cmProc.h/c: cmAudioFileRd now recognizes 'endSmpIdx' == 0 as an indication to

read 'procSmpCnt' blocks until the end-of-file is reached.

cmProc.c

   p->lastReadFrmCnt = 0;
   p->eofFl          = false;
   p->begFrmIdx      = begFrmIdx;
-  p->endFrmIdx      = endFrmIdx;
+  p->endFrmIdx      = endFrmIdx==0 ? p->info.frameCnt : endFrmIdx;
   p->curFrmIdx      = p->begFrmIdx;
 
   if( p->begFrmIdx > 0 )

cmProc.h

   /// set p to NULL to dynamically allocate the object
   /// fn and chIdx are optional - set fn to NULL to allocate the reader without opening a file.
   /// If fn is valid then chIdx must also be valid.
-  /// Set 'endSmpIdx' to cmInvalidIdx to not limit the range of samples returned.
+  /// Set 'endSmpIdx' to cmInvalidIdx to return the entire signal in cmAudioFileRdRead().
+  /// Set 'endSmpIdx' to 0 to return all samples between 0 and the end of the file.
   cmAudioFileRd*     cmAudioFileRdAlloc( cmCtx* c, cmAudioFileRd* p, unsigned procSmpCnt, const char* fn, unsigned chIdx, unsigned begSmpIdx, unsigned endSmpIdx );
   cmRC_t             cmAudioFileRdFree(  cmAudioFileRd** p );
   cmRC_t             cmAudioFileRdOpen(  cmAudioFileRd* p, unsigned procSmpCnt,  const cmChar_t* fn, unsigned chIdx, unsigned begSmpIdx, unsigned endSmpIdx );