diff options
| author | Martin Storsjö <martin@martin.st> | 2014-02-28 12:19:49 +0200 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2014-03-01 00:25:08 +0200 |
| commit | ea7f79f93796d68559a495be824b6bbd94dfe5f6 (patch) | |
| tree | 4d821337c64fa8e79a3887383e24fa420287a225 /tools | |
| parent | bb95334c34d0d9abccea370ae25c4765d7764ab8 (diff) | |
| download | ffmpeg-ea7f79f93796d68559a495be824b6bbd94dfe5f6.tar.gz | |
qt-faststart: Avoid unintentionally sign extending BE_32
Without this cast, the BE_32() expression is sign extended when
assigned to an uint64_t, since the uint8_t|uint8_t expression
is promoted to an int.
Also avoid undefined behaviour when left shifting an uint8_t
by 24 by casting it to an uint32_t explicitly before shifting.
Based on a patch by Michael Niedermayer.
Signed-off-by: Martin Storsjö <martin@martin.st>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/qt-faststart.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/tools/qt-faststart.c b/tools/qt-faststart.c index 792c272193..3a0139fecb 100644 --- a/tools/qt-faststart.c +++ b/tools/qt-faststart.c @@ -41,10 +41,10 @@ #define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1]) -#define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \ - (((uint8_t*)(x))[1] << 16) | \ - (((uint8_t*)(x))[2] << 8) | \ - ((uint8_t*)(x))[3]) +#define BE_32(x) (((uint32_t)(((uint8_t*)(x))[0]) << 24) | \ + (((uint8_t*)(x))[1] << 16) | \ + (((uint8_t*)(x))[2] << 8) | \ + ((uint8_t*)(x))[3]) #define BE_64(x) (((uint64_t)(((uint8_t*)(x))[0]) << 56) | \ ((uint64_t)(((uint8_t*)(x))[1]) << 48) | \ @@ -123,7 +123,7 @@ int main(int argc, char *argv[]) if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) { break; } - atom_size = (uint32_t) BE_32(&atom_bytes[0]); + atom_size = BE_32(&atom_bytes[0]); atom_type = BE_32(&atom_bytes[4]); /* keep ftyp atom */ |