1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/isdn/i4l/isdn_audio.h b/drivers/isdn/i4l/isdn_audio.h
new file mode 100644
index 000000000000..5a977b21dcfa
--- /dev/null
+++ b/drivers/isdn/i4l/isdn_audio.h
@@ -0,0 +1,45 @@
+/* $Id: isdn_audio.h,v 1.1.2.2 2004/01/12 22:37:18 keil Exp $
+ *
+ * Linux ISDN subsystem, audio conversion and compression (linklevel).
+ *
+ * Copyright 1994-1999 by Fritz Elfert (fritz@isdn4linux.de)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ */
+
+#define DTMF_NPOINTS 205        /* Number of samples for DTMF recognition */
+typedef struct adpcm_state {
+        int a;
+        int d;
+        int word;
+        int nleft;
+        int nbits;
+} adpcm_state;
+
+typedef struct dtmf_state {
+        char last;
+        char llast;
+        int idx;
+        int buf[DTMF_NPOINTS];
+} dtmf_state;
+
+typedef struct silence_state {
+        int state;
+        unsigned int idx;
+} silence_state;
+
+extern void isdn_audio_ulaw2alaw(unsigned char *, unsigned long);
+extern void isdn_audio_alaw2ulaw(unsigned char *, unsigned long);
+extern adpcm_state *isdn_audio_adpcm_init(adpcm_state *, int);
+extern int isdn_audio_adpcm2xlaw(adpcm_state *, int, unsigned char *, unsigned char *, int);
+extern int isdn_audio_xlaw2adpcm(adpcm_state *, int, unsigned char *, unsigned char *, int);
+extern int isdn_audio_2adpcm_flush(adpcm_state * s, unsigned char *out);
+extern void isdn_audio_calc_dtmf(modem_info *, unsigned char *, int, int);
+extern void isdn_audio_eval_dtmf(modem_info *);
+dtmf_state *isdn_audio_dtmf_init(dtmf_state *);
+extern void isdn_audio_calc_silence(modem_info *, unsigned char *, int, int);
+extern void isdn_audio_eval_silence(modem_info *);
+silence_state *isdn_audio_silence_init(silence_state *);
+extern void isdn_audio_put_dle_code(modem_info *, u_char);