AAC: move scratch array to context to ensure 16-byte alignment

Originally committed as revision 16043 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/aac.c

@@ -1336,7 +1336,7 @@ static void imdct_and_windowing(AACContext * ac, SingleChannelElement * sce) {
     const float * lwindow_prev = ics->use_kb_window[1] ? ff_aac_kbd_long_1024 : ff_sine_1024;
     const float * swindow_prev = ics->use_kb_window[1] ? ff_aac_kbd_short_128 : ff_sine_128;
     float * buf = ac->buf_mdct;
-    DECLARE_ALIGNED(16, float, temp[128]);
+    float * temp = ac->temp;
     int i;
 
     // imdct

libavcodec/aac.h

@@ -288,6 +288,7 @@ typedef struct {
     int sf_offset;                                    ///< offset into pow2sf_tab as appropriate for dsp.float_to_int16
     /** @} */
 
+    DECLARE_ALIGNED(16, float, temp[128]);
 } AACContext;
 
 #endif /* AVCODEC_AAC_H */