Do not overwrite linesize set by get_buffer().
The last frame in the FATE test is not decoded anymore, since the file
is cut and a part of it is missing.
Right now those muxers use the default timebase in all cases(1/90000).
This patch avoid unnecessary rescaling and makes the printed timestamps
more readable.
Also, extend the printed information to include the timebases and packet
pts/duration and align the columns.
Obviously changes the results of all fate tests which use those two
muxers.