)]}'
{
  "commit": "6f81f128acbd780c0fc263a5f85b75a129c56348",
  "tree": "863670b9213d1378907d17a8f907f7dbebf2ed18",
  "parents": [
    "7d8b13ed2ebc2176181f32ae9b4a0e7729c585d2"
  ],
  "author": {
    "name": "Dominic Symes",
    "email": "dominic.symes@arm.com",
    "time": "Fri Feb 02 15:20:37 2018 +0100"
  },
  "committer": {
    "name": "Angie Chiang",
    "email": "angiebird@google.com",
    "time": "Fri Feb 09 18:10:38 2018 +0000"
  },
  "message": "[NORMATIVE-DECODING, txmg]: Adjust IADST4\n\nCoefficients used for the VP9 version of IADST4 satisfy the\nmathematical relation sinpi[1]+sinpi[2]\u003d\u003dsinpi[4] which is\na trigonometric property useful for optimizing the four point\ntransform. Unfortunately the change in shift used in the latest\ncode means that rounding errors are introduced so that this identity\nno longer holds. We think the identity should be restored by\nrounding 4964.563 to 4964 rather than 4965. Similarly the identity\nhas been fixed for other bit shifts in the table where it does not\nhold (even though these are not currently used I think).\n\nThis change also fixes a bug with the range checking for IADST4.\n\nWe see little change on the statistics from a local ACWY run\non objective-1-fast I-frame only:\n\n         PSNR  PSNR-HVS SSIM  PSNR-Cr APSNR APSNR-Cr MS-SSIM PSRNR-YUV\nAverage  +0.01 +0.01    -0.02 -0.15   +0.01 -0.15    +0.01   +0.01\n\nBUG\u003daomedia:1360\n\nChange-Id: Icc09a1c59929e58bbc922d4b8b73de4a14104a8e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "b61c4c22d9ca7faac4a77bb51e36be16296b5eec",
      "old_mode": 33188,
      "old_path": "av1/common/av1_inv_txfm1d.c",
      "new_id": "46cfc7342b02f394541dde1bc16da0e5e5626e4b",
      "new_mode": 33188,
      "new_path": "av1/common/av1_inv_txfm1d.c"
    },
    {
      "type": "modify",
      "old_id": "62cc43525f677fd286e2c2248cea37629c058844",
      "old_mode": 33188,
      "old_path": "av1/common/av1_txfm.h",
      "new_id": "0f9dff419e0814537ecc6c4812674642c65cacae",
      "new_mode": 33188,
      "new_path": "av1/common/av1_txfm.h"
    }
  ]
}