Merge pull request #2407 from mlavik1/issue_1957

issue 1957: ASCII FBX embedded content
assimp · Apr 8, 2019 · 189bb2a · 189bb2a
2 parents 0973f50 + 6dec134
commit 189bb2a
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Showing 3 changed files with 76 additions and 1 deletion.
diff --git a/code/FBXMaterial.cpp b/code/FBXMaterial.cpp
@@ -55,6 +55,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/ByteSwapper.h>
 
 #include <algorithm> // std::transform
+#include "FBXUtil.h"
 
 namespace Assimp {
 namespace FBX {
@@ -321,7 +322,22 @@ Video::Video(uint64_t id, const Element& element, const Document& doc, const std
             const Token& token = GetRequiredToken(*Content, 0);
             const char* data = token.begin();
             if (!token.IsBinary()) {
-                DOMWarning("video content is not binary data, ignoring", &element);
+                if (*data != '"') {
+                    DOMError("embedded content is not surrounded by quotation marks", &element);
+                }
+                else {
+                    const char* encodedData = data + 1;
+                    size_t encodedDataLen = static_cast<size_t>(token.end() - token.begin());
+                    // search for last quotation mark
+                    while (encodedDataLen > 1 && encodedData[encodedDataLen] != '"')
+                        encodedDataLen--;
+                    if (encodedDataLen % 4 != 0) {
+                        DOMError("embedded content is invalid, needs to be in base64", &element);
+                    }
+                    else {
+                        contentLength = Util::DecodeBase64(encodedData, encodedDataLen, content);
+                    }
+                }
             }
             else if (static_cast<size_t>(token.end() - data) < 5) {
                 DOMError("binary data array is too short, need five (5) bytes for type signature and element count", &element);

diff --git a/code/FBXUtil.cpp b/code/FBXUtil.cpp
@@ -49,6 +49,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <assimp/TinyFormatter.h>
 #include <string>
+#include <cstring>
 
 #ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
 
@@ -113,6 +114,49 @@ std::string AddTokenText(const std::string& prefix, const std::string& text, con
         text) );
 }
 
+static const uint8_t base64DecodeTable[128] = {
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 62,  0,  0,  0, 63,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61,  0,  0,  0, 64,  0,  0,
+    0,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,  0,  0,  0,  0,  0,
+    0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,  0,  0,  0,  0,  0
+};
+
+uint8_t DecodeBase64(char ch)
+{
+    return base64DecodeTable[size_t(ch)];
+}
+
+size_t DecodeBase64(const char* in, size_t inLength, uint8_t*& out)
+{
+    if (inLength < 4) {
+        out = 0;
+        return 0;
+    }
+
+    const size_t outLength = (inLength * 3) / 4;
+    out = new uint8_t[outLength];
+    memset(out, 0, outLength);
+
+    size_t i = 0;
+    size_t j = 0;
+    for (i = 0; i < inLength - 4; i += 4)
+    {
+        uint8_t b0 = Util::DecodeBase64(in[i]);
+        uint8_t b1 = Util::DecodeBase64(in[i + 1]);
+        uint8_t b2 = Util::DecodeBase64(in[i + 2]);
+        uint8_t b3 = Util::DecodeBase64(in[i + 3]);
+
+        out[j++] = (uint8_t)((b0 << 2) | (b1 >> 4));
+        out[j++] = (uint8_t)((b1 << 4) | (b2 >> 2));
+        out[j++] = (uint8_t)((b2 << 6) | b3);
+    }
+    return outLength;
+}
+
 } // !Util
 } // !FBX
 } // !Assimp

diff --git a/code/FBXUtil.h b/code/FBXUtil.h
@@ -48,6 +48,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "FBXCompileConfig.h"
 #include "FBXTokenizer.h"
+#include <stdint.h>
 
 namespace Assimp {
 namespace FBX {
@@ -98,6 +99,20 @@ std::string AddLineAndColumn(const std::string& prefix, const std::string& text,
  *  @return A string of the following format: {prefix} ({token-type}, line {line}, col {column}) {text}*/
 std::string AddTokenText(const std::string& prefix, const std::string& text, const Token* tok);
 
+/** Decode a single Base64-encoded character.
+*
+*  @param ch Character to decode (from base64 to binary).
+*  @return decoded byte value*/
+uint8_t DecodeBase64(char ch);
+
+/** Decode a Base64-encoded string
+*
+*  @param in Characters to decode.
+*  @param inLength Number of characters to decode.
+*  @param out Reference to pointer where we will store the decoded data.
+*  @return size of the decoded data (number of bytes)*/
+size_t DecodeBase64(const char* in, size_t inLength, uint8_t*& out);
+
 }
 }
 }