summaryrefslogtreecommitdiffstats
path: root/src/modules/dcc/adpcmcodec.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/modules/dcc/adpcmcodec.cpp')
-rw-r--r--src/modules/dcc/adpcmcodec.cpp294
1 files changed, 294 insertions, 0 deletions
diff --git a/src/modules/dcc/adpcmcodec.cpp b/src/modules/dcc/adpcmcodec.cpp
new file mode 100644
index 00000000..65f12a00
--- /dev/null
+++ b/src/modules/dcc/adpcmcodec.cpp
@@ -0,0 +1,294 @@
+//
+// File : adpcmcodec.cpp
+// Creation date : Wed Aug 22 19:12:50 2001 GMT by Szymon Stefanek
+//
+// This file is part of the KVirc irc client distribution
+//
+// Code derived from adpcm.c : Intel ADPCM coder/decoder
+// Adapted for the KVirc distribution by Szymon Stefanek (pragma at kvirc dot net)
+// Last revision : 20 Sep 1999
+//
+// Copyright 1992 by Stichting Mathematisch Centrum, Amsterdam, The Netherlands.
+// All Rights Reserved
+//
+// Permission to use, copy, modify, and distribute this software and its
+// documentation for any purpose and without fee is hereby granted,
+// provided that the above copyright notice appear in all copies and that
+// both that copyright notice and this permission notice appear in
+// supporting documentation, and that the names of Stichting Mathematisch
+// Centrum or CWI not be used in advertising or publicity pertaining to
+// distribution of the software without specific, written prior permission.
+//
+// STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
+// THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+// FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
+// FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+// OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+//
+// Intel/DVI ADPCM coder/decoder.
+//
+// The algorithm for this coder was taken from the IMA Compatability Project
+// proceedings, Vol 2, Number 2; May 1992.
+//
+// Version 1.2, 18-Dec-92.
+//
+
+#define _ADPCMCODEC_CPP_
+#include "adpcmcodec.h"
+
+#include <stdio.h> /*DBG*/
+
+#ifndef __STDC__
+ #define signed
+#endif
+
+
+
+#define ADPCM_PACKED_FRAME_SIZE_IN_BYTES 512
+#define ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES 2048
+#define ADPCM_UNPACKED_FRAME_SIZE_IN_SHORTS 1024
+
+// Intel ADPCM step variation table */
+static int indexTable[16] = {
+ -1, -1, -1, -1, 2, 4, 6, 8,
+ -1, -1, -1, -1, 2, 4, 6, 8,
+};
+
+static 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
+};
+
+
+void ADPCM_compress(short indata[],char outdata[],int len,ADPCM_state *state)
+{
+ short *lpIn; /* Input buffer pointer */
+ signed char *lpOut; /* output buffer pointer */
+ int val; /* Current input sample value */
+ int sign; /* Current adpcm sign bit */
+ int delta; /* Current adpcm output value */
+ int diff; /* Difference between val and valprev */
+ int step; /* Stepsize */
+ int valpred; /* Predicted output value */
+ int vpdiff; /* Current change to valpred */
+ int index; /* Current step change index */
+ int outputbuffer = 0; /* place to keep previous 4-bit value */
+ int bufferstep; /* toggle between outputbuffer/output */
+
+ lpOut = (signed char *)outdata;
+ lpIn = indata;
+
+ valpred = state->valprev;
+ index = state->index;
+ step = stepsizeTable[index];
+
+ bufferstep = 1;
+
+ for ( ;len > 0;len-- ) {
+ val = *lpIn++;
+ // Step 1 - compute difference with previous value
+ diff = val - valpred;
+ sign = (diff < 0) ? 8 : 0;
+ if(sign)diff=(-diff);
+ // Step 2 - Divide and clamp
+ // Note:
+ // This code *approximately* computes:
+ // delta = diff*4/step;
+ // vpdiff = (delta+0.5)*step/4;
+ // but in shift step bits are dropped. The net result of this is
+ // that even if you have fast mul/div hardware you cannot put it to
+ // good use since the fixup would be too expensive.
+ //
+ delta = 0;
+ vpdiff = (step >> 3);
+ if (diff >=step){
+ delta = 4;
+ diff -= step;
+ vpdiff += step;
+ }
+ step >>= 1;
+ if (diff >= step) {
+ delta |= 2;
+ diff -= step;
+ vpdiff += step;
+ }
+ step >>= 1;
+ if ( diff >= step ) {
+ delta |= 1;
+ vpdiff += step;
+ }
+ // Step 3 - Update previous value
+ if(sign)valpred -= vpdiff;
+ else valpred += vpdiff;
+ // Step 4 - Clamp previous value to 16 bits
+ if ( valpred > 32767 )valpred = 32767;
+ else if ( valpred < -32768 )valpred = -32768;
+ // Step 5 - Assemble value, update index and step values
+ delta |= sign;
+ index += indexTable[delta];
+ if ( index < 0 ) index = 0;
+ if ( index > 88 ) index = 88;
+ step = stepsizeTable[index];
+ // Step 6 - Output value
+ if ( bufferstep )outputbuffer = (delta << 4) & 0xf0;
+ else *lpOut++ = (delta & 0x0f) | outputbuffer;
+ bufferstep = !bufferstep;
+ }
+ // Output last step, if needed
+ if (!bufferstep)*lpOut++ = outputbuffer;
+ state->valprev = valpred;
+ state->index = index;
+}
+
+void ADPCM_uncompress(char indata[],short outdata[],int len,ADPCM_state *state)
+{
+ signed char *inp; /* Input buffer pointer */
+ short *outp; /* output buffer pointer */
+ int sign; /* Current adpcm sign bit */
+ int delta; /* Current adpcm output value */
+ int step; /* Stepsize */
+ int valpred; /* Predicted value */
+ int vpdiff; /* Current change to valpred */
+ int index; /* Current step change index */
+ int inputbuffer=0; /* place to keep next 4-bit value */
+ int bufferstep; /* toggle between inputbuffer/input */
+
+ outp = outdata;
+ inp = (signed char *)indata;
+
+ valpred = state->valprev;
+ index = state->index;
+ step = stepsizeTable[index];
+
+ bufferstep = 0;
+
+ for ( ; len > 0 ; len-- ) {
+
+ /* Step 1 - get the delta value */
+ if ( bufferstep )delta = inputbuffer & 0xf;
+ else {
+ inputbuffer = *inp++;
+ delta = (inputbuffer >> 4) & 0xf;
+ }
+ bufferstep = !bufferstep;
+
+ /* Step 2 - Find new index value (for later) */
+ index += indexTable[delta];
+ if ( index < 0 ) index = 0;
+ if ( index > 88 ) index = 88;
+
+ /* Step 3 - Separate sign and magnitude */
+ sign = delta & 8;
+ delta = delta & 7;
+
+ /* Step 4 - Compute difference and new predicted value */
+ /*
+ ** Computes 'vpdiff = (delta+0.5)*step/4', but see comment
+ ** in adpcm_coder.
+ */
+ vpdiff = step >> 3;
+ if( delta & 4 )vpdiff += step;
+ if( delta & 2 )vpdiff += step>>1;
+ if( delta & 1 )vpdiff += step>>2;
+
+ if(sign)valpred -= vpdiff;
+ else valpred += vpdiff;
+
+ /* Step 5 - clamp output value */
+ if(valpred > 32767)valpred = 32767;
+ else if(valpred < -32768)valpred = -32768;
+
+ /* Step 6 - Update step value */
+ step = stepsizeTable[index];
+
+ /* Step 7 - Output value */
+ *outp++ = valpred;
+ }
+
+ state->valprev = valpred;
+ state->index = index;
+}
+
+
+KviDccVoiceAdpcmCodec::KviDccVoiceAdpcmCodec()
+: KviDccVoiceCodec()
+{
+ m_pEncodeState = new ADPCM_state;
+ m_pEncodeState->index = 0;
+ m_pEncodeState->valprev = 0;
+ m_pDecodeState = new ADPCM_state;
+ m_pDecodeState->index = 0;
+ m_pDecodeState->valprev = 0;
+ m_szName = "adpcm (compression 1:4)";
+}
+
+KviDccVoiceAdpcmCodec::~KviDccVoiceAdpcmCodec()
+{
+ delete m_pEncodeState;
+ delete m_pDecodeState;
+}
+
+void KviDccVoiceAdpcmCodec::encode(KviDataBuffer * signal,KviDataBuffer * stream)
+{
+ if(signal->size() < ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES)return; // nothing to encode
+
+ char * ptr = (char *)signal->data();
+
+ int uFrames = signal->size() / ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES;
+ int uTotalDataCompressed = uFrames * ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES;
+ int uFrameOffset = stream->size();
+ char * endPtr = ptr + uTotalDataCompressed;
+
+ stream->addSize(ADPCM_PACKED_FRAME_SIZE_IN_BYTES * uFrames);
+
+ while(ptr != endPtr)
+ {
+ ADPCM_compress((short *)ptr,(char *)(stream->data() + uFrameOffset),ADPCM_UNPACKED_FRAME_SIZE_IN_SHORTS,m_pEncodeState);
+ ptr += ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES;
+ uFrameOffset += ADPCM_PACKED_FRAME_SIZE_IN_BYTES;
+ }
+ signal->remove(uTotalDataCompressed);
+}
+
+void KviDccVoiceAdpcmCodec::decode(KviDataBuffer * stream,KviDataBuffer * signal)
+{
+ if(stream->size() < ADPCM_PACKED_FRAME_SIZE_IN_BYTES)return; // nothing to decode
+
+ char * ptr = (char *)stream->data();
+
+ // Adpcm codec
+ int uFrames = stream->size() / ADPCM_PACKED_FRAME_SIZE_IN_BYTES;
+ int uTotalDataDecompressed = uFrames * ADPCM_PACKED_FRAME_SIZE_IN_BYTES;
+ int uSignalOffset = signal->size();
+ char * endPtr = ptr + (uTotalDataDecompressed);
+
+ signal->addSize(ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES * uFrames);
+
+ while(ptr != endPtr)
+ {
+ ADPCM_uncompress((char *)ptr,(short *)(signal->data() + uSignalOffset),ADPCM_UNPACKED_FRAME_SIZE_IN_SHORTS,m_pDecodeState);
+ ptr += ADPCM_PACKED_FRAME_SIZE_IN_BYTES;
+ uSignalOffset += ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES;
+ }
+ stream->remove(uTotalDataDecompressed);
+}
+
+int KviDccVoiceAdpcmCodec::encodedFrameSize()
+{
+ return ADPCM_PACKED_FRAME_SIZE_IN_BYTES;
+}
+
+int KviDccVoiceAdpcmCodec::decodedFrameSize()
+{
+ return ADPCM_UNPACKED_FRAME_SIZE_IN_BYTES;
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-12-12 04:51:29 +0000