Support for webm/mkv and VP8 inside it

We now should wait for libvpx integration
(cherry picked from commit 57fee78fbf80e640695053d016450f92eff152ee)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/demux/mkv/demux.cpp

@@ -67,7 +67,7 @@ matroska_stream_c *demux_sys_t::AnalyseAllSegmentsFound( demux_t *p_demux, EbmlS
     p_l0->Read(*p_estream, EbmlHead::ClassInfos.Context, i_upper_lvl, p_l0, true);
 
     EDocType doc_type = GetChild<EDocType>(*static_cast<EbmlHead*>(p_l0));
-    if (std::string(doc_type) != "matroska")
+    if (std::string(doc_type) != "matroska" && std::string(doc_type) != "webm" )
     {
         msg_Err( p_demux, "Not a Matroska file : DocType = %s ", std::string(doc_type).c_str());
         return NULL;

modules/demux/mkv/matroska_segment.cpp

@@ -856,6 +856,10 @@ bool matroska_segment_c::Select( mtime_t i_start_time )
         {
             tracks[i_track]->fmt.i_codec = VLC_CODEC_DIRAC;
         }
+        else if( !strncmp( tracks[i_track]->psz_codec, "V_VP8", 5 ) )
+        {
+            tracks[i_track]->fmt.i_codec = VLC_CODEC_VP8;
+        }
         else if( !strncmp( tracks[i_track]->psz_codec, "V_MPEG4", 7 ) )
         {
             if( !strcmp( tracks[i_track]->psz_codec, "V_MPEG4/MS/V3" ) )