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// 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.
// -----------------------------------------------------------------------------
//
// Everything about WebPDecBuffer
//
// Author: Skal (pascal.massimino@gmail.com)
#include <stdlib.h>
#include "./vp8i.h"
#include "./webpi.h"
#include "../utils/utils.h"
//------------------------------------------------------------------------------
// WebPDecBuffer
// Number of bytes per pixel for the different color-spaces.
static const int kModeBpp[MODE_LAST] = {
3, 4, 3, 4, 4, 2, 2,
4, 4, 4, 2, // pre-multiplied modes
1, 1 };
// Check that webp_csp_mode is within the bounds of WEBP_CSP_MODE.
// Convert to an integer to handle both the unsigned/signed enum cases
// without the need for casting to remove type limit warnings.
static int IsValidColorspace(int webp_csp_mode) {
return (webp_csp_mode >= MODE_RGB && webp_csp_mode < MODE_LAST);
}
static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) {
int ok = 1;
const WEBP_CSP_MODE mode = buffer->colorspace;
const int width = buffer->width;
const int height = buffer->height;
if (!IsValidColorspace(mode)) {
ok = 0;
} else if (!WebPIsRGBMode(mode)) { // YUV checks
const WebPYUVABuffer* const buf = &buffer->u.YUVA;
const uint64_t y_size = (uint64_t)buf->y_stride * height;
const uint64_t u_size = (uint64_t)buf->u_stride * ((height + 1) / 2);
const uint64_t v_size = (uint64_t)buf->v_stride * ((height + 1) / 2);
const uint64_t a_size = (uint64_t)buf->a_stride * height;
ok &= (y_size <= buf->y_size);
ok &= (u_size <= buf->u_size);
ok &= (v_size <= buf->v_size);
ok &= (buf->y_stride >= width);
ok &= (buf->u_stride >= (width + 1) / 2);
ok &= (buf->v_stride >= (width + 1) / 2);
ok &= (buf->y != NULL);
ok &= (buf->u != NULL);
ok &= (buf->v != NULL);
if (mode == MODE_YUVA) {
ok &= (buf->a_stride >= width);
ok &= (a_size <= buf->a_size);
ok &= (buf->a != NULL);
}
} else { // RGB checks
const WebPRGBABuffer* const buf = &buffer->u.RGBA;
const uint64_t size = (uint64_t)buf->stride * height;
ok &= (size <= buf->size);
ok &= (buf->stride >= width * kModeBpp[mode]);
ok &= (buf->rgba != NULL);
}
return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
}
static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
const int w = buffer->width;
const int h = buffer->height;
const WEBP_CSP_MODE mode = buffer->colorspace;
if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {
return VP8_STATUS_INVALID_PARAM;
}
if (!buffer->is_external_memory && buffer->private_memory == NULL) {
uint8_t* output;
int uv_stride = 0, a_stride = 0;
uint64_t uv_size = 0, a_size = 0, total_size;
// We need memory and it hasn't been allocated yet.
// => initialize output buffer, now that dimensions are known.
const int stride = w * kModeBpp[mode];
const uint64_t size = (uint64_t)stride * h;
if (!WebPIsRGBMode(mode)) {
uv_stride = (w + 1) / 2;
uv_size = (uint64_t)uv_stride * ((h + 1) / 2);
if (mode == MODE_YUVA) {
a_stride = w;
a_size = (uint64_t)a_stride * h;
}
}
total_size = size + 2 * uv_size + a_size;
// Security/sanity checks
output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
if (output == NULL) {
return VP8_STATUS_OUT_OF_MEMORY;
}
buffer->private_memory = output;
if (!WebPIsRGBMode(mode)) { // YUVA initialization
WebPYUVABuffer* const buf = &buffer->u.YUVA;
buf->y = output;
buf->y_stride = stride;
buf->y_size = (size_t)size;
buf->u = output + size;
buf->u_stride = uv_stride;
buf->u_size = (size_t)uv_size;
buf->v = output + size + uv_size;
buf->v_stride = uv_stride;
buf->v_size = (size_t)uv_size;
if (mode == MODE_YUVA) {
buf->a = output + size + 2 * uv_size;
}
buf->a_size = (size_t)a_size;
buf->a_stride = a_stride;
} else { // RGBA initialization
WebPRGBABuffer* const buf = &buffer->u.RGBA;
buf->rgba = output;
buf->stride = stride;
buf->size = (size_t)size;
}
}
return CheckDecBuffer(buffer);
}
VP8StatusCode WebPAllocateDecBuffer(int w, int h,
const WebPDecoderOptions* const options,
WebPDecBuffer* const out) {
if (out == NULL || w <= 0 || h <= 0) {
return VP8_STATUS_INVALID_PARAM;
}
if (options != NULL) { // First, apply options if there is any.
if (options->use_cropping) {
const int cw = options->crop_width;
const int ch = options->crop_height;
const int x = options->crop_left & ~1;
const int y = options->crop_top & ~1;
if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || x + cw > w || y + ch > h) {
return VP8_STATUS_INVALID_PARAM; // out of frame boundary.
}
w = cw;
h = ch;
}
if (options->use_scaling) {
if (options->scaled_width <= 0 || options->scaled_height <= 0) {
return VP8_STATUS_INVALID_PARAM;
}
w = options->scaled_width;
h = options->scaled_height;
}
}
out->width = w;
out->height = h;
// Then, allocate buffer for real
return AllocateBuffer(out);
}
//------------------------------------------------------------------------------
// constructors / destructors
int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {
if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
return 0; // version mismatch
}
if (buffer == NULL) return 0;
memset(buffer, 0, sizeof(*buffer));
return 1;
}
void WebPFreeDecBuffer(WebPDecBuffer* buffer) {
if (buffer != NULL) {
if (!buffer->is_external_memory)
free(buffer->private_memory);
buffer->private_memory = NULL;
}
}
void WebPCopyDecBuffer(const WebPDecBuffer* const src,
WebPDecBuffer* const dst) {
if (src != NULL && dst != NULL) {
*dst = *src;
if (src->private_memory != NULL) {
dst->is_external_memory = 1; // dst buffer doesn't own the memory.
dst->private_memory = NULL;
}
}
}
// Copy and transfer ownership from src to dst (beware of parameter order!)
void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {
if (src != NULL && dst != NULL) {
*dst = *src;
if (src->private_memory != NULL) {
src->is_external_memory = 1; // src relinquishes ownership
src->private_memory = NULL;
}
}
}
//------------------------------------------------------------------------------
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