Initial revision

CVS patchset: 1
CVS date: 2001/04/18 22:33:39

1 files changed, 151 insertions, 0 deletions

diff --git a/src/libmpg123/decode_i386.c b/src/libmpg123/decode_i386.c
new file mode 100644
index 000000000..dc73c33cc
--- /dev/null
+++ b/src/libmpg123/decode_i386.c
@@ -0,0 +1,151 @@
+/* 
+ * Mpeg Layer-1,2,3 audio decoder 
+ * ------------------------------
+ * copyright (c) 1995,1996,1997 by Michael Hipp, All rights reserved.
+ * See also 'README'
+ *
+ * slighlty optimized for machines without autoincrement/decrement.
+ * The performance is highly compiler dependend. Maybe
+ * the decode.c version for 'normal' processor may be faster
+ * even for Intel processors.
+ */
+
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+
+#include "mpg123.h"
+#include "mpglib.h"
+
+ /* old WRITE_SAMPLE */
+#define WRITE_SAMPLE(samples,sum,clip) \
+  if( (sum) > 32767.0) { *(samples) = 0x7fff; (clip)++; } \
+  else if( (sum) < -32768.0) { *(samples) = -0x8000; (clip)++; /* printf ("too small : %f\n",sum);*/} \
+  else { *(samples) = sum;  }
+
+int synth_1to1_mono(mpgaudio_t *mp, real *bandPtr,unsigned char *samples,int *pnt)
+{
+  short samples_tmp[64];
+  short *tmp1 = samples_tmp;
+  int i,ret;
+  int pnt1 = 0;
+
+  ret = synth_1to1(mp, bandPtr,0,(unsigned char *) samples_tmp,&pnt1);
+  samples += *pnt;
+
+  for(i=0;i<32;i++) {
+    *( (short *) samples) = *tmp1;
+    samples += 2;
+    tmp1 += 2;
+  }
+  *pnt += 64;
+
+  return ret;
+}
+
+
+int synth_1to1(mpgaudio_t *mp, real *bandPtr,int channel,unsigned char *out,int *pnt)
+{
+  static const int step = 2;
+  int bo;
+  short *samples = (short *) (out + *pnt);
+
+  real *b0,(*buf)[0x110];
+  int clip = 0; 
+  int bo1;
+
+  bo = mp->synth_bo;
+
+  if(!channel) {
+    bo--;
+    bo &= 0xf;
+    buf = mp->synth_buffs[0];
+  }
+  else {
+    samples++;
+    buf = mp->synth_buffs[1];
+  }
+
+  if(bo & 0x1) {
+    b0 = buf[0];
+    bo1 = bo;
+    dct64(buf[1]+((bo+1)&0xf),buf[0]+bo,bandPtr);
+  }
+  else {
+    b0 = buf[1];
+    bo1 = bo+1;
+    dct64(buf[0]+bo,buf[1]+bo+1,bandPtr);
+  }
+
+  mp->synth_bo = bo;
+  
+  {
+    register int j;
+    real *window = decwin + 16 - bo1;
+
+    for (j=16;j;j--,b0+=0x10,window+=0x20,samples+=step)
+    {
+      real sum;
+      sum  = window[0x0] * b0[0x0];
+      sum -= window[0x1] * b0[0x1];
+      sum += window[0x2] * b0[0x2];
+      sum -= window[0x3] * b0[0x3];
+      sum += window[0x4] * b0[0x4];
+      sum -= window[0x5] * b0[0x5];
+      sum += window[0x6] * b0[0x6];
+      sum -= window[0x7] * b0[0x7];
+      sum += window[0x8] * b0[0x8];
+      sum -= window[0x9] * b0[0x9];
+      sum += window[0xA] * b0[0xA];
+      sum -= window[0xB] * b0[0xB];
+      sum += window[0xC] * b0[0xC];
+      sum -= window[0xD] * b0[0xD];
+      sum += window[0xE] * b0[0xE];
+      sum -= window[0xF] * b0[0xF];
+
+      WRITE_SAMPLE(samples,sum,clip);
+    }
+
+    {
+      real sum;
+      sum  = window[0x0] * b0[0x0];
+      sum += window[0x2] * b0[0x2];
+      sum += window[0x4] * b0[0x4];
+      sum += window[0x6] * b0[0x6];
+      sum += window[0x8] * b0[0x8];
+      sum += window[0xA] * b0[0xA];
+      sum += window[0xC] * b0[0xC];
+      sum += window[0xE] * b0[0xE];
+      WRITE_SAMPLE(samples,sum,clip);
+      b0-=0x10,window-=0x20,samples+=step;
+    }
+    window += bo1<<1;
+
+    for (j=15;j;j--,b0-=0x10,window-=0x20,samples+=step)
+    {
+      real sum;
+      sum = -window[-0x1] * b0[0x0];
+      sum -= window[-0x2] * b0[0x1];
+      sum -= window[-0x3] * b0[0x2];
+      sum -= window[-0x4] * b0[0x3];
+      sum -= window[-0x5] * b0[0x4];
+      sum -= window[-0x6] * b0[0x5];
+      sum -= window[-0x7] * b0[0x6];
+      sum -= window[-0x8] * b0[0x7];
+      sum -= window[-0x9] * b0[0x8];
+      sum -= window[-0xA] * b0[0x9];
+      sum -= window[-0xB] * b0[0xA];
+      sum -= window[-0xC] * b0[0xB];
+      sum -= window[-0xD] * b0[0xC];
+      sum -= window[-0xE] * b0[0xD];
+      sum -= window[-0xF] * b0[0xE];
+      sum -= window[-0x0] * b0[0xF];
+
+      WRITE_SAMPLE(samples,sum,clip);
+    }
+  }
+  *pnt += 128;
+
+  return clip;
+}
+