[FFmpeg-cvslog] avcodec/mpegaudioenc_template: reorder operations to prevent integer overflow

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Wed Apr  9 06:56:53 2014 +0200| [44841528c197435be44f0c3598098e6c52f0df26] | committer: Michael Niedermayer

avcodec/mpegaudioenc_template: reorder operations to prevent integer overflow

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=44841528c197435be44f0c3598098e6c52f0df26
---

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

diff --git a/libavcodec/mpegaudioenc_template.c b/libavcodec/mpegaudioenc_template.c
index 5ae4269..451d140 100644
--- a/libavcodec/mpegaudioenc_template.c
+++ b/libavcodec/mpegaudioenc_template.c
@@ -700,9 +700,10 @@ static void encode_frame(MpegAudioContext *s,
                                 else
                                     q1 = sample >> shift;
                                 q1 = (q1 * mult) >> P;
-                                q[m] = ((q1 + (1 << P)) * steps) >> (P + 1);
-                                if (q[m] < 0)
-                                    q[m] = 0;
+                                q1 += 1 << P;
+                                if (q1 < 0)
+                                    q1 = 0;
+                                q[m] = (unsigned)(q1 * steps) >> (P + 1);
                             }
 #endif
                             if (q[m] >= steps)