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authorMans Rullgard <mans@mansr.com>2011-11-26 18:48:16 +0000
committerMans Rullgard <mans@mansr.com>2011-11-26 20:52:09 +0000
commitb6ae0866821df5f3b83f6b7f5c281d9a3e36b7ee (patch)
tree988f476974ce3f91c62f57dbe135d76e4dfe5a8d /libavcodec
parentb02aa3a8eaa5673f36cfd944fe23dc3ea02b38f6 (diff)
downloadffmpeg-b6ae0866821df5f3b83f6b7f5c281d9a3e36b7ee.tar.gz
dv: simplify bitstream splicing in dv_decode_ac()
This is simpler and fixes some overflow checker warnings. Signed-off-by: Mans Rullgard <mans@mansr.com>
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/dv.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/libavcodec/dv.c b/libavcodec/dv.c
index f16ed624e7..6c50f77d3f 100644
--- a/libavcodec/dv.c
+++ b/libavcodec/dv.c
@@ -364,7 +364,7 @@ typedef struct BlockInfo {
uint8_t pos; /* position in block */
void (*idct_put)(uint8_t *dest, int line_size, DCTELEM *block);
uint8_t partial_bit_count;
- uint16_t partial_bit_buffer;
+ uint32_t partial_bit_buffer;
int shift_offset;
} BlockInfo;
@@ -392,8 +392,7 @@ static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, DCTELEM *block)
/* if we must parse a partial VLC, we do it here */
if (partial_bit_count > 0) {
- re_cache = ((unsigned)re_cache >> partial_bit_count) |
- (mb->partial_bit_buffer << (sizeof(re_cache) * 8 - partial_bit_count));
+ re_cache = re_cache >> partial_bit_count | mb->partial_bit_buffer;
re_index -= partial_bit_count;
mb->partial_bit_count = 0;
}
@@ -416,7 +415,7 @@ static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, DCTELEM *block)
if (re_index + vlc_len > last_index) {
/* should be < 16 bits otherwise a codeword could have been parsed */
mb->partial_bit_count = last_index - re_index;
- mb->partial_bit_buffer = NEG_USR32(re_cache, mb->partial_bit_count);
+ mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
re_index = last_index;
break;
}