2011-08-04 v0.9.7 "Cayuga"
  Our third named release, focused on a faster, higher quality, encoder.

  - Upgrading:
    This release is backwards compatible with Aylesbury (v0.9.5) and
    Bali (v0.9.6). Users of older releases should refer to the Upgrading
    notes in this document for that release.

  - Enhancements:
          Stereo 3D format support for vpxenc
          Runtime detection of available processor cores.
          Allow specifying --end-usage by enum name
          vpxdec: test for frame corruption
          vpxenc: add quantizer histogram display
          vpxenc: add rate histogram display
          Set VPX_FRAME_IS_DROPPABLE
          update configure for ios sdk 4.3
          Avoid text relocations in ARM vp8 decoder
          Generate a vpx.pc file for pkg-config.
          New ways of passing encoded data between encoder and decoder.

  - Speed:
      This release includes across-the-board speed improvements to the
      encoder. On x86, these measure at approximately 11.5% in Best mode,
      21.5% in Good mode (speed 0), and 22.5% in Realtime mode (speed 6).
      On ARM Cortex A9 with Neon extensions, real-time encoding of video
      telephony content is 35% faster than Bali on single core and 48%
      faster on multi-core. On the NVidia Tegra2 platform, real time
      encoding is 40% faster than Bali.

      Decoder speed was not a priority for this release, but improved
      approximately 8.4% on x86.

          Reduce motion vector search on alt-ref frame.
          Encoder loopfilter running in its own thread
          Reworked loopfilter to precalculate more parameters
          SSE2/SSSE3 optimizations for build_predictors_mbuv{,_s}().
          Make hor UV predict ~2x faster (73 vs 132 cycles) using SSSE3.
          Removed redundant checks
          Reduced structure sizes
          utilize preload in ARMv6 MC/LPF/Copy routines
          ARM optimized quantization, dfct, variance, subtract
          Increase chrow row alignment to 16 bytes.
          disable trellis optimization for first pass
          Write SSSE3 sub-pixel filter function
          Improve SSE2 half-pixel filter funtions
          Add vp8_sub_pixel_variance16x8_ssse3 function
          Reduce unnecessary distortion computation
          Use diamond search to replace full search
          Preload reference area in sub-pixel motion search (real-time mode)

  - Quality:
      This release focused primarily on one-pass use cases, including
      video conferencing. Low latency data rate control was significantly
      improved, improving streamability over bandwidth constrained links.
      Added support for error concealment, allowing frames to maintain
      visual quality in the presence of substantial packet loss.

          Add rc_max_intra_bitrate_pct control
          Limit size of initial keyframe in one-pass.
          Improve framerate adaptation
          Improved 1-pass CBR rate control
          Improved KF insertion after fades to still.
          Improved key frame detection.
          Improved activity masking (lower PSNR impact for same SSIM boost)
          Improved interaction between GF and ARFs
          Adding error-concealment to the decoder.
          Adding support for independent partitions
          Adjusted rate-distortion constants

  - Bug Fixes:
          Removed firstpass motion map
          Fix parallel make install
          Fix multithreaded encoding for 1 MB wide frame
          Fixed iwalsh_neon build problems with RVDS4.1
          Fix semaphore emulation, spin-wait intrinsics on Windows
          Fix build with xcode4 and simplify GLOBAL.
          Mark ARM asm objects as allowing a non-executable stack.
          Fix vpxenc encoding incorrect webm file header on big endian

  Note: Updated tag message only, was 60fe833