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avcodec/diracdec: Inline svq3_get_ue_golomb() and merge the sign bit decoding into it

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This avoids closing and opening the bit reader

Reviewed-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2016-01-12 23:32:56 +01:00
parent 9006567bae
commit da144c2ddd
1 changed files with 34 additions and 3 deletions
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37
libavcodec/diracdec.c
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@ -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;
}