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Diffstat (limited to 'media/libwebp/dsp/alpha_processing_neon.c')
| -rw-r--r-- | media/libwebp/dsp/alpha_processing_neon.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/media/libwebp/dsp/alpha_processing_neon.c b/media/libwebp/dsp/alpha_processing_neon.c new file mode 100644 index 000000000..53dfce2b3 --- /dev/null +++ b/media/libwebp/dsp/alpha_processing_neon.c @@ -0,0 +1,191 @@ +// Copyright 2017 Google Inc. All Rights Reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the COPYING file in the root of the source +// tree. An additional intellectual property rights grant can be found +// in the file PATENTS. All contributing project authors may +// be found in the AUTHORS file in the root of the source tree. +// ----------------------------------------------------------------------------- +// +// Utilities for processing transparent channel, NEON version. +// +// Author: Skal (pascal.massimino@gmail.com) + +#include "../dsp/dsp.h" + +#if defined(WEBP_USE_NEON) + +#include "../dsp/neon.h" + +//------------------------------------------------------------------------------ + +#define MULTIPLIER(a) ((a) * 0x8081) +#define PREMULTIPLY(x, m) (((x) * (m)) >> 23) + +#define MULTIPLY_BY_ALPHA(V, ALPHA, OTHER) do { \ + const uint8x8_t alpha = (V).val[(ALPHA)]; \ + const uint16x8_t r1 = vmull_u8((V).val[1], alpha); \ + const uint16x8_t g1 = vmull_u8((V).val[2], alpha); \ + const uint16x8_t b1 = vmull_u8((V).val[(OTHER)], alpha); \ + /* we use: v / 255 = (v + 1 + (v >> 8)) >> 8 */ \ + const uint16x8_t r2 = vsraq_n_u16(r1, r1, 8); \ + const uint16x8_t g2 = vsraq_n_u16(g1, g1, 8); \ + const uint16x8_t b2 = vsraq_n_u16(b1, b1, 8); \ + const uint16x8_t r3 = vaddq_u16(r2, kOne); \ + const uint16x8_t g3 = vaddq_u16(g2, kOne); \ + const uint16x8_t b3 = vaddq_u16(b2, kOne); \ + (V).val[1] = vshrn_n_u16(r3, 8); \ + (V).val[2] = vshrn_n_u16(g3, 8); \ + (V).val[(OTHER)] = vshrn_n_u16(b3, 8); \ +} while (0) + +static void ApplyAlphaMultiply_NEON(uint8_t* rgba, int alpha_first, + int w, int h, int stride) { + const uint16x8_t kOne = vdupq_n_u16(1u); + while (h-- > 0) { + uint32_t* const rgbx = (uint32_t*)rgba; + int i = 0; + if (alpha_first) { + for (; i + 8 <= w; i += 8) { + // load aaaa...|rrrr...|gggg...|bbbb... + uint8x8x4_t RGBX = vld4_u8((const uint8_t*)(rgbx + i)); + MULTIPLY_BY_ALPHA(RGBX, 0, 3); + vst4_u8((uint8_t*)(rgbx + i), RGBX); + } + } else { + for (; i + 8 <= w; i += 8) { + uint8x8x4_t RGBX = vld4_u8((const uint8_t*)(rgbx + i)); + MULTIPLY_BY_ALPHA(RGBX, 3, 0); + vst4_u8((uint8_t*)(rgbx + i), RGBX); + } + } + // Finish with left-overs. + for (; i < w; ++i) { + uint8_t* const rgb = rgba + (alpha_first ? 1 : 0); + const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3); + const uint32_t a = alpha[4 * i]; + if (a != 0xff) { + const uint32_t mult = MULTIPLIER(a); + rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult); + rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult); + rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult); + } + } + rgba += stride; + } +} +#undef MULTIPLY_BY_ALPHA +#undef MULTIPLIER +#undef PREMULTIPLY + +//------------------------------------------------------------------------------ + +static int DispatchAlpha_NEON(const uint8_t* alpha, int alpha_stride, + int width, int height, + uint8_t* dst, int dst_stride) { + uint32_t alpha_mask = 0xffffffffu; + uint8x8_t mask8 = vdup_n_u8(0xff); + uint32_t tmp[2]; + int i, j; + for (j = 0; j < height; ++j) { + // We don't know if alpha is first or last in dst[] (depending on rgbA/Argb + // mode). So we must be sure dst[4*i + 8 - 1] is writable for the store. + // Hence the test with 'width - 1' instead of just 'width'. + for (i = 0; i + 8 <= width - 1; i += 8) { + uint8x8x4_t rgbX = vld4_u8((const uint8_t*)(dst + 4 * i)); + const uint8x8_t alphas = vld1_u8(alpha + i); + rgbX.val[0] = alphas; + vst4_u8((uint8_t*)(dst + 4 * i), rgbX); + mask8 = vand_u8(mask8, alphas); + } + for (; i < width; ++i) { + const uint32_t alpha_value = alpha[i]; + dst[4 * i] = alpha_value; + alpha_mask &= alpha_value; + } + alpha += alpha_stride; + dst += dst_stride; + } + vst1_u8((uint8_t*)tmp, mask8); + alpha_mask &= tmp[0]; + alpha_mask &= tmp[1]; + return (alpha_mask != 0xffffffffu); +} + +static void DispatchAlphaToGreen_NEON(const uint8_t* alpha, int alpha_stride, + int width, int height, + uint32_t* dst, int dst_stride) { + int i, j; + uint8x8x4_t greens; // leave A/R/B channels zero'd. + greens.val[0] = vdup_n_u8(0); + greens.val[2] = vdup_n_u8(0); + greens.val[3] = vdup_n_u8(0); + for (j = 0; j < height; ++j) { + for (i = 0; i + 8 <= width; i += 8) { + greens.val[1] = vld1_u8(alpha + i); + vst4_u8((uint8_t*)(dst + i), greens); + } + for (; i < width; ++i) dst[i] = alpha[i] << 8; + alpha += alpha_stride; + dst += dst_stride; + } +} + +static int ExtractAlpha_NEON(const uint8_t* argb, int argb_stride, + int width, int height, + uint8_t* alpha, int alpha_stride) { + uint32_t alpha_mask = 0xffffffffu; + uint8x8_t mask8 = vdup_n_u8(0xff); + uint32_t tmp[2]; + int i, j; + for (j = 0; j < height; ++j) { + // We don't know if alpha is first or last in dst[] (depending on rgbA/Argb + // mode). So we must be sure dst[4*i + 8 - 1] is writable for the store. + // Hence the test with 'width - 1' instead of just 'width'. + for (i = 0; i + 8 <= width - 1; i += 8) { + const uint8x8x4_t rgbX = vld4_u8((const uint8_t*)(argb + 4 * i)); + const uint8x8_t alphas = rgbX.val[0]; + vst1_u8((uint8_t*)(alpha + i), alphas); + mask8 = vand_u8(mask8, alphas); + } + for (; i < width; ++i) { + alpha[i] = argb[4 * i]; + alpha_mask &= alpha[i]; + } + argb += argb_stride; + alpha += alpha_stride; + } + vst1_u8((uint8_t*)tmp, mask8); + alpha_mask &= tmp[0]; + alpha_mask &= tmp[1]; + return (alpha_mask == 0xffffffffu); +} + +static void ExtractGreen_NEON(const uint32_t* argb, + uint8_t* alpha, int size) { + int i; + for (i = 0; i + 16 <= size; i += 16) { + const uint8x16x4_t rgbX = vld4q_u8((const uint8_t*)(argb + i)); + const uint8x16_t greens = rgbX.val[1]; + vst1q_u8(alpha + i, greens); + } + for (; i < size; ++i) alpha[i] = (argb[i] >> 8) & 0xff; +} + +//------------------------------------------------------------------------------ + +extern void WebPInitAlphaProcessingNEON(void); + +WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingNEON(void) { + WebPApplyAlphaMultiply = ApplyAlphaMultiply_NEON; + WebPDispatchAlpha = DispatchAlpha_NEON; + WebPDispatchAlphaToGreen = DispatchAlphaToGreen_NEON; + WebPExtractAlpha = ExtractAlpha_NEON; + WebPExtractGreen = ExtractGreen_NEON; +} + +#else // !WEBP_USE_NEON + +WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingNEON) + +#endif // WEBP_USE_NEON |