Clean up and simplification of both estimate_max_q
variants and only call once per clip/section.

This leads to a more constrained range of Q values
across a clip / section.

Average gains across all 4 test sets:-

PSNR ~0.5%  SSIM ~0.3%

Change-Id: If77d5f7bb50939a464e117724f4da5b001c62d70

For VP9, lossless coding is enabled by passing 0 for both min_q and
max_q. This is a valid configuration, and should not be warned.

Change-Id: Idd117579cd89cd14c0723b1d7e482067ac12b401

In lossless coding, distortion is always 0. Early exit based on this
metric was incorrect.

This CL also changed to use best_rd instead of distortion as the metric
for easly exit as requested by Jim.

Change-Id: I8ef3e407ac03b4abc3283b273f936a68fad5c2ab

Change-Id: I8ab9bbe2595ed1743f35223b6a6ce6d023b9a20e

Renames:
  vp9_get_pred_context_comp_inter_inter => vp9_get_reference_mode_context
  vp9_get_pred_prob_comp_inter_inter    => vp9_get_reference_mode_prob

Change-Id: I3bbb69481e6b0c848028667c9269f567f293d3bd

Change-Id: Ic3bb862e93aedf6a489a33ea6f7e5097d96855ee

Removed an adaptive rate correction factor that was having
a negative impact on quality in many clips. This factor
was influencing the Q range available to each frame
independently of the bits allocated to each.

Average results with DISABLE_RC_LONG_TERM_MEM.

derf +0.199, -0.059.
yt +3.957, +3.798
std hd +1.577, +2.140
yt hd +4.127, +4.513

Average results without  DISABLE_RC_LONG_TERM_MEM

derf -0.628, -0.665
yt +3.432, +3.015
std hd -0.105, +0.153
yt hd +3.432, +3.015

Change-Id: I45bab6b606f49a442e7b27a6d631f3ffd843bbce

3840x2160

vp90-2-08-tile_1x8_frame_parallel.webm
vp90-2-08-tile_1x8.webm

vpxenc crowd_run_2160p50.y4m \
  --codec=vp9 -p 2 \
  --frame-parallel=${fpm} \
  --tile-columns=${tc} \
  --limit=10 \
  --auto-alt-ref=1 \
  --lag-in-frames=5 \
  --target-bitrate=2500

Change-Id: I6dc19b4fca483d03ef9a897a843bf9037d095c8e

Writing custom coeff branch count calculation (which is much clearer) in
adapt_coef_probs() function. Removing vp9_treecoder.c file.

Change-Id: I8880fb7a39996c8bcf6cd0acf9898a8c712ba91f

Also adding BAND_COEFF_CONTEXTS macro to simplify for loop logic.

Change-Id: I12a78a49cf1addf81e6b3fe2a3736ec2b79bd79e

Renaming:
 vp9_get_pred_context_intra_inter => vp9_get_intra_inter_context
 vp9_get_pred_prob_intra_inter    => vp9_get_intra_inter_prob

Change-Id: I2c1affea2e84f4e616137c6df82adb11c7845781

Includes various cleanups.
Streamlines the interfaces so that all rate control state
updates happen in the vp9_rc_postencode_update() function.
This will hopefully make it easier to support multiple
rate control schemes.
Removes some unnecessary code, which in rare cases can casue
a difference in the constrained quality mode output, but
other than that there is no bitstream change yet.

Change-Id: I3198cc37249932feea1e3691c0b2650e7b0c22fc

NUM_YV12_BUFFERS        => FRAME_BUFFERS
ALLOWED_REFS_PER_FRAME  => REFS_PER_FRAME
NUM_REF_FRAMES_LOG2     => REF_FRAMES_LOG2
NUM_REF_FRAMES          => REF_FRAMES
NUM_FRAME_CONTEXTS_LOG2 => FRAME_CONTEXTS_LOG2
NUM_FRAME_CONTEXTS      => FRAME_CONTEXTS

Change-Id: I4e1ada08f25d8fa30fdf03aebe1b1c9df0f87e63

Change-Id: I299b621fca1c8ff5d296afde9698cdcccfecaf3f

Change-Id: Idfbd87d0a4bebdce7dd587c8446e7fa75b030d91

Removed calls to vp9_update_mode_info_border since
they immediately followed code that initialized the
entire buffer to 0.

Change-Id: Ife06794daa20439a0b607a83a87f88df59afac40

Change-Id: I68d6217db6f67da15380cd59ec5eda0c44da7d34

Buffer 0 would never be decremented, so it could only be used
once.

Change-Id: I605d99fa2a513eadae6a0e230161729880653282

Change-Id: Ia6ef876e3d1e66b2182a9c0bce3fd758691cd381

Change-Id: I40a070c353663e82c59e174d7c92eb84f72ed808