Vorbis optimizations: allocation of PCM buffers in IRAM, avoiding copying.

Slight code improvements to the MDCT functions.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6590 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 11 insertions, 44 deletions

diff --git a/apps/codecs/Tremor/mapping0.c b/apps/codecs/Tremor/mapping0.c
index 26d6289..c88f072 100644
--- a/apps/codecs/Tremor/mapping0.c
+++ b/apps/codecs/Tremor/mapping0.c
@@ -180,12 +180,6 @@ static vorbis_info_mapping *mapping0_unpack(vorbis_info *vi,oggpack_buffer *opb)
 }
 
 
-/* IRAM buffer keep the pcm data; only for windows size upto 2048
-   for space restrictions. No real compromise, larger window sizes
-   are only used for very low quality settings (q<0?) */
-#define IRAM_PCM_SIZE 2048
-static ogg_int32_t pcm_iram[IRAM_PCM_SIZE] IDATA_ATTR;
-
 static int seq = 0;
 
 #define CHANNELS 2    /* max 2 channels on the ihp-1xx (stereo)  */
@@ -201,11 +195,12 @@ static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
   int                   i,j;
   long                  n=vb->pcmend=ci->blocksizes[vb->W];
 
-  /* statically allocate mapping structures in IRAM */
-  static ogg_int32_t *pcmbundle[CHANNELS] IDATA_ATTR;
-  static int    zerobundle[CHANNELS] IDATA_ATTR;
-  static int   nonzero[CHANNELS] IDATA_ATTR;
-  static void *floormemo[CHANNELS] IDATA_ATTR;
+  /* bounded mapping arrays instead of using alloca();
+     avoids memory leak; we can only deal with stereo anyway */
+  ogg_int32_t *pcmbundle[CHANNELS];
+  int   zerobundle[CHANNELS];
+  int   nonzero[CHANNELS];
+  void *floormemo[CHANNELS];
 
   /* test for too many channels; 
      (maybe this is can be checked at the stream level?) */
@@ -249,7 +244,7 @@ static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
 	pcmbundle[ch_in_bundle++]=vb->pcm[j];
       }
     }
-    
+
     look->residue_func[i]->inverse(vb,look->residue_look[i],
 				   pcmbundle,zerobundle,ch_in_bundle);
   }
@@ -286,13 +281,10 @@ static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
     }
   }
 
+
   //for(j=0;j<vi->channels;j++)
   //_analysis_output("residue",seq+j,vb->pcm[j],-8,n/2,0,0);
 
-
-/* pbv: removed this loop by fusion with the following one 
-   to avoid recopying data to/from the IRAM */
-#if 0
   /* compute and apply spectral envelope */
   for(i=0;i<vi->channels;i++){
     ogg_int32_t *pcm=vb->pcm[i];
@@ -300,7 +292,6 @@ static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
     look->floor_func[submap]->
       inverse2(vb,look->floor_look[submap],floormemo[i],pcm);
   } 
-#endif
 
   //for(j=0;j<vi->channels;j++)
   //_analysis_output("mdct",seq+j,vb->pcm[j],-24,n/2,0,1);
@@ -308,32 +299,9 @@ static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
   /* transform the PCM data; takes PCM vector, vb; modifies PCM vector */
   /* only MDCT right now.... */
 
-  /* check if we can do this in IRAM */
-  if(n <= IRAM_PCM_SIZE) {  /* normal window size: yes */
-    for(i=0;i<vi->channels;i++){
-      ogg_int32_t *pcm=vb->pcm[i];
-      int submap=info->chmuxlist[i];
-
-      if(nonzero[i]) {
-	memcpy(pcm_iram, pcm, sizeof(ogg_int32_t)*n);
-	look->floor_func[submap]->
-	  inverse2(vb,look->floor_look[submap],floormemo[i],pcm_iram);
-	mdct_backward(n, pcm_iram, pcm_iram);
-	/* window the data */
-	_vorbis_apply_window(pcm_iram,b->window,ci->blocksizes,vb->lW,vb->W,vb->nW);
-	memcpy(pcm, pcm_iram, sizeof(ogg_int32_t)*n);
-      }
-      else 
-	memset(pcm, 0, sizeof(ogg_int32_t)*n);
-    }
-  }
-  else {         /* large window: no, do it in the normal memory */
-    for(i=0;i<vi->channels;i++){
-      ogg_int32_t *pcm=vb->pcm[i];
-      int submap=info->chmuxlist[i];
-
-      look->floor_func[submap]->
-	inverse2(vb,look->floor_look[submap],floormemo[i],pcm);
+  for(i=0;i<vi->channels;i++){
+    ogg_int32_t *pcm=vb->pcm[i];
+    
       if(nonzero[i]) {
 	mdct_backward(n, pcm, pcm);
 	/* window the data */
@@ -341,7 +309,6 @@ static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
       }
       else 
 	memset(pcm, 0, sizeof(ogg_int32_t)*n);
-    }
   }
 
   //for(j=0;j<vi->channels;j++)