mpegenccontext: Remove unused opaque pointer

Signed-off-by: Diego Biurrun <diego@biurrun.de>
Merge commit '436ced244fadcde2c0b925627920e84b25482542'

* commit '436ced244fadcde2c0b925627920e84b25482542':
  mpegenccontext: Remove unused opaque pointer

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avformat/matroskaenc: print a warning when the relative timestamp wouldnt fit in 16bit

This is somewhat unusual so its better to use warning level than debug

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mux: keep AVPacket fields consistent in ff_write_chained()

This might have caused double frees in theory, i do not have a test case
though

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mux: support re-interleaving packets in ff_write_chained()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/segment: re-interleave packets if needed

Fixes part of Ticket 3797

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