1. 15 Oct, 2012 4 commits
  2. 14 Oct, 2012 3 commits
  3. 11 Oct, 2012 1 commit
  4. 27 Sep, 2012 1 commit
    • Deb Mukherjee's avatar
      Entropy coding for hybrid transform · 3f5d60b3
      Deb Mukherjee authored
      Separates the entropy coding context models for 4x4, 8x8 and 16x16
      ADST variants.
      
      There is a small improvement for HD (hd/std-hd) by about 0.1-0.2%.
      Results on derf/yt are about the same, probably because there is not
      enough statistics.
      
      Results may improve somewhat once the initial probability tables are
      updated for the hybrid transforms which is coming soon.
      
      Change-Id: Ic7c0c62dacc68ef551054fdb575be8b8507d32a8
      3f5d60b3
  5. 30 Aug, 2012 1 commit
    • Jingning Han's avatar
      hybrid transform of 16x16 dimension · de6dfa6b
      Jingning Han authored
      Enable ADST/DCT of dimension 16x16 for I16X16 modes. This change provides
      benefits mostly for hd sequences.
      
      Set up the framework for selectable transform dimension.
      
      Also allowing quantization parameter threshold to control the use
      of hybrid transform (This is currently disabled by setting threshold
      always above the quantization parameter. Adaptive thresholding can
      be built upon this, which will further improve the coding performance.)
      
      The coding performance gains (with respect to the codec that has all
      other configuration settings turned on) are
      
      derf:   0.013
      yt:     0.086
      hd:     0.198
      std-hd: 0.501
      
      Change-Id: Ibb4263a61fc74e0b3c345f54d73e8c73552bf926
      de6dfa6b
  6. 21 Aug, 2012 1 commit
  7. 20 Aug, 2012 1 commit
    • Ronald S. Bultje's avatar
      Superblock coding. · 5d4cffb3
      Ronald S. Bultje authored
      This commit adds a pick_sb_mode() function which selects the best 32x32
      superblock coding mode. Then it selects the best per-MB modes, compares
      the two and encodes that in the bitstream.
      
      The bitstream coding is rather simplistic right now. At the SB level,
      we code a bit to indicate whether this block uses SB-coding (32x32
      prediction) or MB-coding (anything else), and then we follow with the
      actual modes. This could and should be modified in the future, but is
      omitted from this commit because it will likely involve reorganizing
      much more code rather than just adding SB coding, so it's better to let
      that be judged on its own merits.
      
      Gains on derf: about even, YT/HD: +0.75%, STD/HD: +1.5%.
      
      Change-Id: Iae313a7cbd8f75b3c66d04a68b991cb096eaaba6
      5d4cffb3
  8. 16 Aug, 2012 1 commit
  9. 15 Aug, 2012 1 commit
    • Paul Wilkins's avatar
      Code clean up. · 77dc5c65
      Paul Wilkins authored
      Further cases of inconsistent naming convention.
      
      Change-Id: Id3411ecec6f01a4c889268a00f0c9fd5a92ea143
      77dc5c65
  10. 13 Aug, 2012 1 commit
  11. 10 Aug, 2012 1 commit
    • Paul Wilkins's avatar
      Code cleanup. · bd9e5ece
      Paul Wilkins authored
      Add local variable in several places to reference the MB mode
      info structure. Currently this is usually accessed in the code as
      x->e_mbd.mode_info_context->mbmi.* or in some places
      xd->mode_info_context->mbmi.*
      
      Resolved some uses of x-> for the MACROBLOCKD structure.
      
      Rebased without dependency on motion reference experiment.
      
      Change-Id: If6718276ee4f2ef131825d1524dfdb02a3793aed
      bd9e5ece
  12. 09 Aug, 2012 1 commit
  13. 06 Aug, 2012 1 commit
  14. 03 Aug, 2012 1 commit
    • Daniel Kang's avatar
      16x16 DCT blocks. · fed8a183
      Daniel Kang authored
      Set on all 16x16 intra/inter modes
      
      Features:
      - Butterfly fDCT/iDCT
      - Loop filter does not filter internal edges with 16x16
      - Optimize coefficient function
      - Update coefficient probability function
      - RD
      - Entropy stats
      - 16x16 is a config option
      
      Have not tested with experiments.
      
      hd:     2.60%
      std-hd: 2.43%
      yt:     1.32%
      derf:   0.60%
      
      Change-Id: I96fb090517c30c5da84bad4fae602c3ec0c58b1c
      fed8a183
  15. 02 Aug, 2012 1 commit
    • Ronald S. Bultje's avatar
      Make RDCOST() results 64-bit. · a4ad3809
      Ronald S. Bultje authored
      This prevents various integer overflows that several of us have been
      seeing in the past few days.
      
      Change-Id: If0020613a608e13d311b7838796c7ad53cb97255
      a4ad3809
  16. 18 Jul, 2012 1 commit
    • Yaowu Xu's avatar
      removed floating point version 8x8 fdct · d632bf8c
      Yaowu Xu authored
      the integer version has very good precision, the float version is no
      longer useful. this commit also removes the experiment option from
      configure script.
      
      Change-Id: Ibb92e63c9f5083357cdf89c559d584a7deb3353f
      d632bf8c
  17. 17 Jul, 2012 1 commit
  18. 27 Jun, 2012 1 commit
    • Adrian Grange's avatar
      Added Prediction Filter to Mode Selection · bbc926dc
      Adrian Grange authored
      Added the ability to optionally filter the prediction data
      when inter modes are selected (excludes SPLITMV, for now).
      
      The mode selection loop considers both the filtered and
      non-filtered prediction data when choosing mode. The filter
      can be turned on/off at the frame-level, or signaled for
      each MB.
      
      Change-Id: I1b783c71d95a361ab36c761b07e8a6b06bc36822
      bbc926dc
  19. 19 Jun, 2012 1 commit
  20. 15 May, 2012 1 commit
    • Yaowu Xu's avatar
      Changed to use integer 8x8 dct · b22cc559
      Yaowu Xu authored
      The commit added an integer version of 8x8 forward DCT, based on the
      orginal forward DCT from VP6. The constants, roundings, and shifts
      were adjusted to improve the accuracy. The latest patch has a very
      similar accuracy in term of round trip error against the floating
      point version.
      
      It should be noted here that the purpose of the patch is to help
      encoding speed and facilitate all other experiments. There will be
      futher review in combination with inverse DCT before finalization.
      
      configure with "--enable--int_8x8fdct" to use the integer version
      
      Change-Id: I5a4f80507429f0e07cf02a13768ec81cbfddc5bc
      b22cc559
  21. 21 Mar, 2012 1 commit
    • Paul Wilkins's avatar
      Only support improved quant · c88d335f
      Paul Wilkins authored
      Deprecate fast quant and strict_quant code.
      Small effect on quality as fast was used in first pass but the
      effect is basically neutral across the derf set.
      
      The rationale here is to reduce the number of code paths for
      now to make experimentation easier. Optimized and fast code
      options can be re-introduced later along with other  encode
      speed options.
      
      Change-Id: Ia30c5daf3dbc52e72c83b277a1d281e3c934cdad
      c88d335f
  22. 15 Mar, 2012 1 commit
    • Yaowu Xu's avatar
      WebM Experimental Codec Branch Snapshot · 6035da54
      Yaowu Xu authored
      This is a code snapshot of experimental work currently ongoing for a
      next-generation codec.
      
      The codebase has been cut down considerably from the libvpx baseline.
      For example, we are currently only supporting VBR 2-pass rate control
      and have removed most of the code relating to coding speed, threading,
      error resilience, partitions and various other features.  This is in
      part to make the codebase easier to work on and experiment with, but
      also because we want to have an open discussion about how the bitstream
      will be structured and partitioned and not have that conversation
      constrained by past work.
      
      Our basic working pattern has been to initially encapsulate experiments
      using configure options linked to #IF CONFIG_XXX statements in the
      code. Once experiments have matured and we are reasonably happy that
      they give benefit and can be merged without breaking other experiments,
      we remove the conditional compile statements and merge them in.
      
      Current changes include:
      * Temporal coding experiment for segments (though still only 4 max, it
        will likely be increased).
      * Segment feature experiment - to allow various bits of information to
        be coded at the segment level. Features tested so far include mode
        and reference frame information, limiting end of block offset and
        transform size, alongside Q and loop filter parameters, but this set
        is very fluid.
      * Support for 8x8 transform - 8x8 dct with 2nd order 2x2 haar is used
        in MBs using 16x16 prediction modes within inter frames.
      * Compound prediction (combination of signals from existing predictors
        to create a new predictor).
      * 8 tap interpolation filters and 1/8th pel motion vectors.
      * Loop filter modifications.
      * Various entropy modifications and changes to how entropy contexts and
        updates are handled.
      * Extended quantizer range matched to transform precision improvements.
      
      There are also ongoing further experiments that we hope to merge in the
      near future: For example, coding of motion and other aspects of the
      prediction signal to better support larger image formats, use of larger
      block sizes (e.g. 32x32 and up) and lossless non-transform based coding
      options (especially for key frames). It is our hope that we will be
      able to make regular updates and we will warmly welcome community
      contributions.
      
      Please be warned that, at this stage, the codebase is currently slower
      than VP8 stable branch as most new code has not been optimized, and
      even the 'C' has been deliberately written to be simple and obvious,
      not fast.
      
      The following graphs have the initial test results, numbers in the
      tables measure the compression improvement in terms of percentage. The
      build has  the following optional experiments configured:
      --enable-experimental --enable-enhanced_interp --enable-uvintra
      --enable-high_precision_mv --enable-sixteenth_subpel_uv
      
      CIF Size clips:
      http://getwebm.org/tmp/cif/
      HD size clips:
      http://getwebm.org/tmp/hd/
      (stable_20120309 represents encoding results of WebM master branch
      build as of commit#7a159071)
      
      They were encoded using the following encode parameters:
      --good --cpu-used=0 -t 0 --lag-in-frames=25 --min-q=0 --max-q=63
      --end-usage=0 --auto-alt-ref=1 -p 2 --pass=2 --kf-max-dist=9999
      --kf-min-dist=0 --drop-frame=0 --static-thresh=0 --bias-pct=50
      --minsection-pct=0 --maxsection-pct=800 --sharpness=0
      --arnr-maxframes=7 --arnr-strength=3(for HD,6 for CIF)
      --arnr-type=3
      
      Change-Id: I5c62ed09cfff5815a2bb34e7820d6a810c23183c
      6035da54
  23. 01 Mar, 2012 1 commit
  24. 16 Feb, 2012 2 commits
    • Yaowu Xu's avatar
      Reworked context conversion between 8x8 and 4x4 · b92a96d8
      Yaowu Xu authored
      The commit rationized and simplified the entropy context conversion
      betwen MB using 8x8 transform and MB using 4x4 transform. The old version
      had a number of weirdness in how 4x4 transform MB's context is used for
      8x8 blocks other than the first 8x8 within a MB.
      
      Test showed the change has a gain ~.1% for avg psnr, glb psnr and ssim on
      the limited HD set.
      
      Change-Id: I774536c416baa6845aa741f956d8a69fa40e5d47
      b92a96d8
    • Yaowu Xu's avatar
      moved scaling from dequantization to inverse transform for T8x8 · 454c7abc
      Yaowu Xu authored
      Previously, the scaling related to extended quantize range happens in
      dequantization stage, which implies the coefficients form forward
      transform are in different scale(4x) from dequantization coefficients
      This worked fine when there was not distortion computation done based
      on 8x8 transform, but it completely wracked the distortion estimation
      based on transform coefficients and dequantized transform coefficients
      introduced in commit f64725a0 for macroblocks using 8x8 transform.
      This commit fixed the issue by moving the scaling into the stage of
      inverse 8x8 transform.
      
      TODO: Test&Verify the transform/quantization pipeline accuracy.
      
      Change-Id: Iff77b36a965c2a6b247e59b9c59df93eba5d60e2
      454c7abc
  25. 10 Feb, 2012 1 commit
    • Ronald S. Bultje's avatar
      Improved coding using 8x8 transform · f64725a0
      Ronald S. Bultje authored
      In summary, this commit encompasses a series of changes in attempt to
      improve the 8x8 transform based coding to help overall compression
      quality, please refer to the detailed commit history below for what
      are the rationale underly the series of changes:
      
      a. A frame level flag to indicate if 8x8 transform is used at all.
      b. 8x8 transform is not used for key frames and small image size.
      c. On inter coded frame, macroblocks using modes B_PRED, SPLIT_MV
      and I8X8_PRED are forced to using 4x4 transform based coding, the
      rest uses 8x8 transform based coding.
      d. Encoder and decoder has the same assumption on the relationship
      between prediction modes and transform size, therefore no signaling
      is encoded in bitstream.
      e. Mode decision process now calculate the rate and distortion scores
      using their respective transforms.
      
      Overall test results:
      1. HD set
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_20120206.html
      (avg psnr: 3.09% glb psnr: 3.22%, ssim: 3.90%)
      2. Cif set:
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_t8x8_20120206.html
      (avg psnr: -0.03%, glb psnr: -0.02%, ssim: -0.04%)
      It should be noted here, as 8x8 transform coding itself is disabled
      for cif size clips, the 0.03% loss is purely from the 1 bit/frame
      flag overhead on if 8x8 transform is used or not for the frame.
      
      ---patch history for future reference---
      Patch 1:
      this commit tries to select transform size based on macroblock
      prediction mode. If the size of a prediction mode is 16x16, then
      the macroblock is forced to use 8x8 transform. If the prediction
      mode is B_PRED, SPLITMV or I8X8_PRED, then the macroblock is forced
      to use 4x4 transform. Tests on the following HD clips showed mixed
      results: (all hd clips only used first 100 frames in the test)
      
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8.html
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8_log.html
      
      while the results are mixed and overall negative, it is interesting to
      see 8x8 helped a few of the clips.
      
      Patch 2:
      this patch tries to hard-wire selection of transform size based on
      prediction modes without using segmentation to signal the transform size.
      encoder and decoder both takes the same assumption that all macroblocks
      use 8x8 transform except when prediciton mode is B_PRED, I8X8_PRED or
      SPLITMV. Test results are as follows:
      
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/cifmodebase8x8_0125.html
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdmodebased8x8_0125log.html
      
      Interestingly, by removing the overhead or coding the segmentation, the
      results on this limited HD set have turn positive on average.
      
      Patch 3:
      this patch disabled the usage of 8x8 transform on key frames, and kept the
      logic from patch 2 for inter frames only. test results on HD set turned
      decidedly positive with 8x8 transform enabled on inter frame with 16x16
      prediction modes: (avg psnr: .81% glb psnr: .82 ssim: .55%)
      
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/hdintermode8x8_0125.html
      results on cif set still negative overall
      
      Patch 4:
      continued from last patch, but now in mode decision process, the rate and
      distortion estimates are computed based on 8x8 transform results for MBs
      with modes associated with 8x8 transform. This patch also fixed a problem
      related to segment based eob coding when 8x8 transform is used. The patch
      significantly improved the results on HD clips:
      
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/hd8x8RDintermode.html
      (avg psnr: 2.70% glb psnr: 2.76% ssim: 3.34%)
      results on cif also improved, though they are still negative compared to
      baseline that uses 4x4 transform only:
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif8x8RDintermode.html
      (avg psnr: -.78% glb psnr: -.86% ssim: -.19%)
      
      Patch 5:
      This patch does 3 things:
      a. a bunch of decoder bug fixes, encodings and decodings were verified
      to have matched recon buffer on a number of encodes on cif size mobile and
      hd version of _pedestrian.
      b. the patch further improved the rate distortion calculation of MBS that
      use 8x8 transform. This provided some further gain on compression.
      c. the patch also got the experimental work SEG_LVL_EOB to work with 8x8
      transformed macroblock, test results indicates it improves the cif set
      but hurt the HD set slightly.
      
      Tests results on HD clips:
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/HD_t8x8_20120201.html
      (avg psnr: 3.19% glb psnr: 3.30% ssim: 3.93%)
      
      Test results on cif clips:
      http://www.corp.google.com/~yaowu/no_crawl/t8x8/cif_t8x8_20120201.html
      (avg psnr: -.47% glb psnr: -.51% ssim: +.28%)
      
      Patch 6:
      Added a frame level flag to indicate if 8x8 transform is allowed at all.
      temporarily the decision is based on frame size, can be optimized later
      one. This get the cif results to basically unchanged, with one bit per
      frame overhead on both cif and hd clips.
      
      Patch 8:
      Rebase and Merge to head by PGW.
      Fixed some suspect 4s that look like hey should be 64s in regard
      to segmented EOB. Perhaps #defines would be bette.
      Bulit and tested without T8x8 enabled and produces unchanged
      output.
      
      Patch 9:
      Corrected misalligned code/decode of "txfm_mode" bit.
      Limited testing for correct encode and decode with
      T8x8 configured on derf clips.
      
      Change-Id: I156e1405d25f81579d579dff8ab9af53944ec49c
      f64725a0
  26. 09 Feb, 2012 1 commit
  27. 26 Jan, 2012 1 commit
  28. 07 Dec, 2011 1 commit
    • Yaowu Xu's avatar
      Removed #if CONFIG_I8X8 · d37cd976
      Yaowu Xu authored
      This commit removed the macro CONFIG_I8X8, which was used to indicate
      the 8x8 intra prediction experiment, made the change fully merged in.
      
      Change-Id: Iafa4443781ce6e83f5591c12ba615a0e92ce0ea0
      d37cd976
  29. 02 Dec, 2011 1 commit
    • Yaowu Xu's avatar
      enabled 8x8 intra prediction modes on inter frames · a8fbab86
      Yaowu Xu authored
      This commit enabled the usage of 8x8 intra prediction modes on inter
      frames. There are a few TODO items related to this: 1)baseline entropy
      need be calibrated; 2)cost of UV need to be done more properly rather
      than using decision only relying on Y; 3)Threshold for allowing picking
      8x8 intra prediction should be lowered to lower than the B_PRED.
      
      Even with all the TODOs, tests showed consistent gain on derf set ~0.1%
      (PSNR:0.08% and SSIM:0.14%). It is assumed that 8x8 intra prediction
      will help more on large resolution clips, especially with above TODOs
      addressed.
      
      Change-Id: I398ada49dfc32575cfab962a569c2885111ae3ba
      a8fbab86
  30. 01 Dec, 2011 1 commit
    • Yaowu Xu's avatar
      added transform type to MB_MODE_INFO · bba710fc
      Yaowu Xu authored
      this commit is to add an variable in the macroblock level mode
      info structure to track the transform size used in each MB, so
      the information can be used later in the loop filter to change
      how loop filter works on MBs with different transform sizes.
      
      Change-Id: Id0eeaba6cc854c6d1be00ed8d237b3d9e250e447
      bba710fc
  31. 16 Nov, 2011 1 commit
    • Yaowu Xu's avatar
      fixed the scaling in 8x8 trellis quant · 7f33be9e
      Yaowu Xu authored
      This commit has a few minor fixes to the 8x8 trellis quant, so to
      make it work regardless if extend_qrange is enabled or not. It also
      borrowed adaptive RDMULT constants from 4x4 trellis that was missed
      in the 8x8 trellis quant.
      
      Change-Id: I60d7769071f102c699b5084597e62bca87a1f759
      7f33be9e
  32. 11 Nov, 2011 1 commit
    • Yaowu Xu's avatar
      Make 8x8 and extend_qrange to work together · 982b061d
      Yaowu Xu authored
      This commit added scaling factors to 8x8 transform, quant, dequant and
      inverse transform pipeline to make 8x8 transform to work when configed
      with enable-extend_qrange. This commit also disabled the trellis-quant
      when extend_qrange is configured.
      
      Change-Id: Icfb3192e4746f70a4bb35ad18b7b47705b657e52
      982b061d
  33. 10 Nov, 2011 1 commit
    • Yaowu Xu's avatar
      scaled the threshold for 2nd order coefficient reset · cbcba9e7
      Yaowu Xu authored
      extend_qrange introduces a different scaling factor, this commit takes
      the scaling difference into account for reset 2nd order coefficients.
      
      Change-Id: Ie58bca9f52698fa759e3f88da2aa4d82630fa91a
      cbcba9e7
  34. 09 Nov, 2011 1 commit
    • Yaowu Xu's avatar
      make debug match release build on win32 with 8x8 transform enabled · 5883246d
      Yaowu Xu authored
      The 8x8 forward transform makes use of floating operations, therefore
      requires emms call to reset mmx registers to correct state. Without
      the resets, the 8x8 forward transform results are indefinite on win32
      platform.
      
      Change-Id: Ib5b71c3213e10b8a04fe776adf885f3714e7deb1
      5883246d