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{
  "commit": "5b42ae09aeecedfdff1dae9d59be9fbb2aba3392",
  "tree": "7e6bb870fbb3130fc8a45c953d755cd0f42396e5",
  "parents": [
    "ae4db164e5ece4ffdf8d2f460940244763e5052d"
  ],
  "author": {
    "name": "Yaowu Xu",
    "email": "yaowu@google.com",
    "time": "Wed Dec 01 15:50:14 2010 -0800"
  },
  "committer": {
    "name": "Yaowu Xu",
    "email": "yaowu@google.com",
    "time": "Wed Jan 19 13:22:35 2011 -0800"
  },
  "message": "experiment extending the quantizer range\n\nPrior to this change, VP8 min quantizer is 4, which caps the\nhighest quality around 51DB. This experimental change extends\nthe min quantizer to 1, removes the cap and allows the highest\nquality to be around ~73DB, consistent with the fdct/idct round trip\nerror. To test this change, at configure time use options:\n\n--enable-experimental --enable-extend_qrange\n\nThe following is a brief log of changes in each of the patch sets\n\npatch set 1:\nIn this commit, the quantization/dequantization constants are kept\nunchanged, instead scaling factor 4 is rolled into fdct/idct.\nFixed Q0 encoding tests on mobile:\n  Before:    9560.567kbps Overall PSNR:50.255DB VPXSSIM:98.288\n  Now:   18035.774kbps Overall PSNR:73.022DB VPXSSIM:99.991\n\npatch set 2:\nregenerated dc/ac quantizer lookup tables based on the scaling\nfactor rolled in the fdct/idct. Also slightly extended the range\ntowards the high quantizer end.\n\npatch set 3:\nslightly tweaked the quantizer tables and generated bits_per_mb\ntable based on Paul\u0027s suggestions.\n\npatch set 4:\nfix a typo in idct, re-calculated tables relating active max Q\nto active min Q\n\npatch set 5:\nadded rdmult lookup table based on Q\n\npatch set 6:\nfix rdmult scale: dct coefficient has scaled up by 4\n\npatch set 7:\nmake transform coefficients to be within 16bits\n\npatch set 8:\nnormalize 2nd order quantizers\n\npatch set 9:\nfix mis-spellings\n\npatch set 10:\nchange the configure script and macros to allow experimental code\nto be enabled at configure time with --enable-extend_qrange\n\npatch set 11:\nrebase for merge\n\nChange-Id: Ib50641ddd44aba2a52ed890222c309faa31cc59c\n",
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