tweak

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@10732 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/libg722_1/src/bitstream.c

@@ -0,0 +1,113 @@
+/*
+ * g722_1 - a library for the G.722.1 and Annex C codecs
+ *
+ * bitstream.c
+ *
+ * Copyright (C) 2006 Steve Underwood
+ *
+ * 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.
+ *
+ * $Id: bitstream.c,v 1.2 2008/10/17 13:18:21 steveu Exp $
+ */
+
+/*! \file */
+
+#if defined(HAVE_CONFIG_H)
+#include <config.h>
+#endif
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "g722_1/g722_1.h"
+#include "bitstream.h"
+
+void g722_1_bitstream_put(g722_1_bitstream_state_t *s, uint8_t **c, uint32_t value, int bits)
+{
+    if (bits < 32)
+        value &= ((1 << bits) - 1);
+    if (bits > 24)
+    {
+        /* We can't deal with this many bits in one go. Split up the operation */
+        bits -= 8;
+        s->bitstream = (s->bitstream << bits) | (value >> 8);
+        s->residue += bits;
+        while (s->residue >= 8)
+        {
+            s->residue -= 8;
+            *(*c)++ = (uint8_t) ((s->bitstream >> s->residue) & 0xFF);
+        }
+        bits = 8;
+        value &= 0xFF;
+    }
+    s->bitstream = (s->bitstream << bits) | value;
+    s->residue += bits;
+    while (s->residue >= 8)
+    {
+        s->residue -= 8;
+        *(*c)++ = (uint8_t) ((s->bitstream >> s->residue) & 0xFF);
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+uint32_t g722_1_bitstream_get(g722_1_bitstream_state_t *s, const uint8_t **c, int bits)
+{
+    uint32_t x;
+
+    if (bits > 24)
+    {
+        /* We can't deal with this many bits in one go. Split up the operation */
+        while (s->residue < 24)
+        {
+            s->bitstream = (s->bitstream << 8) | ((uint32_t) *(*c)++);
+            s->residue += 8;
+        }
+        s->residue -= 24;
+        bits -= 24;
+        x = ((s->bitstream >> s->residue) & 0xFFFFFF) << bits;
+        while (s->residue < bits)
+        {
+            s->bitstream = (s->bitstream << 8) | ((uint32_t) *(*c)++);
+            s->residue += 8;
+        }
+        s->residue -= bits;
+        x |= (s->bitstream >> s->residue) & ((1 << bits) - 1);
+    }
+    else
+    {
+        while (s->residue < bits)
+        {
+            s->bitstream = (s->bitstream << 8) | ((uint32_t) *(*c)++);
+            s->residue += 8;
+        }
+        s->residue -= bits;
+        x = (s->bitstream >> s->residue) & ((1 << bits) - 1);
+    }
+    return x;
+}
+/*- End of function --------------------------------------------------------*/
+
+void g722_1_bitstream_flush(g722_1_bitstream_state_t *s, uint8_t **c)
+{
+    if (s->residue > 0)
+    {
+        *(*c)++ = (uint8_t) ((s->bitstream << (8 - s->residue)) & 0xFF);
+        s->residue = 0;
+    }
+}
+/*- End of function --------------------------------------------------------*/
+
+g722_1_bitstream_state_t *g722_1_bitstream_init(g722_1_bitstream_state_t *s)
+{
+    if (s == NULL)
+        return NULL;
+    s->bitstream = 0;
+    s->residue = 0;
+    return s;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/