Extract BD-Rate per clip using the BD-Rate

[vibhoothi]

Things to do

• Make as a main function and have the arg parser comments inside, so we can call bd-rate standalone
• Passing clip name for computing BD-Rate

[vibhoothi]

If we isolate the main function and import bdrate from the bd_rate_report.py
and run
bdrate('/home/mindfreeze/awcy/runs/av1-test-vimeo-single-acbr-s8-2021-06-17_122019-4fb45ab04/vimeo-corpus-10s-single/ffmpeg.y4m-daala.out', '/home/mindfreeze/awcy/runs/av1-directopt-vimeo-single-acbr-s9-1.3-2021-06-19_154934-4fb45ab04/vimeo-corpus-10s-single/ffmpeg.y4m-daala.out', None, True)
We do get the metrics