third_party/libwebp/dec/buffer.c

   1 // Copyright 2011 Google Inc. All Rights Reserved.
   2 //
   3 // Use of this source code is governed by a BSD-style license
   4 // that can be found in the COPYING file in the root of the source
   5 // tree. An additional intellectual property rights grant can be found
   6 // in the file PATENTS. All contributing project authors may
   7 // be found in the AUTHORS file in the root of the source tree.
   8 // -----------------------------------------------------------------------------
   9 //
  10 // Everything about WebPDecBuffer
  11 //
  12 // Author: Skal (pascal.massimino@gmail.com)
  13
  14 #include <stdlib.h>
  15
  16 #include "./vp8i.h"
  17 #include "./webpi.h"
  18 #include "../utils/utils.h"
  19
  20 //------------------------------------------------------------------------------
  21 // WebPDecBuffer
  22
  23 // Number of bytes per pixel for the different color-spaces.
  24 static const int kModeBpp[MODE_LAST] = {
  25   3, 4, 3, 4, 4, 2, 2,
  26   4, 4, 4, 2,    // pre-multiplied modes
  27   1, 1 };
  28
  29 // Check that webp_csp_mode is within the bounds of WEBP_CSP_MODE.
  30 // Convert to an integer to handle both the unsigned/signed enum cases
  31 // without the need for casting to remove type limit warnings.
  32 static int IsValidColorspace(int webp_csp_mode) {
  33   return (webp_csp_mode >= MODE_RGB && webp_csp_mode < MODE_LAST);
  34 }
  35
  36 static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) {
  37   int ok = 1;
  38   const WEBP_CSP_MODE mode = buffer->colorspace;
  39   const int width = buffer->width;
  40   const int height = buffer->height;
  41   if (!IsValidColorspace(mode)) {
  42     ok = 0;
  43   } else if (!WebPIsRGBMode(mode)) {   // YUV checks
  44     const WebPYUVABuffer* const buf = &buffer->u.YUVA;
  45     const uint64_t y_size = (uint64_t)buf->y_stride * height;
  46     const uint64_t u_size = (uint64_t)buf->u_stride * ((height + 1) / 2);
  47     const uint64_t v_size = (uint64_t)buf->v_stride * ((height + 1) / 2);
  48     const uint64_t a_size = (uint64_t)buf->a_stride * height;
  49     ok &= (y_size <= buf->y_size);
  50     ok &= (u_size <= buf->u_size);
  51     ok &= (v_size <= buf->v_size);
  52     ok &= (buf->y_stride >= width);
  53     ok &= (buf->u_stride >= (width + 1) / 2);
  54     ok &= (buf->v_stride >= (width + 1) / 2);
  55     ok &= (buf->y != NULL);
  56     ok &= (buf->u != NULL);
  57     ok &= (buf->v != NULL);
  58     if (mode == MODE_YUVA) {
  59       ok &= (buf->a_stride >= width);
  60       ok &= (a_size <= buf->a_size);
  61       ok &= (buf->a != NULL);
  62     }
  63   } else {    // RGB checks
  64     const WebPRGBABuffer* const buf = &buffer->u.RGBA;
  65     const uint64_t size = (uint64_t)buf->stride * height;
  66     ok &= (size <= buf->size);
  67     ok &= (buf->stride >= width * kModeBpp[mode]);
  68     ok &= (buf->rgba != NULL);
  69   }
  70   return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
  71 }
  72
  73 static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
  74   const int w = buffer->width;
  75   const int h = buffer->height;
  76   const WEBP_CSP_MODE mode = buffer->colorspace;
  77
  78   if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {
  79     return VP8_STATUS_INVALID_PARAM;
  80   }
  81
  82   if (!buffer->is_external_memory && buffer->private_memory == NULL) {
  83     uint8_t* output;
  84     int uv_stride = 0, a_stride = 0;
  85     uint64_t uv_size = 0, a_size = 0, total_size;
  86     // We need memory and it hasn't been allocated yet.
  87     // => initialize output buffer, now that dimensions are known.
  88     const int stride = w * kModeBpp[mode];
  89     const uint64_t size = (uint64_t)stride * h;
  90
  91     if (!WebPIsRGBMode(mode)) {
  92       uv_stride = (w + 1) / 2;
  93       uv_size = (uint64_t)uv_stride * ((h + 1) / 2);
  94       if (mode == MODE_YUVA) {
  95         a_stride = w;
  96         a_size = (uint64_t)a_stride * h;
  97       }
  98     }
  99     total_size = size + 2 * uv_size + a_size;
 100
 101     // Security/sanity checks
 102     output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
 103     if (output == NULL) {
 104       return VP8_STATUS_OUT_OF_MEMORY;
 105     }
 106     buffer->private_memory = output;
 107
 108     if (!WebPIsRGBMode(mode)) {   // YUVA initialization
 109       WebPYUVABuffer* const buf = &buffer->u.YUVA;
 110       buf->y = output;
 111       buf->y_stride = stride;
 112       buf->y_size = (size_t)size;
 113       buf->u = output + size;
 114       buf->u_stride = uv_stride;
 115       buf->u_size = (size_t)uv_size;
 116       buf->v = output + size + uv_size;
 117       buf->v_stride = uv_stride;
 118       buf->v_size = (size_t)uv_size;
 119       if (mode == MODE_YUVA) {
 120         buf->a = output + size + 2 * uv_size;
 121       }
 122       buf->a_size = (size_t)a_size;
 123       buf->a_stride = a_stride;
 124     } else {  // RGBA initialization
 125       WebPRGBABuffer* const buf = &buffer->u.RGBA;
 126       buf->rgba = output;
 127       buf->stride = stride;
 128       buf->size = (size_t)size;
 129     }
 130   }
 131   return CheckDecBuffer(buffer);
 132 }
 133
 134 VP8StatusCode WebPAllocateDecBuffer(int w, int h,
 135                                     const WebPDecoderOptions* const options,
 136                                     WebPDecBuffer* const out) {
 137   if (out == NULL || w <= 0 || h <= 0) {
 138     return VP8_STATUS_INVALID_PARAM;
 139   }
 140   if (options != NULL) {    // First, apply options if there is any.
 141     if (options->use_cropping) {
 142       const int cw = options->crop_width;
 143       const int ch = options->crop_height;
 144       const int x = options->crop_left & ~1;
 145       const int y = options->crop_top & ~1;
 146       if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || x + cw > w || y + ch > h) {
 147         return VP8_STATUS_INVALID_PARAM;   // out of frame boundary.
 148       }
 149       w = cw;
 150       h = ch;
 151     }
 152     if (options->use_scaling) {
 153       if (options->scaled_width <= 0 || options->scaled_height <= 0) {
 154         return VP8_STATUS_INVALID_PARAM;
 155       }
 156       w = options->scaled_width;
 157       h = options->scaled_height;
 158     }
 159   }
 160   out->width = w;
 161   out->height = h;
 162
 163   // Then, allocate buffer for real
 164   return AllocateBuffer(out);
 165 }
 166
 167 //------------------------------------------------------------------------------
 168 // constructors / destructors
 169
 170 int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {
 171   if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
 172     return 0;  // version mismatch
 173   }
 174   if (buffer == NULL) return 0;
 175   memset(buffer, 0, sizeof(*buffer));
 176   return 1;
 177 }
 178
 179 void WebPFreeDecBuffer(WebPDecBuffer* buffer) {
 180   if (buffer != NULL) {
 181     if (!buffer->is_external_memory)
 182       free(buffer->private_memory);
 183     buffer->private_memory = NULL;
 184   }
 185 }
 186
 187 void WebPCopyDecBuffer(const WebPDecBuffer* const src,
 188                        WebPDecBuffer* const dst) {
 189   if (src != NULL && dst != NULL) {
 190     *dst = *src;
 191     if (src->private_memory != NULL) {
 192       dst->is_external_memory = 1;   // dst buffer doesn't own the memory.
 193       dst->private_memory = NULL;
 194     }
 195   }
 196 }
 197
 198 // Copy and transfer ownership from src to dst (beware of parameter order!)
 199 void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {
 200   if (src != NULL && dst != NULL) {
 201     *dst = *src;
 202     if (src->private_memory != NULL) {
 203       src->is_external_memory = 1;   // src relinquishes ownership
 204       src->private_memory = NULL;
 205     }
 206   }
 207 }
 208
 209 //------------------------------------------------------------------------------
 210