Hello, everybody: I'm developing an application using Asterisk and a TDM-400 card.
I understand the concept of the difference between GSM and WAV files when using Asterisk, but I'm not happy with the sound quality with the GSM compression. It's merely *acceptable* for a telephone call, but for anything else, it leaves something to be desired. Case in point -- if you compare the sound quality of the prompts with, say, an Octel voicemail system, there's no contest -- and this is through a standard telephone. 1. Can I *record* audio from a TDM-400 channel at a sample rate above 8000 kHz? Can I record at 16 bits? (This is most important.) 2. Can I use a prompt with a sample rate above 8000 kHz? Will the TDM-400 card support it? How can I do this? The voip-info wiki hints that Asterisk can support whatever codecs listed after a "show codecs" command: > *CLI> show codecs > Disclaimer: this command is for informational purposes only. > It does not indicate anything about your configuration. > INT BINARY HEX TYPE NAME DESC > -------------------------------------------------------------------------------- > 1 (1 << 0) (0x1) audio g723 (G.723.1) > 2 (1 << 1) (0x2) audio gsm (GSM) > 4 (1 << 2) (0x4) audio ulaw (G.711 u-law) > 8 (1 << 3) (0x8) audio alaw (G.711 A-law) > 16 (1 << 4) (0x10) audio g726 (G.726) > 32 (1 << 5) (0x20) audio adpcm (ADPCM) > 64 (1 << 6) (0x40) audio slin (16 bit Signed Linear PCM) > 128 (1 << 7) (0x80) audio lpc10 (LPC10) > 256 (1 << 8) (0x100) audio g729 (G.729A) > 512 (1 << 9) (0x200) audio speex (SpeeX) > 1024 (1 << 10) (0x400) audio ilbc (iLBC) > 65536 (1 << 16) (0x10000) image jpeg (JPEG image) > 131072 (1 << 17) (0x20000) image png (PNG image) > 262144 (1 << 18) (0x40000) video h261 (H.261 Video) > 524288 (1 << 19) (0x80000) video h263 (H.263 Video) > 1048576 (1 << 20) (0x100000) video h263p (H.263+ Video) What is the 16 bit signed Linear PCM format? How do I get Asterisk (1.2) to use such a sound file instead of a *.gsm file? Your feedback is very much appreciated. Cheers, Stephen Bosch _______________________________________________ --Bandwidth and Colocation sponsored by Easynews.com -- Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
