1 pass vbr: Allow for lookahead alt-ref in real-time mode.
For 1 pass vbr real-time mode: Allow for the usage of alt-ref frame when non-zero lag-in-frames is used. Use non-filtered alt-ref, and select usage based on fast scene/content analysis/detection within the lag of frames. Positive gains on ytlive set: overall avgPSNR ~3-4%. Several clips are up between 5-14%, a few clips are neutral/small change. Current speed decrease is about ~5-10%. Use the flag USE_ALTREF_FOR_ONE_PASS to enable this feature (off by default for now). Change-Id: I802d2bf3d44f9cf01f6d15c76be9c90192314769
Showing with 110 additions and 27 deletions