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| author | Mans Rullgard <mans@mansr.com> | 2011-11-25 20:43:05 +0000 |
|---|---|---|
| committer | Mans Rullgard <mans@mansr.com> | 2011-11-26 11:38:41 +0000 |
| commit | b7581b5c839d1e293bb9dc34352a76df9d3158a9 (patch) | |
| tree | 0b825ad0e2727a54518f87f213ff8508ef94779e /libavcodec | |
| parent | 644bff6c9bf15b5ed723a893236dbc8c29579c93 (diff) | |
| download | ffmpeg-b7581b5c839d1e293bb9dc34352a76df9d3158a9.tar.gz | |
cook: use a table for xor key rotation
This is simpler and avoids an invalid shift by 32 in the
aligned case.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/cook.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/libavcodec/cook.c b/libavcodec/cook.c index 186c3e70dd..8b0a351495 100644 --- a/libavcodec/cook.c +++ b/libavcodec/cook.c @@ -273,6 +273,10 @@ static av_cold void init_cplscales_table (COOKContext *q) { */ static inline int decode_bytes(const uint8_t* inbuffer, uint8_t* out, int bytes){ + static const uint32_t tab[4] = { + AV_BE2NE32C(0x37c511f2), AV_BE2NE32C(0xf237c511), + AV_BE2NE32C(0x11f237c5), AV_BE2NE32C(0xc511f237), + }; int i, off; uint32_t c; const uint32_t* buf; @@ -285,7 +289,7 @@ static inline int decode_bytes(const uint8_t* inbuffer, uint8_t* out, int bytes) off = (intptr_t)inbuffer & 3; buf = (const uint32_t*) (inbuffer - off); - c = av_be2ne32((0x37c511f2 >> (off*8)) | (0x37c511f2 << (32-(off*8)))); + c = tab[off]; bytes += 3 + off; for (i = 0; i < bytes/4; i++) obuf[i] = c ^ buf[i]; |