[FFmpeg-cvslog] avcodec/diracdec: Inline svq3_get_ue_golomb() and merge the sign bit decoding into it
Michael Niedermayer
git at videolan.org
Wed Jan 13 19:28:29 CET 2016
ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Jan 12 23:32:56 2016 +0100| [da144c2ddd8cb002540c219dce9ef4303d2b4ee5] | committer: Michael Niedermayer
avcodec/diracdec: Inline svq3_get_ue_golomb() and merge the sign bit decoding into it
This avoids closing and opening the bit reader
Reviewed-by: Rostislav Pehlivanov <atomnuker at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=da144c2ddd8cb002540c219dce9ef4303d2b4ee5
---
libavcodec/diracdec.c | 37 ++++++++++++++++++++++++++++++++++---
1 file changed, 34 insertions(+), 3 deletions(-)
diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index c67f845..fe879bb 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -485,13 +485,44 @@ static av_cold int dirac_decode_end(AVCodecContext *avctx)
static inline int coeff_unpack_golomb(GetBitContext *gb, int qfactor, int qoffset)
{
int sign, coeff;
+ uint32_t buf;
- coeff = svq3_get_ue_golomb(gb);
+ OPEN_READER(re, gb);
+ UPDATE_CACHE(re, gb);
+ buf = GET_CACHE(re, gb);
+
+ if (buf & 0xAA800000) {
+ buf >>= 32 - 8;
+ SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
+
+ coeff = ff_interleaved_ue_golomb_vlc_code[buf];
+ } else {
+ unsigned ret = 1;
+
+ do {
+ buf >>= 32 - 8;
+ SKIP_BITS(re, gb,
+ FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
+
+ if (ff_interleaved_golomb_vlc_len[buf] != 9) {
+ ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
+ ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
+ break;
+ }
+ ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
+ UPDATE_CACHE(re, gb);
+ buf = GET_CACHE(re, gb);
+ } while (ret<0x8000000U && BITS_AVAILABLE(re, gb));
+
+ coeff = ret - 1;
+ }
if (coeff) {
coeff = (coeff * qfactor + qoffset + 2) >> 2;
- sign = get_bits1(gb);
- coeff = (coeff ^ -sign) + sign;
+ sign = SHOW_SBITS(re, gb, 1);
+ LAST_SKIP_BITS(re, gb, 1);
+ coeff = (coeff ^ sign) - sign;
}
+ CLOSE_READER(re, gb);
return coeff;
}
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