diff options
author | David Conrad <lessen42@gmail.com> | 2010-07-24 01:46:08 +0400 |
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committer | David Conrad <lessen42@gmail.com> | 2010-07-24 01:46:08 +0400 |
commit | b3d755ec8b516ff45a9cfff9066922ff8196694f (patch) | |
tree | 4b0096dafb4eabecb18f2b60820c61a2f1626121 /libavcodec | |
parent | 24675b8093e2f6944a1014e98ac455d4df75e8a2 (diff) |
Split renorm of vp56 arith decoder to its own function
Originally committed as revision 24466 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r-- | libavcodec/vp56.h | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/libavcodec/vp56.h b/libavcodec/vp56.h index 298aba3d2d..a1904d56d5 100644 --- a/libavcodec/vp56.h +++ b/libavcodec/vp56.h @@ -191,16 +191,30 @@ static inline void vp56_init_range_decoder(VP56RangeCoder *c, c->code_word = bytestream_get_be16(&c->buffer); } +static av_always_inline void vp56_rac_renorm(VP56RangeCoder *c, unsigned int code_word) +{ + int shift = ff_h264_norm_shift[c->high] - 1; + int bits = c->bits; + + c->high <<= shift; + code_word <<= shift; + bits += shift; + if(bits >= 0 && c->buffer < c->end) { + code_word |= *c->buffer++ << bits; + bits -= 8; + } + c->bits = bits; + c->code_word = code_word; +} + static inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob) { /* Don't put c->high in a local variable; if we do that, gcc gets * the stupids and turns the code below into a branch again. */ - int bits = c->bits; unsigned int code_word = c->code_word; unsigned int low = 1 + (((c->high - 1) * prob) >> 8); unsigned int low_shift = low << 8; int bit = code_word >= low_shift; - int shift; /* Incantation to convince GCC to turn these into conditional moves * instead of branches -- faster, as this branch is basically @@ -208,17 +222,7 @@ static inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob) c->high = bit ? c->high - low : low; code_word = bit ? code_word - low_shift : code_word; - /* normalize */ - shift = ff_h264_norm_shift[c->high] - 1; - c->high <<= shift; - code_word <<= shift; - bits += shift; - if(bits >= 0 && c->buffer < c->end) { - code_word |= *c->buffer++ << bits; - bits -= 8; - } - c->bits = bits; - c->code_word = code_word; + vp56_rac_renorm(c, code_word); return bit; } |