diff options
Diffstat (limited to 'thirdparty/libwebp/src/dsp/rescaler.c')
| -rw-r--r-- | thirdparty/libwebp/src/dsp/rescaler.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/thirdparty/libwebp/src/dsp/rescaler.c b/thirdparty/libwebp/src/dsp/rescaler.c new file mode 100644 index 0000000000..4b6b7834e5 --- /dev/null +++ b/thirdparty/libwebp/src/dsp/rescaler.c @@ -0,0 +1,257 @@ +// Copyright 2014 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. +// ----------------------------------------------------------------------------- +// +// Rescaling functions +// +// Author: Skal (pascal.massimino@gmail.com) + +#include <assert.h> + +#include "src/dsp/dsp.h" +#include "src/utils/rescaler_utils.h" + +//------------------------------------------------------------------------------ +// Implementations of critical functions ImportRow / ExportRow + +#define ROUNDER (WEBP_RESCALER_ONE >> 1) +#define MULT_FIX(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX) + +//------------------------------------------------------------------------------ +// Row import + +void WebPRescalerImportRowExpand_C(WebPRescaler* const wrk, + const uint8_t* src) { + const int x_stride = wrk->num_channels; + const int x_out_max = wrk->dst_width * wrk->num_channels; + int channel; + assert(!WebPRescalerInputDone(wrk)); + assert(wrk->x_expand); + for (channel = 0; channel < x_stride; ++channel) { + int x_in = channel; + int x_out = channel; + // simple bilinear interpolation + int accum = wrk->x_add; + int left = src[x_in]; + int right = (wrk->src_width > 1) ? src[x_in + x_stride] : left; + x_in += x_stride; + while (1) { + wrk->frow[x_out] = right * wrk->x_add + (left - right) * accum; + x_out += x_stride; + if (x_out >= x_out_max) break; + accum -= wrk->x_sub; + if (accum < 0) { + left = right; + x_in += x_stride; + assert(x_in < wrk->src_width * x_stride); + right = src[x_in]; + accum += wrk->x_add; + } + } + assert(wrk->x_sub == 0 /* <- special case for src_width=1 */ || accum == 0); + } +} + +void WebPRescalerImportRowShrink_C(WebPRescaler* const wrk, + const uint8_t* src) { + const int x_stride = wrk->num_channels; + const int x_out_max = wrk->dst_width * wrk->num_channels; + int channel; + assert(!WebPRescalerInputDone(wrk)); + assert(!wrk->x_expand); + for (channel = 0; channel < x_stride; ++channel) { + int x_in = channel; + int x_out = channel; + uint32_t sum = 0; + int accum = 0; + while (x_out < x_out_max) { + uint32_t base = 0; + accum += wrk->x_add; + while (accum > 0) { + accum -= wrk->x_sub; + assert(x_in < wrk->src_width * x_stride); + base = src[x_in]; + sum += base; + x_in += x_stride; + } + { // Emit next horizontal pixel. + const rescaler_t frac = base * (-accum); + wrk->frow[x_out] = sum * wrk->x_sub - frac; + // fresh fractional start for next pixel + sum = (int)MULT_FIX(frac, wrk->fx_scale); + } + x_out += x_stride; + } + assert(accum == 0); + } +} + +//------------------------------------------------------------------------------ +// Row export + +void WebPRescalerExportRowExpand_C(WebPRescaler* const wrk) { + int x_out; + uint8_t* const dst = wrk->dst; + rescaler_t* const irow = wrk->irow; + const int x_out_max = wrk->dst_width * wrk->num_channels; + const rescaler_t* const frow = wrk->frow; + assert(!WebPRescalerOutputDone(wrk)); + assert(wrk->y_accum <= 0); + assert(wrk->y_expand); + assert(wrk->y_sub != 0); + if (wrk->y_accum == 0) { + for (x_out = 0; x_out < x_out_max; ++x_out) { + const uint32_t J = frow[x_out]; + const int v = (int)MULT_FIX(J, wrk->fy_scale); + assert(v >= 0 && v <= 255); + dst[x_out] = v; + } + } else { + const uint32_t B = WEBP_RESCALER_FRAC(-wrk->y_accum, wrk->y_sub); + const uint32_t A = (uint32_t)(WEBP_RESCALER_ONE - B); + for (x_out = 0; x_out < x_out_max; ++x_out) { + const uint64_t I = (uint64_t)A * frow[x_out] + + (uint64_t)B * irow[x_out]; + const uint32_t J = (uint32_t)((I + ROUNDER) >> WEBP_RESCALER_RFIX); + const int v = (int)MULT_FIX(J, wrk->fy_scale); + assert(v >= 0 && v <= 255); + dst[x_out] = v; + } + } +} + +void WebPRescalerExportRowShrink_C(WebPRescaler* const wrk) { + int x_out; + uint8_t* const dst = wrk->dst; + rescaler_t* const irow = wrk->irow; + const int x_out_max = wrk->dst_width * wrk->num_channels; + const rescaler_t* const frow = wrk->frow; + const uint32_t yscale = wrk->fy_scale * (-wrk->y_accum); + assert(!WebPRescalerOutputDone(wrk)); + assert(wrk->y_accum <= 0); + assert(!wrk->y_expand); + if (yscale) { + for (x_out = 0; x_out < x_out_max; ++x_out) { + const uint32_t frac = (uint32_t)MULT_FIX(frow[x_out], yscale); + const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale); + assert(v >= 0 && v <= 255); + dst[x_out] = v; + irow[x_out] = frac; // new fractional start + } + } else { + for (x_out = 0; x_out < x_out_max; ++x_out) { + const int v = (int)MULT_FIX(irow[x_out], wrk->fxy_scale); + assert(v >= 0 && v <= 255); + dst[x_out] = v; + irow[x_out] = 0; + } + } +} + +#undef MULT_FIX +#undef ROUNDER + +//------------------------------------------------------------------------------ +// Main entry calls + +void WebPRescalerImportRow(WebPRescaler* const wrk, const uint8_t* src) { + assert(!WebPRescalerInputDone(wrk)); + if (!wrk->x_expand) { + WebPRescalerImportRowShrink(wrk, src); + } else { + WebPRescalerImportRowExpand(wrk, src); + } +} + +void WebPRescalerExportRow(WebPRescaler* const wrk) { + if (wrk->y_accum <= 0) { + assert(!WebPRescalerOutputDone(wrk)); + if (wrk->y_expand) { + WebPRescalerExportRowExpand(wrk); + } else if (wrk->fxy_scale) { + WebPRescalerExportRowShrink(wrk); + } else { // special case + int i; + assert(wrk->src_height == wrk->dst_height && wrk->x_add == 1); + assert(wrk->src_width == 1 && wrk->dst_width <= 2); + for (i = 0; i < wrk->num_channels * wrk->dst_width; ++i) { + wrk->dst[i] = wrk->irow[i]; + wrk->irow[i] = 0; + } + } + wrk->y_accum += wrk->y_add; + wrk->dst += wrk->dst_stride; + ++wrk->dst_y; + } +} + +//------------------------------------------------------------------------------ + +WebPRescalerImportRowFunc WebPRescalerImportRowExpand; +WebPRescalerImportRowFunc WebPRescalerImportRowShrink; + +WebPRescalerExportRowFunc WebPRescalerExportRowExpand; +WebPRescalerExportRowFunc WebPRescalerExportRowShrink; + +extern void WebPRescalerDspInitSSE2(void); +extern void WebPRescalerDspInitMIPS32(void); +extern void WebPRescalerDspInitMIPSdspR2(void); +extern void WebPRescalerDspInitMSA(void); +extern void WebPRescalerDspInitNEON(void); + +static volatile VP8CPUInfo rescaler_last_cpuinfo_used = + (VP8CPUInfo)&rescaler_last_cpuinfo_used; + +WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInit(void) { + if (rescaler_last_cpuinfo_used == VP8GetCPUInfo) return; +#if !defined(WEBP_REDUCE_SIZE) +#if !WEBP_NEON_OMIT_C_CODE + WebPRescalerExportRowExpand = WebPRescalerExportRowExpand_C; + WebPRescalerExportRowShrink = WebPRescalerExportRowShrink_C; +#endif + + WebPRescalerImportRowExpand = WebPRescalerImportRowExpand_C; + WebPRescalerImportRowShrink = WebPRescalerImportRowShrink_C; + + if (VP8GetCPUInfo != NULL) { +#if defined(WEBP_USE_SSE2) + if (VP8GetCPUInfo(kSSE2)) { + WebPRescalerDspInitSSE2(); + } +#endif +#if defined(WEBP_USE_MIPS32) + if (VP8GetCPUInfo(kMIPS32)) { + WebPRescalerDspInitMIPS32(); + } +#endif +#if defined(WEBP_USE_MIPS_DSP_R2) + if (VP8GetCPUInfo(kMIPSdspR2)) { + WebPRescalerDspInitMIPSdspR2(); + } +#endif +#if defined(WEBP_USE_MSA) + if (VP8GetCPUInfo(kMSA)) { + WebPRescalerDspInitMSA(); + } +#endif + } + +#if defined(WEBP_USE_NEON) + if (WEBP_NEON_OMIT_C_CODE || + (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) { + WebPRescalerDspInitNEON(); + } +#endif + + assert(WebPRescalerExportRowExpand != NULL); + assert(WebPRescalerExportRowShrink != NULL); + assert(WebPRescalerImportRowExpand != NULL); + assert(WebPRescalerImportRowShrink != NULL); +#endif // WEBP_REDUCE_SIZE + rescaler_last_cpuinfo_used = VP8GetCPUInfo; +} |