[FFmpeg-cvslog] avcodec/vc2enc_dwt: Fix left shifts of negative numbers

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Tue Sep 27 15:19:53 2022 +0200| [22e7e4e19d4a874edcbbf03dcde07cf44af3f783] | committer: Andreas Rheinhardt

avcodec/vc2enc_dwt: Fix left shifts of negative numbers

Fixes the vsynth(1|2|_lena)-vc2-(thaar|t5_3) FATE tests.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=22e7e4e19d4a874edcbbf03dcde07cf44af3f783
---

 libavcodec/vc2enc_dwt.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/libavcodec/vc2enc_dwt.c b/libavcodec/vc2enc_dwt.c
index 441af040ec..809f938e1b 100644
--- a/libavcodec/vc2enc_dwt.c
+++ b/libavcodec/vc2enc_dwt.c
@@ -151,7 +151,7 @@ static void vc2_subband_dwt_53(VC2TransformContext *t, dwtcoef *data,
      */
     for (y = 0; y < synth_height; y++) {
         for (x = 0; x < synth_width; x++)
-            synthl[x] = datal[x] << 1;
+            synthl[x] = datal[x] * 2;
         synthl += synth_width;
         datal  += stride;
     }
@@ -223,9 +223,8 @@ static av_always_inline void dwt_haar(VC2TransformContext *t, dwtcoef *data,
     /* Horizontal synthesis. */
     for (y = 0; y < synth_height; y++) {
         for (x = 0; x < synth_width; x += 2) {
-            synthl[y*synth_width + x + 1] = (datal[y*stride + x + 1] << s) -
-                                            (datal[y*stride + x] << s);
-            synthl[y*synth_width + x] = (datal[y*stride + x + 0] << s) +
+            synthl[y*synth_width + x + 1] = (datal[y*stride + x + 1] - datal[y*stride + x]) * (1 << s);
+            synthl[y*synth_width + x] = datal[y*stride + x + 0] * (1 << s) +
                                         ((synthl[y*synth_width + x + 1] + 1) >> 1);
         }
     }