Instead of saving huge raw files, use the md5: output pseudo-protocol
to calculate the checksum of the file directly. This is especially
useful when testing on remote targets as it avoids transferring 3.6GB
over the network.
(cherry picked from commit f4b1e21a6304cda58ac36401d8f8dec7ff61d056)
The corresponding lavfi-pixfmts BE tests are not yet added, as there
are some bugs in the scaler (scaling rgba, argb, bgra, abgr, yuva420p)
which result in differences with the LE reference, and I cannot
visually check the generated files on BE.
Originally committed as revision 24657 to svn://svn.ffmpeg.org/ffmpeg/trunk