--- /home/peter/src/mISDN-1_1_5/drivers/isdn/hardware/mISDN/dsp_audio.c	2007-07-02 11:31:34.000000000 +0200
+++ ./dsp_audio.c	2007-09-15 19:12:34.000000000 +0200
@@ -15,331 +15,173 @@
 #include "dsp.h"
 
 /* ulaw[unsigned char] -> signed 16-bit */
-s32 dsp_audio_ulaw_to_s32[256] =
-{
-	0xffff8284, 0xffff8684, 0xffff8a84, 0xffff8e84,
-	0xffff9284, 0xffff9684, 0xffff9a84, 0xffff9e84,
-	0xffffa284, 0xffffa684, 0xffffaa84, 0xffffae84,
-	0xffffb284, 0xffffb684, 0xffffba84, 0xffffbe84,
-	0xffffc184, 0xffffc384, 0xffffc584, 0xffffc784,
-	0xffffc984, 0xffffcb84, 0xffffcd84, 0xffffcf84,
-	0xffffd184, 0xffffd384, 0xffffd584, 0xffffd784,
-	0xffffd984, 0xffffdb84, 0xffffdd84, 0xffffdf84,
-	0xffffe104, 0xffffe204, 0xffffe304, 0xffffe404,
-	0xffffe504, 0xffffe604, 0xffffe704, 0xffffe804,
-	0xffffe904, 0xffffea04, 0xffffeb04, 0xffffec04,
-	0xffffed04, 0xffffee04, 0xffffef04, 0xfffff004,
-	0xfffff0c4, 0xfffff144, 0xfffff1c4, 0xfffff244,
-	0xfffff2c4, 0xfffff344, 0xfffff3c4, 0xfffff444,
-	0xfffff4c4, 0xfffff544, 0xfffff5c4, 0xfffff644,
-	0xfffff6c4, 0xfffff744, 0xfffff7c4, 0xfffff844,
-	0xfffff8a4, 0xfffff8e4, 0xfffff924, 0xfffff964,
-	0xfffff9a4, 0xfffff9e4, 0xfffffa24, 0xfffffa64,
-	0xfffffaa4, 0xfffffae4, 0xfffffb24, 0xfffffb64,
-	0xfffffba4, 0xfffffbe4, 0xfffffc24, 0xfffffc64,
-	0xfffffc94, 0xfffffcb4, 0xfffffcd4, 0xfffffcf4,
-	0xfffffd14, 0xfffffd34, 0xfffffd54, 0xfffffd74,
-	0xfffffd94, 0xfffffdb4, 0xfffffdd4, 0xfffffdf4,
-	0xfffffe14, 0xfffffe34, 0xfffffe54, 0xfffffe74,
-	0xfffffe8c, 0xfffffe9c, 0xfffffeac, 0xfffffebc,
-	0xfffffecc, 0xfffffedc, 0xfffffeec, 0xfffffefc,
-	0xffffff0c, 0xffffff1c, 0xffffff2c, 0xffffff3c,
-	0xffffff4c, 0xffffff5c, 0xffffff6c, 0xffffff7c,
-	0xffffff88, 0xffffff90, 0xffffff98, 0xffffffa0,
-	0xffffffa8, 0xffffffb0, 0xffffffb8, 0xffffffc0,
-	0xffffffc8, 0xffffffd0, 0xffffffd8, 0xffffffe0,
-	0xffffffe8, 0xfffffff0, 0xfffffff8, 0xffffffff,
-	0x00007d7c, 0x0000797c, 0x0000757c, 0x0000717c,
-	0x00006d7c, 0x0000697c, 0x0000657c, 0x0000617c,
-	0x00005d7c, 0x0000597c, 0x0000557c, 0x0000517c,
-	0x00004d7c, 0x0000497c, 0x0000457c, 0x0000417c,
-	0x00003e7c, 0x00003c7c, 0x00003a7c, 0x0000387c,
-	0x0000367c, 0x0000347c, 0x0000327c, 0x0000307c,
-	0x00002e7c, 0x00002c7c, 0x00002a7c, 0x0000287c,
-	0x0000267c, 0x0000247c, 0x0000227c, 0x0000207c,
-	0x00001efc, 0x00001dfc, 0x00001cfc, 0x00001bfc,
-	0x00001afc, 0x000019fc, 0x000018fc, 0x000017fc,
-	0x000016fc, 0x000015fc, 0x000014fc, 0x000013fc,
-	0x000012fc, 0x000011fc, 0x000010fc, 0x00000ffc,
-	0x00000f3c, 0x00000ebc, 0x00000e3c, 0x00000dbc,
-	0x00000d3c, 0x00000cbc, 0x00000c3c, 0x00000bbc,
-	0x00000b3c, 0x00000abc, 0x00000a3c, 0x000009bc,
-	0x0000093c, 0x000008bc, 0x0000083c, 0x000007bc,
-	0x0000075c, 0x0000071c, 0x000006dc, 0x0000069c,
-	0x0000065c, 0x0000061c, 0x000005dc, 0x0000059c,
-	0x0000055c, 0x0000051c, 0x000004dc, 0x0000049c,
-	0x0000045c, 0x0000041c, 0x000003dc, 0x0000039c,
-	0x0000036c, 0x0000034c, 0x0000032c, 0x0000030c,
-	0x000002ec, 0x000002cc, 0x000002ac, 0x0000028c,
-	0x0000026c, 0x0000024c, 0x0000022c, 0x0000020c,
-	0x000001ec, 0x000001cc, 0x000001ac, 0x0000018c,
-	0x00000174, 0x00000164, 0x00000154, 0x00000144,
-	0x00000134, 0x00000124, 0x00000114, 0x00000104,
-	0x000000f4, 0x000000e4, 0x000000d4, 0x000000c4,
-	0x000000b4, 0x000000a4, 0x00000094, 0x00000084,
-	0x00000078, 0x00000070, 0x00000068, 0x00000060,
-	0x00000058, 0x00000050, 0x00000048, 0x00000040,
-	0x00000038, 0x00000030, 0x00000028, 0x00000020,
-	0x00000018, 0x00000010, 0x00000008, 0x00000000
-};
-
+s32 dsp_audio_ulaw_to_s32[256];
 /* alaw[unsigned char] -> signed 16-bit */
-s32 dsp_audio_alaw_to_s32[256] =
-{
-	0x000013fc, 0xffffec04, 0x00000144, 0xfffffebc,
-	0x0000517c, 0xffffae84, 0x0000051c, 0xfffffae4,
-	0x00000a3c, 0xfffff5c4, 0x00000048, 0xffffffb8,
-	0x0000287c, 0xffffd784, 0x0000028c, 0xfffffd74,
-	0x00001bfc, 0xffffe404, 0x000001cc, 0xfffffe34,
-	0x0000717c, 0xffff8e84, 0x0000071c, 0xfffff8e4,
-	0x00000e3c, 0xfffff1c4, 0x000000c4, 0xffffff3c,
-	0x0000387c, 0xffffc784, 0x0000039c, 0xfffffc64,
-	0x00000ffc, 0xfffff004, 0x00000104, 0xfffffefc,
-	0x0000417c, 0xffffbe84, 0x0000041c, 0xfffffbe4,
-	0x0000083c, 0xfffff7c4, 0x00000008, 0xfffffff8,
-	0x0000207c, 0xffffdf84, 0x0000020c, 0xfffffdf4,
-	0x000017fc, 0xffffe804, 0x0000018c, 0xfffffe74,
-	0x0000617c, 0xffff9e84, 0x0000061c, 0xfffff9e4,
-	0x00000c3c, 0xfffff3c4, 0x00000084, 0xffffff7c,
-	0x0000307c, 0xffffcf84, 0x0000030c, 0xfffffcf4,
-	0x000015fc, 0xffffea04, 0x00000164, 0xfffffe9c,
-	0x0000597c, 0xffffa684, 0x0000059c, 0xfffffa64,
-	0x00000b3c, 0xfffff4c4, 0x00000068, 0xffffff98,
-	0x00002c7c, 0xffffd384, 0x000002cc, 0xfffffd34,
-	0x00001dfc, 0xffffe204, 0x000001ec, 0xfffffe14,
-	0x0000797c, 0xffff8684, 0x000007bc, 0xfffff844,
-	0x00000f3c, 0xfffff0c4, 0x000000e4, 0xffffff1c,
-	0x00003c7c, 0xffffc384, 0x000003dc, 0xfffffc24,
-	0x000011fc, 0xffffee04, 0x00000124, 0xfffffedc,
-	0x0000497c, 0xffffb684, 0x0000049c, 0xfffffb64,
-	0x0000093c, 0xfffff6c4, 0x00000028, 0xffffffd8,
-	0x0000247c, 0xffffdb84, 0x0000024c, 0xfffffdb4,
-	0x000019fc, 0xffffe604, 0x000001ac, 0xfffffe54,
-	0x0000697c, 0xffff9684, 0x0000069c, 0xfffff964,
-	0x00000d3c, 0xfffff2c4, 0x000000a4, 0xffffff5c,
-	0x0000347c, 0xffffcb84, 0x0000034c, 0xfffffcb4,
-	0x000012fc, 0xffffed04, 0x00000134, 0xfffffecc,
-	0x00004d7c, 0xffffb284, 0x000004dc, 0xfffffb24,
-	0x000009bc, 0xfffff644, 0x00000038, 0xffffffc8,
-	0x0000267c, 0xffffd984, 0x0000026c, 0xfffffd94,
-	0x00001afc, 0xffffe504, 0x000001ac, 0xfffffe54,
-	0x00006d7c, 0xffff9284, 0x000006dc, 0xfffff924,
-	0x00000dbc, 0xfffff244, 0x000000b4, 0xffffff4c,
-	0x0000367c, 0xffffc984, 0x0000036c, 0xfffffc94,
-	0x00000f3c, 0xfffff0c4, 0x000000f4, 0xffffff0c,
-	0x00003e7c, 0xffffc184, 0x000003dc, 0xfffffc24,
-	0x000007bc, 0xfffff844, 0x00000008, 0xfffffff8,
-	0x00001efc, 0xffffe104, 0x000001ec, 0xfffffe14,
-	0x000016fc, 0xffffe904, 0x00000174, 0xfffffe8c,
-	0x00005d7c, 0xffffa284, 0x000005dc, 0xfffffa24,
-	0x00000bbc, 0xfffff444, 0x00000078, 0xffffff88,
-	0x00002e7c, 0xffffd184, 0x000002ec, 0xfffffd14,
-	0x000014fc, 0xffffeb04, 0x00000154, 0xfffffeac,
-	0x0000557c, 0xffffaa84, 0x0000055c, 0xfffffaa4,
-	0x00000abc, 0xfffff544, 0x00000058, 0xffffffa8,
-	0x00002a7c, 0xffffd584, 0x000002ac, 0xfffffd54,
-	0x00001cfc, 0xffffe304, 0x000001cc, 0xfffffe34,
-	0x0000757c, 0xffff8a84, 0x0000075c, 0xfffff8a4,
-	0x00000ebc, 0xfffff144, 0x000000d4, 0xffffff2c,
-	0x00003a7c, 0xffffc584, 0x0000039c, 0xfffffc64,
-	0x000010fc, 0xffffef04, 0x00000114, 0xfffffeec,
-	0x0000457c, 0xffffba84, 0x0000045c, 0xfffffba4,
-	0x000008bc, 0xfffff744, 0x00000018, 0xffffffe8,
-	0x0000227c, 0xffffdd84, 0x0000022c, 0xfffffdd4,
-	0x000018fc, 0xffffe704, 0x0000018c, 0xfffffe74,
-	0x0000657c, 0xffff9a84, 0x0000065c, 0xfffff9a4,
-	0x00000cbc, 0xfffff344, 0x00000094, 0xffffff6c,
-	0x0000327c, 0xffffcd84, 0x0000032c, 0xfffffcd4
-};
+s32 dsp_audio_alaw_to_s32[256];
 
 s32 *dsp_audio_law_to_s32;
 
 /* signed 16-bit -> law */
 u8 dsp_audio_s16_to_law[65536];
 
-/* table is used to generate s16_to_alaw */
-static short dsp_audio_alaw_relations[512] =
+/* alaw -> ulaw */
+u8 dsp_audio_alaw_to_ulaw[256];
+/* ulaw -> alaw */
+u8 dsp_audio_ulaw_to_alaw[256];
+u8 dsp_silence;
+
+
+/*****************************************************
+ * generate table for conversion of s16 to alaw/ulaw *
+ *****************************************************/
+
+#define AMI_MASK 0x55
+
+static inline unsigned char linear2alaw (short int linear)
 {
-	0x8684, 0x55, 0x8a84, 0xd5, 0x8e84, 0x15, 0x9284, 0x95,
-	0x9684, 0x75, 0x9a84, 0xf5, 0x9e84, 0x35, 0xa284, 0xb5,
-	0xa684, 0x45, 0xaa84, 0xc5, 0xae84, 0x05, 0xb284, 0x85,
-	0xb684, 0x65, 0xba84, 0xe5, 0xbe84, 0x25, 0xc184, 0xa5,
-	0xc384, 0x5d, 0xc584, 0xdd, 0xc784, 0x1d, 0xc984, 0x9d,
-	0xcb84, 0x7d, 0xcd84, 0xfd, 0xcf84, 0x3d, 0xd184, 0xbd,
-	0xd384, 0x4d, 0xd584, 0xcd, 0xd784, 0x0d, 0xd984, 0x8d,
-	0xdb84, 0x6d, 0xdd84, 0xed, 0xdf84, 0x2d, 0xe104, 0xad,
-	0xe204, 0x51, 0xe304, 0xd1, 0xe404, 0x11, 0xe504, 0x91,
-	0xe604, 0x71, 0xe704, 0xf1, 0xe804, 0x31, 0xe904, 0xb1,
-	0xea04, 0x41, 0xeb04, 0xc1, 0xec04, 0x01, 0xed04, 0x81,
-	0xee04, 0x61, 0xef04, 0xe1, 0xf004, 0x21, 0xf0c4, 0x59,
-	0xf0c4, 0xa1, 0xf144, 0xd9, 0xf1c4, 0x19, 0xf244, 0x99,
-	0xf2c4, 0x79, 0xf344, 0xf9, 0xf3c4, 0x39, 0xf444, 0xb9,
-	0xf4c4, 0x49, 0xf544, 0xc9, 0xf5c4, 0x09, 0xf644, 0x89,
-	0xf6c4, 0x69, 0xf744, 0xe9, 0xf7c4, 0x29, 0xf844, 0x57,
-	0xf844, 0xa9, 0xf8a4, 0xd7, 0xf8e4, 0x17, 0xf924, 0x97,
-	0xf964, 0x77, 0xf9a4, 0xf7, 0xf9e4, 0x37, 0xfa24, 0xb7,
-	0xfa64, 0x47, 0xfaa4, 0xc7, 0xfae4, 0x07, 0xfb24, 0x87,
-	0xfb64, 0x67, 0xfba4, 0xe7, 0xfbe4, 0x27, 0xfc24, 0x5f,
-	0xfc24, 0xa7, 0xfc64, 0x1f, 0xfc64, 0xdf, 0xfc94, 0x9f,
-	0xfcb4, 0x7f, 0xfcd4, 0xff, 0xfcf4, 0x3f, 0xfd14, 0xbf,
-	0xfd34, 0x4f, 0xfd54, 0xcf, 0xfd74, 0x0f, 0xfd94, 0x8f,
-	0xfdb4, 0x6f, 0xfdd4, 0xef, 0xfdf4, 0x2f, 0xfe14, 0x53,
-	0xfe14, 0xaf, 0xfe34, 0x13, 0xfe34, 0xd3, 0xfe54, 0x73,
-	0xfe54, 0x93, 0xfe74, 0x33, 0xfe74, 0xf3, 0xfe8c, 0xb3,
-	0xfe9c, 0x43, 0xfeac, 0xc3, 0xfebc, 0x03, 0xfecc, 0x83,
-	0xfedc, 0x63, 0xfeec, 0xe3, 0xfefc, 0x23, 0xff0c, 0xa3,
-	0xff1c, 0x5b, 0xff2c, 0xdb, 0xff3c, 0x1b, 0xff4c, 0x9b,
-	0xff5c, 0x7b, 0xff6c, 0xfb, 0xff7c, 0x3b, 0xff88, 0xbb,
-	0xff98, 0x4b, 0xffa8, 0xcb, 0xffb8, 0x0b, 0xffc8, 0x8b,
-	0xffd8, 0x6b, 0xffe8, 0xeb, 0xfff8, 0x2b, 0xfff8, 0xab,
-	0x0008, 0x2a, 0x0008, 0xaa, 0x0018, 0xea, 0x0028, 0x6a,
-	0x0038, 0x8a, 0x0048, 0x0a, 0x0058, 0xca, 0x0068, 0x4a,
-	0x0078, 0xba, 0x0084, 0x3a, 0x0094, 0xfa, 0x00a4, 0x7a,
-	0x00b4, 0x9a, 0x00c4, 0x1a, 0x00d4, 0xda, 0x00e4, 0x5a,
-	0x00f4, 0xa2, 0x0104, 0x22, 0x0114, 0xe2, 0x0124, 0x62,
-	0x0134, 0x82, 0x0144, 0x02, 0x0154, 0xc2, 0x0164, 0x42,
-	0x0174, 0xb2, 0x018c, 0x32, 0x018c, 0xf2, 0x01ac, 0x72,
-	0x01ac, 0x92, 0x01cc, 0x12, 0x01cc, 0xd2, 0x01ec, 0x52,
-	0x01ec, 0xae, 0x020c, 0x2e, 0x022c, 0xee, 0x024c, 0x6e,
-	0x026c, 0x8e, 0x028c, 0x0e, 0x02ac, 0xce, 0x02cc, 0x4e,
-	0x02ec, 0xbe, 0x030c, 0x3e, 0x032c, 0xfe, 0x034c, 0x7e,
-	0x036c, 0x9e, 0x039c, 0x1e, 0x039c, 0xde, 0x03dc, 0x5e,
-	0x03dc, 0xa6, 0x041c, 0x26, 0x045c, 0xe6, 0x049c, 0x66,
-	0x04dc, 0x86, 0x051c, 0x06, 0x055c, 0xc6, 0x059c, 0x46,
-	0x05dc, 0xb6, 0x061c, 0x36, 0x065c, 0xf6, 0x069c, 0x76,
-	0x06dc, 0x96, 0x071c, 0x16, 0x075c, 0xd6, 0x07bc, 0x56,
-	0x07bc, 0xa8, 0x083c, 0x28, 0x08bc, 0xe8, 0x093c, 0x68,
-	0x09bc, 0x88, 0x0a3c, 0x08, 0x0abc, 0xc8, 0x0b3c, 0x48,
-	0x0bbc, 0xb8, 0x0c3c, 0x38, 0x0cbc, 0xf8, 0x0d3c, 0x78,
-	0x0dbc, 0x98, 0x0e3c, 0x18, 0x0ebc, 0xd8, 0x0f3c, 0x58,
-	0x0f3c, 0xa0, 0x0ffc, 0x20, 0x10fc, 0xe0, 0x11fc, 0x60,
-	0x12fc, 0x80, 0x13fc, 0x00, 0x14fc, 0xc0, 0x15fc, 0x40,
-	0x16fc, 0xb0, 0x17fc, 0x30, 0x18fc, 0xf0, 0x19fc, 0x70,
-	0x1afc, 0x90, 0x1bfc, 0x10, 0x1cfc, 0xd0, 0x1dfc, 0x50,
-	0x1efc, 0xac, 0x207c, 0x2c, 0x227c, 0xec, 0x247c, 0x6c,
-	0x267c, 0x8c, 0x287c, 0x0c, 0x2a7c, 0xcc, 0x2c7c, 0x4c,
-	0x2e7c, 0xbc, 0x307c, 0x3c, 0x327c, 0xfc, 0x347c, 0x7c,
-	0x367c, 0x9c, 0x387c, 0x1c, 0x3a7c, 0xdc, 0x3c7c, 0x5c,
-	0x3e7c, 0xa4, 0x417c, 0x24, 0x457c, 0xe4, 0x497c, 0x64,
-	0x4d7c, 0x84, 0x517c, 0x04, 0x557c, 0xc4, 0x597c, 0x44,
-	0x5d7c, 0xb4, 0x617c, 0x34, 0x657c, 0xf4, 0x697c, 0x74,
-	0x6d7c, 0x94, 0x717c, 0x14, 0x757c, 0xd4, 0x797c, 0x54
-};
+	int mask;
+	int seg;
+	int pcm_val;
+	static int seg_end[8] = {
+		0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF
+	};
+
+	pcm_val = linear;
+	if (pcm_val >= 0) {
+		/* Sign (7th) bit = 1 */
+		mask = AMI_MASK | 0x80;
+	} else {
+		/* Sign bit = 0 */
+		mask = AMI_MASK;
+		pcm_val = -pcm_val;
+	}
 
+	/* Convert the scaled magnitude to segment number. */
+	for (seg = 0;  seg < 8;  seg++) {
+		if (pcm_val <= seg_end[seg])
+			break;
+	}
+	/* Combine the sign, segment, and quantization bits. */
+	return  ((seg << 4) | 
+		 ((pcm_val >> ((seg)  ?  (seg + 3)  :  4)) & 0x0F)) ^ mask;
+}
 
-/* alaw -> ulaw */
-u8 dsp_audio_alaw_to_ulaw[256] =
+
+static inline short int alaw2linear (unsigned char alaw)
 {
-	0xab, 0x2b, 0xe3, 0x63, 0x8b, 0x0b, 0xc9, 0x49,
-	0xba, 0x3a, 0xf6, 0x76, 0x9b, 0x1b, 0xd7, 0x57,
-	0xa3, 0x23, 0xdd, 0x5d, 0x83, 0x03, 0xc1, 0x41,
-	0xb2, 0x32, 0xeb, 0x6b, 0x93, 0x13, 0xcf, 0x4f,
-	0xaf, 0x2f, 0xe7, 0x67, 0x8f, 0x0f, 0xcd, 0x4d,
-	0xbe, 0x3e, 0xfe, 0x7e, 0x9f, 0x1f, 0xdb, 0x5b,
-	0xa7, 0x27, 0xdf, 0x5f, 0x87, 0x07, 0xc5, 0x45,
-	0xb6, 0x36, 0xef, 0x6f, 0x97, 0x17, 0xd3, 0x53,
-	0xa9, 0x29, 0xe1, 0x61, 0x89, 0x09, 0xc7, 0x47,
-	0xb8, 0x38, 0xf2, 0x72, 0x99, 0x19, 0xd5, 0x55,
-	0xa1, 0x21, 0xdc, 0x5c, 0x81, 0x01, 0xbf, 0x3f,
-	0xb0, 0x30, 0xe9, 0x69, 0x91, 0x11, 0xce, 0x4e,
-	0xad, 0x2d, 0xe5, 0x65, 0x8d, 0x0d, 0xcb, 0x4b,
-	0xbc, 0x3c, 0xfa, 0x7a, 0x9d, 0x1d, 0xd9, 0x59,
-	0xa5, 0x25, 0xde, 0x5e, 0x85, 0x05, 0xc3, 0x43,
-	0xb4, 0x34, 0xed, 0x6d, 0x95, 0x15, 0xd1, 0x51,
-	0xac, 0x2c, 0xe4, 0x64, 0x8c, 0x0c, 0xca, 0x4a,
-	0xbb, 0x3b, 0xf8, 0x78, 0x9c, 0x1c, 0xd8, 0x58,
-	0xa4, 0x24, 0xde, 0x5e, 0x84, 0x04, 0xc2, 0x42,
-	0xb3, 0x33, 0xec, 0x6c, 0x94, 0x14, 0xd0, 0x50,
-	0xb0, 0x30, 0xe8, 0x68, 0x90, 0x10, 0xce, 0x4e,
-	0xbf, 0x3f, 0xfe, 0x7e, 0xa0, 0x20, 0xdc, 0x5c,
-	0xa8, 0x28, 0xe0, 0x60, 0x88, 0x08, 0xc6, 0x46,
-	0xb7, 0x37, 0xf0, 0x70, 0x98, 0x18, 0xd4, 0x54,
-	0xaa, 0x2a, 0xe2, 0x62, 0x8a, 0x0a, 0xc8, 0x48,
-	0xb9, 0x39, 0xf4, 0x74, 0x9a, 0x1a, 0xd6, 0x56,
-	0xa2, 0x22, 0xdd, 0x5d, 0x82, 0x02, 0xc0, 0x40,
-	0xb1, 0x31, 0xea, 0x6a, 0x92, 0x12, 0xcf, 0x4f,
-	0xae, 0x2e, 0xe6, 0x66, 0x8e, 0x0e, 0xcc, 0x4c,
-	0xbd, 0x3d, 0xfc, 0x7c, 0x9e, 0x1e, 0xda, 0x5a,
-	0xa6, 0x26, 0xdf, 0x5f, 0x86, 0x06, 0xc4, 0x44,
-	0xb5, 0x35, 0xee, 0x6e, 0x96, 0x16, 0xd2, 0x52
-};
+	int i;
+	int seg;
 
-/* ulaw -> alaw */
-u8 dsp_audio_ulaw_to_alaw[256] =
+	alaw ^= AMI_MASK;
+	i = ((alaw & 0x0F) << 4) + 8 /* rounding error */;
+	seg = (((int) alaw & 0x70) >> 4);
+	if (seg)
+		i = (i + 0x100) << (seg - 1);
+	return (short int) ((alaw & 0x80)  ?  i  :  -i);
+}
+
+static inline short int ulaw2linear(unsigned char ulaw)
 {
-	0xab, 0x55, 0xd5, 0x15, 0x95, 0x75, 0xf5, 0x35,
-	0xb5, 0x45, 0xc5, 0x05, 0x85, 0x65, 0xe5, 0x25,
-	0xa5, 0x5d, 0xdd, 0x1d, 0x9d, 0x7d, 0xfd, 0x3d,
-	0xbd, 0x4d, 0xcd, 0x0d, 0x8d, 0x6d, 0xed, 0x2d,
-	0xad, 0x51, 0xd1, 0x11, 0x91, 0x71, 0xf1, 0x31,
-	0xb1, 0x41, 0xc1, 0x01, 0x81, 0x61, 0xe1, 0x21,
-	0x59, 0xd9, 0x19, 0x99, 0x79, 0xf9, 0x39, 0xb9,
-	0x49, 0xc9, 0x09, 0x89, 0x69, 0xe9, 0x29, 0xa9,
-	0xd7, 0x17, 0x97, 0x77, 0xf7, 0x37, 0xb7, 0x47,
-	0xc7, 0x07, 0x87, 0x67, 0xe7, 0x27, 0xa7, 0xdf,
-	0x9f, 0x7f, 0xff, 0x3f, 0xbf, 0x4f, 0xcf, 0x0f,
-	0x8f, 0x6f, 0xef, 0x2f, 0x53, 0x13, 0x73, 0x33,
-	0xb3, 0x43, 0xc3, 0x03, 0x83, 0x63, 0xe3, 0x23,
-	0xa3, 0x5b, 0xdb, 0x1b, 0x9b, 0x7b, 0xfb, 0x3b,
-	0xbb, 0xbb, 0x4b, 0x4b, 0xcb, 0xcb, 0x0b, 0x0b,
-	0x8b, 0x8b, 0x6b, 0x6b, 0xeb, 0xeb, 0x2b, 0x2b,
-	0xab, 0x54, 0xd4, 0x14, 0x94, 0x74, 0xf4, 0x34,
-	0xb4, 0x44, 0xc4, 0x04, 0x84, 0x64, 0xe4, 0x24,
-	0xa4, 0x5c, 0xdc, 0x1c, 0x9c, 0x7c, 0xfc, 0x3c,
-	0xbc, 0x4c, 0xcc, 0x0c, 0x8c, 0x6c, 0xec, 0x2c,
-	0xac, 0x50, 0xd0, 0x10, 0x90, 0x70, 0xf0, 0x30,
-	0xb0, 0x40, 0xc0, 0x00, 0x80, 0x60, 0xe0, 0x20,
-	0x58, 0xd8, 0x18, 0x98, 0x78, 0xf8, 0x38, 0xb8,
-	0x48, 0xc8, 0x08, 0x88, 0x68, 0xe8, 0x28, 0xa8,
-	0xd6, 0x16, 0x96, 0x76, 0xf6, 0x36, 0xb6, 0x46,
-	0xc6, 0x06, 0x86, 0x66, 0xe6, 0x26, 0xa6, 0xde,
-	0x9e, 0x7e, 0xfe, 0x3e, 0xbe, 0x4e, 0xce, 0x0e,
-	0x8e, 0x6e, 0xee, 0x2e, 0x52, 0x12, 0x72, 0x32,
-	0xb2, 0x42, 0xc2, 0x02, 0x82, 0x62, 0xe2, 0x22,
-	0xa2, 0x5a, 0xda, 0x1a, 0x9a, 0x7a, 0xfa, 0x3a,
-	0xba, 0xba, 0x4a, 0x4a, 0xca, 0xca, 0x0a, 0x0a,
-	0x8a, 0x8a, 0x6a, 0x6a, 0xea, 0xea, 0x2a, 0x2a
-};
+	short mu, e, f, y;
+	static short etab[] = {0,132,396,924,1980,4092,8316,16764};
 
-u8 dsp_silence;
+	mu = 255 - ulaw;
+	e = (mu & 0x70) / 16;
+	f = mu & 0x0f;
+	y = f * (1 << (e + 3));
+	y += etab[e];
+	if (mu & 0x80)
+		y = -y;
+	return y;
+}
 
+#define BIAS 0x84   /*!< define the add-in bias for 16 bit samples */
 
-/*****************************************************
- * generate table for conversion of s16 to alaw/ulaw *
- *****************************************************/
+static unsigned char linear2ulaw(short sample)
+{
+        static int exp_lut[256] = {
+                0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
+                4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
+                5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+                5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+                6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+                6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+                6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+                6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7 };
+        int sign, exponent, mantissa;
+        unsigned char ulawbyte;
+
+        /* Get the sample into sign-magnitude. */
+        sign = (sample >> 8) & 0x80;          /* set aside the sign */
+        if (sign != 0)
+                sample = -sample;              /* get magnitude */
+
+        /* Convert from 16 bit linear to ulaw. */
+        sample = sample + BIAS;
+        exponent = exp_lut[(sample >> 7) & 0xFF];
+        mantissa = (sample >> (exponent + 3)) & 0x0F;
+        ulawbyte = ~(sign | (exponent << 4) | mantissa);
+
+        return ulawbyte;
+}
+
+static int reverse_bits(int i)
+{
+	int z,j;
+	z = 0;
+
+	for (j = 0; j < 8; j++) {
+		if ((i & (1 << j)) != 0) {
+			z |= 1 << (7 - j);
+		}
+	}
+	return z;
+}
+
+
+void dsp_audio_generate_law_tables(void)
+{
+	int i;
+	for (i = 0; i < 256; i++) {
+		dsp_audio_alaw_to_s32[i] = alaw2linear(reverse_bits(i));
+	}
+
+        for (i = 0; i < 256; i++) {
+                dsp_audio_ulaw_to_s32[i] = ulaw2linear(reverse_bits(i));
+        }
+
+	for (i = 0; i < 256; i++) {
+		dsp_audio_alaw_to_ulaw[i] = 
+			linear2ulaw(dsp_audio_alaw_to_s32[i]);
+		dsp_audio_ulaw_to_alaw[i] = 
+			linear2alaw(dsp_audio_ulaw_to_s32[i]);
+	}
+}
 
 void
 dsp_audio_generate_s2law_table(void)
 {
-	int i, j;
+	int i;
 
 	if (dsp_options & DSP_OPT_ULAW) {
 		/* generating ulaw-table */
-		i = j = 0;
-		while(i < 32768) {
-			if (i-32768 > dsp_audio_law_to_s32[j])
-				j++;
-			dsp_audio_s16_to_law[(i-32768) & 0xffff] = j;
-			i++;
-		}
-		j = 255;
-		while(i < 65536) {
-			if (i-32768 > dsp_audio_law_to_s32[j])
-				j--;
-			dsp_audio_s16_to_law[(i-32768) & 0xffff] = j;
-			i++;
+		for (i = -32768; i < 32768; i++) {
+			dsp_audio_s16_to_law[i & 0xffff] = 
+				reverse_bits(linear2ulaw(i));
 		}
 	} else {
 		/* generating alaw-table */
-		i = j = 0;
-		while(i < 65536) {
-			if (i-32768 > dsp_audio_alaw_relations[j<<1])
-				j++;
-			if (j>255)
-				j=255;
-			dsp_audio_s16_to_law[(i-32768) & 0xffff]
-				 = dsp_audio_alaw_relations[(j<<1)|1];
-			i++;
+		for (i = -32768; i < 32768; i++) {
+			dsp_audio_s16_to_law[i & 0xffff] = 
+				reverse_bits(linear2alaw(i));
 		}
 	}
 }
@@ -359,7 +201,7 @@
 void
 dsp_audio_generate_seven(void)
 {
-	int i, j;
+	int i, j, z;
 	u8 spl;
 
 	/* conversion from law to seven bit audio */
@@ -370,30 +212,16 @@
 		if (dsp_options & DSP_OPT_ULAW)
 			spl = dsp_audio_ulaw_to_alaw[i];
 		/* find the 7-bit-sample */
-		j = 0;
-		while(j < 256) {
-			if (dsp_audio_alaw_relations[(j<<1)|1] == spl)
-				break;
-			j++;
-		}
-		if (j == 256) {
-			printk(KERN_WARNING "fatal error in %s: alaw-sample '0x%2x' not found in relations-table.\n", __FUNCTION__, spl);
+		j = 0; 
+		for (z = 0; z < 256; z++) {
+			if (dsp_audio_alaw_to_s32[z] < dsp_audio_alaw_to_s32[spl]) {
+				j++;
+			}
 		}
+
 		/* write 7-bit audio value */
 		dsp_audio_law2seven[i] = j >> 1;
-		i++;
-	}
-
-	/* conversion from seven bit audio to law */
-	i = 0;
-	while(i < 128) {
-		/* find alaw-spl */
-		spl = dsp_audio_alaw_relations[(i<<2)|1];
-		/* convert to ulaw, if required */
-		if (dsp_options & DSP_OPT_ULAW)
-			spl = dsp_audio_alaw_to_ulaw[spl];
-		/* write 8-bit law sample */
-		dsp_audio_seven2law[i] = spl;
+		if ((j & 1) == 0) dsp_audio_seven2law[j >> 1] = i;
 		i++;
 	}
 }
@@ -475,60 +303,62 @@
 {
 	register s32 sample;
 	int i;
+	int num[]   = { 110, 125, 150, 175, 200, 300, 400, 500 };
+	int denum[] = { 100, 100, 100, 100, 100, 100, 100, 100 };
 
 	i = 0;
 	while(i < 256) {
-		dsp_audio_reduce8[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>8) & 0xffff];
-		dsp_audio_reduce7[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>7) & 0xffff];
-		dsp_audio_reduce6[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>6) & 0xffff];
-		dsp_audio_reduce5[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>5) & 0xffff];
-		dsp_audio_reduce4[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>4) & 0xffff];
-		dsp_audio_reduce3[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>3) & 0xffff];
-		dsp_audio_reduce2[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>2) & 0xffff];
-		dsp_audio_reduce1[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i]>>1) & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 1;
+		dsp_audio_reduce8[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[7] / num[7] ) & 0xffff];
+		dsp_audio_reduce7[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[6] / num[6]) & 0xffff];
+		dsp_audio_reduce6[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[5] / num[5]) & 0xffff];
+		dsp_audio_reduce5[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[4] / num[4]) & 0xffff];
+		dsp_audio_reduce4[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[3] / num[3]) & 0xffff];
+		dsp_audio_reduce3[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[2] / num[2]) & 0xffff];
+		dsp_audio_reduce2[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[1] / num[1]) & 0xffff];
+		dsp_audio_reduce1[i] = dsp_audio_s16_to_law[(dsp_audio_law_to_s32[i] * denum[0] / num[0]) & 0xffff];
+		sample = dsp_audio_law_to_s32[i] * num[0] / denum[0];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase1[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 2;
+		sample = dsp_audio_law_to_s32[i] * num[1] / denum[1];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase2[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 3;
+		sample = dsp_audio_law_to_s32[i] * num[2] / denum[2];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase3[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 4;
+		sample = dsp_audio_law_to_s32[i] * num[3] / denum[3];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase4[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 5;
+		sample = dsp_audio_law_to_s32[i] * num[4] / denum[4];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase5[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 6;
+		sample = dsp_audio_law_to_s32[i] * num[5] / denum[5];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase6[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 7;
+		sample = dsp_audio_law_to_s32[i] * num[6] / denum[6];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
 			sample = 32767;
 		dsp_audio_increase7[i] = dsp_audio_s16_to_law[sample & 0xffff];
-		sample = dsp_audio_law_to_s32[i] << 8;
+		sample = dsp_audio_law_to_s32[i] * num[7] / denum[7];
 		if (sample < -32768)
 			sample = -32768;
 		else if (sample > 32767)
--- /home/peter/src/mISDN-1_1_5/drivers/isdn/hardware/mISDN/dsp.h	2007-07-02 11:31:34.000000000 +0200
+++ ./dsp.h	2007-09-15 14:08:57.000000000 +0200
@@ -76,6 +80,7 @@
 extern u8 dsp_audio_mix_law[65536];
 extern u8 dsp_audio_seven2law[128];
 extern u8 dsp_audio_law2seven[256];
+extern void dsp_audio_generate_law_tables(void);
 extern void dsp_audio_generate_s2law_table(void);
 extern void dsp_audio_generate_seven(void);
 extern void dsp_audio_generate_mix_table(void);
--- /home/peter/src/mISDN-1_1_5/drivers/isdn/hardware/mISDN/dsp_core.c	2007-07-02 11:31:34.000000000 +0200
+++ ./dsp_core.c	2007-09-15 14:02:43.000000000 +0200
@@ -1013,6 +1013,7 @@
 	INIT_LIST_HEAD(&dsp_obj.ilist);
 
 	/* initialize audio tables */
+	dsp_audio_generate_law_tables();
 	dsp_silence = (dsp_options&DSP_OPT_ULAW)?0xff:0x2a;
 	dsp_audio_law_to_s32 = (dsp_options&DSP_OPT_ULAW)?dsp_audio_ulaw_to_s32:dsp_audio_alaw_to_s32;
 	dsp_audio_generate_s2law_table();