1. 09 Feb, 2012 1 commit
  2. 08 Nov, 2011 1 commit
  3. 24 Oct, 2011 1 commit
    • Yaowu Xu's avatar
      added a last stage rounding for 8x8 inverse dct · a66c945c
      Yaowu Xu authored
      Prior to the added rounding, tests on randomly generated data showed
      that forward-inverse transform round trip errors are about 3.02/block
      for input range [-10,10] and 2.68/block for input range [-256, 255].
      The added rounding reduced the errors to 0.031/block for input range
      [-10,10] and 0.037/block for input range [-256, 255].
      
      Maximum round trip error on for any pixel position is 1.
      
      The average errors are calculated based on 100,000 blocks of randomly
      with the specified ranges.
      
      Paul mentioned in discussion that the change was not clear on why we
      need change the rounding, so Patch 2 intends to make the rationale
      obvious in code, it merged the two separate shifts into one, and the
      two separate rounding factors into one. Patch 1 and 2 have same
      numerical test results.
      
      Change-Id: Ic5e2f5463de17253084d8b2398c4a210194b20de
      a66c945c
  4. 14 Oct, 2011 1 commit
    • Yaowu Xu's avatar
      fixed the wrong rounding in inverse haar transform · 152ce6b2
      Yaowu Xu authored
      Given the current forward haar transform:
       f0 = I0 + I1 + I2 + I3
       f1 = I0 + I1 - I2 - I3
       f2 = I0 - I1 + I2 - I3
       f3 = I0 - I1 - I2 + I3
      the output of the inverse haar prior rounding:
       i0 = f0 + f1 + f2 + f3 = I0 * 4;
       i1 = f0 + f1 - f2 - f3 = I1 * 4;
       i2 = f0 - f1 + f2 - f3 = I2 * 4;
       i3 = f0 - f1 - f2 + f3 = I3 * 4;
      As all the numbers are 4 multiples, simply >>2 always produces prefect
      results in term of forward-inverse transform round trip error.
      
      Change-Id: Id6658b00ea819ee61cfeef8c5985d4cd3e77f44e
      152ce6b2
  5. 21 Jul, 2011 1 commit
    • Yaowu Xu's avatar
      fix more merge issues · 8c31484e
      Yaowu Xu authored
      With this fix, the experimental branch now builds and encodes correctly
      with the following two configure options respectively:
      --enable-experimental --enable-t8x8
      --enable-experimental
      
      Change-Id: I3147c33c503fe713a85fd371e4f1a974805778bf
      8c31484e
  6. 20 Jul, 2011 1 commit
  7. 19 Jan, 2011 1 commit
    • Yaowu Xu's avatar
      experiment extending the quantizer range · 5b42ae09
      Yaowu Xu authored
      Prior to this change, VP8 min quantizer is 4, which caps the
      highest quality around 51DB. This experimental change extends
      the min quantizer to 1, removes the cap and allows the highest
      quality to be around ~73DB, consistent with the fdct/idct round trip
      error. To test this change, at configure time use options:
      
      --enable-experimental --enable-extend_qrange
      
      The following is a brief log of changes in each of the patch sets
      
      patch set 1:
      In this commit, the quantization/dequantization constants are kept
      unchanged, instead scaling factor 4 is rolled into fdct/idct.
      Fixed Q0 encoding tests on mobile:
        Before:    9560.567kbps Overall PSNR:50.255DB VPXSSIM:98.288
        Now:   18035.774kbps Overall PSNR:73.022DB VPXSSIM:99.991
      
      patch set 2:
      regenerated dc/ac quantizer lookup tables based on the scaling
      factor rolled in the fdct/idct. Also slightly extended the range
      towards the high quantizer end.
      
      patch set 3:
      slightly tweaked the quantizer tables and generated bits_per_mb
      table based on Paul's suggestions.
      
      patch set 4:
      fix a typo in idct, re-calculated tables relating active max Q
      to active min Q
      
      patch set 5:
      added rdmult lookup table based on Q
      
      patch set 6:
      fix rdmult scale: dct coefficient has scaled up by 4
      
      patch set 7:
      make transform coefficients to be within 16bits
      
      patch set 8:
      normalize 2nd order quantizers
      
      patch set 9:
      fix mis-spellings
      
      patch set 10:
      change the configure script and macros to allow experimental code
      to be enabled at configure time with --enable-extend_qrange
      
      patch set 11:
      rebase for merge
      
      Change-Id: Ib50641ddd44aba2a52ed890222c309faa31cc59c
      5b42ae09
  8. 09 Sep, 2010 1 commit
  9. 23 Jul, 2010 1 commit
    • Jeff Muizelaar's avatar
      Combine idct and reconstruction steps · b2fa74ac
      Jeff Muizelaar authored
      This moves the prediction step before the idct and combines the idct and
      reconstruction steps into a single step. Combining them seems to give an
      overall decoder performance improvement of about 1%.
      
      Change-Id: I90d8b167ec70d79c7ba2ee484106a78b3d16e318
      b2fa74ac
  10. 18 Jun, 2010 1 commit
    • John Koleszar's avatar
      cosmetics: trim trailing whitespace · 94c52e4d
      John Koleszar authored
      When the license headers were updated, they accidentally contained
      trailing whitespace, so unfortunately we have to touch all the files
      again.
      
      Change-Id: I236c05fade06589e417179c0444cb39b09e4200d
      94c52e4d
  11. 04 Jun, 2010 1 commit
  12. 18 May, 2010 1 commit