ffmpeg configured with webm decode only to avoid postproc that pulls in unuse...

patches/to_upstream/11_mkv_buffer_overflow.patch

 diff -rpu -N orig/libavformat/matroskadec.c ffmpeg-mt/libavformat/matroskadec.c
---- orig/libavformat/matroskadec.c      2010-07-19 12:54:00.462379500 -0700
-+++ ffmpeg-mt/libavformat/matroskadec.c 2010-07-19 12:54:01.928779500 -0700
+--- orig/libavformat/matroskadec.c      2010-07-27 13:08:26.240398300 -0700
++++ ffmpeg-mt/libavformat/matroskadec.c 2010-07-27 13:08:27.346508900 -0700
 @@ -34,13 +34,17 @@
  /* For ff_codec_get_id(). */
  #include "riff.h"
  #include "isom.h"
 +#if CONFIG_SIPR_DECODER
  #include "rm.h"
 +#endif
  #include "matroska.h"
  #include "libavcodec/mpeg4audio.h"
  #include "libavutil/intfloat_readwrite.h"
@@ skipping 111 matching lines @@
                              memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
  
                      if (++track->audio.sub_packet_cnt >= h) {
 +#if CONFIG_SIPR_DECODER
                          if (st->codec->codec_id == CODEC_ID_SIPR)
                              ff_rm_reorder_sipr_data(track->audio.buf, h, w);
 +#endif
                          track->audio.sub_packet_cnt = 0;
                          track->audio.pkt_cnt = h*w / a;
                      }