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https://github.com/webmproject/libwebp.git
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wasm: Add VFilter16
BUG=webp:352 Change-Id: I97f38aee5de063957c1512f6bd429c0e84c02087
This commit is contained in:
Scott LaVarnway
parent
e6e3ec335c
commit
bafa90ccd8
@ -305,6 +305,299 @@ static void Transform(const int16_t* in, uint8_t* dst, int do_two) {
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}
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}
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//------------------------------------------------------------------------------
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// Loop Filter (Paragraph 15)
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/*
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Currently, the add/sub sat instructions are not supported, however in the
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future, they will be. So for now, we will cheat and use the builtins.
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See https://github.com/WebAssembly/meetings/blob/master/2017/CG-05.md
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Poll: Adopt the saturating integer arithmetic operations
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{i8x16,i16x8}.{add,sub}_saturate_[su].
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*/
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static WEBP_INLINE uint8x16 uint8x16_add_sat(const uint8x16 a,
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const uint8x16 b) {
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// TODO(slavarnway): add generic implementation for non-x86
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return (uint8x16)__builtin_ia32_paddusb128(a, b);
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}
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static WEBP_INLINE int8x16 int8x16_add_sat(const int8x16 a, const int8x16 b) {
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// TODO(slavarnway): add generic implementation for non-x86
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return (int8x16)__builtin_ia32_paddsb128(a, b);
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}
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static WEBP_INLINE uint8x16 uint8x16_sub_sat(const uint8x16 a,
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const uint8x16 b) {
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// TODO(slavarnway): add generic implementation for non-x86
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return (uint8x16)__builtin_ia32_psubusb128(a, b);
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}
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static WEBP_INLINE int8x16 int8x16_sub_sat(const int8x16 a, const int8x16 b) {
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// TODO(slavarnway): add generic implementation for non-x86
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return (int8x16)__builtin_ia32_psubsb128(a, b);
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}
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static WEBP_INLINE uint8x16 _max_u8x16(const uint8x16 a, const uint8x16 b) {
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const uint8x16 s1 = (a > b);
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return (s1 & a) | (~s1 & b);
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}
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// Compute abs(p - q) = subs(p - q) OR subs(q - p)
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static WEBP_INLINE int8x16 abs_diff(int8x16 p, int8x16 q) {
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const int8x16 a = uint8x16_sub_sat(p, q);
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const int8x16 b = uint8x16_sub_sat(q, p);
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return a | b;
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}
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// int16 to int8 with saturation.
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static inline int8x16 _pack_sw_2_sb(const int16x8 lo, const int16x8 hi) {
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#if 1
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const int16x8 k7f = splat_int16(0x007f);
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const int16x8 kff80 = splat_int16(0xff80);
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const int16x8 s1_lo = (lo < k7f);
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const int16x8 a_lo = (s1_lo & lo) | (~s1_lo & k7f);
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const int16x8 s2_lo = (a_lo > kff80);
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const int16x8 a2_lo = (s2_lo & a_lo) | (~s2_lo & kff80);
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const int16x8 s1_hi = (hi < k7f);
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const int16x8 a_hi = (s1_hi & hi) | (~s1_hi & k7f);
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const int16x8 s2_hi = (a_hi > kff80);
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const int16x8 a2_hi = (s2_hi & a_hi) | (~s2_hi & kff80);
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return (int8x16)__builtin_shufflevector((int8x16)a2_lo, (int8x16)a2_hi, 0, 2,
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4, 6, 8, 10, 12, 14, 16, 18, 20, 22,
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24, 26, 28, 30);
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#else
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return (int8x16)__builtin_ia32_packsswb128(lo, hi);
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#endif
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}
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// Shift each byte of "x" by 3 bits while preserving by the sign bit.
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static WEBP_INLINE void SignedShift8b(int8x16* const x) {
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const int8x16 zero = {0};
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const int16x8 eleven = splat_int16(3 + 8);
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const int16x8 lo_0 = (int16x8)__builtin_shufflevector(
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*x, zero, 16, 0, 16, 1, 16, 2, 16, 3, 16, 4, 16, 5, 16, 6, 16, 7);
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const int16x8 hi_0 = (int16x8)__builtin_shufflevector(
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*x, zero, 16, 8, 16, 9, 16, 10, 16, 11, 16, 12, 16, 13, 16, 14, 16, 15);
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const int16x8 lo_1 = lo_0 >> eleven;
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const int16x8 hi_1 = hi_0 >> eleven;
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*x = _pack_sw_2_sb(lo_1, hi_1);
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}
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#define FLIP_SIGN_BIT2(a, b) \
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{ \
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a = a ^ sign_bit; \
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b = b ^ sign_bit; \
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}
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#define FLIP_SIGN_BIT4(a, b, c, d) \
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{ \
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FLIP_SIGN_BIT2(a, b); \
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FLIP_SIGN_BIT2(c, d); \
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}
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// input/output is uint8_t
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static WEBP_INLINE void GetNotHEV(const int8x16* const p1,
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const int8x16* const p0,
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const int8x16* const q0,
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const int8x16* const q1, int hev_thresh,
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int8x16* const not_hev) {
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const int8x16 zero = {0};
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const int8x16 t_1 = abs_diff(*p1, *p0);
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const int8x16 t_2 = abs_diff(*q1, *q0);
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const int8x16 h = splat_uint8(hev_thresh);
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const int8x16 t_max = _max_u8x16(t_1, t_2);
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const int8x16 t_max_h = uint8x16_sub_sat(t_max, h);
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*not_hev = (t_max_h == zero); // not_hev <= t1 && not_hev <= t2
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}
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// input pixels are int8_t
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static WEBP_INLINE void GetBaseDelta(const int8x16* const p1,
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const int8x16* const p0,
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const int8x16* const q0,
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const int8x16* const q1,
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int8x16* const delta) {
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// beware of addition order, for saturation!
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const int8x16 p1_q1 = int8x16_sub_sat(*p1, *q1); // p1 - q1
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const int8x16 q0_p0 = int8x16_sub_sat(*q0, *p0); // q0 - p0
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const int8x16 s1 = int8x16_add_sat(p1_q1, q0_p0); // p1 - q1 + 1 * (q0 - p0)
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const int8x16 s2 = int8x16_add_sat(q0_p0, s1); // p1 - q1 + 2 * (q0 - p0)
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const int8x16 s3 = int8x16_add_sat(q0_p0, s2); // p1 - q1 + 3 * (q0 - p0)
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*delta = s3;
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}
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// input and output are int8_t
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static WEBP_INLINE void DoSimpleFilter(int8x16* const p0, int8x16* const q0,
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const int8x16* const fl) {
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const int8x16 k3 = splat_uint8(3);
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const int8x16 k4 = splat_uint8(4);
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int8x16 v3 = int8x16_add_sat(*fl, k3);
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int8x16 v4 = int8x16_add_sat(*fl, k4);
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SignedShift8b(&v4); // v4 >> 3
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SignedShift8b(&v3); // v3 >> 3
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*q0 = int8x16_sub_sat(*q0, v4); // q0 -= v4
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*p0 = int8x16_add_sat(*p0, v3); // p0 += v3
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}
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// Updates values of 2 pixels at MB edge during complex filtering.
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// Update operations:
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// q = q - delta and p = p + delta; where delta = [(a_hi >> 7), (a_lo >> 7)]
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// Pixels 'pi' and 'qi' are int8_t on input, uint8_t on output (sign flip).
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static WEBP_INLINE void Update2Pixels(int8x16* const pi, int8x16* const qi,
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const int16x8* const a0_lo,
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const int16x8* const a0_hi) {
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const int16x8 _7 = splat_int16(7);
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const int16x8 a1_lo = *a0_lo >> _7;
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const int16x8 a1_hi = *a0_hi >> _7;
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const int8x16 delta = _pack_sw_2_sb(a1_lo, a1_hi);
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const int8x16 sign_bit = (int8x16)splat_uint8(0x80);
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*pi = int8x16_add_sat(*pi, delta);
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*qi = int8x16_sub_sat(*qi, delta);
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FLIP_SIGN_BIT2(*pi, *qi);
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}
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// input pixels are uint8_t
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static WEBP_INLINE void NeedsFilter(const int8x16* const p1,
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const int8x16* const p0,
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const int8x16* const q0,
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const int8x16* const q1, int thresh,
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int8x16* const mask) {
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const int8x16 zero = {0};
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const int16x8 one = {1, 1, 1, 1, 1, 1, 1, 1};
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const int8x16 m_thresh = splat_uint8(thresh);
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const int8x16 t1 = abs_diff(*p1, *q1); // abs(p1 - q1)
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const uint8x16 kFE = splat_uint8(0xFE);
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const uint16x8 t2 = t1 & kFE; // set lsb of each byte to zero
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const uint16x8 t3 = t2 >> one; // abs(p1 - q1) / 2
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const int8x16 t4 = abs_diff(*p0, *q0); // abs(p0 - q0)
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const int8x16 t5 = uint8x16_add_sat(t4, t4); // abs(p0 - q0) * 2
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const int8x16 t6 = uint8x16_add_sat(t5, t3); // abs(p0-q0)*2 + abs(p1-q1)/2
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const int8x16 t7 = uint8x16_sub_sat(t6, m_thresh); // mask <= m_thresh
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*mask = (t7 == zero);
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}
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//------------------------------------------------------------------------------
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// Edge filtering functions
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// Applies filter on 6 pixels (p2, p1, p0, q0, q1 and q2)
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static WEBP_INLINE void DoFilter6(int8x16* const p2, int8x16* const p1,
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int8x16* const p0, int8x16* const q0,
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int8x16* const q1, int8x16* const q2,
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const int8x16* const mask, int hev_thresh) {
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const int8x16 zero = {0};
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const int8x16 sign_bit = splat_uint8(0x80);
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int8x16 a, not_hev;
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// compute hev mask
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GetNotHEV(p1, p0, q0, q1, hev_thresh, ¬_hev);
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FLIP_SIGN_BIT4(*p1, *p0, *q0, *q1);
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FLIP_SIGN_BIT2(*p2, *q2);
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GetBaseDelta(p1, p0, q0, q1, &a);
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{ // do simple filter on pixels with hev
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const int8x16 m = (~not_hev) & *mask;
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const int8x16 f = a & m;
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DoSimpleFilter(p0, q0, &f);
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}
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{ // do strong filter on pixels with not hev
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const int32x4 k9 = {0x0900, 0x0900, 0x0900, 0x0900};
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const int16x8 k63 = splat_int16(63);
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const int16x8 m = not_hev & *mask;
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const int16x8 f = a & m;
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const int16x8 f_lo =
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(int16x8)__builtin_shufflevector((int8x16)f, zero, 16, 0, 16, 1, 16, 2,
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16, 3, 16, 4, 16, 5, 16, 6, 16, 7);
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const int16x8 f_hi = (int16x8)__builtin_shufflevector(
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(int8x16)f, zero, 16, 8, 16, 9, 16, 10, 16, 11, 16, 12, 16, 13, 16, 14,
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16, 15);
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const int16x8 f9_lo = _mulhi_int16x8(f_lo, k9); // Filter (lo) * 9
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const int16x8 f9_hi = _mulhi_int16x8(f_hi, k9); // Filter (hi) * 9
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const int16x8 a2_lo = f9_lo + k63; // Filter * 9 + 63
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const int16x8 a2_hi = f9_hi + k63; // Filter * 9 + 63
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const int16x8 a1_lo = a2_lo + f9_lo; // Filter * 18 + 63
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const int16x8 a1_hi = a2_hi + f9_hi; // Filter * 18 + 63
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const int16x8 a0_lo = a1_lo + f9_lo; // Filter * 27 + 63
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const int16x8 a0_hi = a1_hi + f9_hi; // Filter * 27 + 63
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Update2Pixels(p2, q2, &a2_lo, &a2_hi);
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Update2Pixels(p1, q1, &a1_lo, &a1_hi);
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Update2Pixels(p0, q0, &a0_lo, &a0_hi);
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}
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}
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//------------------------------------------------------------------------------
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// Complex In-loop filtering (Paragraph 15.3)
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#define MAX_DIFF1(p3, p2, p1, p0, m) \
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do { \
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m = abs_diff(p1, p0); \
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m = _max_u8x16(m, abs_diff(p3, p2)); \
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m = _max_u8x16(m, abs_diff(p2, p1)); \
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} while (0)
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#define MAX_DIFF2(p3, p2, p1, p0, m) \
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do { \
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m = _max_u8x16(m, abs_diff(p1, p0)); \
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m = _max_u8x16(m, abs_diff(p3, p2)); \
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m = _max_u8x16(m, abs_diff(p2, p1)); \
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} while (0)
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#define LOAD_H_EDGES4(p, stride, e1, e2, e3, e4) \
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{ \
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memcpy(&e1, &(p)[0 * stride], 16); \
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memcpy(&e2, &(p)[1 * stride], 16); \
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memcpy(&e3, &(p)[2 * stride], 16); \
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memcpy(&e4, &(p)[3 * stride], 16); \
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}
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static WEBP_INLINE void ComplexMask(const int8x16* const p1,
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const int8x16* const p0,
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const int8x16* const q0,
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const int8x16* const q1, int thresh,
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int ithresh, int8x16* const mask) {
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const int8x16 zero = {0};
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const uint8x16 it = splat_uint8(ithresh);
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const int8x16 diff = uint8x16_sub_sat(*mask, it);
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const int8x16 thresh_mask = (diff == zero);
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int8x16 filter_mask;
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NeedsFilter(p1, p0, q0, q1, thresh, &filter_mask);
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*mask = thresh_mask & filter_mask;
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}
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// on macroblock edges
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static void VFilter16(uint8_t* p, int stride, int thresh, int ithresh,
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int hev_thresh) {
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int8x16 t1;
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int8x16 mask;
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int8x16 p2, p1, p0, q0, q1, q2;
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// Load p3, p2, p1, p0
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LOAD_H_EDGES4(p - 4 * stride, stride, t1, p2, p1, p0);
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MAX_DIFF1(t1, p2, p1, p0, mask);
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// Load q0, q1, q2, q3
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LOAD_H_EDGES4(p, stride, q0, q1, q2, t1);
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MAX_DIFF2(t1, q2, q1, q0, mask);
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ComplexMask(&p1, &p0, &q0, &q1, thresh, ithresh, &mask);
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DoFilter6(&p2, &p1, &p0, &q0, &q1, &q2, &mask, hev_thresh);
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// Store
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memcpy(&p[-3 * stride], &p2, 16);
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memcpy(&p[-2 * stride], &p1, 16);
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memcpy(&p[-1 * stride], &p0, 16);
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memcpy(&p[+0 * stride], &q0, 16);
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memcpy(&p[+1 * stride], &q1, 16);
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memcpy(&p[+2 * stride], &q2, 16);
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}
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//------------------------------------------------------------------------------
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// 4x4 predictions
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@ -700,6 +993,8 @@ extern void VP8DspInitWASM(void);
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WEBP_TSAN_IGNORE_FUNCTION void VP8DspInitWASM(void) {
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VP8Transform = Transform;
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VP8VFilter16 = VFilter16;
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VP8PredLuma4[1] = TM4;
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VP8PredLuma4[2] = VE4;
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VP8PredLuma4[4] = RD4;
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