ff_get_plane_bytewidth().
The new implementation is more generic, more compact and more correct.
Originally committed as revision 24786 to svn://svn.ffmpeg.org/ffmpeg/trunk
the pixdescs.
The new implementation is more compact, and does not need to be
updated at each pixel format addition.
Originally committed as revision 24590 to svn://svn.ffmpeg.org/ffmpeg/trunk
max_plane_step_comp by removing the "plane_" word, and add a comment
for explaining what they represent.
Increase readability.
Originally committed as revision 24588 to svn://svn.ffmpeg.org/ffmpeg/trunk
libavcodec/imgconvert.c and make them public in libavcore/imgutils.h,
with the names av_fill_image_linesizes() and av_fill_image_pointers().
Originally committed as revision 24583 to svn://svn.ffmpeg.org/ffmpeg/trunk
