1 files changed, 235 insertions, 0 deletions

diff --git a/core/multimedia/opieplayer/libflash/adpcm.cc b/core/multimedia/opieplayer/libflash/adpcm.cc
new file mode 100644
index 0000000..a4bc435
--- a/dev/null
+++ b/core/multimedia/opieplayer/libflash/adpcm.cc
@@ -0,0 +1,235 @@
+
+#include "swf.h"
+
+#ifdef RCSID
+static char *rcsid = "$Id$";
+#endif
+
+// This file has been rearranged from the code posted
+// on news:forums.macromedia.com by Jonathan Gay.
+// Courtesy of Macromedia
+
+//
+// ADPCM tables
+//
+
+static const int indexTable2[2] = {
+    -1, 2,
+};
+
+// Is this ok?
+static const int indexTable3[4] = {
+    -1, -1, 2, 4,
+};
+
+static const int indexTable4[8] = {
+    -1, -1, -1, -1, 2, 4, 6, 8,
+};
+
+static const int indexTable5[16] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16,
+};
+
+static const int* indexTables[] = {
+ indexTable2,
+ indexTable3,
+ indexTable4,
+ indexTable5
+};
+
+static const int stepsizeTable[89] = {
+    7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
+    19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
+    50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
+    130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
+    337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
+    876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
+    2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
+    5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
+    15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
+};
+
+long
+Adpcm::GetBits(int n)
+{
+        if ( bitPos < n ) FillBuffer();
+
+        assert(bitPos >= n);
+
+        long v = ((unsigned long)bitBuf << (32-bitPos)) >> (32-n);
+        bitPos -= n;
+
+        return v;
+}
+
+long
+Adpcm::GetSBits(int n)
+{
+        if ( bitPos < n ) FillBuffer();
+
+        assert(bitPos >= n);
+
+        long v = ((long)bitBuf << (32-bitPos)) >> (32-n);
+        bitPos -= n;
+
+        return v;
+}
+
+//
+// The Decompressor
+//
+
+// Constructor
+Adpcm::Adpcm(unsigned char *buffer, long isStereo)
+{
+        stereo = isStereo;
+        src = buffer;
+
+        nBits = 0; // flag that it is not inited
+        nSamples = 0;
+
+        bitPos = 0;
+        bitBuf = 0;
+}
+
+void
+Adpcm::FillBuffer()
+{
+        while ( bitPos <= 24 /*&& srcSize > 0*/ ) {
+                bitBuf = (bitBuf<<8) | *src++;
+                bitPos += 8;
+        }
+}
+
+void
+Adpcm::Decompress(short *dst, long n)
+{
+        if ( nBits == 0 ) {
+                // Get the compression header
+                nBits = (int)GetBits(2)+2;
+        }
+
+        const int* indexTable = indexTables[nBits-2];
+        int k0 = 1 << (nBits-2);
+        int signmask = 1 << (nBits-1);
+
+        if ( !stereo ) {
+                // Optimize for mono
+                        long    vp = valpred[0]; // maybe these can get into registers...
+                        int     ind = index[0];
+                        long    ns = nSamples;
+
+                while ( n-- > 0 ) {
+                        ns++;
+
+                        if ( (ns & 0xFFF) == 1 ) {
+                                // Get a new block header
+                                *dst++ = (short)(vp = GetSBits(16));
+
+                                ind = (int)GetBits(6); // The first sample in a block does not have a delta
+                        } else {
+                                // Process a delta value
+                                int delta = (int)GetBits(nBits);
+
+                                // Compute difference and new predicted value
+                                // Computes 'vpdiff = (delta+0.5)*step/4'
+                                int step = stepsizeTable[ind];
+                                long vpdiff = 0;
+                                int k = k0;
+
+                                do {
+                                        if ( delta & k )
+                                        vpdiff += step;
+                                        step >>= 1;
+                                        k >>= 1;
+                                } while ( k );
+
+                                vpdiff += step; // add 0.5
+
+                                if ( delta & signmask ) // the sign bit
+                                        vp -= vpdiff;
+                                else
+                                        vp += vpdiff;
+
+                                // Find new index value
+                                ind += indexTable[delta&(~signmask)];
+
+                                if ( ind < 0 )
+                                        ind = 0;
+                                else if ( ind > 88 )
+                                        ind = 88;
+
+                                // clamp output value
+                                if ( vp != (short)vp )
+                                        vp = vp < 0 ? -32768 : 32767;
+
+                                /* Step 7 - Output value */
+                                *dst++ = (short)vp;
+                        }
+                }
+
+                valpred[0] = vp;
+                index[0] = ind;
+                nSamples = ns;
+
+        } else {
+                int sn = stereo ? 2 : 1;
+
+                // Stereo
+                while ( n-- > 0 ) {
+
+                        nSamples++;
+
+                        if ( (nSamples & 0xFFF) == 1 ) {
+                                // Get a new block header
+                                for ( int i = 0; i < sn; i++ ) {
+
+                                        *dst++ = (short)(valpred[i] = GetSBits(16));
+
+                                        // The first sample in a block does not have a delta
+                                        index[i] = (int)GetBits(6);
+                                }
+                        } else {
+                                // Process a delta value
+                                for ( int i = 0; i < sn; i++ ) {
+                                        int delta = (int)GetBits(nBits);
+
+                                        // Compute difference and new predicted value
+                                        // Computes 'vpdiff = (delta+0.5)*step/4'
+
+                                        int step = stepsizeTable[index[i]];
+                                        long vpdiff = 0;
+                                        int k = k0;
+
+                                        do {
+                                                if ( delta & k ) vpdiff += step;
+                                                step >>= 1;
+                                                k >>= 1;
+                                        } while ( k );
+                                        vpdiff += step; // add 0.5
+
+
+                                        if ( delta & signmask ) // the sign bit
+                                                valpred[i] -= vpdiff;
+                                        else
+                                                valpred[i] += vpdiff;
+
+                                        // Find new index value
+                                        index[i] += indexTable[delta&(~signmask)];
+
+                                        if ( index[i] < 0 )
+                                                index[i] = 0;
+                                        else if ( index[i] > 88 )
+                                                index[i] = 88;
+
+                                        // clamp output value
+                                        if ( valpred[i] != (short)valpred[i] )
+                                                valpred[i] = valpred[i] < 0 ? -32768 : 32767;
+
+                                        /* Step 7 - Output value */
+                                        *dst++ = (short)valpred[i];
+                                }
+                        }
+                }
+        }
+}