payloads.sgml

ortp协议栈（实时传输协议）

<!-- ##### SECTION Title ##### -->
RTP payloads and profiles

<!-- ##### SECTION Short_Description ##### -->
This section describes the way that the oRTP stack manages RTP profiles and payload types.

<!-- ##### SECTION Long_Description ##### -->
<para>
A rtp payload type is a number between 0 and 127 that identifies a particular payload 
(GSM, PCMU, MPEG,...) within a given rtp profile. The #PayloadType object in oRTP describes
a payload.

An RTP profile is a table that assigns particular payloads (GSM, MPEG...) to a payload type
number within the range 0..127. In oRTP, profiles are represented by the #RtpProfile object.

For example in the AV profile (Audio Video profile, defined in RFC1890), often used 
by telephony applications, the payload type number 8 is assigned to PCMA 
(A-law compressed audio) at sampling frequency 8000 Hz, mono.

By default, all RTP sessions created by oRTP use the AV profile, but you can change the profile
of an RTP session using rtp_session_set_profile().
</para>

<!-- ##### SECTION See_Also ##### -->
<para>
rtp_session_set_profile()
</para>

<!-- ##### STRUCT PayloadType ##### -->
<para>

</para>

@type: 
@bytes_per_sample: 
@zero_pattern: 
@pattern_length: 
@normal_bitrate: 
@mime_type: 
@flags: 

<!-- ##### STRUCT RtpProfile ##### -->
<para>

</para>

@name: 
@payload: 

<!-- ##### VARIABLE av_profile ##### -->
<para>
This is the Audio Video profile defined in RFC1890.
</para>


<!-- ##### MACRO rtp_profile_clear_all ##### -->
<para>

</para>

@profile: 


<!-- ##### MACRO rtp_profile_get_name ##### -->
<para>

</para>

@profile: 


<!-- ##### MACRO rtp_profile_set_name ##### -->
<para>

</para>

@profile: 
@nm: 


<!-- ##### MACRO rtp_profile_set_payload ##### -->
<para>

</para>

@profile: 
@index: 
@pt: 


<!-- ##### MACRO rtp_profile_get_payload ##### -->
<para>

</para>

@profile: 
@index: 


<!-- ##### MACRO rtp_profile_clear_payload ##### -->
<para>

</para>

@profile: 
@index: 


<!-- ##### MACRO rtp_profile_clear_all ##### -->
<para>

</para>

@profile: