lavf/avio: Introduce avio_find_protocol_name

Make it possible to find out what protocol will be chosen
for a given URL.

Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
ffmpeg_opt: assert_file_overwrite: Work for all file protocol outputs

Currently the file overwrite check does not work for paths that
contain a colon.

Use avio_find_protocol to always execute the existence check if
the file protocol is going to be used.

Fix remaining part of ticket #3249.

Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
doc/APIchanges: Update for new function avio_find_protocol_name

Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
avcodec/msrle: use av_image_get_linesize() to calculate the linesize

Fixes out of array access
Fixes: 14a74a0a2dc67ede543f0e35d834fbbe-asan_heap-oob_49572c_556_cov_215466444_44_001_engine_room.mov
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>