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Diffstat (limited to 'third_party/libwebp/dec/buffer.c')
| -rw-r--r-- | third_party/libwebp/dec/buffer.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/third_party/libwebp/dec/buffer.c b/third_party/libwebp/dec/buffer.c new file mode 100644 index 0000000..5de5e6f --- /dev/null +++ b/third_party/libwebp/dec/buffer.c @@ -0,0 +1,198 @@ +// Copyright 2011 Google Inc. +// +// This code is licensed under the same terms as WebM: +// Software License Agreement: http://www.webmproject.org/license/software/ +// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ +// ----------------------------------------------------------------------------- +// +// Everything about WebPDecBuffer +// +// Author: Skal (pascal.massimino@gmail.com) + +#include <stdlib.h> +#include "vp8i.h" +#include "webpi.h" + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +//------------------------------------------------------------------------------ +// WebPDecBuffer + +// Number of bytes per pixel for the different color-spaces. +static const int kModeBpp[MODE_LAST] = { 3, 4, 3, 4, 4, 2, 2, 1, 1 }; + +static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) { + int ok = 1; + WEBP_CSP_MODE mode = buffer->colorspace; + const int width = buffer->width; + const int height = buffer->height; + if (mode >= MODE_YUV) { // YUV checks + const WebPYUVABuffer* const buf = &buffer->u.YUVA; + const int size = buf->y_stride * height; + const int u_size = buf->u_stride * ((height + 1) / 2); + const int v_size = buf->v_stride * ((height + 1) / 2); + const int a_size = buf->a_stride * height; + ok &= (size <= buf->y_size); + ok &= (u_size <= buf->u_size); + ok &= (v_size <= buf->v_size); + ok &= (a_size <= buf->a_size); + ok &= (buf->y_stride >= width); + ok &= (buf->u_stride >= (width + 1) / 2); + ok &= (buf->v_stride >= (width + 1) / 2); + if (buf->a) { + ok &= (buf->a_stride >= width); + } + } else { // RGB checks + const WebPRGBABuffer* const buf = &buffer->u.RGBA; + ok &= (buf->stride * height <= buf->size); + ok &= (buf->stride >= width * kModeBpp[mode]); + } + 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; + + if (w <= 0 || h <= 0) { + return VP8_STATUS_INVALID_PARAM; + } + + if (!buffer->is_external_memory && buffer->private_memory == NULL) { + uint8_t* output; + WEBP_CSP_MODE mode = buffer->colorspace; + int stride; + int uv_stride = 0, a_stride = 0; + int uv_size = 0; + uint64_t size, a_size = 0, total_size; + // We need memory and it hasn't been allocated yet. + // => initialize output buffer, now that dimensions are known. + stride = w * kModeBpp[mode]; + size = (uint64_t)stride * h; + + if (mode >= MODE_YUV) { + 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 + if (((size_t)total_size != total_size) || (total_size >= (1ULL << 40))) { + return VP8_STATUS_INVALID_PARAM; + } + + buffer->private_memory = output = (uint8_t*)malloc((size_t)total_size); + if (output == NULL) { + return VP8_STATUS_OUT_OF_MEMORY; + } + + if (mode >= MODE_YUV) { // YUVA initialization + WebPYUVABuffer* const buf = &buffer->u.YUVA; + buf->y = output; + buf->y_stride = stride; + buf->y_size = size; + buf->u = output + size; + buf->u_stride = uv_stride; + buf->u_size = uv_size; + buf->v = output + size + uv_size; + buf->v_stride = uv_stride; + buf->v_size = uv_size; + if (mode == MODE_YUVA) { + buf->a = output + size + 2 * uv_size; + } + buf->a_size = 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; + } + } + 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* const buffer, int version) { + if (version != WEBP_DECODER_ABI_VERSION) return 0; // version mismatch + if (!buffer) return 0; + memset(buffer, 0, sizeof(*buffer)); + return 1; +} + +void WebPFreeDecBuffer(WebPDecBuffer* const buffer) { + if (buffer) { + if (!buffer->is_external_memory) + free(buffer->private_memory); + buffer->private_memory = NULL; + } +} + +void WebPCopyDecBuffer(const WebPDecBuffer* const src, + WebPDecBuffer* const dst) { + if (src && dst) { + *dst = *src; + if (src->private_memory) { + 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 && dst) { + *dst = *src; + if (src->private_memory) { + src->is_external_memory = 1; // src relinquishes ownership + src->private_memory = NULL; + } + } +} + +//------------------------------------------------------------------------------ + +#if defined(__cplusplus) || defined(c_plusplus) +} // extern "C" +#endif |