1. 31 Oct, 2012 1 commit
  2. 17 Jul, 2012 1 commit
  3. 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
  4. 22 Sep, 2011 1 commit
  5. 17 Jun, 2011 1 commit
  6. 10 Feb, 2011 1 commit
    • John Koleszar's avatar
      Fix relative include paths · 02321de0
      John Koleszar authored
      Allow compiling without adding vp8/{common,encoder,decoder} to the
      include paths.
      
      Change-Id: Ifeb5dac351cdfadcd659736f5158b315a0030b6c
      02321de0
  7. 08 Feb, 2011 1 commit
    • Johann's avatar
      clean up bilinear filter · e5aaac24
      Johann authored
      make reference version of bilinear_filters short.
      use reference versions of bilinear_filters and sub_pel_filters when
      possible.
      
      recognize that Width was being passed into
      filter_block2d_bil_first_pass multiple times. ARM version had already
      fixed this. propegate to C.
      
      change references to src_pixels_per_line to src_pitch and standardize on
      src/dst (instead of input/output).
      
      recognize that first_pass is only run in the verticle and second_pass
      only horizontal. ARM version had already fixed this. propegate to C
      
      Change-Id: I292d376d239a9a7ca37ec2bf03cc0720606983e2
      e5aaac24
  8. 28 Oct, 2010 2 commits
    • Timothy B. Terriberry's avatar
      Eliminate more warnings. · 97b766a4
      Timothy B. Terriberry authored
      This eliminates a large set of warnings exposed by the Mozilla build
       system (Use of C++ comments in ISO C90 source, commas at the end of
       enum lists, a couple incomplete initializers, and signed/unsigned
       comparisons).
      It also eliminates many (but not all) of the warnings expose by newer
       GCC versions and _FORTIFY_SOURCE (e.g., calling fread and fwrite
       without checking the return values).
      There are a few spurious warnings left on my system:
      
      ../vp8/encoder/encodemb.c:274:9: warning: 'sz' may be used
       uninitialized in this function
      gcc seems to be unable to figure out that the value shortcut doesn't
       change between the two if blocks that test it here.
      
      ../vp8/encoder/onyx_if.c:5314:5: warning: comparison of unsigned
       expression >= 0 is always true
      ../vp8/encoder/onyx_if.c:5319:5: warning: comparison of unsigned
       expression >= 0 is always true
      This is true, so far as it goes, but it's comparing against an enum,
       and the C standard does not mandate that enums be unsigned, so the
       checks can't be removed.
      
      Change-Id: Iead6cd561a2afaa3d801fd63f1d8d58953da7426
      97b766a4
    • Timothy B. Terriberry's avatar
      Eliminate more warnings. · c4d7e5e6
      Timothy B. Terriberry authored
      This eliminates a large set of warnings exposed by the Mozilla build
       system (Use of C++ comments in ISO C90 source, commas at the end of
       enum lists, a couple incomplete initializers, and signed/unsigned
       comparisons).
      It also eliminates many (but not all) of the warnings expose by newer
       GCC versions and _FORTIFY_SOURCE (e.g., calling fread and fwrite
       without checking the return values).
      There are a few spurious warnings left on my system:
      
      ../vp8/encoder/encodemb.c:274:9: warning: 'sz' may be used
       uninitialized in this function
      gcc seems to be unable to figure out that the value shortcut doesn't
       change between the two if blocks that test it here.
      
      ../vp8/encoder/onyx_if.c:5314:5: warning: comparison of unsigned
       expression >= 0 is always true
      ../vp8/encoder/onyx_if.c:5319:5: warning: comparison of unsigned
       expression >= 0 is always true
      This is true, so far as it goes, but it's comparing against an enum, and the C
       standard does not mandate that enums be unsigned, so the checks can't be
       removed.
      
      Change-Id: Iaf689ae3e3d0ddc5ade00faa474debe73b8d3395
      c4d7e5e6
  9. 28 Sep, 2010 1 commit
    • Timothy B. Terriberry's avatar
      Add 4-tap version of 2nd-pass ARMv6 MC filter. · 18dc92fd
      Timothy B. Terriberry authored
      The existing code applied a 6-tap filter with 0's on either end.
      We're already paying the branch penalty to avoid computing the two
       extra columns needed as input to this filter.
      We might as well save time computing the filter as well.
      This reduces the inner loop from 21 instructions to 16, the number
       of loads per iteration from 4 to 1, and the number of multiplies
       from 7 to 4.
      The gain in overall decoding performance, however, is small (less
       than 1%).
      
      This change also means we now valgrind clean on ARMv6, which is
       its real purpose.
      The errors reported here were valgrind's fault (it does not detect
       that 0 times an uninitialized value is initialized), but Julian
       Seward says it would slow down valgrind considerably to make such
       checks.
      Speeding up libvpx rather, even by a small amount, seems a much
       better idea if only to enable proper valgrind checking of the
       rest of the codec.
      
      Change-Id: Ifb376ea195e086b60f61daf1097d8910c4d8ff16
      18dc92fd
  10. 09 Sep, 2010 1 commit
  11. 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
  12. 04 Jun, 2010 1 commit
  13. 18 May, 2010 1 commit