ref: 03d5fec2033b1a8ddab5da7603abc77507d34348
parent: 0094c881059af78dda93ee1d2ef65d8d7d6453ef
author: Julian Spittka <[email protected]>
date: Thu Nov 29 22:12:59 EST 2012
RTP draft updates addressing the rest of Tina's comments
--- a/doc/draft-spittka-payload-rtp-opus.xml
+++ b/doc/draft-spittka-payload-rtp-opus.xml
@@ -406,12 +406,16 @@
</figure>
<t>
- <xref target='opus-packetization'/> shows supported frame sizes for different modes
- and sampling rates of Opus and how the timestamp needs to be incremented for
- packetization.
+ <xref target='opus-packetization'/> shows supported frame sizes in
+ milliseconds of encoded speech or audio data for speech and audio mode
+ (Mode) and sampling rates (fs) of Opus and how the timestamp needs to
+ be incremented for packetization (ts incr). If the Opus encoder
+ outputs multiple encoded frames into a single packet the timestamps
+ have to be added up according to the combined frames.
</t>
- <texttable anchor='opus-packetization'>
+ <texttable anchor='opus-packetization' title="Supported Opus frame
+ sizes and timestamp increments">
<ttcol align='center'>Mode</ttcol>
<ttcol align='center'>fs</ttcol>
<ttcol align='center'>2.5</ttcol>
@@ -444,14 +448,6 @@
<c>x</c>
<c></c>
<c></c>
- <postamble>
- Mode specifies the Opus mode of operation; fs specifies the audio sampling
- frequency in Hertz (Hz); 2.5, 5, 10, 20, 40, and 60 represent the duration of
- encoded speech or audio data in a packet; ts incr specifies the
- value the timestamp needs to be incremented for the representing packet size.
- For multiple frames in a packet these values have to be multiplied with the
- respective number of frames.
- </postamble>
</texttable>
</section>
@@ -620,11 +616,11 @@
</t>
<t hangText="useinbandfec:"> specifies that the decoder has the capability to
- use the Opus in-band FEC. Possible values are 1 and 0. It is RECOMMENDED to provide
- 0 in case FEC cannot be used on the receiving side. If no
- value is specified, useinbandfec is assumed to be 1.
+ take advantage of the Opus in-band FEC. Possible values are 1 and 0. It is RECOMMENDED to provide
+ 0 in case FEC cannot be utilized on the receiving side. If no
+ value is specified, useinbandfec is assumed to be 0.
This parameter is only a preference and the receiver MUST be able to process
- packets that have FEC information, even if it means the FEC part is discarded.
+ packets that include FEC information, even if it means the FEC part is discarded.
<vspace blankLines='1'/></t>
<t hangText="usedtx:"> specifies if the decoder prefers the use of
@@ -672,8 +668,8 @@
<t>Author:</t>
<t><list style="hanging">
- <t>Julian Spittka [email protected]<vspace blankLines='1'/></t>
- <t>Koen Vos [email protected]<vspace blankLines='1'/></t>
+ <t>Julian Spittka [email protected]<vspace blankLines='1'/></t>
+ <t>Koen Vos [email protected]<vspace blankLines='1'/></t>
<t>Jean-Marc Valin [email protected]<vspace blankLines='1'/></t>
</list></t>
@@ -699,10 +695,10 @@
mapped to "a=ptime" and "a=maxptime" attributes, respectively, in the
SDP.</t>
- <t>The OPTIONAL media type parameters "maxaveragebitrate",
- "minptime", "stereo", "cbr", "useinbandfec", and "usedtx", when
- present, MUST be included in the "a=fmtp" attribute in the SDP,
- expressed as a media type string in the form of a
+ <t>The OPTIONAL media type parameters "maxaveragebitrate",
+ "maxplaybackrate", "minptime", "stereo", "cbr", "useinbandfec", and
+ "usedtx", when present, MUST be included in the "a=fmtp" attribute
+ in the SDP, expressed as a media type string in the form of a
semicolon-separated list of parameter=value pairs (e.g.,
maxaveragebitrate=20000). They MUST NOT be specified in an
SSRC-specific "fmtp" source-level attribute (as defined in
@@ -829,13 +825,13 @@
the parameter the performance of the application may suffer and should
be set with care.</t>
- <t>The "sprop-maxcaptureerate" and "sprop-stereo" parameters are
+ <t>The "sprop-maxcapturerate" and "sprop-stereo" parameters are
unidirectional sender-only parameters that reflect limitations of
the sender side.
They allow the receiver to set up a reduced-complexity audio
processing pipeline if the sender is not planning to use the full
range of Opus's capabilities.
- Neither "sprop-maxcaptureerate" nor "sprop-stereo" affect
+ Neither "sprop-maxcapturerate" nor "sprop-stereo" affect
interoperability and the receiver MUST be capable of receiving any signal.
</t>