Include toolame-dab as library

1 files changed, 69 insertions, 0 deletions

diff --git a/libtoolame-dab/psycho_0.c b/libtoolame-dab/psycho_0.c
new file mode 100644
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+++ b/libtoolame-dab/psycho_0.c
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+#include <stdio.h>
+#include <math.h>
+#include "common.h"
+#include "ath.h"
+#include "encoder.h"
+#include "psycho_0.h"
+
+/* MFC Mar 03
+   It's almost obscene how well this psycho model works for the amount of 
+   computational effort that's put in.
+
+   I got the idea from:
+   Hyen-O Oh et al "Low power mpeg audio encoders using simplified psychoacoustic model
+                    and fast bit allocation"
+                    IEEE Trans on Consumer Electronics v47 n3 August 2001. p613
+
+   All this model does is look at the lowest ATH value within the subband, and then looks
+   at the scalefactors. It combines the two in a real dodgy way to get the SMRs.
+
+   Although the output values aren't really close to any of the other psycho models, 
+   the spread of values and the relative sizes of the values for the different subbands
+   is about right 
+
+   Feel free to make any sort of generic change you want. Add or subtract numbers, take
+   logs, whatever. Fiddle with the numbers until we get a good SMR output */
+
+void psycho_0(double SMR[2][SBLIMIT], int nch, unsigned int scalar[2][3][SBLIMIT], FLOAT sfreq) {
+  int ch, sb, gr;
+  int minscaleindex[2][SBLIMIT]; /* Smaller scale indexes mean bigger scalefactors */
+  static FLOAT ath_min[SBLIMIT];
+  int i;
+  static int init=0;
+
+  if (!init) {
+    FLOAT freqperline = sfreq/1024.0;
+    for (sb=0;sb<SBLIMIT;sb++) {
+      ath_min[sb] = 1000; /* set it huge */
+    }
+    
+    /* Find the minimum ATH in each subband */
+    for (i=0;i<512;i++) {
+      FLOAT thisfreq = i * freqperline;
+      FLOAT ath_val = ATH_dB(thisfreq, 0);
+      if (ath_val < ath_min[i>>4])
+	ath_min[i>>4] = ath_val;
+    }
+    init++;
+  }
+
+  /* Find the minimum scalefactor index for each ch/sb */
+  for (ch=0;ch<nch;ch++) 
+      for (sb=0;sb<SBLIMIT;sb++) 
+	minscaleindex[ch][sb] = scalar[ch][0][sb];
+
+  for (ch=0;ch<nch;ch++) 
+    for (gr=1;gr<3;gr++) 
+      for (sb=0;sb<SBLIMIT;sb++) 
+	if (minscaleindex[ch][sb] > scalar[ch][gr][sb])
+	  minscaleindex[ch][sb] = scalar[ch][gr][sb];
+
+  /* Oh yeah. Fudge the hell out of the SMR calculations 
+     by combining the scalefactor table index and the min ATH in that subband
+     There are probably more elegant/correct ways of combining these values,
+     but who cares? It works pretty well 
+     MFC Mar 03 */
+  for (ch=0;ch<nch;ch++)
+    for (sb=0;sb<SBLIMIT;sb++)
+      SMR[ch][sb] = 2.0 * (30.0 - minscaleindex[ch][sb]) - ath_min[sb];
+}