Subject: [media-types] Registration of audio/aptx

From: "Ali C. Begen (abegen)" <[email-masked]>
Date: Sat, 19 Oct 2013 05:27:10 +0000

Hello, 

The following draft is requesting to register a new media subtype (Section 6.1). Your review is appreciated. 
https://datatracker.ietf.org/doc/draft-ietf-payload-rtp-aptx/?include_text=1

Below is the text.

Thanks,
-acbegen
Payload WG Co-Chair

Registration of media subtype audio/aptx.

      MIME media type name: audio

      MIME subtype name: aptx

      Required parameters:

         rate:
         RTP timestamp clock rate, which is equal to the sampling rate
         in Hz.  -- RECOMMENDED values for rate are 8000, 11025, 16000, 
         22050, 24000, 32000, 44100 and 48000 samples per second. Other 
         values are permissible.

         channels:
         The number of logical audio channels that are present in the  
         audio stream.

         variant:
         The variant of apt-X (i.e.  Standard or Enhanced) that is being
         used.  The following variants can be signalled:

            variant=standard
            variant=enhanced

         bitresolution:
         The number of bits used by the algorithm to encode 4 PCM
         samples.  This value MAY only be set to 16 for Standard apt-X
         and 16 or 24 for Enhanced apt-X.

      Optional parameters:

         ptime:
         The recommended length of time (in milliseconds) represented by
         the media in a packet.  Defaults to 4 ms. See Section 6 of 
         [RFC4566].

         maxptime:
         The maximum length of time (in milliseconds) that can be
         encapsulated in a packet.  See Section 6 of [RFC4566].

         stereo-channel-pairs:
         Defines audio channels that are stereo paired in the stream. 
         See Section 3.  Each pair of audio channels is defined as two 
         comma-separated values that correspond to channel numbers in 
         the range 1..channels.  Each stereo channel pair is preceded 
         by a '{', and followed by a '}'.  Pairs of audio channels are 
         separated by a comma.  A channel MUST NOT be paired with more
         than one other channel.  Absence of this parameter signals that
         each channel has been independently encoded.
 
         embedded-autosync-channels:
         Defines channels that carry embedded autosync.  embedded-
         autosync-channels is defined as a list of comma-separated 
         values that correspond to channel numbers in the range 1..
         channels.  When a channel is stereo paired, embedded autosync
         is shared across channels in the pair. Only the first channel 
         as defined in stereo-channel-pairs MUST be specified in the 
         embedded-autosync-channels list.

         embedded-aux-channels: 
         Defines channels that carry embedded auxiliary data.  embedded-
         aux-channel is defined as a list of comma-separated values 
         that correspond to channel numbers in the range 1..channels.
         When a channel is stereo paired, embedded auxiliary data is 
         shared across channels in the pair. Only the second channel as 
         defined in stereo-channel-pairs MUST be specified in the
         embedded-autosync-channels list.

      Encoding considerations: This type is only defined for transfer
      via RTP [RFC3550].

      Security considerations: See Section 5 of [RFC4855] and Section 4
      of [RFC4856].

      Interoperability considerations: none

      Published specification: RFC XXXX

      Applications which use this media type: Audio streaming

      Additional information: none

      Person & email address to contact for further information: John 
      Lindsay email:[email-masked]

      Intended usage: COMMON

      Author/Change controller: John Lindsay