Support for end trimming Opus in Matroska is implemented by using
the DiscardPadding container element in the Block data. The last
chunk is stored as a Block instead of SimpleBlock and the
trimming information is stored and used to discard samples that
were padded by the Opus codec. This patch adds support for muxing
DiscardPadding element into the container with appropriate value.
Matroska spec for the DiscardPadding element can be found here:
http://matroska.org/technical/specs/index.html#DiscardPaddingSigned-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>