US 12,273,533 B2
Video stream adaptive filtering for bitrate reduction
Mohammad Izadi, San Jose, CA (US); and Balineedu Adsumilli, Foster City, CA (US)
Assigned to GOOGLE LLC, Mountain View, CA (US)
Appl. No. 17/416,235
Filed by Google LLC, Mountain View, CA (US)
PCT Filed Apr. 25, 2019, PCT No. PCT/US2019/029088
§ 371(c)(1), (2) Date Jun. 18, 2021,
PCT Pub. No. WO2020/139414, PCT Pub. Date Jul. 2, 2020.
Claims priority of provisional application 62/784,626, filed on Dec. 24, 2018.
Prior Publication US 2022/0078446 A1, Mar. 10, 2022
Int. Cl. H04N 19/147 (2014.01); H04N 19/105 (2014.01); H04N 19/117 (2014.01); H04N 19/176 (2014.01); H04N 19/82 (2014.01)
CPC H04N 19/147 (2014.11) [H04N 19/105 (2014.11); H04N 19/117 (2014.11); H04N 19/176 (2014.11); H04N 19/82 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A method for encoding an unfiltered input video stream to an output bitstream, the method comprising:
encoding a first copy of the unfiltered input video stream to a reference bitstream;
comparing the unfiltered input video stream and the reference bitstream to determine a first distortion value and a first bitrate for the reference bitstream;
for each candidate filter of a number of candidate filters:
applying the candidate filter to each frame of a second copy of the unfiltered input video stream to produce a filtered input video stream;
encoding the filtered input video stream to a candidate bitstream;
comparing the unfiltered input video stream and the candidate bitstream to determine a second distortion value and a second bitrate for the candidate bitstream; and
determining a cost value for the candidate filter based on a difference between the first distortion value and the second distortion value and based on a difference between the first bitrate and the second bitrate;
selecting, as the output bitstream, the candidate bitstream corresponding to the candidate filter with a lowest one of the cost values; and
outputting or storing the output bitstream.