mkvparser: add support for compression elements

ContentCompression elements are now parsed.

Change-Id: I9a67ae444ed929e49c7ea223a16c13c9d16a4c13

mkvparser.cpp

@@ -5032,7 +5032,8 @@ const char* SegmentInfo::GetTitleAsUTF8() const
 // ContentEncoding element
 ContentEncoding::ContentCompression::ContentCompression()
     : algo(0),
-      settings(NULL) {
+      settings(NULL),
+      settings_len(0) {
 }
 
 ContentEncoding::ContentCompression::~ContentCompression() {
@@ -5238,7 +5239,17 @@ long ContentEncoding::ParseContentEncodingEntry(long long start,
       encoding_type_ = UnserializeUInt(pReader, pos, size);
     } else if (id == 0x1034) {
       // ContentCompression ID
-      // TODO(fgaligan): Add code to parse ContentCompression elements.
+      ContentCompression* const compression =
+        new (std::nothrow) ContentCompression();
+      if (!compression)
+        return -1;
+
+      status = ParseCompressionEntry(pos, size, pReader, compression);
+      if (status) {
+        delete compression;
+        return status;
+      }
+      *compression_entries_end_++ = compression;
     } else if (id == 0x1035) {
       // ContentEncryption ID
       ContentEncryption* const encryption =
@@ -5262,6 +5273,68 @@ long ContentEncoding::ParseContentEncodingEntry(long long start,
   return 0;
 }
 
+long ContentEncoding::ParseCompressionEntry(
+    long long start,
+    long long size,
+    IMkvReader* pReader,
+    ContentCompression* compression) {
+  assert(pReader);
+  assert(compression);
+
+  long long pos = start;
+  const long long stop = start + size;
+
+  bool valid = false;
+
+  while (pos < stop) {
+    long long id, size;
+    const long status = ParseElementHeader(pReader,
+                                           pos,
+                                           stop,
+                                           id,
+                                           size);
+    if (status < 0)  //error
+      return status;
+
+    if (id == 0x254) {
+      // ContentCompAlgo
+      long long algo = UnserializeUInt(pReader, pos, size);
+      if (algo < 0)
+        return E_FILE_FORMAT_INVALID;
+      compression->algo = algo;
+      valid = true;
+    } else if (id == 0x255) {
+      // ContentCompSettings
+      if (size <= 0)
+        return E_FILE_FORMAT_INVALID;
+
+      const size_t buflen = static_cast<size_t>(size);
+      typedef unsigned char* buf_t;
+      const buf_t buf = new (std::nothrow) unsigned char[buflen];
+      if (buf == NULL)
+        return -1;
+
+      const int read_status = pReader->Read(pos, buflen, buf);
+      if (read_status) {
+        delete [] buf;
+        return status;
+      }
+
+      compression->settings = buf;
+      compression->settings_len = buflen;
+    }
+
+    pos += size;  //consume payload
+    assert(pos <= stop);
+  }
+
+  // ContentCompAlgo is mandatory
+  if (!valid)
+    return E_FILE_FORMAT_INVALID;
+
+  return 0;
+}
+
 long ContentEncoding::ParseEncryptionEntry(
     long long start,
     long long size,

mkvparser.hpp

@@ -217,6 +217,7 @@ public:
 
         unsigned long long algo;
         unsigned char* settings;
+        long long settings_len;
     };
 
     // ContentEncAESSettings element names
@@ -253,6 +254,15 @@ public:
     // element.
     unsigned long GetCompressionCount() const;
 
+    // Parses the ContentCompression element from |pReader|. |start| is the
+    // starting offset of the ContentCompression payload. |size| is the size in
+    // bytes of the ContentCompression payload. |compression| is where the parsed
+    // values will be stored.
+    long ParseCompressionEntry(long long start,
+                               long long size,
+                               IMkvReader* pReader,
+                               ContentCompression* compression);
+
     // Returns ContentEncryption represented by |idx|. Returns NULL if |idx|
     // is out of bounds.
     const ContentEncryption* GetEncryptionByIndex(unsigned long idx) const;