From 17caae72025fd77d8edc07d5b2017b09cf0b1dda Mon Sep 17 00:00:00 2001 From: Rostislav Pehlivanov Date: Thu, 23 Jun 2016 18:06:57 +0100 Subject: [PATCH] diracdec: simplify golomb parsing and dequantization In preparation for the following commits, this commit simplifies the coefficient parsing and dequantization function. It was needlessly inlined without much performance gain. Signed-off-by: Rostislav Pehlivanov --- libavcodec/diracdec.c | 53 +++++-------------------------------------- 1 file changed, 6 insertions(+), 47 deletions(-) diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c index c473e8778f3..72947ec22c7 100644 --- a/libavcodec/diracdec.c +++ b/libavcodec/diracdec.c @@ -406,58 +406,17 @@ static av_cold int dirac_decode_end(AVCodecContext *avctx) return 0; } -#define SIGN_CTX(x) (CTX_SIGN_ZERO + ((x) > 0) - ((x) < 0)) - static inline int coeff_unpack_golomb(GetBitContext *gb, int qfactor, int qoffset) { - int sign, coeff; - uint32_t buf; - - OPEN_READER(re, gb); - UPDATE_CACHE(re, gb); - buf = GET_CACHE(re, gb); - - if (buf & 0x80000000) { - LAST_SKIP_BITS(re,gb,1); - CLOSE_READER(re, gb); - return 0; - } - - 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; - } - - coeff = (coeff * qfactor + qoffset) >> 2; - sign = SHOW_SBITS(re, gb, 1); - LAST_SKIP_BITS(re, gb, 1); - coeff = (coeff ^ sign) - sign; - - CLOSE_READER(re, gb); + int coeff = dirac_get_se_golomb(gb); + const int sign = FFSIGN(coeff); + if (coeff) + coeff = sign*((sign * coeff * qfactor + qoffset) >> 2); return coeff; } +#define SIGN_CTX(x) (CTX_SIGN_ZERO + ((x) > 0) - ((x) < 0)) + #define UNPACK_ARITH(n, type) \ static inline void coeff_unpack_arith_##n(DiracArith *c, int qfactor, int qoffset, \ SubBand *b, type *buf, int x, int y) \ -- 2.39.5