| // Copyright 2011 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. |
| // ----------------------------------------------------------------------------- |
| // |
| // functions for sample output. |
| // |
| // Author: Skal (pascal.massimino@gmail.com) |
| |
| #if defined(STARBOARD) |
| #include "starboard/log.h" |
| #include "starboard/memory.h" |
| #else |
| #include <assert.h> |
| #include <stdlib.h> |
| #endif |
| |
| #include "../dec/vp8i.h" |
| #include "./webpi.h" |
| #include "../dsp/dsp.h" |
| #include "../dsp/yuv.h" |
| |
| #if defined(__cplusplus) || defined(c_plusplus) |
| extern "C" { |
| #endif |
| |
| //------------------------------------------------------------------------------ |
| // Main YUV<->RGB conversion functions |
| |
| static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) { |
| WebPDecBuffer* output = p->output; |
| const WebPYUVABuffer* const buf = &output->u.YUVA; |
| uint8_t* const y_dst = buf->y + io->mb_y * buf->y_stride; |
| uint8_t* const u_dst = buf->u + (io->mb_y >> 1) * buf->u_stride; |
| uint8_t* const v_dst = buf->v + (io->mb_y >> 1) * buf->v_stride; |
| const int mb_w = io->mb_w; |
| const int mb_h = io->mb_h; |
| const int uv_w = (mb_w + 1) / 2; |
| const int uv_h = (mb_h + 1) / 2; |
| int j; |
| for (j = 0; j < mb_h; ++j) { |
| SbMemoryCopy(y_dst + j * buf->y_stride, io->y + j * io->y_stride, mb_w); |
| } |
| for (j = 0; j < uv_h; ++j) { |
| SbMemoryCopy(u_dst + j * buf->u_stride, io->u + j * io->uv_stride, uv_w); |
| SbMemoryCopy(v_dst + j * buf->v_stride, io->v + j * io->uv_stride, uv_w); |
| } |
| return io->mb_h; |
| } |
| |
| // Point-sampling U/V sampler. |
| static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) { |
| WebPDecBuffer* output = p->output; |
| const WebPRGBABuffer* const buf = &output->u.RGBA; |
| uint8_t* dst = buf->rgba + io->mb_y * buf->stride; |
| const uint8_t* y_src = io->y; |
| const uint8_t* u_src = io->u; |
| const uint8_t* v_src = io->v; |
| const WebPSampleLinePairFunc sample = WebPSamplers[output->colorspace]; |
| const int mb_w = io->mb_w; |
| const int last = io->mb_h - 1; |
| int j; |
| for (j = 0; j < last; j += 2) { |
| sample(y_src, y_src + io->y_stride, u_src, v_src, |
| dst, dst + buf->stride, mb_w); |
| y_src += 2 * io->y_stride; |
| u_src += io->uv_stride; |
| v_src += io->uv_stride; |
| dst += 2 * buf->stride; |
| } |
| if (j == last) { // Just do the last line twice |
| sample(y_src, y_src, u_src, v_src, dst, dst, mb_w); |
| } |
| return io->mb_h; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // YUV444 -> RGB conversion |
| |
| #if 0 // TODO(skal): this is for future rescaling. |
| static int EmitRGB(const VP8Io* const io, WebPDecParams* const p) { |
| WebPDecBuffer* output = p->output; |
| const WebPRGBABuffer* const buf = &output->u.RGBA; |
| uint8_t* dst = buf->rgba + io->mb_y * buf->stride; |
| const uint8_t* y_src = io->y; |
| const uint8_t* u_src = io->u; |
| const uint8_t* v_src = io->v; |
| const WebPYUV444Converter convert = WebPYUV444Converters[output->colorspace]; |
| const int mb_w = io->mb_w; |
| const int last = io->mb_h; |
| int j; |
| for (j = 0; j < last; ++j) { |
| convert(y_src, u_src, v_src, dst, mb_w); |
| y_src += io->y_stride; |
| u_src += io->uv_stride; |
| v_src += io->uv_stride; |
| dst += buf->stride; |
| } |
| return io->mb_h; |
| } |
| #endif |
| |
| //------------------------------------------------------------------------------ |
| // Fancy upsampling |
| |
| #ifdef FANCY_UPSAMPLING |
| static int EmitFancyRGB(const VP8Io* const io, WebPDecParams* const p) { |
| int num_lines_out = io->mb_h; // a priori guess |
| const WebPRGBABuffer* const buf = &p->output->u.RGBA; |
| uint8_t* dst = buf->rgba + io->mb_y * buf->stride; |
| WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace]; |
| const uint8_t* cur_y = io->y; |
| const uint8_t* cur_u = io->u; |
| const uint8_t* cur_v = io->v; |
| const uint8_t* top_u = p->tmp_u; |
| const uint8_t* top_v = p->tmp_v; |
| int y = io->mb_y; |
| const int y_end = io->mb_y + io->mb_h; |
| const int mb_w = io->mb_w; |
| const int uv_w = (mb_w + 1) / 2; |
| |
| if (y == 0) { |
| // First line is special cased. We mirror the u/v samples at boundary. |
| upsample(NULL, cur_y, cur_u, cur_v, cur_u, cur_v, NULL, dst, mb_w); |
| } else { |
| // We can finish the left-over line from previous call. |
| upsample(p->tmp_y, cur_y, top_u, top_v, cur_u, cur_v, |
| dst - buf->stride, dst, mb_w); |
| ++num_lines_out; |
| } |
| // Loop over each output pairs of row. |
| for (; y + 2 < y_end; y += 2) { |
| top_u = cur_u; |
| top_v = cur_v; |
| cur_u += io->uv_stride; |
| cur_v += io->uv_stride; |
| dst += 2 * buf->stride; |
| cur_y += 2 * io->y_stride; |
| upsample(cur_y - io->y_stride, cur_y, |
| top_u, top_v, cur_u, cur_v, |
| dst - buf->stride, dst, mb_w); |
| } |
| // move to last row |
| cur_y += io->y_stride; |
| if (io->crop_top + y_end < io->crop_bottom) { |
| // Save the unfinished samples for next call (as we're not done yet). |
| SbMemoryCopy(p->tmp_y, cur_y, mb_w * sizeof(*p->tmp_y)); |
| SbMemoryCopy(p->tmp_u, cur_u, uv_w * sizeof(*p->tmp_u)); |
| SbMemoryCopy(p->tmp_v, cur_v, uv_w * sizeof(*p->tmp_v)); |
| // The fancy upsampler leaves a row unfinished behind |
| // (except for the very last row) |
| num_lines_out--; |
| } else { |
| // Process the very last row of even-sized picture |
| if (!(y_end & 1)) { |
| upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, |
| dst + buf->stride, NULL, mb_w); |
| } |
| } |
| return num_lines_out; |
| } |
| |
| #endif /* FANCY_UPSAMPLING */ |
| |
| //------------------------------------------------------------------------------ |
| |
| static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p) { |
| const uint8_t* alpha = io->a; |
| const WebPYUVABuffer* const buf = &p->output->u.YUVA; |
| const int mb_w = io->mb_w; |
| const int mb_h = io->mb_h; |
| uint8_t* dst = buf->a + io->mb_y * buf->a_stride; |
| int j; |
| |
| if (alpha != NULL) { |
| for (j = 0; j < mb_h; ++j) { |
| SbMemoryCopy(dst, alpha, mb_w * sizeof(*dst)); |
| alpha += io->width; |
| dst += buf->a_stride; |
| } |
| } else if (buf->a != NULL) { |
| // the user requested alpha, but there is none, set it to opaque. |
| for (j = 0; j < mb_h; ++j) { |
| SbMemorySet(dst, 0xff, mb_w * sizeof(*dst)); |
| dst += buf->a_stride; |
| } |
| } |
| return 0; |
| } |
| |
| static int GetAlphaSourceRow(const VP8Io* const io, |
| const uint8_t** alpha, int* const num_rows) { |
| int start_y = io->mb_y; |
| *num_rows = io->mb_h; |
| |
| // Compensate for the 1-line delay of the fancy upscaler. |
| // This is similar to EmitFancyRGB(). |
| if (io->fancy_upsampling) { |
| if (start_y == 0) { |
| // We don't process the last row yet. It'll be done during the next call. |
| --*num_rows; |
| } else { |
| --start_y; |
| // Fortunately, *alpha data is persistent, so we can go back |
| // one row and finish alpha blending, now that the fancy upscaler |
| // completed the YUV->RGB interpolation. |
| *alpha -= io->width; |
| } |
| if (io->crop_top + io->mb_y + io->mb_h == io->crop_bottom) { |
| // If it's the very last call, we process all the remaining rows! |
| *num_rows = io->crop_bottom - io->crop_top - start_y; |
| } |
| } |
| return start_y; |
| } |
| |
| static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p) { |
| const uint8_t* alpha = io->a; |
| if (alpha != NULL) { |
| const int mb_w = io->mb_w; |
| const WEBP_CSP_MODE colorspace = p->output->colorspace; |
| const int alpha_first = |
| (colorspace == MODE_ARGB || colorspace == MODE_Argb); |
| const WebPRGBABuffer* const buf = &p->output->u.RGBA; |
| int num_rows; |
| const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows); |
| uint8_t* const base_rgba = buf->rgba + start_y * buf->stride; |
| uint8_t* dst = base_rgba + (alpha_first ? 0 : 3); |
| uint32_t alpha_mask = 0xff; |
| int i, j; |
| |
| for (j = 0; j < num_rows; ++j) { |
| for (i = 0; i < mb_w; ++i) { |
| const uint32_t alpha_value = alpha[i]; |
| dst[4 * i] = alpha_value; |
| alpha_mask &= alpha_value; |
| } |
| alpha += io->width; |
| dst += buf->stride; |
| } |
| // alpha_mask is < 0xff if there's non-trivial alpha to premultiply with. |
| if (alpha_mask != 0xff && WebPIsPremultipliedMode(colorspace)) { |
| WebPApplyAlphaMultiply(base_rgba, alpha_first, |
| mb_w, num_rows, buf->stride); |
| } |
| } |
| return 0; |
| } |
| |
| static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p) { |
| const uint8_t* alpha = io->a; |
| if (alpha != NULL) { |
| const int mb_w = io->mb_w; |
| const WEBP_CSP_MODE colorspace = p->output->colorspace; |
| const WebPRGBABuffer* const buf = &p->output->u.RGBA; |
| int num_rows; |
| const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows); |
| uint8_t* const base_rgba = buf->rgba + start_y * buf->stride; |
| uint8_t* alpha_dst = base_rgba + 1; |
| uint32_t alpha_mask = 0x0f; |
| int i, j; |
| |
| for (j = 0; j < num_rows; ++j) { |
| for (i = 0; i < mb_w; ++i) { |
| // Fill in the alpha value (converted to 4 bits). |
| const uint32_t alpha_value = alpha[i] >> 4; |
| alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value; |
| alpha_mask &= alpha_value; |
| } |
| alpha += io->width; |
| alpha_dst += buf->stride; |
| } |
| if (alpha_mask != 0x0f && WebPIsPremultipliedMode(colorspace)) { |
| WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride); |
| } |
| } |
| return 0; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // YUV rescaling (no final RGB conversion needed) |
| |
| static int Rescale(const uint8_t* src, int src_stride, |
| int new_lines, WebPRescaler* const wrk) { |
| int num_lines_out = 0; |
| while (new_lines > 0) { // import new contributions of source rows. |
| const int lines_in = WebPRescalerImport(wrk, new_lines, src, src_stride); |
| src += lines_in * src_stride; |
| new_lines -= lines_in; |
| num_lines_out += WebPRescalerExport(wrk); // emit output row(s) |
| } |
| return num_lines_out; |
| } |
| |
| static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) { |
| const int mb_h = io->mb_h; |
| const int uv_mb_h = (mb_h + 1) >> 1; |
| const int num_lines_out = Rescale(io->y, io->y_stride, mb_h, &p->scaler_y); |
| Rescale(io->u, io->uv_stride, uv_mb_h, &p->scaler_u); |
| Rescale(io->v, io->uv_stride, uv_mb_h, &p->scaler_v); |
| return num_lines_out; |
| } |
| |
| static int EmitRescaledAlphaYUV(const VP8Io* const io, WebPDecParams* const p) { |
| if (io->a != NULL) { |
| Rescale(io->a, io->width, io->mb_h, &p->scaler_a); |
| } |
| return 0; |
| } |
| |
| static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) { |
| const int has_alpha = WebPIsAlphaMode(p->output->colorspace); |
| const WebPYUVABuffer* const buf = &p->output->u.YUVA; |
| const int out_width = io->scaled_width; |
| const int out_height = io->scaled_height; |
| const int uv_out_width = (out_width + 1) >> 1; |
| const int uv_out_height = (out_height + 1) >> 1; |
| const int uv_in_width = (io->mb_w + 1) >> 1; |
| const int uv_in_height = (io->mb_h + 1) >> 1; |
| const size_t work_size = 2 * out_width; // scratch memory for luma rescaler |
| const size_t uv_work_size = 2 * uv_out_width; // and for each u/v ones |
| size_t tmp_size; |
| int32_t* work; |
| |
| tmp_size = work_size + 2 * uv_work_size; |
| if (has_alpha) { |
| tmp_size += work_size; |
| } |
| p->memory = SbMemoryCalloc(1, tmp_size * sizeof(*work)); |
| if (p->memory == NULL) { |
| return 0; // memory error |
| } |
| work = (int32_t*)p->memory; |
| WebPRescalerInit(&p->scaler_y, io->mb_w, io->mb_h, |
| buf->y, out_width, out_height, buf->y_stride, 1, |
| io->mb_w, out_width, io->mb_h, out_height, |
| work); |
| WebPRescalerInit(&p->scaler_u, uv_in_width, uv_in_height, |
| buf->u, uv_out_width, uv_out_height, buf->u_stride, 1, |
| uv_in_width, uv_out_width, |
| uv_in_height, uv_out_height, |
| work + work_size); |
| WebPRescalerInit(&p->scaler_v, uv_in_width, uv_in_height, |
| buf->v, uv_out_width, uv_out_height, buf->v_stride, 1, |
| uv_in_width, uv_out_width, |
| uv_in_height, uv_out_height, |
| work + work_size + uv_work_size); |
| p->emit = EmitRescaledYUV; |
| |
| if (has_alpha) { |
| WebPRescalerInit(&p->scaler_a, io->mb_w, io->mb_h, |
| buf->a, out_width, out_height, buf->a_stride, 1, |
| io->mb_w, out_width, io->mb_h, out_height, |
| work + work_size + 2 * uv_work_size); |
| p->emit_alpha = EmitRescaledAlphaYUV; |
| } |
| return 1; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // RGBA rescaling |
| |
| static int ExportRGB(WebPDecParams* const p, int y_pos) { |
| const WebPYUV444Converter convert = |
| WebPYUV444Converters[p->output->colorspace]; |
| const WebPRGBABuffer* const buf = &p->output->u.RGBA; |
| uint8_t* dst = buf->rgba + (p->last_y + y_pos) * buf->stride; |
| int num_lines_out = 0; |
| // For RGB rescaling, because of the YUV420, current scan position |
| // U/V can be +1/-1 line from the Y one. Hence the double test. |
| while (WebPRescalerHasPendingOutput(&p->scaler_y) && |
| WebPRescalerHasPendingOutput(&p->scaler_u)) { |
| SB_DCHECK(p->last_y + y_pos + num_lines_out < p->output->height); |
| SB_DCHECK(p->scaler_u.y_accum == p->scaler_v.y_accum); |
| WebPRescalerExportRow(&p->scaler_y); |
| WebPRescalerExportRow(&p->scaler_u); |
| WebPRescalerExportRow(&p->scaler_v); |
| convert(p->scaler_y.dst, p->scaler_u.dst, p->scaler_v.dst, |
| dst, p->scaler_y.dst_width); |
| dst += buf->stride; |
| ++num_lines_out; |
| } |
| return num_lines_out; |
| } |
| |
| static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) { |
| const int mb_h = io->mb_h; |
| const int uv_mb_h = (mb_h + 1) >> 1; |
| int j = 0, uv_j = 0; |
| int num_lines_out = 0; |
| while (j < mb_h) { |
| const int y_lines_in = |
| WebPRescalerImport(&p->scaler_y, mb_h - j, |
| io->y + j * io->y_stride, io->y_stride); |
| const int u_lines_in = |
| WebPRescalerImport(&p->scaler_u, uv_mb_h - uv_j, |
| io->u + uv_j * io->uv_stride, io->uv_stride); |
| const int v_lines_in = |
| WebPRescalerImport(&p->scaler_v, uv_mb_h - uv_j, |
| io->v + uv_j * io->uv_stride, io->uv_stride); |
| (void)v_lines_in; // remove a gcc warning |
| SB_DCHECK(u_lines_in == v_lines_in); |
| j += y_lines_in; |
| uv_j += u_lines_in; |
| num_lines_out += ExportRGB(p, num_lines_out); |
| } |
| return num_lines_out; |
| } |
| |
| static int ExportAlpha(WebPDecParams* const p, int y_pos) { |
| const WebPRGBABuffer* const buf = &p->output->u.RGBA; |
| uint8_t* const base_rgba = buf->rgba + (p->last_y + y_pos) * buf->stride; |
| const WEBP_CSP_MODE colorspace = p->output->colorspace; |
| const int alpha_first = |
| (colorspace == MODE_ARGB || colorspace == MODE_Argb); |
| uint8_t* dst = base_rgba + (alpha_first ? 0 : 3); |
| int num_lines_out = 0; |
| const int is_premult_alpha = WebPIsPremultipliedMode(colorspace); |
| uint32_t alpha_mask = 0xff; |
| const int width = p->scaler_a.dst_width; |
| |
| while (WebPRescalerHasPendingOutput(&p->scaler_a)) { |
| int i; |
| SB_DCHECK(p->last_y + y_pos + num_lines_out < p->output->height); |
| WebPRescalerExportRow(&p->scaler_a); |
| for (i = 0; i < width; ++i) { |
| const uint32_t alpha_value = p->scaler_a.dst[i]; |
| dst[4 * i] = alpha_value; |
| alpha_mask &= alpha_value; |
| } |
| dst += buf->stride; |
| ++num_lines_out; |
| } |
| if (is_premult_alpha && alpha_mask != 0xff) { |
| WebPApplyAlphaMultiply(base_rgba, alpha_first, |
| width, num_lines_out, buf->stride); |
| } |
| return num_lines_out; |
| } |
| |
| static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos) { |
| const WebPRGBABuffer* const buf = &p->output->u.RGBA; |
| uint8_t* const base_rgba = buf->rgba + (p->last_y + y_pos) * buf->stride; |
| uint8_t* alpha_dst = base_rgba + 1; |
| int num_lines_out = 0; |
| const WEBP_CSP_MODE colorspace = p->output->colorspace; |
| const int width = p->scaler_a.dst_width; |
| const int is_premult_alpha = WebPIsPremultipliedMode(colorspace); |
| uint32_t alpha_mask = 0x0f; |
| |
| while (WebPRescalerHasPendingOutput(&p->scaler_a)) { |
| int i; |
| SB_DCHECK(p->last_y + y_pos + num_lines_out < p->output->height); |
| WebPRescalerExportRow(&p->scaler_a); |
| for (i = 0; i < width; ++i) { |
| // Fill in the alpha value (converted to 4 bits). |
| const uint32_t alpha_value = p->scaler_a.dst[i] >> 4; |
| alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value; |
| alpha_mask &= alpha_value; |
| } |
| alpha_dst += buf->stride; |
| ++num_lines_out; |
| } |
| if (is_premult_alpha && alpha_mask != 0x0f) { |
| WebPApplyAlphaMultiply4444(base_rgba, width, num_lines_out, buf->stride); |
| } |
| return num_lines_out; |
| } |
| |
| static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p) { |
| if (io->a != NULL) { |
| WebPRescaler* const scaler = &p->scaler_a; |
| int j = 0; |
| int pos = 0; |
| while (j < io->mb_h) { |
| j += WebPRescalerImport(scaler, io->mb_h - j, |
| io->a + j * io->width, io->width); |
| pos += p->emit_alpha_row(p, pos); |
| } |
| } |
| return 0; |
| } |
| |
| static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) { |
| const int has_alpha = WebPIsAlphaMode(p->output->colorspace); |
| const int out_width = io->scaled_width; |
| const int out_height = io->scaled_height; |
| const int uv_in_width = (io->mb_w + 1) >> 1; |
| const int uv_in_height = (io->mb_h + 1) >> 1; |
| const size_t work_size = 2 * out_width; // scratch memory for one rescaler |
| int32_t* work; // rescalers work area |
| uint8_t* tmp; // tmp storage for scaled YUV444 samples before RGB conversion |
| size_t tmp_size1, tmp_size2; |
| |
| tmp_size1 = 3 * work_size; |
| tmp_size2 = 3 * out_width; |
| if (has_alpha) { |
| tmp_size1 += work_size; |
| tmp_size2 += out_width; |
| } |
| p->memory = SbMemoryCalloc(1, tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp)); |
| if (p->memory == NULL) { |
| return 0; // memory error |
| } |
| work = (int32_t*)p->memory; |
| tmp = (uint8_t*)(work + tmp_size1); |
| WebPRescalerInit(&p->scaler_y, io->mb_w, io->mb_h, |
| tmp + 0 * out_width, out_width, out_height, 0, 1, |
| io->mb_w, out_width, io->mb_h, out_height, |
| work + 0 * work_size); |
| WebPRescalerInit(&p->scaler_u, uv_in_width, uv_in_height, |
| tmp + 1 * out_width, out_width, out_height, 0, 1, |
| io->mb_w, 2 * out_width, io->mb_h, 2 * out_height, |
| work + 1 * work_size); |
| WebPRescalerInit(&p->scaler_v, uv_in_width, uv_in_height, |
| tmp + 2 * out_width, out_width, out_height, 0, 1, |
| io->mb_w, 2 * out_width, io->mb_h, 2 * out_height, |
| work + 2 * work_size); |
| p->emit = EmitRescaledRGB; |
| |
| if (has_alpha) { |
| WebPRescalerInit(&p->scaler_a, io->mb_w, io->mb_h, |
| tmp + 3 * out_width, out_width, out_height, 0, 1, |
| io->mb_w, out_width, io->mb_h, out_height, |
| work + 3 * work_size); |
| p->emit_alpha = EmitRescaledAlphaRGB; |
| if (p->output->colorspace == MODE_RGBA_4444 || |
| p->output->colorspace == MODE_rgbA_4444) { |
| p->emit_alpha_row = ExportAlphaRGBA4444; |
| } else { |
| p->emit_alpha_row = ExportAlpha; |
| } |
| } |
| return 1; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // Default custom functions |
| |
| static int CustomSetup(VP8Io* io) { |
| WebPDecParams* const p = (WebPDecParams*)io->opaque; |
| const WEBP_CSP_MODE colorspace = p->output->colorspace; |
| const int is_rgb = WebPIsRGBMode(colorspace); |
| const int is_alpha = WebPIsAlphaMode(colorspace); |
| |
| p->memory = NULL; |
| p->emit = NULL; |
| p->emit_alpha = NULL; |
| p->emit_alpha_row = NULL; |
| if (!WebPIoInitFromOptions(p->options, io, is_alpha ? MODE_YUV : MODE_YUVA)) { |
| return 0; |
| } |
| |
| if (io->use_scaling) { |
| const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p); |
| if (!ok) { |
| return 0; // memory error |
| } |
| } else { |
| if (is_rgb) { |
| p->emit = EmitSampledRGB; // default |
| #ifdef FANCY_UPSAMPLING |
| if (io->fancy_upsampling) { |
| const int uv_width = (io->mb_w + 1) >> 1; |
| p->memory = SbMemoryAllocate(io->mb_w + 2 * uv_width); |
| if (p->memory == NULL) { |
| return 0; // memory error. |
| } |
| p->tmp_y = (uint8_t*)p->memory; |
| p->tmp_u = p->tmp_y + io->mb_w; |
| p->tmp_v = p->tmp_u + uv_width; |
| p->emit = EmitFancyRGB; |
| WebPInitUpsamplers(); |
| } |
| #endif |
| } else { |
| p->emit = EmitYUV; |
| } |
| if (is_alpha) { // need transparency output |
| if (WebPIsPremultipliedMode(colorspace)) WebPInitPremultiply(); |
| p->emit_alpha = |
| (colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ? |
| EmitAlphaRGBA4444 |
| : is_rgb ? EmitAlphaRGB |
| : EmitAlphaYUV; |
| } |
| } |
| |
| if (is_rgb) { |
| VP8YUVInit(); |
| } |
| return 1; |
| } |
| |
| //------------------------------------------------------------------------------ |
| |
| static int CustomPut(const VP8Io* io) { |
| WebPDecParams* const p = (WebPDecParams*)io->opaque; |
| const int mb_w = io->mb_w; |
| const int mb_h = io->mb_h; |
| int num_lines_out; |
| SB_DCHECK(!(io->mb_y & 1)); |
| |
| if (mb_w <= 0 || mb_h <= 0) { |
| return 0; |
| } |
| num_lines_out = p->emit(io, p); |
| if (p->emit_alpha) { |
| p->emit_alpha(io, p); |
| } |
| p->last_y += num_lines_out; |
| return 1; |
| } |
| |
| //------------------------------------------------------------------------------ |
| |
| static void CustomTeardown(const VP8Io* io) { |
| WebPDecParams* const p = (WebPDecParams*)io->opaque; |
| SbMemoryDeallocate(p->memory); |
| p->memory = NULL; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // Main entry point |
| |
| void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io) { |
| io->put = CustomPut; |
| io->setup = CustomSetup; |
| io->teardown = CustomTeardown; |
| io->opaque = params; |
| } |
| |
| //------------------------------------------------------------------------------ |
| |
| #if defined(__cplusplus) || defined(c_plusplus) |
| } // extern "C" |
| #endif |