avcodec/vp9: use av_freep() for above_partition_ctx

Fixes use after free if memory allocation fails.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avformat/vqf: check a few more bits in probe

Fixes probetest failure
The threshold is choosen so that a all printale ascii string will never be
detected as vqf

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
vorbis: handle special packets in the middle of a stream

This allows for updating metadata from new metadata packets in the
middle of a stream (e.g., MPD streams). There still needs to be a signal
that there *is* new metadata, but this is at least gets the data into a
data structure.

Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>