Merge commit 'ab35ec29'

* commit 'ab35ec29':
  vf_overlay: get rid of pointless messing with timebase.
  samplefmt: make av_samples_alloc() initialize the data to silence.
  libspeexdec: handle NULL return value from speex_packet_to_header()
  h264probe: Don't error out on bits that no longer are reserved
  mpegvideo: set extended_data in ff_update_duplicate_context()
  libspeexdec: properly handle DTX for multiple frames-per-packet
  libspeexdec: move the SpeexHeader from LibSpeexContext to where it is used
  libspeexdec: simplify setting of frame_size
  libspeexdec: set channel_layout

Conflicts:
	libavfilter/vf_overlay.c
	libavformat/h264dec.c
	libavutil/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>