Matroska : Set default compression type for the ContentCompAlgo element to 0...

Matroska : Set default compression type for the ContentCompAlgo element to 0 (indicating zlib). Some muxers (for example mkvmerge v4.0.0) do not write ebml elements which correspond to the default values (as defined in the spec).
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/demux/mkv/matroska_segment_parse.cpp

@@ -395,6 +395,8 @@ void matroska_segment_c::ParseTrackEntry( KaxTrackEntry *m )
                         {
                             EbmlMaster *compr = static_cast<EbmlMaster*>(l3);
                             MkvTree( sys.demuxer, 5, "Content Compression" );
+                            //Default compression type is 0 (Zlib)
+                            tk->i_compression_type = MATROSKA_COMPRESSION_ZLIB;
                             for( size_t n = 0; n < compr->ListSize(); n++ )
                             {
                                 EbmlElement *l4 = (*compr)[n];