Asterisk naming convention for codecs

This document suggests a naming convention for codecs across Asterisk configuration files, applications, GUIs, file extensions.

Up to now the chosen names are exactly those assigned by IANA for RTP streams, but written in low-case.

media type * name IANA RTP ast_ constant also know in * as Comments
audiopcmuPCMUAST_FORMAT_ULAWulawG.711-µ law, PCM µ-law, North American and Japanese standards
pcmaPCMAAST_FORMAT_ALAWalawG.711-A law, PCM A-law, European standards
g723G723AST_FORMAT_G723_1g723.1In * g723 always refers to G.723.1 whose bitrates can be 6.3 kbps or 5.3 kbps.

There is also an old "G.723" (without ".1" as "G.723.1") developped by Sun. Its bitrates are 24 kbps or 40 kbps. This old one is completely outdated, not supported by asterisk, never used as an RTP codec, and does not even have an entry in the IANA RTP codecs table.
Caution: SOX includes support for the old G.723, not the real G.723.1
gsmGSMAST_FORMAT_GSM
g726-32G726-32AST_FORMAT_G726
dvi4DVI4AST_FORMAT_ADPCMAlso know as ADPCM (ADaptive PCM)
l16L16AST_FORMAT_SLINEAR16 bits Signed Linear
lpcLPCAST_FORMAT_LPC10
g729G729AST_FORMAT_G729A
speexSPEEXAST_FORMAT_SPEEXFree open codec
ilbciLBCAST_FORMAT_ILBC
imagejpegJPEGAST_FORMAT_JPEGJoint Photographic Experts Group
pngPNGAST_FORMAT_PNGlossless, free open codec
videoh261H261AST_FORMAT_H261
h263H263AST_FORMAT_H263

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