Change-Id: Ibf360fe0728e07de448e77e3841c49eb25d3ba2d

This commit compares the current original frame to the previous
original frame at 64x64 block level and decides if the entire
block belongs to background area. If it is in the background area,
skip non-RD partition search and copy the partition types of the
collocated block in the previous frame.

For vidyo1 in the rtc set, this makes the speed -5 coding speed
about 8% faster. The overall compression performance is down by
1.37% for rtc set.

Change-Id: Iccf920562fcc88f21d377fb6a44c547c8689b7ea

This commit added a check of reference frame to make sure that pre
buffer pointers are initialized only when necessary and make them
to 0 if ref frame is intra, hence those buffer should never be used.

Change-Id: Ieb474fcd9feb759f02e2f9c282b7348a8fa31117

Delete code relating to the old VP8_TUNE_SSIM flag
as this code does not currently work and is largely made
redundant in VP9 by the various AQ modes.

Change-Id: I71f28e1f680573d296422254489000678552b17b

Remove duplicate rd_thresh code introduced when vp9_rd_pick_inter_mode_sub8x8()
was forked from vp9_rd_pick_inter_mode_sb().

Change-Id: I3c9b7143d182e1f28b29c16518eaca81dc2ecfed

Fix rate control bug whereby the rate factor heuristics
were being updated on arf overlays causing a rate surge
for a few frames followed by a corrective drop.

This fix eliminates many of the overshoot problems that
we were seeing on hard clips (even without applying
stricter vbr rate control) and also helps quality on
almost all clips with some hard clips improving by >5%.

Overall quality results measured at speed 2.
Derf  +1.78% opsnr , +2.44% SSIM
Stdhd +2.41% opsnr, +2.85% SSIM

Change-Id: I2369df6295c2705963fa6307877f6acb304bcc39

Just to be consistent with min_frame_bandwidth & max_frame_bandwidth names.

Change-Id: I36702c708cba9ad1a5c36393f37758a2edeadb90

Change-Id: If6f013835b69ae61b0a0c6006fe0955303f579a5

Change-Id: I87819fed5aebb6ffe2f4d4655df226235a3d21cb

Change-Id: I988eea8f78f71135b914661420c5c75674e5c010

Fix return values for webm_read_frame so that we can distinguish between
error and end of stream. 0 - Success, 1 - End of stream, -1 error.

Change-Id: Ic35d0c7d7a166e027711a3d2300ecdda25a5d0cc

Change-Id: Ib8c1b3b0a5a5689d3261dc822a69e9d473b89be1

Change-Id: Id156af5662ebe6fbe1cab636564f5f4bedb85ab0

Change-Id: Id687aa617650a859463e7ae63dd4c0dc4f3e4779

Change-Id: I5ed360585dae2c9fea6c32058dbfb8ec07700677