shithub: opus

--- a/doc/draft-ietf-codec-oggopus.xml

+++ b/doc/draft-ietf-codec-oggopus.xml

@@ -666,7 +666,7 @@

 <vspace blankLines="1"/>

 Each packet in an Opus stream has an internal channel count of 1 or 2, which

  can change from packet to packet.

-This is selected by the encoder depending on the bitrate and the contents being

+This is selected by the encoder depending on the bitrate and the audio being

  encoded.

 The original channel count of the encoder input is not preserved by the lossy

  compression.

@@ -723,8 +723,9 @@

 </list>

 <spanx style="strong">Special mapping</spanx>: This channel mapping value also

  indicates that the contents consists of a single Opus stream that is stereo if

- and only if C==2, with stream index 0 mapped to channel 0, and (if stereo)

- stream index 1 mapped to channel 1.

+ and only if C==2, with stream index 0 mapped to output channel 0 (mono, or

+ left channel) and stream index 1 mapped to output channel 1 (right channel)

+ if stereo.

 When the 'channel mapping family' octet has this value, the channel mapping

  table MUST be omitted from the ID header packet.

 <vspace blankLines="1"/>

@@ -754,9 +755,11 @@

  FLAC <xref target="flac"/> formats,

  although the configurations match, so correct ordering requires permutation

  of the output channels when encoding from or decoding to those formats.

+'LFE' here refers to a Low Frequency Effects, often mapped to a subwoofer

+ with no particular spacial position.

 Implementations SHOULD identify 'side' or 'rear' speaker locations with

- 'surround' as appropriate when interfacing with audio formats or systems

- which prefer that terminology.

+ 'surround' and 'back' as appropriate when interfacing with audio formats

+ or systems which prefer that terminology.

 <vspace blankLines="1"/>

 </t>

 <t>Family&nbsp;255 (no defined channel meaning):