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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 "src/dec/vp8i_dec.h"
#include "src/dec/webpi_dec.h"
#include "src/utils/utils.h"
//------------------------------------------------------------------------------
// WebPDecBuffer
// Number of bytes per pixel for the different color-spaces.
static const uint8_t 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);
}
// strictly speaking, the very last (or first, if flipped) row
// doesn't require padding.
#define MIN_BUFFER_SIZE(WIDTH, HEIGHT, STRIDE) \
((uint64_t)(STRIDE) * ((HEIGHT) - 1) + (WIDTH))
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 int uv_width = (width + 1) / 2;
const int uv_height = (height + 1) / 2;
const int y_stride = abs(buf->y_stride);
const int u_stride = abs(buf->u_stride);
const int v_stride = abs(buf->v_stride);
const int a_stride = abs(buf->a_stride);
const uint64_t y_size = MIN_BUFFER_SIZE(width, height, y_stride);
const uint64_t u_size = MIN_BUFFER_SIZE(uv_width, uv_height, u_stride);
const uint64_t v_size = MIN_BUFFER_SIZE(uv_width, uv_height, v_stride);
const uint64_t a_size = MIN_BUFFER_SIZE(width, height, a_stride);
ok &= (y_size <= buf->y_size);
ok &= (u_size <= buf->u_size);
ok &= (v_size <= buf->v_size);
ok &= (y_stride >= width);
ok &= (u_stride >= uv_width);
ok &= (v_stride >= uv_width);
ok &= (buf->y != NULL);
ok &= (buf->u != NULL);
ok &= (buf->v != NULL);
if (mode == MODE_YUVA) {
ok &= (a_stride >= width);
ok &= (a_size <= buf->a_size);
ok &= (buf->a != NULL);
}
} else { // RGB checks
const WebPRGBABuffer* const buf = &buffer->u.RGBA;
const int stride = abs(buf->stride);
const uint64_t size =
MIN_BUFFER_SIZE((uint64_t)width * kModeBpp[mode], height, stride);
ok &= (size <= buf->size);
ok &= (stride >= width * kModeBpp[mode]);
ok &= (buf->rgba != NULL);
}
return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
}
#undef MIN_BUFFER_SIZE
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 <= 0 && 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.
int stride;
uint64_t size;
if ((uint64_t)w * kModeBpp[mode] >= (1ull << 31)) {
return VP8_STATUS_INVALID_PARAM;
}
stride = w * kModeBpp[mode];
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;
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 WebPFlipBuffer(WebPDecBuffer* const buffer) {
if (buffer == NULL) {
return VP8_STATUS_INVALID_PARAM;
}
if (WebPIsRGBMode(buffer->colorspace)) {
WebPRGBABuffer* const buf = &buffer->u.RGBA;
buf->rgba += (int64_t)(buffer->height - 1) * buf->stride;
buf->stride = -buf->stride;
} else {
WebPYUVABuffer* const buf = &buffer->u.YUVA;
const int64_t H = buffer->height;
buf->y += (H - 1) * buf->y_stride;
buf->y_stride = -buf->y_stride;
buf->u += ((H - 1) >> 1) * buf->u_stride;
buf->u_stride = -buf->u_stride;
buf->v += ((H - 1) >> 1) * buf->v_stride;
buf->v_stride = -buf->v_stride;
if (buf->a != NULL) {
buf->a += (H - 1) * buf->a_stride;
buf->a_stride = -buf->a_stride;
}
}
return VP8_STATUS_OK;
}
VP8StatusCode WebPAllocateDecBuffer(int width, int height,
const WebPDecoderOptions* const options,
WebPDecBuffer* const buffer) {
VP8StatusCode status;
if (buffer == NULL || width <= 0 || height <= 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 (!WebPCheckCropDimensions(width, height, x, y, cw, ch)) {
return VP8_STATUS_INVALID_PARAM; // out of frame boundary.
}
width = cw;
height = ch;
}
if (options->use_scaling) {
#if !defined(WEBP_REDUCE_SIZE)
int scaled_width = options->scaled_width;
int scaled_height = options->scaled_height;
if (!WebPRescalerGetScaledDimensions(
width, height, &scaled_width, &scaled_height)) {
return VP8_STATUS_INVALID_PARAM;
}
width = scaled_width;
height = scaled_height;
#else
return VP8_STATUS_INVALID_PARAM; // rescaling not supported
#endif
}
}
buffer->width = width;
buffer->height = height;
// Then, allocate buffer for real.
status = AllocateBuffer(buffer);
if (status != VP8_STATUS_OK) return status;
// Use the stride trick if vertical flip is needed.
if (options != NULL && options->flip) {
status = WebPFlipBuffer(buffer);
}
return status;
}
//------------------------------------------------------------------------------
// 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 <= 0) {
WebPSafeFree(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;
}
}
}
VP8StatusCode WebPCopyDecBufferPixels(const WebPDecBuffer* const src_buf,
WebPDecBuffer* const dst_buf) {
assert(src_buf != NULL && dst_buf != NULL);
assert(src_buf->colorspace == dst_buf->colorspace);
dst_buf->width = src_buf->width;
dst_buf->height = src_buf->height;
if (CheckDecBuffer(dst_buf) != VP8_STATUS_OK) {
return VP8_STATUS_INVALID_PARAM;
}
if (WebPIsRGBMode(src_buf->colorspace)) {
const WebPRGBABuffer* const src = &src_buf->u.RGBA;
const WebPRGBABuffer* const dst = &dst_buf->u.RGBA;
WebPCopyPlane(src->rgba, src->stride, dst->rgba, dst->stride,
src_buf->width * kModeBpp[src_buf->colorspace],
src_buf->height);
} else {
const WebPYUVABuffer* const src = &src_buf->u.YUVA;
const WebPYUVABuffer* const dst = &dst_buf->u.YUVA;
WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride,
src_buf->width, src_buf->height);
WebPCopyPlane(src->u, src->u_stride, dst->u, dst->u_stride,
(src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
WebPCopyPlane(src->v, src->v_stride, dst->v, dst->v_stride,
(src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
if (WebPIsAlphaMode(src_buf->colorspace)) {
WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride,
src_buf->width, src_buf->height);
}
}
return VP8_STATUS_OK;
}
int WebPAvoidSlowMemory(const WebPDecBuffer* const output,
const WebPBitstreamFeatures* const features) {
assert(output != NULL);
return (output->is_external_memory >= 2) &&
WebPIsPremultipliedMode(output->colorspace) &&
(features != NULL && features->has_alpha);
}
//------------------------------------------------------------------------------