// Copyright 2012 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 #include #include "./rescaler.h" #include "../dsp/dsp.h" //------------------------------------------------------------------------------ // Implementations of critical functions ImportRow / ExportRow void (*WebPRescalerImportRow)(WebPRescaler* const wrk, const uint8_t* const src, int channel) = NULL; void (*WebPRescalerExportRow)(WebPRescaler* const wrk, int x_out) = NULL; #define RFIX 30 #define MULT_FIX(x, y) (((int64_t)(x) * (y) + (1 << (RFIX - 1))) >> RFIX) static void ImportRowC(WebPRescaler* const wrk, const uint8_t* const src, int channel) { const int x_stride = wrk->num_channels; const int x_out_max = wrk->dst_width * wrk->num_channels; int x_in = channel; int x_out; int accum = 0; if (!wrk->x_expand) { int sum = 0; for (x_out = channel; x_out < x_out_max; x_out += x_stride) { accum += wrk->x_add; for (; accum > 0; accum -= wrk->x_sub) { sum += src[x_in]; x_in += x_stride; } { // Emit next horizontal pixel. const int32_t base = src[x_in]; const int32_t frac = base * (-accum); x_in += x_stride; wrk->frow[x_out] = (sum + base) * wrk->x_sub - frac; // fresh fractional start for next pixel sum = (int)MULT_FIX(frac, wrk->fx_scale); } } } else { // simple bilinear interpolation int left = src[channel], right = src[channel]; for (x_out = channel; x_out < x_out_max; x_out += x_stride) { if (accum < 0) { left = right; x_in += x_stride; right = src[x_in]; accum += wrk->x_add; } wrk->frow[x_out] = right * wrk->x_add + (left - right) * accum; accum -= wrk->x_sub; } } // Accumulate the contribution of the new row. for (x_out = channel; x_out < x_out_max; x_out += x_stride) { wrk->irow[x_out] += wrk->frow[x_out]; } } static void ExportRowC(WebPRescaler* const wrk, int x_out) { if (wrk->y_accum <= 0) { uint8_t* const dst = wrk->dst; int32_t* const irow = wrk->irow; const int32_t* const frow = wrk->frow; const int yscale = wrk->fy_scale * (-wrk->y_accum); const int x_out_max = wrk->dst_width * wrk->num_channels; for (; x_out < x_out_max; ++x_out) { const int frac = (int)MULT_FIX(frow[x_out], yscale); const int v = (int)MULT_FIX(irow[x_out] - frac, wrk->fxy_scale); dst[x_out] = (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255; irow[x_out] = frac; // new fractional start } wrk->y_accum += wrk->y_add; wrk->dst += wrk->dst_stride; } } //------------------------------------------------------------------------------ // MIPS version #if defined(WEBP_USE_MIPS32) static void ImportRowMIPS(WebPRescaler* const wrk, const uint8_t* const src, int channel) { const int x_stride = wrk->num_channels; const int x_out_max = wrk->dst_width * wrk->num_channels; const int fx_scale = wrk->fx_scale; const int x_add = wrk->x_add; const int x_sub = wrk->x_sub; int* frow = wrk->frow + channel; int* irow = wrk->irow + channel; const uint8_t* src1 = src + channel; int temp1, temp2, temp3; int base, frac, sum; int accum, accum1; const int x_stride1 = x_stride << 2; int loop_c = x_out_max - channel; if (!wrk->x_expand) { __asm__ volatile ( "li %[temp1], 0x8000 \n\t" "li %[temp2], 0x10000 \n\t" "li %[sum], 0 \n\t" "li %[accum], 0 \n\t" "1: \n\t" "addu %[accum], %[accum], %[x_add] \n\t" "blez %[accum], 3f \n\t" "2: \n\t" "lbu %[temp3], 0(%[src1]) \n\t" "subu %[accum], %[accum], %[x_sub] \n\t" "addu %[src1], %[src1], %[x_stride] \n\t" "addu %[sum], %[sum], %[temp3] \n\t" "bgtz %[accum], 2b \n\t" "3: \n\t" "lbu %[base], 0(%[src1]) \n\t" "addu %[src1], %[src1], %[x_stride] \n\t" "negu %[accum1], %[accum] \n\t" "mul %[frac], %[base], %[accum1] \n\t" "addu %[temp3], %[sum], %[base] \n\t" "mul %[temp3], %[temp3], %[x_sub] \n\t" "lw %[base], 0(%[irow]) \n\t" "subu %[loop_c], %[loop_c], %[x_stride] \n\t" "sll %[accum1], %[frac], 2 \n\t" "mult %[temp1], %[temp2] \n\t" "madd %[accum1], %[fx_scale] \n\t" "mfhi %[sum] \n\t" "subu %[temp3], %[temp3], %[frac] \n\t" "sw %[temp3], 0(%[frow]) \n\t" "add %[base], %[base], %[temp3] \n\t" "sw %[base], 0(%[irow]) \n\t" "addu %[irow], %[irow], %[x_stride1] \n\t" "addu %[frow], %[frow], %[x_stride1] \n\t" "bgtz %[loop_c], 1b \n\t" : [accum] "=&r" (accum), [src1] "+r" (src1), [temp3] "=&r" (temp3), [sum] "=&r" (sum), [base] "=&r" (base), [frac] "=&r" (frac), [frow] "+r" (frow), [irow] "+r" (irow), [accum1] "=&r" (accum1), [temp2] "=&r" (temp2), [temp1] "=&r" (temp1) : [x_stride] "r" (x_stride), [fx_scale] "r" (fx_scale), [x_sub] "r" (x_sub), [x_add] "r" (x_add), [loop_c] "r" (loop_c), [x_stride1] "r" (x_stride1) : "memory", "hi", "lo" ); } else { __asm__ volatile ( "lbu %[temp1], 0(%[src1]) \n\t" "move %[temp2], %[temp1] \n\t" "li %[accum], 0 \n\t" "1: \n\t" "bgez %[accum], 2f \n\t" "move %[temp2], %[temp1] \n\t" "addu %[src1], %[x_stride] \n\t" "lbu %[temp1], 0(%[src1]) \n\t" "addu %[accum], %[x_add] \n\t" "2: \n\t" "subu %[temp3], %[temp2], %[temp1] \n\t" "mul %[temp3], %[temp3], %[accum] \n\t" "mul %[base], %[temp1], %[x_add] \n\t" "subu %[accum], %[accum], %[x_sub] \n\t" "lw %[frac], 0(%[irow]) \n\t" "subu %[loop_c], %[loop_c], %[x_stride] \n\t" "addu %[temp3], %[base], %[temp3] \n\t" "sw %[temp3], 0(%[frow]) \n\t" "addu %[frow], %[x_stride1] \n\t" "addu %[frac], %[temp3] \n\t" "sw %[frac], 0(%[irow]) \n\t" "addu %[irow], %[x_stride1] \n\t" "bgtz %[loop_c], 1b \n\t" : [src1] "+r" (src1), [accum] "=&r" (accum), [temp1] "=&r" (temp1), [temp2] "=&r" (temp2), [temp3] "=&r" (temp3), [base] "=&r" (base), [frac] "=&r" (frac), [frow] "+r" (frow), [irow] "+r" (irow) : [x_stride] "r" (x_stride), [x_add] "r" (x_add), [x_sub] "r" (x_sub), [x_stride1] "r" (x_stride1), [loop_c] "r" (loop_c) : "memory", "hi", "lo" ); } } static void ExportRowMIPS(WebPRescaler* const wrk, int x_out) { if (wrk->y_accum <= 0) { uint8_t* const dst = wrk->dst; int32_t* const irow = wrk->irow; const int32_t* const frow = wrk->frow; const int yscale = wrk->fy_scale * (-wrk->y_accum); const int x_out_max = wrk->dst_width * wrk->num_channels; // if wrk->fxy_scale can fit into 32 bits use optimized code, // otherwise use C code if ((wrk->fxy_scale >> 32) == 0) { int temp0, temp1, temp3, temp4, temp5, temp6, temp7, loop_end; const int temp2 = (int)(wrk->fxy_scale); const int temp8 = x_out_max << 2; uint8_t* dst_t = (uint8_t*)dst; int32_t* irow_t = (int32_t*)irow; const int32_t* frow_t = (const int32_t*)frow; __asm__ volatile( "addiu %[temp6], $zero, -256 \n\t" "addiu %[temp7], $zero, 255 \n\t" "li %[temp3], 0x10000 \n\t" "li %[temp4], 0x8000 \n\t" "addu %[loop_end], %[frow_t], %[temp8] \n\t" "1: \n\t" "lw %[temp0], 0(%[frow_t]) \n\t" "mult %[temp3], %[temp4] \n\t" "addiu %[frow_t], %[frow_t], 4 \n\t" "sll %[temp0], %[temp0], 2 \n\t" "madd %[temp0], %[yscale] \n\t" "mfhi %[temp1] \n\t" "lw %[temp0], 0(%[irow_t]) \n\t" "addiu %[dst_t], %[dst_t], 1 \n\t" "addiu %[irow_t], %[irow_t], 4 \n\t" "subu %[temp0], %[temp0], %[temp1] \n\t" "mult %[temp3], %[temp4] \n\t" "sll %[temp0], %[temp0], 2 \n\t" "madd %[temp0], %[temp2] \n\t" "mfhi %[temp5] \n\t" "sw %[temp1], -4(%[irow_t]) \n\t" "and %[temp0], %[temp5], %[temp6] \n\t" "slti %[temp1], %[temp5], 0 \n\t" "beqz %[temp0], 2f \n\t" "xor %[temp5], %[temp5], %[temp5] \n\t" "movz %[temp5], %[temp7], %[temp1] \n\t" "2: \n\t" "sb %[temp5], -1(%[dst_t]) \n\t" "bne %[frow_t], %[loop_end], 1b \n\t" : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp3]"=&r"(temp3), [temp4]"=&r"(temp4), [temp5]"=&r"(temp5), [temp6]"=&r"(temp6), [temp7]"=&r"(temp7), [frow_t]"+r"(frow_t), [irow_t]"+r"(irow_t), [dst_t]"+r"(dst_t), [loop_end]"=&r"(loop_end) : [temp2]"r"(temp2), [yscale]"r"(yscale), [temp8]"r"(temp8) : "memory", "hi", "lo" ); wrk->y_accum += wrk->y_add; wrk->dst += wrk->dst_stride; } else { ExportRowC(wrk, x_out); } } } #endif // WEBP_USE_MIPS32 //------------------------------------------------------------------------------ void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height, uint8_t* const dst, int dst_width, int dst_height, int dst_stride, int num_channels, int x_add, int x_sub, int y_add, int y_sub, int32_t* const work) { wrk->x_expand = (src_width < dst_width); wrk->src_width = src_width; wrk->src_height = src_height; wrk->dst_width = dst_width; wrk->dst_height = dst_height; wrk->dst = dst; wrk->dst_stride = dst_stride; wrk->num_channels = num_channels; // for 'x_expand', we use bilinear interpolation wrk->x_add = wrk->x_expand ? (x_sub - 1) : x_add - x_sub; wrk->x_sub = wrk->x_expand ? (x_add - 1) : x_sub; wrk->y_accum = y_add; wrk->y_add = y_add; wrk->y_sub = y_sub; wrk->fx_scale = (1 << RFIX) / x_sub; wrk->fy_scale = (1 << RFIX) / y_sub; wrk->fxy_scale = wrk->x_expand ? ((int64_t)dst_height << RFIX) / (x_sub * src_height) : ((int64_t)dst_height << RFIX) / (x_add * src_height); wrk->irow = work; wrk->frow = work + num_channels * dst_width; if (WebPRescalerImportRow == NULL) { WebPRescalerImportRow = ImportRowC; WebPRescalerExportRow = ExportRowC; if (VP8GetCPUInfo != NULL) { #if defined(WEBP_USE_MIPS32) if (VP8GetCPUInfo(kMIPS32)) { WebPRescalerImportRow = ImportRowMIPS; WebPRescalerExportRow = ExportRowMIPS; } #endif } } } #undef MULT_FIX #undef RFIX //------------------------------------------------------------------------------ // all-in-one calls int WebPRescaleNeededLines(const WebPRescaler* const wrk, int max_num_lines) { const int num_lines = (wrk->y_accum + wrk->y_sub - 1) / wrk->y_sub; return (num_lines > max_num_lines) ? max_num_lines : num_lines; } int WebPRescalerImport(WebPRescaler* const wrk, int num_lines, const uint8_t* src, int src_stride) { int total_imported = 0; while (total_imported < num_lines && wrk->y_accum > 0) { int channel; for (channel = 0; channel < wrk->num_channels; ++channel) { WebPRescalerImportRow(wrk, src, channel); } src += src_stride; ++total_imported; wrk->y_accum -= wrk->y_sub; } return total_imported; } int WebPRescalerExport(WebPRescaler* const rescaler) { int total_exported = 0; while (WebPRescalerHasPendingOutput(rescaler)) { WebPRescalerExportRow(rescaler, 0); ++total_exported; } return total_exported; } //------------------------------------------------------------------------------