Fix nasty bug that causes low bitrate files to crash because of an incorrect assumption about MDCT window sizes on my part. Clears the way for further low bitrate fixes.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13937 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 25 insertions, 59 deletions

diff --git a/apps/codecs/libwma/wmadeci.c b/apps/codecs/libwma/wmadeci.c
index 4b16acd038..118b17126f 100644
--- a/apps/codecs/libwma/wmadeci.c
+++ b/apps/codecs/libwma/wmadeci.c
@@ -150,58 +150,6 @@ static VLC_TYPE vlcbuf3[1536][2] IBSS_ATTR;    //small so lets try iram
 
 #include "wmadata.h" // PJJ
 
-/**
- * The size of the FFT is 2^nbits. If inverse is TRUE, inverse FFT is
- * done
- */
-int fft_inits(FFTContext *s, int nbits, int inverse)
-{
-    int i, n;
-    fixed32 c1, s1;
-    int s2;
-
-    s->nbits = nbits;
-    n = 1 << nbits;
-
-    s->inverse = inverse;
-
-    s2 = inverse ? 1 : -1;
-
-    if(nbits == 10){        //we folded all these stupid tables into the nbits==10 table, so don't make it for the others!
-                    //should probably just remove exptab building out of this function and do it higher up for neatness
-        for(i=0;i<(n/2);++i)
-        {
-          //we're going to redo this in CORDIC fixed format!     Hold onto your butts
-
-          /*
-          input to cordic is from 0 ->2pi with 0->0 and 2^32-1 ->2pi
-          output, which is what we'll store the variables as is
-            -1->-2^31 and 1->2^31-1
-
-          */
-
-          fixed32 ifix = itofix32(i);
-          fixed32 nfix = itofix32(n);
-          fixed32 res = fixdiv32(ifix,nfix);        //this is really bad here since nfix can be as large as 1024 !
-                            //also, make this a shift, since its a fucking power of two divide
-          //alpha = fixmul32(TWO_M_PI_F, res);
-          //ct = fixcos32(alpha);                    //need to correct alpha for 0->2pi scale
-          //st = fixsin32(alpha);// * s2;
-
-          s1 = fsincos(res<<16, &c1);        //does sin and cos in one pass!
-
-        //I really have my doubts about the correctness of the alpha to cordic mapping here, but it seems to work well enough
-        //double check this later!
-
-          exptab0[i].re = c1;
-          exptab0[i].im = s1*s2;
-        }
-    }
-   // s->fft_calc = fft_calc;
-    s->exptab1 = NULL;
-
-    return 0;
-}
 
 /* butter fly op */
 #define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
@@ -338,14 +286,13 @@ int ff_mdct_init(MDCTContext *s, int nbits, int inverse)
     s->tsin[i] = - fsincos(ip<<16, &(s->tcos[i]));            //I can't remember why this works, but it seems to agree for ~24 bits, maybe more!
     s->tcos[i] *=-1;
   }
-    if (fft_inits(&s->fft, s->nbits - 2, inverse) < 0)
-        goto fail;
+      s->fft.nbits = s->nbits - 2;
+
+
+    s->fft.inverse = inverse;
 
     return 0;
-fail:
-//    av_freep(&s->tcos);
-//    av_freep(&s->tsin);
-    return -1;
+
 }
 
 /**
@@ -824,12 +771,31 @@ int wma_decode_init(WMADecodeContext* s, asf_waveformatex_t *wfx)
     exparray[0] = exptab0; //exparray[1] = exptab1; exparray[2] = exptab2; exparray[3] = exptab3; exparray[4] = exptab4;
     revarray[0]=revtab0; //revarray[1]=revtab1; revarray[2]=revtab2; revarray[3]=revtab3; revarray[4]=revtab4;
 
-      s->mdct_tmp = mdct_tmp; /* temporary storage for imdct */
+    s->mdct_tmp = mdct_tmp; /* temporary storage for imdct */
     for(i = 0; i < s->nb_block_sizes; ++i)
     {
         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
     }
 
+        {
+                int i, n;
+                fixed32 c1, s1, s2;
+
+                n=1<<10;
+                s2 = 1 ? 1 : -1;
+                  for(i=0;i<(n/2);++i)
+                  {
+                    fixed32 ifix = itofix32(i);
+                    fixed32 nfix = itofix32(n);
+                    fixed32 res = fixdiv32(ifix,nfix);
+
+                    s1 = fsincos(res<<16, &c1);
+
+                    exptab0[i].re = c1;
+                    exptab0[i].im = s1*s2;
+                }
+        }
+
     /* init the MDCT bit reverse table here rather then in fft_init */
 
       for(i=0;i<1024;i++)           /*hard coded to a 2048 bit rotation*/