Refactoring analysis downmix to use sig scaling

xiph · Nov 2, 2024 · 5daf8d5 · 5daf8d5
1 parent 69adba3
commit 5daf8d5
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Showing 3 changed files with 16 additions and 29 deletions.
diff --git a/celt/arch.h b/celt/arch.h
@@ -138,7 +138,6 @@ typedef opus_val32 celt_ener;
 #ifdef ENABLE_RES24
 typedef opus_val32 opus_res;
 #define RES_SHIFT 8
-#define SCALEIN(a)      (a)
 #define SIG2RES(a)      PSHR32(a, SIG_SHIFT-RES_SHIFT)
 #define RES2INT16(a)    SAT16(PSHR32(a, RES_SHIFT))
 #define RES2FLOAT(a)    ((1.f/32768.f/256.)*(a))
@@ -150,7 +149,6 @@ typedef opus_val32 opus_res;
 #else
 typedef opus_val16 opus_res;
 #define RES_SHIFT 0
-#define SCALEIN(a)      (a)
 #define SIG2RES(a)      SIG2WORD16(a)
 #define RES2INT16(a)    (a)
 #define RES2FLOAT(a)    ((1.f/32768.f)*(a))
@@ -162,6 +160,8 @@ typedef opus_val16 opus_res;
 #endif
 
 #define RES2VAL16(a)    RES2INT16(a)
+#define FLOAT2SIG(a)    float2int(((opus_int32)32768<<SIG_SHIFT)*(a))
+#define INT16TOSIG(a)   SHL32(EXTEND32(a), SIG_SHIFT)
 
 #define celt_isnan(x) 0
 
@@ -314,8 +314,6 @@ static OPUS_INLINE int celt_isnan(float x)
 #define DIV32_16(a,b)     (((opus_val32)(a))/(opus_val16)(b))
 #define DIV32(a,b)     (((opus_val32)(a))/(opus_val32)(b))
 
-#define SCALEIN(a)      ((a)*CELT_SIG_SCALE)
-
 #define SIG2RES(a)      ((1/CELT_SIG_SCALE)*(a))
 #define RES2INT16(a)    FLOAT2INT16(a)
 #define RES2FLOAT(a)    (a)
@@ -326,6 +324,8 @@ static OPUS_INLINE int celt_isnan(float x)
 #define MULT16_RES_Q15(a,b) MULT16_16_Q15(a,b)
 
 #define RES2VAL16(a)    (a)
+#define FLOAT2SIG(a)    ((a)*CELT_SIG_SCALE)
+#define INT16TOSIG(a)   ((float)(a))
 
 
 #endif /* !FIXED_POINT */

diff --git a/src/analysis.c b/src/analysis.c
@@ -163,7 +163,6 @@ static opus_val32 silk_resampler_down2_hp(
 static opus_val32 downmix_and_resample(downmix_func downmix, const void *_x, opus_val32 *y, opus_val32 S[3], int subframe, int offset, int c1, int c2, int C, int Fs)
 {
    VARDECL(opus_val32, tmp);
-   opus_val32 scale;
    int j;
    opus_val32 ret = 0;
    SAVE_STACK;
@@ -180,17 +179,11 @@ static opus_val32 downmix_and_resample(downmix_func downmix, const void *_x, opu
    ALLOC(tmp, subframe, opus_val32);
 
    downmix(_x, tmp, subframe, offset, c1, c2, C);
-#ifdef FIXED_POINT
-   scale = (1<<SIG_SHIFT);
-#else
-   scale = 1.f/32768;
-#endif
-   if (c2==-2)
-      scale /= C;
-   else if (c2>-1)
-      scale /= 2;
-   for (j=0;j<subframe;j++)
-      tmp[j] *= scale;
+   if ((c2==-2 && C==2) || c2>-1) {
+      for (j=0;j<subframe;j++) {
+         tmp[j] = HALF32(tmp[j]);
+      }
+   }
    if (Fs == 48000)
    {
       ret = silk_resampler_down2_hp(S, y, tmp, subframe);
@@ -422,7 +415,7 @@ static const float std_feature_bias[9] = {
 #define SCALE_COMPENS (1.f/((opus_int32)1<<(15+SIG_SHIFT)))
 #define SCALE_ENER(e) ((SCALE_COMPENS*SCALE_COMPENS)*(e))
 #else
-#define SCALE_ENER(e) (e)
+#define SCALE_ENER(e) ((1.f/32768/32768)*e)
 #endif
 
 #ifdef FIXED_POINT

diff --git a/src/opus_encoder.c b/src/opus_encoder.c
@@ -692,31 +692,25 @@ static opus_int32 user_bitrate_to_bitrate(OpusEncoder *st, int frame_size, int m
 }
 
 #ifndef DISABLE_FLOAT_API
-#ifdef FIXED_POINT
-#define PCM2VAL(x) FLOAT2INT16(x)
-#else
-#define PCM2VAL(x) SCALEIN(x)
-#endif
-
 void downmix_float(const void *_x, opus_val32 *y, int subframe, int offset, int c1, int c2, int C)
 {
    const float *x;
    int j;
 
    x = (const float *)_x;
    for (j=0;j<subframe;j++)
-      y[j] = PCM2VAL(x[(j+offset)*C+c1]);
+      y[j] = FLOAT2SIG(x[(j+offset)*C+c1]);
    if (c2>-1)
    {
       for (j=0;j<subframe;j++)
-         y[j] += PCM2VAL(x[(j+offset)*C+c2]);
+         y[j] += FLOAT2SIG(x[(j+offset)*C+c2]);
    } else if (c2==-2)
    {
       int c;
       for (c=1;c<C;c++)
       {
          for (j=0;j<subframe;j++)
-            y[j] += PCM2VAL(x[(j+offset)*C+c]);
+            y[j] += FLOAT2SIG(x[(j+offset)*C+c]);
       }
    }
 }
@@ -729,18 +723,18 @@ void downmix_int(const void *_x, opus_val32 *y, int subframe, int offset, int c1
 
    x = (const opus_int16 *)_x;
    for (j=0;j<subframe;j++)
-      y[j] = x[(j+offset)*C+c1];
+      y[j] = INT16TOSIG(x[(j+offset)*C+c1]);
    if (c2>-1)
    {
       for (j=0;j<subframe;j++)
-         y[j] += x[(j+offset)*C+c2];
+         y[j] += INT16TOSIG(x[(j+offset)*C+c2]);
    } else if (c2==-2)
    {
       int c;
       for (c=1;c<C;c++)
       {
          for (j=0;j<subframe;j++)
-            y[j] += x[(j+offset)*C+c];
+            y[j] += INT16TOSIG(x[(j+offset)*C+c]);
       }
    }
 }