doc/protocols/rtp: apply misc fixes

Partially suggested-by Burek Pekaric <burek021@gmail.com>.
doc/encoders: add libshine doc

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
avcodec/tiff: Fix use of uninitialized off variable

Fixes CID1108608

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/tiff: remove TIFF_LONG special case

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/tiff: factorize offset init code

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