<pre>
$ sudo # pacman -S openshot
resolving dependencies...
warning: cannot resolve "libavcodec.so=57-64", a -Syu
error: libquicktime: installing ffmpeg (1:4.0-1) breaks dependency of "libquicktime"
warning: cannot resolve "libswscale.so=4-64", a dependency of "libquicktime"
warning: cannot resolve "libquicktime", a dependency of "dvgrab"
warning: cannot resolve "dvgrab", a dependency of "openshot"
:: The following package cannot be upgraded due to unresolvable dependencies:
openshot 'libavcodec.so=57-64'"
</pre>

building libquicktime fails with:
<pre>

In file included from lqt_ffmpeg.c:32:
params.h:152:33: error: ‘FF_MAX_B_FRAMES’ undeclared here (not in a function); did you mean ‘PARAM_MAX_B_FRAMES’?
.val_max = { .val_int = FF_MAX_B_FRAMES }, \
^~~~~~~~~~~~~~~
lqt_ffmpeg.c:108:3: note: in expansion of macro ‘PARAM_MAX_B_FRAMES’
PARAM_MAX_B_FRAMES, \
^~~~~~~~~~~~~~~~~~
lqt_ffmpeg.c:196:3: note: in expansion of macro ‘ENCODE_PARAM_VIDEO_FRAMETYPES_IPB’
ENCODE_PARAM_VIDEO_FRAMETYPES_IPB,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lqt_ffmpeg.c: In function ‘ffmpeg_map_init’:
lqt_ffmpeg.c:934:3: warning: ‘avcodec_register_all’ is deprecated [-Wdeprecated-declarations]
avcodec_register_all();
^~~~~~~~~~~~~~~~~~~~
In file included from ffmpeg.h:29,
from lqt_ffmpeg.c:31:
/usr/include/libavcodec/avcodec.h:4086:6: note: declared here
void avcodec_register_all(void);
^~~~~~~~~~~~~~~~~~~~
make[3]: *** [Makefile:407: lqt_ffmpeg.lo] Error 1
make[3]: Leaving directory '/home/freemor/build/abs/libquicktime/src/libquicktime-1.2.4/plugins/ffmpeg'
make[2]: *** [Makefile:371: all-recursive] Error 1
make[2]: Leaving directory '/home/freemor/build/abs/libquicktime/src/libquicktime-1.2.4/plugins'
make[1]: *** [Makefile:444: all-recursive] Error 1
make[1]: Leaving directory '/home/freemor/build/abs/libquicktime/src/libquicktime-1.2.4'
make: *** [Makefile:351: all] Error 2
==> ERROR: A failure occurred in build().
Aborting...

</pre>