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Diffstat (limited to 'media/libwebp/dec/buffer_dec.c')
| -rw-r--r-- | media/libwebp/dec/buffer_dec.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/media/libwebp/dec/buffer_dec.c b/media/libwebp/dec/buffer_dec.c new file mode 100644 index 000000000..c685fd564 --- /dev/null +++ b/media/libwebp/dec/buffer_dec.c @@ -0,0 +1,300 @@ +// 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_dec.h" +#include "./webpi_dec.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); +} + +// 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(width, 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. + 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 WebPFlipBuffer(WebPDecBuffer* const buffer) { + if (buffer == NULL) { + return VP8_STATUS_INVALID_PARAM; + } + if (WebPIsRGBMode(buffer->colorspace)) { + WebPRGBABuffer* const buf = &buffer->u.RGBA; + buf->rgba += (buffer->height - 1) * buf->stride; + buf->stride = -buf->stride; + } else { + WebPYUVABuffer* const buf = &buffer->u.YUVA; + const int 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 w, int h, + const WebPDecoderOptions* const options, + WebPDecBuffer* const out) { + VP8StatusCode status; + 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) { + int scaled_width = options->scaled_width; + int scaled_height = options->scaled_height; + if (!WebPRescalerGetScaledDimensions( + w, h, &scaled_width, &scaled_height)) { + return VP8_STATUS_INVALID_PARAM; + } + w = scaled_width; + h = scaled_height; + } + } + out->width = w; + out->height = h; + + // Then, allocate buffer for real. + status = AllocateBuffer(out); + if (status != VP8_STATUS_OK) return status; + + // Use the stride trick if vertical flip is needed. + if (options != NULL && options->flip) { + status = WebPFlipBuffer(out); + } + 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); +} + +//------------------------------------------------------------------------------ |