(RFC 3190 published January 2002, subtype last updated January 2002) MIME media type name: audio MIME subtype name: L20 Required parameters: rate: number of samples per second -- RECOMMENDED values for rate are 8000, 11025, 16000, 22050, 24000, 32000, 44100 and 48000 samples per second. Other values are permissible. Optional parameters: channels: how many audio streams are interleaved -- defaults to 1; stereo would be 2, etc. Interleaving takes place between individual 20-bit samples. emphasis: analog preemphasis applied to the data before quantization. The only emphasis value defined here is emphasis=50-15 to indicate 50/15 microsecond preemphasis. This parameter MUST be omitted if no analog preemphasis was applied. channel-order: specifies the sample interleaving order for multiple-channel audio streams (see RFC 3190 Section 7). Permissible values are DV.LRLsRs, DV.LRCS, DV.LRCWo, DV.LRLsRsC, DV.LRLsRsCS, DV.LmixRmixTWoQ1Q2, DV.LRCWoLsRsLmixRmix, DV.LRCWoLs1Rs1Ls2Rs2, DV.LRCWoLsRsLcRc. For interoperation with DV video systems, none of these channel combinations is specified for use with 20-bit linear encoding in the DV video specification [4]; only mono and stereo are allowed. This parameter MUST be omitted when the AIFF-C channel order convention is in use. Encoding considerations: L20 audio can be transmitted with RTP as specified in RFC 3190. Security considerations: See Section 9. Interoperability considerations: NONE Published specification: RFC 3190. Applications which use this media type: Audio communication. Additional information: Magic number(s): None File extension(s): None Macintosh File Type Code(s): None Person & email address to contact for further information: Katsushi Kobayashi e-mail: ikob&koganei.wide.ad.jp Intended usage: COMMON Author/Change controller: Katsushi Kobayashi e-mail: ikob&koganei.wide.ad.jp