patch-pre2.0.10 linux/Documentation/isdn/README.audio

• Lines: 116
• Date: Sat Jun 1 11:56:51 1996
• Orig file: pre2.0.9/linux/Documentation/isdn/README.audio
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file pre2.0.9/linux/Documentation/isdn/README.audio linux/Documentation/isdn/README.audio
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+$Id: README.audio,v 1.1 1996/05/19 00:07:35 fritz Exp $
+
+ISDN subsystem for Linux.
+  Description of audio mode.
+
+When enabled during kernel configuration, the tty emulator of the ISDN
+subsystem is capable of a reduced set of commands to support audio.
+This document describes the commands supported and the format of
+audio data.
+
+Commands for enabling/disabling audio mode:
+
+        AT+FCLASS=8      Enable audio mode.
+                         This affects the following registers:
+                           S18: Bits 0 and 3 are set.
+                           S16: Set to 48 and any further change to
+                                larger values is blocked.
+        AT+FCLASS=0      Disable audio mode.
+                         Register 18 is set to 4.
+        AT+FCLASS=?      Show possible modes.
+        AT+FCLASS?       Report current mode (0 or 8).
+
+Commands supported in audio mode:
+
+All audio mode commands have the one of the following form:
+
+        AT+Vxx?          Show current setting.
+        AT+Vxx=?         Show possible settings.
+        AT+Vxx=v         Set simple parameter.
+        AT+Vxx=v,v ...   Set complex parameter.
+
+where xx is a two-character code and v are alphanumerical parameters.
+The following commands are supported:
+
+        AT+VNH=x         Auto hangup settting. NO EFFECT, supported
+                         for compatibility only.
+        AT+VNH?          Always reporting "1"
+        AT+VNH=?         Always reporting "1"
+
+        AT+VIP           Reset all audio parameters.
+
+        AT+VLS=x         Line select. x is one of the following:
+                           0 = No device.
+                           2 = Phone line.
+        AT+VLS=?         Always reporting "0,2"
+        AT+VLS?          Show current line.
+
+        AT+VRX           Start recording. Emulator responds with
+                         CONNECT and starts sending audio data to
+                         the application. See below for data format
+
+        AT+VSD=x,y       Set silence-detection parameters.
+                         NO EFFECT, supported for compatibility
+                         only. Possible parameters:
+                           x = 0 ... 31
+                           y = 0 ... 255
+        AT+VSD=?         Report possible parameters.
+        AT+VSD?          Show current parameters.
+
+        AT+VSM=x         Select audio data format.
+                         Possible parameters:
+                           2 = ADPCM-2
+                           3 = ADPCM-3
+                           4 = ADPCM-4
+                           5 = aLAW
+                           6 = uLAW
+        AT+VSM=?         Show possible audio formats.
+
+        AT+VTX           Start audio playback. Emulator responds
+                         with CONNECT and starts sending audio data
+                         received from the application via phone line.
+General behavior and description of data formats/protocol.
+    when a connection is made:
+
+      On incoming calls, if the application responds to a RING
+      with ATA, depending on the calling service, the emulator
+      responds with either CONNECT (data call) or VCON (voice call).
+      
+      On outgoing voice calls, the emulator responds with VCON
+      upon connection setup.
+
+  Audio recording.
+
+    When receiving audio data, a kind of bisync protocol is used.
+    Upon AT+VRX command, the emulator responds with CONNECT, and
+    starts sending audio data to the application. There are several
+    escape sequences defined, all using DLE (0x10) as Escape char:
+
+    <DLE><ETX>              End of audio data. Emulator stops
+                            recording, responding with VCON.
+    <DLE><DLE>              Escape sequence for DLE in data stream.
+
+    Currently unsupported DLE sequences:
+
+    <DLE>0                  Touchtone "0" received.
+         ...
+    <DLE>9                  Touchtone "9" received.
+    <DLE>#                  Touchtone "#" received.
+    <DLE>*                  Touchtone "*" received.
+    <DLE>c                  FAX calling tone received.
+    <DLE>b                  busy tone received.
+    <DLE>q                  quiet. Silence detected after non-silence.
+    <DLE>s                  silence. Silence dectected from the
+                            start of recording.
+
+    Any character sent by the application, except XON (0x11) or XOFF (0x13)
+    immediately stops recording.
+
+  Audio playback.
+
+    When sending audio data, upon AT+VTX command, emulator responds with
+    CONNECT, and starts transfering data from application to the phone line.
+    The same DLE sequences apply to this mode.
+
+