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Move rescaler methods out of io.c.

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(cherry picked from commit b5e9db1824f6efbe0bfb87e94b8d6e88a7973ef7)
This commit is contained in:
Urvang Joshi 2012-03-20 10:59:22 +00:00 committed by James Zern
parent 6f7bf645b4
commit 3eacee8158
3 changed files with 202 additions and 188 deletions
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179
src/dec/io.c
View File

@ -228,98 +228,6 @@ static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p) {
return 0;
}
//------------------------------------------------------------------------------
// Simple picture rescaler
// TODO(skal): start a common library for encoder and decoder, and factorize
// this code in.
#define RFIX 30
#define MULT(x,y) (((int64_t)(x) * (y) + (1 << (RFIX - 1))) >> RFIX)
static void InitRescaler(WebPRescaler* const wrk,
int src_width, int src_height,
uint8_t* dst,
int dst_width, int dst_height, int dst_stride,
int x_add, int x_sub, int y_add, int y_sub,
int32_t* 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;
// 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 + dst_width;
}
static WEBP_INLINE void ImportRow(const uint8_t* const src,
WebPRescaler* const wrk) {
int x_in = 0;
int x_out;
int accum = 0;
if (!wrk->x_expand) {
int sum = 0;
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
accum += wrk->x_add;
for (; accum > 0; accum -= wrk->x_sub) {
sum += src[x_in++];
}
{ // Emit next horizontal pixel.
const int32_t base = src[x_in++];
const int32_t frac = base * (-accum);
wrk->frow[x_out] = (sum + base) * wrk->x_sub - frac;
// fresh fractional start for next pixel
sum = (int)MULT(frac, wrk->fx_scale);
}
}
} else { // simple bilinear interpolation
int left = src[0], right = src[0];
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
if (accum < 0) {
left = right;
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 new row's contribution
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
wrk->irow[x_out] += wrk->frow[x_out];
}
}
static void ExportRow(WebPRescaler* const wrk) {
int x_out;
const int yscale = wrk->fy_scale * (-wrk->y_accum);
assert(wrk->y_accum <= 0);
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
const int frac = (int)MULT(wrk->frow[x_out], yscale);
const int v = (int)MULT(wrk->irow[x_out] - frac, wrk->fxy_scale);
wrk->dst[x_out] = (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255;
wrk->irow[x_out] = frac; // new fractional start
}
wrk->y_accum += wrk->y_add;
wrk->dst += wrk->dst_stride;
}
#undef MULT
#undef RFIX
//------------------------------------------------------------------------------
// YUV rescaling (no final RGB conversion needed)
@ -327,11 +235,11 @@ 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 contribution of one source row.
ImportRow(src, wrk);
WebPRescalerImportRow(src, wrk);
src += src_stride;
wrk->y_accum -= wrk->y_sub;
while (wrk->y_accum <= 0) { // emit output row(s)
ExportRow(wrk);
WebPRescalerExportRow(wrk);
++num_lines_out;
}
}
@ -382,23 +290,23 @@ static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) {
return 0; // memory error
}
work = (int32_t*)p->memory;
InitRescaler(&p->scaler_y, io->mb_w, io->mb_h,
WebPRescalerInit(&p->scaler_y, io->mb_w, io->mb_h,
buf->y, out_width, out_height, buf->y_stride,
io->mb_w, out_width, io->mb_h, out_height,
work);
InitRescaler(&p->scaler_u, uv_in_width, uv_in_height,
WebPRescalerInit(&p->scaler_u, uv_in_width, uv_in_height,
buf->u, uv_out_width, uv_out_height, buf->u_stride,
uv_in_width, uv_out_width,
uv_in_height, uv_out_height,
work + work_size);
InitRescaler(&p->scaler_v, uv_in_width, uv_in_height,
WebPRescalerInit(&p->scaler_v, uv_in_width, uv_in_height,
buf->v, uv_out_width, uv_out_height, buf->v_stride,
uv_in_width, uv_out_width,
uv_in_height, uv_out_height,
work + work_size + uv_work_size);
p->emit = EmitRescaledYUV;
if (has_alpha) {
InitRescaler(&p->scaler_a, io->mb_w, io->mb_h,
WebPRescalerInit(&p->scaler_a, io->mb_w, io->mb_h,
buf->a, out_width, out_height, buf->a_stride,
io->mb_w, out_width, io->mb_h, out_height,
work + work_size + 2 * uv_work_size);
@ -416,7 +324,7 @@ static int Import(const uint8_t* src, int src_stride,
int new_lines, WebPRescaler* const wrk) {
int num_lines_in = 0;
while (num_lines_in < new_lines && wrk->y_accum > 0) {
ImportRow(src, wrk);
WebPRescalerImportRow(src, wrk);
src += src_stride;
++num_lines_in;
wrk->y_accum -= wrk->y_sub;
@ -435,9 +343,9 @@ static int ExportRGB(WebPDecParams* const p, int y_pos) {
while (p->scaler_y.y_accum <= 0 && p->scaler_u.y_accum <= 0) {
assert(p->last_y + y_pos + num_lines_out < p->output->height);
assert(p->scaler_u.y_accum == p->scaler_v.y_accum);
ExportRow(&p->scaler_y);
ExportRow(&p->scaler_u);
ExportRow(&p->scaler_v);
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;
@ -475,7 +383,7 @@ static int ExportAlpha(WebPDecParams* const p, int y_pos) {
while (p->scaler_a.y_accum <= 0) {
int i;
assert(p->last_y + y_pos + num_lines_out < p->output->height);
ExportRow(&p->scaler_a);
WebPRescalerExportRow(&p->scaler_a);
for (i = 0; i < p->scaler_a.dst_width; ++i) {
dst[4 * i] = p->scaler_a.dst[i];
}
@ -492,7 +400,7 @@ static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos) {
while (p->scaler_a.y_accum <= 0) {
int i;
assert(p->last_y + y_pos + num_lines_out < p->output->height);
ExportRow(&p->scaler_a);
WebPRescalerExportRow(&p->scaler_a);
for (i = 0; i < p->scaler_a.dst_width; ++i) {
// Fill in the alpha value (converted to 4 bits).
const uint32_t alpha_val = clip((p->scaler_a.dst[i] + 8) >> 4, 15);
@ -543,22 +451,22 @@ static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) {
}
work = (int32_t*)p->memory;
tmp = (uint8_t*)(work + tmp_size1);
InitRescaler(&p->scaler_y, io->mb_w, io->mb_h,
WebPRescalerInit(&p->scaler_y, io->mb_w, io->mb_h,
tmp + 0 * out_width, out_width, out_height, 0,
io->mb_w, out_width, io->mb_h, out_height,
work + 0 * work_size);
InitRescaler(&p->scaler_u, uv_in_width, uv_in_height,
WebPRescalerInit(&p->scaler_u, uv_in_width, uv_in_height,
tmp + 1 * out_width, out_width, out_height, 0,
io->mb_w, 2 * out_width, io->mb_h, 2 * out_height,
work + 1 * work_size);
InitRescaler(&p->scaler_v, uv_in_width, uv_in_height,
WebPRescalerInit(&p->scaler_v, uv_in_width, uv_in_height,
tmp + 2 * out_width, out_width, out_height, 0,
io->mb_w, 2 * out_width, io->mb_h, 2 * out_height,
work + 2 * work_size);
p->emit = EmitRescaledRGB;
if (has_alpha) {
InitRescaler(&p->scaler_a, io->mb_w, io->mb_h,
WebPRescalerInit(&p->scaler_a, io->mb_w, io->mb_h,
tmp + 3 * out_width, out_width, out_height, 0,
io->mb_w, out_width, io->mb_h, out_height,
work + 3 * work_size);
@ -570,59 +478,6 @@ static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) {
//------------------------------------------------------------------------------
// Default custom functions
// Setup crop_xxx fields, mb_w and mb_h
static int InitFromOptions(const WebPDecoderOptions* const options,
VP8Io* const io) {
const int W = io->width;
const int H = io->height;
int x = 0, y = 0, w = W, h = H;
// Cropping
io->use_cropping = (options != NULL) && (options->use_cropping > 0);
if (io->use_cropping) {
w = options->crop_width;
h = options->crop_height;
// TODO(skal): take colorspace into account. Don't assume YUV420.
x = options->crop_left & ~1;
y = options->crop_top & ~1;
if (x < 0 || y < 0 || w <= 0 || h <= 0 || x + w > W || y + h > H) {
return 0; // out of frame boundary error
}
}
io->crop_left = x;
io->crop_top = y;
io->crop_right = x + w;
io->crop_bottom = y + h;
io->mb_w = w;
io->mb_h = h;
// Scaling
io->use_scaling = (options != NULL) && (options->use_scaling > 0);
if (io->use_scaling) {
if (options->scaled_width <= 0 || options->scaled_height <= 0) {
return 0;
}
io->scaled_width = options->scaled_width;
io->scaled_height = options->scaled_height;
}
// Filter
io->bypass_filtering = options && options->bypass_filtering;
// Fancy upsampler
#ifdef FANCY_UPSAMPLING
io->fancy_upsampling = (options == NULL) || (!options->no_fancy_upsampling);
#endif
if (io->use_scaling) {
// disable filter (only for large downscaling ratio).
io->bypass_filtering = (io->scaled_width < W * 3 / 4) &&
(io->scaled_height < H * 3 / 4);
io->fancy_upsampling = 0;
}
return 1;
}
static int CustomSetup(VP8Io* io) {
WebPDecParams* const p = (WebPDecParams*)io->opaque;
const int is_rgb = (p->output->colorspace < MODE_YUV);
@ -630,7 +485,7 @@ static int CustomSetup(VP8Io* io) {
p->memory = NULL;
p->emit = NULL;
p->emit_alpha = NULL;
if (!InitFromOptions(p->options, io)) {
if (!WebPIoInitFromOptions(p->options, io)) {
return 0;
}

140
src/dec/webp.c
View File

@ -609,6 +609,146 @@ VP8StatusCode WebPDecode(const uint8_t* data, uint32_t data_size,
return status;
}
//------------------------------------------------------------------------------
// Simple picture rescaler
int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
VP8Io* const io) {
const int W = io->width;
const int H = io->height;
int x = 0, y = 0, w = W, h = H;
// Cropping
io->use_cropping = (options != NULL) && (options->use_cropping > 0);
if (io->use_cropping) {
w = options->crop_width;
h = options->crop_height;
// TODO(skal): take colorspace into account. Don't assume YUV420.
x = options->crop_left & ~1;
y = options->crop_top & ~1;
if (x < 0 || y < 0 || w <= 0 || h <= 0 || x + w > W || y + h > H) {
return 0; // out of frame boundary error
}
}
io->crop_left = x;
io->crop_top = y;
io->crop_right = x + w;
io->crop_bottom = y + h;
io->mb_w = w;
io->mb_h = h;
// Scaling
io->use_scaling = (options != NULL) && (options->use_scaling > 0);
if (io->use_scaling) {
if (options->scaled_width <= 0 || options->scaled_height <= 0) {
return 0;
}
io->scaled_width = options->scaled_width;
io->scaled_height = options->scaled_height;
}
// Filter
io->bypass_filtering = options && options->bypass_filtering;
// Fancy upsampler
#ifdef FANCY_UPSAMPLING
io->fancy_upsampling = (options == NULL) || (!options->no_fancy_upsampling);
#endif
if (io->use_scaling) {
// disable filter (only for large downscaling ratio).
io->bypass_filtering = (io->scaled_width < W * 3 / 4) &&
(io->scaled_height < H * 3 / 4);
io->fancy_upsampling = 0;
}
return 1;
}
#define RFIX 30
#define MULT(x,y) (((int64_t)(x) * (y) + (1 << (RFIX - 1))) >> RFIX)
void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height,
uint8_t* dst, int dst_width, int dst_height,
int dst_stride, int x_add, int x_sub, int y_add,
int y_sub, int32_t* 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;
// 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 + dst_width;
}
void WebPRescalerImportRow(const uint8_t* const src, WebPRescaler* const wrk) {
int x_in = 0;
int x_out;
int accum = 0;
if (!wrk->x_expand) {
int sum = 0;
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
accum += wrk->x_add;
for (; accum > 0; accum -= wrk->x_sub) {
sum += src[x_in++];
}
{ // Emit next horizontal pixel.
const int32_t base = src[x_in++];
const int32_t frac = base * (-accum);
wrk->frow[x_out] = (sum + base) * wrk->x_sub - frac;
// fresh fractional start for next pixel
sum = (int)MULT(frac, wrk->fx_scale);
}
}
} else { // simple bilinear interpolation
int left = src[0], right = src[0];
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
if (accum < 0) {
left = right;
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 new row's contribution
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
wrk->irow[x_out] += wrk->frow[x_out];
}
}
void WebPRescalerExportRow(WebPRescaler* const wrk) {
int x_out;
const int yscale = wrk->fy_scale * (-wrk->y_accum);
assert(wrk->y_accum <= 0);
for (x_out = 0; x_out < wrk->dst_width; ++x_out) {
const int frac = (int)MULT(wrk->frow[x_out], yscale);
const int v = (int)MULT(wrk->irow[x_out] - frac, wrk->fxy_scale);
wrk->dst[x_out] = (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255;
wrk->irow[x_out] = frac; // new fractional start
}
wrk->y_accum += wrk->y_add;
wrk->dst += wrk->dst_stride;
}
#undef MULT
#undef RFIX
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif

19
src/dec/webpi.h
View File

@ -159,6 +159,25 @@ void WebPCopyDecBuffer(const WebPDecBuffer* const src,
// Copy and transfer ownership from src to dst (beware of parameter order!)
void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst);
//------------------------------------------------------------------------------
// Cropping and rescaling.
// Setup crop_xxx fields, mb_w and mb_h
int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
VP8Io* const io);
// Initialize a rescaler given scratch area 'work' and dimensions of src & dst.
void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height,
uint8_t* dst, int dst_width, int dst_height,
int dst_stride, int x_add, int x_sub, int y_add,
int y_sub, int32_t* work);
// Import a row of data and save its contribution in the rescaler.
void WebPRescalerImportRow(const uint8_t* const src, WebPRescaler* const wrk);
// Export a row from rescaler.
void WebPRescalerExportRow(WebPRescaler* const wrk);
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)