libavcodec/alacenc.c:219: error: Buffer Overrun L1
  Offset: [3, `s->frame_size`] (⇐ 1 + [2, `s->frame_size` - 1]) Size: 2 by call to `estimate_stereo_mode`.

libavcodec/alacenc.c:213:1: Parameter `s->sample_buf[*]`
211. }
212. 
213. static void alac_stereo_decorrelation(AlacEncodeContext *s)
     ^
214. {
215.     int32_t *left = s->sample_buf[0], *right = s->sample_buf[1];

libavcodec/alacenc.c:215:5: Assignment
213. static void alac_stereo_decorrelation(AlacEncodeContext *s)
214. {
215.     int32_t *left = s->sample_buf[0], *right = s->sample_buf[1];
         ^
216.     int i, mode, n = s->frame_size;
217.     int32_t tmp;

libavcodec/alacenc.c:219:12: Call
217.     int32_t tmp;
218. 
219.     mode = estimate_stereo_mode(left, right, n);
                ^
220. 
221.     switch (mode) {

libavcodec/alacenc.c:180:1: <Offset trace>
178. }
179. 
180. static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
     ^
181. {
182.     int i, best;

libavcodec/alacenc.c:180:1: Parameter `n`
  178. }
  179. 
  180. static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
       ^
  181. {
  182.     int i, best;

libavcodec/alacenc.c:180:1: <Length trace>
178. }
179. 
180. static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
     ^
181. {
182.     int i, best;

libavcodec/alacenc.c:180:1: Parameter `*right_ch`
  178. }
  179. 
  180. static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
       ^
  181. {
  182.     int i, best;

libavcodec/alacenc.c:191:14: Array access: Offset: [3, s->frame_size] (⇐ 1 + [2, s->frame_size - 1]) Size: 2 by call to `estimate_stereo_mode` 
  189.     for (i = 2; i < n; i++) {
  190.         lt =  left_ch[i] - 2 *  left_ch[i - 1] +  left_ch[i - 2];
  191.         rt = right_ch[i] - 2 * right_ch[i - 1] + right_ch[i - 2];
                    ^
  192.         sum[2] += FFABS((lt + rt) >> 1);
  193.         sum[3] += FFABS(lt - rt);
