Move overflow checks into SkipCutBuffer

Previously SkipCutBuffer would check its input parameters to ensure
they were sane, however since bogus values might be the result of
overflows, and overflow protection was recently turned on for
libstagefright, the compiler's overflow checks were performed before
SkipCutBuffer's, resulting in abort rather than just ignoring the
bogus values.
Moving the multiplication by framesize into SkipCutBuffer fixes this.

Change-Id: I1ad6744bb045a5212701bbf6ee44eecb5f318210

1 files changed, 4 insertions, 3 deletions

diff --git a/include/media/stagefright/SkipCutBuffer.h b/include/media/stagefright/SkipCutBuffer.h
index 098aa69..61f9949 100644
--- a/include/media/stagefright/SkipCutBuffer.h
+++ b/include/media/stagefright/SkipCutBuffer.h
@@ -29,9 +29,10 @@ namespace android {
  */
 class SkipCutBuffer: public RefBase {
  public:
-    // 'skip' is the number of bytes to skip from the beginning
-    // 'cut' is the number of bytes to cut from the end
-    SkipCutBuffer(int32_t skip, int32_t cut);
+    // 'skip' is the number of frames to skip from the beginning
+    // 'cut' is the number of frames to cut from the end
+    // 'num16BitChannels' is the number of channels, which are assumed to be 16 bit wide each
+    SkipCutBuffer(size_t skip, size_t cut, size_t num16Channels);
 
     // Submit one MediaBuffer for skipping and cutting. This may consume all or
     // some of the data in the buffer, or it may add data to it.