syntax, it indicates that uri-reference is a relative-reference.

the URI referenced by relative-reference is called the target URI.

In mpeg Dash , it is only necessary to know that BaseURL may need to refer to the ancestor's BaseURL to combine it into a complete The HTTP link can be as follows:

<?xml version= "1.0"?>

<mpd

Xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"

Xmlns= "urn:mpeg:dash:schema:mpd:2011"

xsi:schemalocation= "urn:mpeg:dash:schema:mpd:2011 dash-mpd.xsd"

Type= "Static"

mediapresentationduration= "pt3256s"

Minbuffertime= "Pt1.2s"

profiles= "urn:mpeg:dash:profile:isoff-on-demand:2011" >

<BaseURL>http://cdn1.example.com/</BaseURL>

<BaseURL>http://cdn2.example.com/</BaseURL>

<Period>

<!--中文版 Audio--

<adaptationset mimetype= "Audio/mp4" codecs= "mp4a.0x40" lang= "en" subsegmentalignment= "true"

subsegmentstartswithsap= "1" >

<contentprotection schemeiduri= "urn:uuid:706d6953-656c-5244-4d48-656164657221"/>

<representation id= "1" bandwidth= "64000" >

<BaseURL>7657412348.mp4</BaseURL>

</Representation>

<representation id= "2" bandwidth= "32000" >

<BaseURL>3463646346.mp4</BaseURL>

</Representation>

</AdaptationSet>

</Period>

</MPD>

The HTTP URL to access two MP4 files requires the combination of the BaseURL in the baseurl and representation in MPD:

Http://cdn1.example.com/7657412348.mp4

Http://cdn1.example.com/3463646346.mp4

Or

Http://cdn2.example.com/7657412348.mp4

Http://cdn2.example.com/3463646346.mp4

Structure of the RFC 3986 URI