eden-emu/opus
19
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Updated RTP draft

Browse source
This commit is contained in:
Jean-Marc Valin 2009-05-11 12:53:46 -04:00
parent 8842fdee21
commit e95de9a244
1 changed files with 4 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

12
doc/ietf/draft-valin-celt-rtp-profile.xml
View file

@ -438,24 +438,20 @@ headers and the length bytes). The value MUST be rounded to an integer number
of bytes per frame. The round-to-nearest method is RECOMMENDED. The default
bit-rate value is 64 kbit/s per channel.</t>
<t>frame-size: The frame size is the duration of each frame in samples. If more than one frame size is supported, a comma-separated list can be used. It is possible to use "any" to denote that
all even frame sizes are supported. The default is 480.</t>
<t>frame-size: The frame size is the duration of each frame in samples and has to be even.
The default is 480.</t>
<t>mapping: Optional string describing the multi-channel mapping.</t>
</list>
</t>
<t>Because the frame-size is not transmitted in-band, an SDP answer MUST
contain only one frame-size, even if multiple frame sizes were offered.
</t>
<t>
The selected frame-size values MUST be even. For quality and complexity
reasons, they SHOULD also be divisible by 8 and have a prime factorization
which consists only of 2, 3, or 5 factors.
For example, powers-of-two and values such as 160, 320, 240, and 480 are
recommended. Implementations MUST support receiving and sending the default
value of 480, and if the size 480 is supported it MUST be offered. Implementations
value of 480. Implementations
SHOULD also support frame sizes of 256 and 512 since these are the ones that lead
to the lowest complexity. When frame sizes that are powers-of-two are supported,
they SHOULD be listed first in the offer and chosen over non-powers-of-two in the
@ -571,7 +567,7 @@ For example a stereo configuration might signal:
<t>m=audio 8008 RTP/AVP 97</t>
<t>a=ptime: 5</t>
<t>a=rtpmap:97 CELT/44100/2</t>
<t>a=fmtp:97 frame-size=256;</t>
<t>a=fmtp:97 frame-size=256</t>
</list>
Which specifies a single two-channel CELT stream according to the default
mapping.