1. 24 Apr, 2013 4 commits
    • Jingning Han's avatar
      Contextual entropy coding of partition syntax · ff2b8aa2
      Jingning Han authored
      This commit enables selecting probability models for recursive block
      partition information syntax, depending on its above/left partition
      information, as well as the current block size. These conditional
      probability models are reasonably stationary and consistent across
      frames, hence the backward adaptive approach is used to maintain and
      update the contextual models.
      
      It achieves coding performance gains (on top of enabling rectangular
      block sizes):
      derf:   0.242%
      yt:     0.391%
      hd:     0.376%
      stdhd:  0.645%
      
      Change-Id: Ie513d9673337f0d27abd65fb566b711d0844ec2e
      ff2b8aa2
    • Paul Wilkins's avatar
      Extension of segmentation to 8 segments. · 31ee193a
      Paul Wilkins authored
      Also some further simplification following removal
      of top node code.
      
      There is an issue in regards to the shared file vp8cx.h
      in regard to the roi_map as this interface assumes that
      there are only 4 segments. I have left the value here as
      4 for now meaning that the roi_map interface is broken
      for VP9.
      
      Note that this change would have been easier if I hadn't
      had to search for hard wire instances of the number 4
      and <= 3.
      
      Change-Id: Ia8b6deea4be4dbd20deb1656e689dd43a5f190e8
      31ee193a
    • Paul Wilkins's avatar
      Simplify Segment Coding · c77aff12
      Paul Wilkins authored
      Remove top node optimization.
      The improvement this gives is not sufficient to justify
      the extra complexity.
      
      Change-Id: I2bb4a12a50ffd52cacfa4a3e8acbb2e522066905
      c77aff12
    • Paul Wilkins's avatar
      Simple implicit segmentation experiment. · 27bb4777
      Paul Wilkins authored
      Change-Id: Iaef16122732c2a81e0927f9862b51b68dc788712
      27bb4777
  2. 23 Apr, 2013 1 commit
  3. 22 Apr, 2013 3 commits
    • Deb Mukherjee's avatar
      Bugfix from reordering frame probs patch · 5fa64bde
      Deb Mukherjee authored
      This fixes an intermittent mismatch issue cause by moving
      the lossless mode decoding bit to after the loop filter
      setup information. We need to ensure that the lossless bit
      is decoded prior to loop filter setup.
      
      Change-Id: I3faa3fff8e1013b7405dac91268350e059ed121e
      5fa64bde
    • Deb Mukherjee's avatar
      Removes the code_nonzerocount experiment · 0aa79be7
      Deb Mukherjee authored
      This patch does not seem to give any benefits.
      
      Change-Id: I9d2b4091d6af3dfc0875f24db86c01e2de57f8db
      0aa79be7
    • Deb Mukherjee's avatar
      End of orientation zero group experiment · 70d9f116
      Deb Mukherjee authored
      Adds an experiment that codes an end-of-orientation symbol
      for every eligible zero encountered in scan order.
      
      This cleans out various other sub-experiments that were part
      of the origiinal patch, which will be later included if found
      useful.
      
      Results are slightly positive on all sets (0.1 - 0.2% range).
      
      Change-Id: I57765c605fefc7fb9d1b57f1b356843602abefaf
      70d9f116
  4. 19 Apr, 2013 3 commits
  5. 18 Apr, 2013 2 commits
  6. 17 Apr, 2013 1 commit
    • Jingning Han's avatar
      Recursive partition syntax coding · 90a91cc6
      Jingning Han authored
      Enable recursive partition information coding from SB64X64 down to
      MB16X16. The bit-stream syntax is now supporting rectangular block
      sizes. It starts from SB64X64 and recursively describes the partition
      type of the current block. If the partition type is PARTITION_NONE,
      the block is coded as a single unit; if it is PARTITION_HORZ or
      PARTITION_VERT, the block is segmented into two independently coded
      rectangular units, with no further partition needed; otherwise, the
      block is segmented into 4 square blocks. i.e., PARTITION_SPLIT case,
      each can be potentially further partitioned.
      
      Forward adaptive probability modeling is used for the partition
      information coding, conditioned on the current block size.
      
      Change-Id: I499365fb547839d555498e3bcc0387d8a3587d87
      90a91cc6
  7. 16 Apr, 2013 4 commits
  8. 15 Apr, 2013 1 commit
    • Adrian Grange's avatar
      Initial addition of multiple ARF frames · c2876cf0
      Adrian Grange authored
      This is work-in-progress, it implements multiple ARF
      encoding behind an experimental flag.
      
      It adds the ability to insert multiple ARF frames into a
      single ARF group. This patch implements the reordering
      of the coded frames, and implements a fixed-length coding
      pattern. It applies a fixed quantizer strategy based on
      where the frame is in the coding sequence.
      
      Further work to modify the rate control strategy is
      ongoing and will be submitted via a set of future patches.
      
      In this first step, each ARF group is recursively
      bisected and an ARF frame added at that position in the
      sequence. The recursion continues until ARF frames are
      within MIN_GF_INTERVAL frames.
      
      The code sits behind the "multiple-arf" experimental
      flag ("CONFIG_MULTIPLE_ARF"). The experimental flag
      "oneshotq" ("CONFIG_ONESHOTQ") also needs to be enabled
      for this patch to work correctly.
      
      Change-Id: Ie473b05ebb43ac473c0cfb659b2b8042823085e2
      c2876cf0
  9. 12 Apr, 2013 1 commit
  10. 11 Apr, 2013 4 commits
  11. 09 Apr, 2013 1 commit
  12. 03 Apr, 2013 1 commit
  13. 28 Mar, 2013 1 commit
    • Deb Mukherjee's avatar
      Framework changes in nzc to allow more flexibility · fe9b5143
      Deb Mukherjee authored
      The patch adds the flexibility to use standard EOB based coding
      on smaller block sizes and nzc based coding on larger blocksizes.
      The tx-sizes that use nzc based coding and those that use EOB based
      coding are controlled by a function get_nzc_used().
      By default, this function uses nzc based coding for 16x16 and 32x32
      transform blocks, which seem to bridge the performance gap
      substantially.
      
      All sets are now lower by 0.5% to 0.7%, as opposed to ~1.8% before.
      
      Change-Id: I06abed3df57b52d241ea1f51b0d571c71e38fd0b
      fe9b5143
  14. 27 Mar, 2013 1 commit
  15. 26 Mar, 2013 3 commits
    • Ronald S. Bultje's avatar
      Use above/left (instead of previous in scan-order) as token context. · 790fb132
      Ronald S. Bultje authored
      Pearson correlation for above or left is significantly higher than for
      previous-in-scan-order (absolute values depend on position in scan, but
      in general, we gain about 0.1-0.2 by using either above or left; using
      both basically just makes this even better). For eob branch skipping,
      we continue to use the previous token in scan order.
      
      This helps about 0.9% on derf after re-training on a limited data set.
      Full re-training and results on larger-resolution clips are pending.
      
      Note that this commit breaks trellis, so we can probably get further
      gains out of it by fixing trellis at some later point.
      
      Change-Id: Iead68e296fc3a105cca746b5e3da9555d6010cfe
      790fb132
    • John Koleszar's avatar
      Add an in-loop deringing experiment · 441e2eab
      John Koleszar authored
      Adds a per-frame, strength adjustable, in loop deringing filter. Uses
      the existing vp9_post_proc_down_and_across 5 tap thresholded blur
      code, with a brute force search for the threshold.
      
      Results almost strictly positive on the YT HD set, either having no
      effect or helping PSNR in the range of 1-3% (overall average 0.8%).
      Results more mixed for the CIF set, (-0.5 min, 1.4 max, 0.1 avg).
      This has an almost strictly negative impact to SSIM, so examining a
      different filter or a more balanced search heuristic is in order.
      
      Other test set results pending.
      
      Change-Id: I5ca6ee8fe292dfa3f2eab7f65332423fa1710b58
      441e2eab
    • Deb Mukherjee's avatar
      Modeling default coef probs with distribution · fd18d5df
      Deb Mukherjee authored
      Replaces the default tables for single coefficient magnitudes with
      those obtained from an appropriate distribution. The EOB node
      is left unchanged. The model is represeted as a 256-size codebook
      where the index corresponds to the probability of the Zero or the
      One node. Two variations are implemented corresponding to whether
      the Zero node or the One-node is used as the peg. The main advantage
      is that the default prob tables will become considerably smaller and
      manageable. Besides there is substantially less risk of over-fitting
      for a training set.
      
      Various distributions are tried and the one that gives the best
      results is the family of Generalized Gaussian distributions with
      shape parameter 0.75. The results are within about 0.2% of fully
      trained tables for the Zero peg variant, and within 0.1% of the
      One peg variant.
      
      The forward updates are optionally (controlled by a macro)
      model-based, i.e. restricted to only convey probabilities from the
      codebook. Backward updates can also be optionally (controlled by
      another macro) model-based, but is turned off by default. Currently
      model-based forward updates work about the same as unconstrained
      updates, but there is a drop in performance with backward-updates
      being model based.
      
      The model based approach also allows the probabilities for the key
      frames to be adjusted from the defaults based on the base_qindex of
      the frame. Currently the adjustment function is a placeholder that
      adjusts the prob of EOB and Zero node from the nominal one at higher
      quality (lower qindex) or lower quality (higher qindex) ends of the
      range. The rest of the probabilities are then derived based on the
      model from the adjusted prob of zero.
      
      Change-Id: Iae050f3cbcc6d8b3f204e8dc395ae47b3b2192c9
      fd18d5df
  16. 20 Mar, 2013 1 commit
  17. 18 Mar, 2013 1 commit
    • John Koleszar's avatar
      Replace scaling byte with explicit display size · 8a3f55f2
      John Koleszar authored
      If the intended display size is different than the size the frame is
      coded at, then send that size explicitly in the bitstream. Adds a new
      bit to the frame header to indicate whether the extra size fields
      are present.
      
      Change-Id: I525c66f22d207efaf1e5f903c6a2a91b80245854
      8a3f55f2
  18. 11 Mar, 2013 1 commit
  19. 10 Mar, 2013 1 commit
    • John Koleszar's avatar
      Optimize vp9_tree_probs_from_distribution · bd84685f
      John Koleszar authored
      The previous implementation visited each node in the tree multiple times
      because it used each symbol's encoding to revisit the branches taken and
      increment its count. Instead, we can traverse the tree depth first and
      calculate the probabilities and branch counts as we walk back up. The
      complexity goes from somewhere between O(nlogn) and O(n^2) (depending on
      how balanced the tree is) to O(n).
      
      Only tested one clip (256kbps, CIF), saw 13% decoding perf improvement.
      
      Note that this optimization should port trivially to VP8 as well. In VP8,
      the decoder doesn't use this function, but it does routinely show up
      on the profile for realtime encoding.
      
      Change-Id: I4f2848e4f41dc9a7694f73f3e75034bce08d1b12
      bd84685f
  20. 09 Mar, 2013 1 commit
    • Deb Mukherjee's avatar
      Continued experiment with nonzero count · a28139c8
      Deb Mukherjee authored
      Adds probability updates for extra bits for the nzcs, code for
      getting nzc stats, plus some minor cleanups and fixes.
      
      Change-Id: If2814e7f04fb52f5025ad9f400f3e6c50a00b543
      a28139c8
  21. 07 Mar, 2013 1 commit
    • Deb Mukherjee's avatar
      Coding con-zero count rather than EOB for coeffs · eb6ef241
      Deb Mukherjee authored
      This patch revamps the entropy coding of coefficients to code first
      a non-zero count per coded block and correspondingly remove the EOB
      token from the token set.
      
      STATUS:
      Main encode/decode code achieving encode/decode sync - done.
      Forward and backward probability updates to the nzcs - done.
      Rd costing updates for nzcs - done.
      Note: The dynamic progrmaming apporach used in trellis quantization
      is not exactly compatible with nzcs. A suboptimal approach has been
      used instead where branch costs are updated to account for changes
      in the nzcs.
      
      TODO:
      Training the default probs/counts for nzcs
      
      Change-Id: I951bc1e22f47885077a7453a09b0493daa77883d
      eb6ef241
  22. 05 Mar, 2013 1 commit
    • Ronald S. Bultje's avatar
      Make superblocks independent of macroblock code and data. · 111ca421
      Ronald S. Bultje authored
      Split macroblock and superblock tokenization and detokenization
      functions and coefficient-related data structs so that the bitstream
      layout and related code of superblock coefficients looks less like it's
      a hack to fit macroblocks in superblocks.
      
      In addition, unify chroma transform size selection from luma transform
      size (i.e. always use the same size, as long as it fits the predictor);
      in practice, this means 32x32 and 64x64 superblocks using the 16x16 luma
      transform will now use the 16x16 (instead of the 8x8) chroma transform,
      and 64x64 superblocks using the 32x32 luma transform will now use the
      32x32 (instead of the 16x16) chroma transform.
      
      Lastly, add a trellis optimize function for 32x32 transform blocks.
      
      HD gains about 0.3%, STDHD about 0.15% and derf about 0.1%. There's
      a few negative points here and there that I might want to analyze
      a little closer.
      
      Change-Id: Ibad7c3ddfe1acfc52771dfc27c03e9783e054430
      111ca421
  23. 04 Mar, 2013 1 commit
    • Jingning Han's avatar
      Support 16K sequence coding · 5957b2b5
      Jingning Han authored
      Fixed a couple of variable/function definitions, as well as header
      handling to support 16K sequence coding at high bit-rates.
      
      The width and height are each specified by two bytes in the header.
      Use an extra byte to explicitly indicate the scaling factors in
      both directions, each ranging from 0 to 15.
      
      Tested coding up to 16400x16400 dimension.
      
      Change-Id: Ibc2225c6036620270f2c0cf5172d1760aaec10ec
      5957b2b5
  24. 23 Feb, 2013 1 commit