1// Copyright 2011 Google Inc. All Rights Reserved.
2//
3// Use of this source code is governed by a BSD-style license
4// that can be found in the COPYING file in the root of the source
5// tree. An additional intellectual property rights grant can be found
6// in the file PATENTS. All contributing project authors may
7// be found in the AUTHORS file in the root of the source tree.
8// -----------------------------------------------------------------------------
9//
10// functions for sample output.
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include <assert.h>
15#include <stdlib.h>
16#include "src/dec/vp8i_dec.h"
17#include "src/dec/webpi_dec.h"
18#include "src/dsp/dsp.h"
19#include "src/dsp/yuv.h"
20#include "src/utils/utils.h"
21
22//------------------------------------------------------------------------------
23// Main YUV<->RGB conversion functions
24
25static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) {
26 WebPDecBuffer* output = p->output;
27 const WebPYUVABuffer* const buf = &output->u.YUVA;
28 uint8_t* const y_dst = buf->y + (size_t)io->mb_y * buf->y_stride;
29 uint8_t* const u_dst = buf->u + (size_t)(io->mb_y >> 1) * buf->u_stride;
30 uint8_t* const v_dst = buf->v + (size_t)(io->mb_y >> 1) * buf->v_stride;
31 const int mb_w = io->mb_w;
32 const int mb_h = io->mb_h;
33 const int uv_w = (mb_w + 1) / 2;
34 const int uv_h = (mb_h + 1) / 2;
35 WebPCopyPlane(io->y, io->y_stride, y_dst, buf->y_stride, mb_w, mb_h);
36 WebPCopyPlane(io->u, io->uv_stride, u_dst, buf->u_stride, uv_w, uv_h);
37 WebPCopyPlane(io->v, io->uv_stride, v_dst, buf->v_stride, uv_w, uv_h);
38 return io->mb_h;
39}
40
41// Point-sampling U/V sampler.
42static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) {
43 WebPDecBuffer* const output = p->output;
44 WebPRGBABuffer* const buf = &output->u.RGBA;
45 uint8_t* const dst = buf->rgba + (size_t)io->mb_y * buf->stride;
46 WebPSamplerProcessPlane(io->y, io->y_stride,
47 io->u, io->v, io->uv_stride,
48 dst, buf->stride, io->mb_w, io->mb_h,
49 WebPSamplers[output->colorspace]);
50 return io->mb_h;
51}
52
53//------------------------------------------------------------------------------
54// Fancy upsampling
55
56#ifdef FANCY_UPSAMPLING
57static int EmitFancyRGB(const VP8Io* const io, WebPDecParams* const p) {
58 int num_lines_out = io->mb_h; // a priori guess
59 const WebPRGBABuffer* const buf = &p->output->u.RGBA;
60 uint8_t* dst = buf->rgba + (size_t)io->mb_y * buf->stride;
61 WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace];
62 const uint8_t* cur_y = io->y;
63 const uint8_t* cur_u = io->u;
64 const uint8_t* cur_v = io->v;
65 const uint8_t* top_u = p->tmp_u;
66 const uint8_t* top_v = p->tmp_v;
67 int y = io->mb_y;
68 const int y_end = io->mb_y + io->mb_h;
69 const int mb_w = io->mb_w;
70 const int uv_w = (mb_w + 1) / 2;
71
72 if (y == 0) {
73 // First line is special cased. We mirror the u/v samples at boundary.
74 upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, mb_w);
75 } else {
76 // We can finish the left-over line from previous call.
77 upsample(p->tmp_y, cur_y, top_u, top_v, cur_u, cur_v,
78 dst - buf->stride, dst, mb_w);
79 ++num_lines_out;
80 }
81 // Loop over each output pairs of row.
82 for (; y + 2 < y_end; y += 2) {
83 top_u = cur_u;
84 top_v = cur_v;
85 cur_u += io->uv_stride;
86 cur_v += io->uv_stride;
87 dst += 2 * buf->stride;
88 cur_y += 2 * io->y_stride;
89 upsample(cur_y - io->y_stride, cur_y,
90 top_u, top_v, cur_u, cur_v,
91 dst - buf->stride, dst, mb_w);
92 }
93 // move to last row
94 cur_y += io->y_stride;
95 if (io->crop_top + y_end < io->crop_bottom) {
96 // Save the unfinished samples for next call (as we're not done yet).
97 memcpy(p->tmp_y, cur_y, mb_w * sizeof(*p->tmp_y));
98 memcpy(p->tmp_u, cur_u, uv_w * sizeof(*p->tmp_u));
99 memcpy(p->tmp_v, cur_v, uv_w * sizeof(*p->tmp_v));
100 // The fancy upsampler leaves a row unfinished behind
101 // (except for the very last row)
102 num_lines_out--;
103 } else {
104 // Process the very last row of even-sized picture
105 if (!(y_end & 1)) {
106 upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v,
107 dst + buf->stride, NULL, mb_w);
108 }
109 }
110 return num_lines_out;
111}
112
113#endif /* FANCY_UPSAMPLING */
114
115//------------------------------------------------------------------------------
116
117static void FillAlphaPlane(uint8_t* dst, int w, int h, int stride) {
118 int j;
119 for (j = 0; j < h; ++j) {
120 memset(dst, 0xff, w * sizeof(*dst));
121 dst += stride;
122 }
123}
124
125static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
126 int expected_num_lines_out) {
127 const uint8_t* alpha = io->a;
128 const WebPYUVABuffer* const buf = &p->output->u.YUVA;
129 const int mb_w = io->mb_w;
130 const int mb_h = io->mb_h;
131 uint8_t* dst = buf->a + (size_t)io->mb_y * buf->a_stride;
132 int j;
133 (void)expected_num_lines_out;
134 assert(expected_num_lines_out == mb_h);
135 if (alpha != NULL) {
136 for (j = 0; j < mb_h; ++j) {
137 memcpy(dst, alpha, mb_w * sizeof(*dst));
138 alpha += io->width;
139 dst += buf->a_stride;
140 }
141 } else if (buf->a != NULL) {
142 // the user requested alpha, but there is none, set it to opaque.
143 FillAlphaPlane(dst, mb_w, mb_h, buf->a_stride);
144 }
145 return 0;
146}
147
148static int GetAlphaSourceRow(const VP8Io* const io,
149 const uint8_t** alpha, int* const num_rows) {
150 int start_y = io->mb_y;
151 *num_rows = io->mb_h;
152
153 // Compensate for the 1-line delay of the fancy upscaler.
154 // This is similar to EmitFancyRGB().
155 if (io->fancy_upsampling) {
156 if (start_y == 0) {
157 // We don't process the last row yet. It'll be done during the next call.
158 --*num_rows;
159 } else {
160 --start_y;
161 // Fortunately, *alpha data is persistent, so we can go back
162 // one row and finish alpha blending, now that the fancy upscaler
163 // completed the YUV->RGB interpolation.
164 *alpha -= io->width;
165 }
166 if (io->crop_top + io->mb_y + io->mb_h == io->crop_bottom) {
167 // If it's the very last call, we process all the remaining rows!
168 *num_rows = io->crop_bottom - io->crop_top - start_y;
169 }
170 }
171 return start_y;
172}
173
174static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
175 int expected_num_lines_out) {
176 const uint8_t* alpha = io->a;
177 if (alpha != NULL) {
178 const int mb_w = io->mb_w;
179 const WEBP_CSP_MODE colorspace = p->output->colorspace;
180 const int alpha_first =
181 (colorspace == MODE_ARGB || colorspace == MODE_Argb);
182 const WebPRGBABuffer* const buf = &p->output->u.RGBA;
183 int num_rows;
184 const size_t start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
185 uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
186 uint8_t* const dst = base_rgba + (alpha_first ? 0 : 3);
187 const int has_alpha = WebPDispatchAlpha(alpha, io->width, mb_w,
188 num_rows, dst, buf->stride);
189 (void)expected_num_lines_out;
190 assert(expected_num_lines_out == num_rows);
191 // has_alpha is true if there's non-trivial alpha to premultiply with.
192 if (has_alpha && WebPIsPremultipliedMode(colorspace)) {
193 WebPApplyAlphaMultiply(base_rgba, alpha_first,
194 mb_w, num_rows, buf->stride);
195 }
196 }
197 return 0;
198}
199
200static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p,
201 int expected_num_lines_out) {
202 const uint8_t* alpha = io->a;
203 if (alpha != NULL) {
204 const int mb_w = io->mb_w;
205 const WEBP_CSP_MODE colorspace = p->output->colorspace;
206 const WebPRGBABuffer* const buf = &p->output->u.RGBA;
207 int num_rows;
208 const size_t start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
209 uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
210#if (WEBP_SWAP_16BIT_CSP == 1)
211 uint8_t* alpha_dst = base_rgba;
212#else
213 uint8_t* alpha_dst = base_rgba + 1;
214#endif
215 uint32_t alpha_mask = 0x0f;
216 int i, j;
217 for (j = 0; j < num_rows; ++j) {
218 for (i = 0; i < mb_w; ++i) {
219 // Fill in the alpha value (converted to 4 bits).
220 const uint32_t alpha_value = alpha[i] >> 4;
221 alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value;
222 alpha_mask &= alpha_value;
223 }
224 alpha += io->width;
225 alpha_dst += buf->stride;
226 }
227 (void)expected_num_lines_out;
228 assert(expected_num_lines_out == num_rows);
229 if (alpha_mask != 0x0f && WebPIsPremultipliedMode(colorspace)) {
230 WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride);
231 }
232 }
233 return 0;
234}
235
236//------------------------------------------------------------------------------
237// YUV rescaling (no final RGB conversion needed)
238
239#if !defined(WEBP_REDUCE_SIZE)
240static int Rescale(const uint8_t* src, int src_stride,
241 int new_lines, WebPRescaler* const wrk) {
242 int num_lines_out = 0;
243 while (new_lines > 0) { // import new contributions of source rows.
244 const int lines_in = WebPRescalerImport(wrk, new_lines, src, src_stride);
245 src += lines_in * src_stride;
246 new_lines -= lines_in;
247 num_lines_out += WebPRescalerExport(wrk); // emit output row(s)
248 }
249 return num_lines_out;
250}
251
252static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) {
253 const int mb_h = io->mb_h;
254 const int uv_mb_h = (mb_h + 1) >> 1;
255 WebPRescaler* const scaler = p->scaler_y;
256 int num_lines_out = 0;
257 if (WebPIsAlphaMode(p->output->colorspace) && io->a != NULL) {
258 // Before rescaling, we premultiply the luma directly into the io->y
259 // internal buffer. This is OK since these samples are not used for
260 // intra-prediction (the top samples are saved in cache_y_/u_/v_).
261 // But we need to cast the const away, though.
262 WebPMultRows((uint8_t*)io->y, io->y_stride,
263 io->a, io->width, io->mb_w, mb_h, 0);
264 }
265 num_lines_out = Rescale(io->y, io->y_stride, mb_h, scaler);
266 Rescale(io->u, io->uv_stride, uv_mb_h, p->scaler_u);
267 Rescale(io->v, io->uv_stride, uv_mb_h, p->scaler_v);
268 return num_lines_out;
269}
270
271static int EmitRescaledAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
272 int expected_num_lines_out) {
273 const WebPYUVABuffer* const buf = &p->output->u.YUVA;
274 uint8_t* const dst_a = buf->a + (size_t)p->last_y * buf->a_stride;
275 if (io->a != NULL) {
276 uint8_t* const dst_y = buf->y + (size_t)p->last_y * buf->y_stride;
277 const int num_lines_out = Rescale(io->a, io->width, io->mb_h, p->scaler_a);
278 assert(expected_num_lines_out == num_lines_out);
279 if (num_lines_out > 0) { // unmultiply the Y
280 WebPMultRows(dst_y, buf->y_stride, dst_a, buf->a_stride,
281 p->scaler_a->dst_width, num_lines_out, 1);
282 }
283 } else if (buf->a != NULL) {
284 // the user requested alpha, but there is none, set it to opaque.
285 assert(p->last_y + expected_num_lines_out <= io->scaled_height);
286 FillAlphaPlane(dst_a, io->scaled_width, expected_num_lines_out,
287 buf->a_stride);
288 }
289 return 0;
290}
291
292static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) {
293 const int has_alpha = WebPIsAlphaMode(p->output->colorspace);
294 const WebPYUVABuffer* const buf = &p->output->u.YUVA;
295 const int out_width = io->scaled_width;
296 const int out_height = io->scaled_height;
297 const int uv_out_width = (out_width + 1) >> 1;
298 const int uv_out_height = (out_height + 1) >> 1;
299 const int uv_in_width = (io->mb_w + 1) >> 1;
300 const int uv_in_height = (io->mb_h + 1) >> 1;
301 // scratch memory for luma rescaler
302 const size_t work_size = 2 * (size_t)out_width;
303 const size_t uv_work_size = 2 * uv_out_width; // and for each u/v ones
304 uint64_t total_size;
305 size_t rescaler_size;
306 rescaler_t* work;
307 WebPRescaler* scalers;
308 const int num_rescalers = has_alpha ? 4 : 3;
309
310 total_size = ((uint64_t)work_size + 2 * uv_work_size) * sizeof(*work);
311 if (has_alpha) {
312 total_size += (uint64_t)work_size * sizeof(*work);
313 }
314 rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
315 total_size += rescaler_size;
316 if (!CheckSizeOverflow(total_size)) {
317 return 0;
318 }
319
320 p->memory = WebPSafeMalloc(1ULL, (size_t)total_size);
321 if (p->memory == NULL) {
322 return 0; // memory error
323 }
324 work = (rescaler_t*)p->memory;
325
326 scalers = (WebPRescaler*)WEBP_ALIGN(
327 (const uint8_t*)work + total_size - rescaler_size);
328 p->scaler_y = &scalers[0];
329 p->scaler_u = &scalers[1];
330 p->scaler_v = &scalers[2];
331 p->scaler_a = has_alpha ? &scalers[3] : NULL;
332
333 if (!WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
334 buf->y, out_width, out_height, buf->y_stride, 1,
335 work) ||
336 !WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
337 buf->u, uv_out_width, uv_out_height, buf->u_stride, 1,
338 work + work_size) ||
339 !WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
340 buf->v, uv_out_width, uv_out_height, buf->v_stride, 1,
341 work + work_size + uv_work_size)) {
342 return 0;
343 }
344 p->emit = EmitRescaledYUV;
345
346 if (has_alpha) {
347 if (!WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
348 buf->a, out_width, out_height, buf->a_stride, 1,
349 work + work_size + 2 * uv_work_size)) {
350 return 0;
351 }
352 p->emit_alpha = EmitRescaledAlphaYUV;
353 WebPInitAlphaProcessing();
354 }
355 return 1;
356}
357
358//------------------------------------------------------------------------------
359// RGBA rescaling
360
361static int ExportRGB(WebPDecParams* const p, int y_pos) {
362 const WebPYUV444Converter convert =
363 WebPYUV444Converters[p->output->colorspace];
364 const WebPRGBABuffer* const buf = &p->output->u.RGBA;
365 uint8_t* dst = buf->rgba + (size_t)y_pos * buf->stride;
366 int num_lines_out = 0;
367 // For RGB rescaling, because of the YUV420, current scan position
368 // U/V can be +1/-1 line from the Y one. Hence the double test.
369 while (WebPRescalerHasPendingOutput(p->scaler_y) &&
370 WebPRescalerHasPendingOutput(p->scaler_u)) {
371 assert(y_pos + num_lines_out < p->output->height);
372 assert(p->scaler_u->y_accum == p->scaler_v->y_accum);
373 WebPRescalerExportRow(p->scaler_y);
374 WebPRescalerExportRow(p->scaler_u);
375 WebPRescalerExportRow(p->scaler_v);
376 convert(p->scaler_y->dst, p->scaler_u->dst, p->scaler_v->dst,
377 dst, p->scaler_y->dst_width);
378 dst += buf->stride;
379 ++num_lines_out;
380 }
381 return num_lines_out;
382}
383
384static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) {
385 const int mb_h = io->mb_h;
386 const int uv_mb_h = (mb_h + 1) >> 1;
387 int j = 0, uv_j = 0;
388 int num_lines_out = 0;
389 while (j < mb_h) {
390 const int y_lines_in =
391 WebPRescalerImport(p->scaler_y, mb_h - j,
392 io->y + (size_t)j * io->y_stride, io->y_stride);
393 j += y_lines_in;
394 if (WebPRescaleNeededLines(p->scaler_u, uv_mb_h - uv_j)) {
395 const int u_lines_in = WebPRescalerImport(
396 p->scaler_u, uv_mb_h - uv_j, io->u + (size_t)uv_j * io->uv_stride,
397 io->uv_stride);
398 const int v_lines_in = WebPRescalerImport(
399 p->scaler_v, uv_mb_h - uv_j, io->v + (size_t)uv_j * io->uv_stride,
400 io->uv_stride);
401 (void)v_lines_in; // remove a gcc warning
402 assert(u_lines_in == v_lines_in);
403 uv_j += u_lines_in;
404 }
405 num_lines_out += ExportRGB(p, p->last_y + num_lines_out);
406 }
407 return num_lines_out;
408}
409
410static int ExportAlpha(WebPDecParams* const p, int y_pos, int max_lines_out) {
411 const WebPRGBABuffer* const buf = &p->output->u.RGBA;
412 uint8_t* const base_rgba = buf->rgba + (size_t)y_pos * buf->stride;
413 const WEBP_CSP_MODE colorspace = p->output->colorspace;
414 const int alpha_first =
415 (colorspace == MODE_ARGB || colorspace == MODE_Argb);
416 uint8_t* dst = base_rgba + (alpha_first ? 0 : 3);
417 int num_lines_out = 0;
418 const int is_premult_alpha = WebPIsPremultipliedMode(colorspace);
419 uint32_t non_opaque = 0;
420 const int width = p->scaler_a->dst_width;
421
422 while (WebPRescalerHasPendingOutput(p->scaler_a) &&
423 num_lines_out < max_lines_out) {
424 assert(y_pos + num_lines_out < p->output->height);
425 WebPRescalerExportRow(p->scaler_a);
426 non_opaque |= WebPDispatchAlpha(p->scaler_a->dst, 0, width, 1, dst, 0);
427 dst += buf->stride;
428 ++num_lines_out;
429 }
430 if (is_premult_alpha && non_opaque) {
431 WebPApplyAlphaMultiply(base_rgba, alpha_first,
432 width, num_lines_out, buf->stride);
433 }
434 return num_lines_out;
435}
436
437static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos,
438 int max_lines_out) {
439 const WebPRGBABuffer* const buf = &p->output->u.RGBA;
440 uint8_t* const base_rgba = buf->rgba + (size_t)y_pos * buf->stride;
441#if (WEBP_SWAP_16BIT_CSP == 1)
442 uint8_t* alpha_dst = base_rgba;
443#else
444 uint8_t* alpha_dst = base_rgba + 1;
445#endif
446 int num_lines_out = 0;
447 const WEBP_CSP_MODE colorspace = p->output->colorspace;
448 const int width = p->scaler_a->dst_width;
449 const int is_premult_alpha = WebPIsPremultipliedMode(colorspace);
450 uint32_t alpha_mask = 0x0f;
451
452 while (WebPRescalerHasPendingOutput(p->scaler_a) &&
453 num_lines_out < max_lines_out) {
454 int i;
455 assert(y_pos + num_lines_out < p->output->height);
456 WebPRescalerExportRow(p->scaler_a);
457 for (i = 0; i < width; ++i) {
458 // Fill in the alpha value (converted to 4 bits).
459 const uint32_t alpha_value = p->scaler_a->dst[i] >> 4;
460 alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value;
461 alpha_mask &= alpha_value;
462 }
463 alpha_dst += buf->stride;
464 ++num_lines_out;
465 }
466 if (is_premult_alpha && alpha_mask != 0x0f) {
467 WebPApplyAlphaMultiply4444(base_rgba, width, num_lines_out, buf->stride);
468 }
469 return num_lines_out;
470}
471
472static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
473 int expected_num_out_lines) {
474 if (io->a != NULL) {
475 WebPRescaler* const scaler = p->scaler_a;
476 int lines_left = expected_num_out_lines;
477 const int y_end = p->last_y + lines_left;
478 while (lines_left > 0) {
479 const int64_t row_offset = (int64_t)scaler->src_y - io->mb_y;
480 WebPRescalerImport(scaler, io->mb_h + io->mb_y - scaler->src_y,
481 io->a + row_offset * io->width, io->width);
482 lines_left -= p->emit_alpha_row(p, y_end - lines_left, lines_left);
483 }
484 }
485 return 0;
486}
487
488static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) {
489 const int has_alpha = WebPIsAlphaMode(p->output->colorspace);
490 const int out_width = io->scaled_width;
491 const int out_height = io->scaled_height;
492 const int uv_in_width = (io->mb_w + 1) >> 1;
493 const int uv_in_height = (io->mb_h + 1) >> 1;
494 // scratch memory for one rescaler
495 const size_t work_size = 2 * (size_t)out_width;
496 rescaler_t* work; // rescalers work area
497 uint8_t* tmp; // tmp storage for scaled YUV444 samples before RGB conversion
498 uint64_t tmp_size1, tmp_size2, total_size;
499 size_t rescaler_size;
500 WebPRescaler* scalers;
501 const int num_rescalers = has_alpha ? 4 : 3;
502
503 tmp_size1 = (uint64_t)num_rescalers * work_size;
504 tmp_size2 = (uint64_t)num_rescalers * out_width;
505 total_size = tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp);
506 rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
507 total_size += rescaler_size;
508 if (!CheckSizeOverflow(total_size)) {
509 return 0;
510 }
511
512 p->memory = WebPSafeMalloc(1ULL, (size_t)total_size);
513 if (p->memory == NULL) {
514 return 0; // memory error
515 }
516 work = (rescaler_t*)p->memory;
517 tmp = (uint8_t*)(work + tmp_size1);
518
519 scalers = (WebPRescaler*)WEBP_ALIGN(
520 (const uint8_t*)work + total_size - rescaler_size);
521 p->scaler_y = &scalers[0];
522 p->scaler_u = &scalers[1];
523 p->scaler_v = &scalers[2];
524 p->scaler_a = has_alpha ? &scalers[3] : NULL;
525
526 if (!WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
527 tmp + 0 * out_width, out_width, out_height, 0, 1,
528 work + 0 * work_size) ||
529 !WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
530 tmp + 1 * out_width, out_width, out_height, 0, 1,
531 work + 1 * work_size) ||
532 !WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
533 tmp + 2 * out_width, out_width, out_height, 0, 1,
534 work + 2 * work_size)) {
535 return 0;
536 }
537 p->emit = EmitRescaledRGB;
538 WebPInitYUV444Converters();
539
540 if (has_alpha) {
541 if (!WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
542 tmp + 3 * out_width, out_width, out_height, 0, 1,
543 work + 3 * work_size)) {
544 return 0;
545 }
546 p->emit_alpha = EmitRescaledAlphaRGB;
547 if (p->output->colorspace == MODE_RGBA_4444 ||
548 p->output->colorspace == MODE_rgbA_4444) {
549 p->emit_alpha_row = ExportAlphaRGBA4444;
550 } else {
551 p->emit_alpha_row = ExportAlpha;
552 }
553 WebPInitAlphaProcessing();
554 }
555 return 1;
556}
557
558#endif // WEBP_REDUCE_SIZE
559
560//------------------------------------------------------------------------------
561// Default custom functions
562
563static int CustomSetup(VP8Io* io) {
564 WebPDecParams* const p = (WebPDecParams*)io->opaque;
565 const WEBP_CSP_MODE colorspace = p->output->colorspace;
566 const int is_rgb = WebPIsRGBMode(colorspace);
567 const int is_alpha = WebPIsAlphaMode(colorspace);
568
569 p->memory = NULL;
570 p->emit = NULL;
571 p->emit_alpha = NULL;
572 p->emit_alpha_row = NULL;
573 if (!WebPIoInitFromOptions(p->options, io, is_alpha ? MODE_YUV : MODE_YUVA)) {
574 return 0;
575 }
576 if (is_alpha && WebPIsPremultipliedMode(colorspace)) {
577 WebPInitUpsamplers();
578 }
579 if (io->use_scaling) {
580#if !defined(WEBP_REDUCE_SIZE)
581 const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p);
582 if (!ok) {
583 return 0; // memory error
584 }
585#else
586 return 0; // rescaling support not compiled
587#endif
588 } else {
589 if (is_rgb) {
590 WebPInitSamplers();
591 p->emit = EmitSampledRGB; // default
592 if (io->fancy_upsampling) {
593#ifdef FANCY_UPSAMPLING
594 const int uv_width = (io->mb_w + 1) >> 1;
595 p->memory = WebPSafeMalloc(1ULL, (size_t)(io->mb_w + 2 * uv_width));
596 if (p->memory == NULL) {
597 return 0; // memory error.
598 }
599 p->tmp_y = (uint8_t*)p->memory;
600 p->tmp_u = p->tmp_y + io->mb_w;
601 p->tmp_v = p->tmp_u + uv_width;
602 p->emit = EmitFancyRGB;
603 WebPInitUpsamplers();
604#endif
605 }
606 } else {
607 p->emit = EmitYUV;
608 }
609 if (is_alpha) { // need transparency output
610 p->emit_alpha =
611 (colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ?
612 EmitAlphaRGBA4444
613 : is_rgb ? EmitAlphaRGB
614 : EmitAlphaYUV;
615 if (is_rgb) {
616 WebPInitAlphaProcessing();
617 }
618 }
619 }
620
621 return 1;
622}
623
624//------------------------------------------------------------------------------
625
626static int CustomPut(const VP8Io* io) {
627 WebPDecParams* const p = (WebPDecParams*)io->opaque;
628 const int mb_w = io->mb_w;
629 const int mb_h = io->mb_h;
630 int num_lines_out;
631 assert(!(io->mb_y & 1));
632
633 if (mb_w <= 0 || mb_h <= 0) {
634 return 0;
635 }
636 num_lines_out = p->emit(io, p);
637 if (p->emit_alpha != NULL) {
638 p->emit_alpha(io, p, num_lines_out);
639 }
640 p->last_y += num_lines_out;
641 return 1;
642}
643
644//------------------------------------------------------------------------------
645
646static void CustomTeardown(const VP8Io* io) {
647 WebPDecParams* const p = (WebPDecParams*)io->opaque;
648 WebPSafeFree(p->memory);
649 p->memory = NULL;
650}
651
652//------------------------------------------------------------------------------
653// Main entry point
654
655void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io) {
656 io->put = CustomPut;
657 io->setup = CustomSetup;
658 io->teardown = CustomTeardown;
659 io->opaque = params;
660}
661
662//------------------------------------------------------------------------------
663