1 files changed, 374 insertions, 0 deletions

diff --git a/drivers/isdn/mISDN/l1oip_codec.c b/drivers/isdn/mISDN/l1oip_codec.c
new file mode 100644
index 000000000000..a2dc4570ef43
--- /dev/null
+++ b/drivers/isdn/mISDN/l1oip_codec.c
@@ -0,0 +1,374 @@
+/*
+
+ * l1oip_codec.c  generic codec using lookup table
+ *  -> conversion from a-Law to u-Law
+ *  -> conversion from u-Law to a-Law
+ *  -> compression by reducing the number of sample resolution to 4
+ *
+ * NOTE: It is not compatible with any standard codec like ADPCM.
+ *
+ * Author       Andreas Eversberg (jolly@eversberg.eu)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ */
+
+/*
+
+How the codec works:
+--------------------
+
+The volume is increased to increase the dynamic range of the audio signal.
+Each sample is converted to a-LAW with only 16 steps of level resolution.
+A pair of two samples are stored in one byte.
+
+The first byte is stored in the upper bits, the second byte is stored in the
+lower bits.
+
+To speed up compression and decompression, two lookup tables are formed:
+
+- 16 bits index for two samples (law encoded) with 8 bit compressed result.
+- 8 bits index for one compressed data with 16 bits decompressed result.
+
+NOTE: The bytes are handled as they are law-encoded.
+
+*/
+
+#include <linux/vmalloc.h>
+#include <linux/mISDNif.h>
+#include "core.h"
+
+/* definitions of codec. don't use calculations, code may run slower. */
+
+static u8 *table_com;
+static u16 *table_dec;
+
+
+/* alaw -> ulaw */
+static u8 alaw_to_ulaw[256] =
+{
+        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
+};
+
+/* ulaw -> alaw */
+static u8 ulaw_to_alaw[256] =
+{
+        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
+};
+
+/* alaw -> 4bit compression */
+static u8 alaw_to_4bit[256] = {
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0d, 0x02,
+        0x0e, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x01, 0x0a, 0x05,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x08, 0x07, 0x0f, 0x00, 0x0b, 0x04,
+        0x0e, 0x01, 0x0a, 0x05, 0x0f, 0x00, 0x0c, 0x03,
+        0x0d, 0x02, 0x09, 0x06, 0x0f, 0x00, 0x0b, 0x04,
+};
+
+/* 4bit -> alaw decompression */
+static u8 _4bit_to_alaw[16] = {
+        0x5d, 0x51, 0xd9, 0xd7, 0x5f, 0x53, 0xa3, 0x4b,
+        0x2a, 0x3a, 0x22, 0x2e, 0x26, 0x56, 0x20, 0x2c,
+};
+
+/* ulaw -> 4bit compression */
+static u8 ulaw_to_4bit[256] = {
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+        0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
+        0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
+        0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
+        0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04,
+        0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
+        0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05,
+        0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
+        0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
+        0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
+        0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08,
+        0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
+        0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
+        0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
+        0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
+        0x0f, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e,
+        0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e,
+        0x0e, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d,
+        0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d,
+        0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+        0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0b, 0x0b,
+        0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+        0x0b, 0x0b, 0x0b, 0x0b, 0x0a, 0x0a, 0x0a, 0x0a,
+        0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a,
+        0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
+        0x09, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
+        0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
+};
+
+/* 4bit -> ulaw decompression */
+static u8 _4bit_to_ulaw[16] = {
+        0x11, 0x21, 0x31, 0x40, 0x4e, 0x5c, 0x68, 0x71,
+        0xfe, 0xef, 0xe7, 0xdb, 0xcd, 0xbf, 0xaf, 0x9f,
+};
+
+
+/*
+ * Compresses data to the result buffer
+ * The result size must be at least half of the input buffer.
+ * The number of samples also must be even!
+ */
+int
+l1oip_law_to_4bit(u8 *data, int len, u8 *result, u32 *state)
+{
+        int ii, i = 0, o = 0;
+
+        if (!len)
+                return 0;
+
+        /* send saved byte and first input byte */
+        if (*state) {
+                *result++ = table_com[(((*state)<<8)&0xff00) | (*data++)];
+                len--;
+                o++;
+        }
+
+        ii = len >> 1;
+
+        while (i < ii) {
+                *result++ = table_com[(data[0]<<8) | (data[1])];
+                data += 2;
+                i++;
+                o++;
+        }
+
+        /* if len has an odd number, we save byte for next call */
+        if (len & 1)
+                *state = 0x100 + *data;
+        else
+                *state = 0;
+
+        return o;
+}
+
+/* Decompress data to the result buffer
+ * The result size must be the number of sample in packet. (2 * input data)
+ * The number of samples in the result are even!
+ */
+int
+l1oip_4bit_to_law(u8 *data, int len, u8 *result)
+{
+        int i = 0;
+        u16 r;
+
+        while (i < len) {
+                r = table_dec[*data++];
+                *result++ = r>>8;
+                *result++ = r;
+                i++;
+        }
+
+        return len << 1;
+}
+
+
+/*
+ * law conversion
+ */
+int
+l1oip_alaw_to_ulaw(u8 *data, int len, u8 *result)
+{
+        int i = 0;
+
+        while (i < len) {
+                *result++ = alaw_to_ulaw[*data++];
+                i++;
+        }
+
+        return len;
+}
+
+int
+l1oip_ulaw_to_alaw(u8 *data, int len, u8 *result)
+{
+        int i = 0;
+
+        while (i < len) {
+                *result++ = ulaw_to_alaw[*data++];
+                i++;
+        }
+
+        return len;
+}
+
+
+/*
+ * generate/free compression and decompression table
+ */
+void
+l1oip_4bit_free(void)
+{
+        if (table_dec)
+                vfree(table_dec);
+        if (table_com)
+                vfree(table_com);
+        table_com = NULL;
+        table_dec = NULL;
+}
+
+int
+l1oip_4bit_alloc(int ulaw)
+{
+        int i1, i2, c, sample;
+
+        /* in case, it is called again */
+        if (table_dec)
+                return 0;
+
+        /* alloc conversion tables */
+        table_com = vmalloc(65536);
+        table_dec = vmalloc(512);
+        if (!table_com | !table_dec) {
+                l1oip_4bit_free();
+                return -ENOMEM;
+        }
+        memset(table_com, 0, 65536);
+        memset(table_dec, 0, 512);
+        /* generate compression table */
+        i1 = 0;
+        while (i1 < 256) {
+                if (ulaw)
+                        c = ulaw_to_4bit[i1];
+                else
+                        c = alaw_to_4bit[i1];
+                i2 = 0;
+                while (i2 < 256) {
+                        table_com[(i1<<8) | i2] |= (c<<4);
+                        table_com[(i2<<8) | i1] |= c;
+                        i2++;
+                }
+                i1++;
+        }
+
+        /* generate decompression table */
+        i1 = 0;
+        while (i1 < 16) {
+                if (ulaw)
+                        sample = _4bit_to_ulaw[i1];
+                else
+                        sample = _4bit_to_alaw[i1];
+                i2 = 0;
+                while (i2 < 16) {
+                        table_dec[(i1<<4) | i2] |= (sample<<8);
+                        table_dec[(i2<<4) | i1] |= sample;
+                        i2++;
+                }
+                i1++;
+        }
+
+        return 0;
+}
+
+