media type | * name | IANA RTP | ast_ constant | also know in * as | Comments |
---|---|---|---|---|---|
audio | pcmu | PCMU | AST_FORMAT_ULAW | ulaw | G.711-µ law, PCM µ-law, North American and Japanese standards |
pcma | PCMA | AST_FORMAT_ALAW | alaw | G.711-A law, PCM A-law, European standards | |
g723 | G723 | AST_FORMAT_G723_1 | g723.1 | In * 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 This old one is completely outdated, not supported by asterisk, never used as an RTP codec, and does not even have an entry in the IANA RTP codecs table.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 | |
gsm | GSM | AST_FORMAT_GSM | |||
g726-32 | G726-32 | AST_FORMAT_G726 | |||
dvi4 | DVI4 | AST_FORMAT_ADPCM | Also know as ADPCM (ADaptive PCM) | ||
l16 | L16 | AST_FORMAT_SLINEAR | 16 bits Signed Linear | ||
lpc | LPC | AST_FORMAT_LPC10 | |||
g729 | G729 | AST_FORMAT_G729A | |||
speex | SPEEX | AST_FORMAT_SPEEX | Free open codec | ||
ilbc | iLBC | AST_FORMAT_ILBC | |||
image | jpeg | JPEG | AST_FORMAT_JPEG | Joint Photographic Experts Group | |
png | PNG | AST_FORMAT_PNG | lossless, free open codec | ||
video | h261 | H261 | AST_FORMAT_H261 | ||
h263 | H263 | AST_FORMAT_H263 |