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| author | Martin Storsjö <martin@martin.st> | 2014-02-28 12:19:49 +0200 |
|---|---|---|
| committer | Reinhard Tartler <siretart@tauware.de> | 2014-03-02 11:42:37 -0500 |
| commit | 9841617b7f862fcf24ad05eda865a3f323ee0dd0 (patch) | |
| tree | dcf4842e4bac89bc32fcacde8471ca9bf927edad | |
| parent | 7754d4838178a5c09c3c3953bb2b90d1abc639e3 (diff) | |
| download | ffmpeg-9841617b7f862fcf24ad05eda865a3f323ee0dd0.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>
(cherry picked from commit ea7f79f93796d68559a495be824b6bbd94dfe5f6)
| -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 */ |