static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos,
int max_lines_out) {
const WebPRGBABuffer* const buf = &p->output->u.RGBA;
uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride;
#ifdef WEBP_SWAP_16BIT_CSP
uint8_t* alpha_dst = base_rgba;
#else
uint8_t* alpha_dst = base_rgba + 1;
#endif
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) &&
num_lines_out < max_lines_out) {
int i;
assert(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 EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p,
int expected_num_lines_out) {
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;
#ifdef WEBP_SWAP_16BIT_CSP
uint8_t* alpha_dst = base_rgba;
#else
uint8_t* alpha_dst = base_rgba + 1;
#endif
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;
}
(void)expected_num_lines_out;
assert(expected_num_lines_out == num_rows);
if (alpha_mask != 0x0f && WebPIsPremultipliedMode(colorspace)) {
WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride);
}
}
return 0;
}
static int ExportAlpha(WebPDecParams* const p, int y_pos, int max_lines_out) {
const WebPRGBABuffer* const buf = &p->output->u.RGBA;
uint8_t* const base_rgba = buf->rgba + 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 non_opaque = 0;
const int width = p->scaler_a->dst_width;
while (WebPRescalerHasPendingOutput(p->scaler_a) &&
num_lines_out < max_lines_out) {
assert(y_pos + num_lines_out < p->output->height);
WebPRescalerExportRow(p->scaler_a);
non_opaque |= WebPDispatchAlpha(p->scaler_a->dst, 0, width, 1, dst, 0);
dst += buf->stride;
++num_lines_out;
}
if (is_premult_alpha && non_opaque) {
WebPApplyAlphaMultiply(base_rgba, alpha_first,
width, num_lines_out, buf->stride);
}
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;
assert(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 EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
int expected_num_lines_out) {
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* const dst = base_rgba + (alpha_first ? 0 : 3);
const int has_alpha = WebPDispatchAlpha(alpha, io->width, mb_w,
num_rows, dst, buf->stride);
(void)expected_num_lines_out;
assert(expected_num_lines_out == num_rows);
// has_alpha is true if there's non-trivial alpha to premultiply with.
if (has_alpha && WebPIsPremultipliedMode(colorspace)) {
WebPApplyAlphaMultiply(base_rgba, alpha_first,
mb_w, num_rows, buf->stride);
}
}
return 0;
}
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) {
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;
}
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 (is_alpha && WebPIsPremultipliedMode(colorspace)) {
WebPInitUpsamplers();
}
if (io->use_scaling) {
#if !defined(WEBP_REDUCE_SIZE)
const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p);
if (!ok) {
return 0; // memory error
}
#else
return 0; // rescaling support not compiled
#endif
} else {
if (is_rgb) {
WebPInitSamplers();
p->emit = EmitSampledRGB; // default
if (io->fancy_upsampling) {
#ifdef FANCY_UPSAMPLING
const int uv_width = (io->mb_w + 1) >> 1;
p->memory = WebPSafeMalloc(1ULL, (size_t)(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
p->emit_alpha =
(colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ?
EmitAlphaRGBA4444
: is_rgb ? EmitAlphaRGB
: EmitAlphaYUV;
if (is_rgb) {
WebPInitAlphaProcessing();
}
}
}
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;
}
} else {
if (is_rgb) {
p->emit = EmitSampledRGB;
#ifdef FANCY_UPSAMPLING
if (io->fancy_upsampling) {
const int uv_width = (io->mb_w + 1) >> 1;
p->memory = malloc(io->mb_w + 2 * uv_width);
if (p->memory == NULL) {
return 0;
}
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) {
if (WebPIsPremultipliedMode(colorspace)) WebPInitPremultiply();
p->emit_alpha =
(colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ?
EmitAlphaRGBA4444
: is_rgb ? EmitAlphaRGB
: EmitAlphaYUV;
}
}
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 (is_alpha && WebPIsPremultipliedMode(colorspace)) {
WebPInitUpsamplers();
}
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
if (io->fancy_upsampling) {
#ifdef FANCY_UPSAMPLING
const int uv_width = (io->mb_w + 1) >> 1;
p->memory = WebPSafeMalloc(1ULL, (size_t)(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 {
WebPInitSamplers();
}
} else {